HK1244360B - Methods, apparatuses, and systems for multi-point, multi-cell single-user based multiple input and multiple output transmissions - Google Patents

Description

Method, device, and system for multi-point, multi-cell, single-user multi-input, multi-output transmission

Related applications

This application claims priority to U.S. Patent Application No. 14/928,759, filed on October 30, 2015, entitled “METHODS, APPARATUSES AND SYSTEMS FOR MULTI-POINT, MULTI-CELL SINGLE-USER BASED MULTIPLE INPUT AND MULTIPLE OUTPUT TRANSMISSIONS,” which claims priority under 35 U.S.C. §119 to U.S. Provisional Application No. 62/119,386, filed on February 23, 2015, entitled “METHOD FOR MULTI-POINT, MULTI-CELL SINGLE-USER MIMO TRANSMISSION,” and to U.S. Provisional Application No. 62/119,386, filed on April 15, 2015, entitled “DOWNLINK CONTROL SIGNALING TO [0014] The present invention is based on the priority of U.S. Provisional Application No. 62/147,972, entitled "SUPPORT MULTI-CELL, MULTI-POINT SU-MIMO IN LTE-A SYSTEMS," which is hereby incorporated by reference in its entirety.

Technical Field

Implementations of the claimed invention relate generally to the field of wireless communications, and more particularly to providing downlink channels from neighboring transmission points in a Long Term Evolution (LTE) wireless communication network.

Background Art

Current wireless communication standards are based on antenna configurations that include two transmit antenna elements (referred to as "2Tx antennas"), which are based in part on current deployment assumptions that typically rely on 2Tx antennas at evolved Node Bs (eNBs). Due to the high costs associated with network deployments of eNBs with four antenna elements (4Tx) or eight antenna elements (8Tx), many eNBs are likely to continue to include 2Tx antennas (referred to as "2Tx eNBs") for the near future. Consequently, in traditional single-point, single-cell, multiple-input, multiple-output (MIMO) transmission schemes, the maximum number of transmission layers that can be simultaneously transmitted to a user equipment (UE) is typically limited to two transmission layers. Consequently, in many cases, a UE can only receive two downlink transmissions from a serving eNB, regardless of the UE's reception capabilities.

UEs that include four receive antenna elements (referred to as "4Rx UEs") are being developed and will be available in the near future. Because most eNBs may still include 2Tx antennas, these 2Tx eNBs may not be able to fully utilize 4Rx UEs in terms of peak data rate enhancement.

Summary of the Invention

In a first aspect, one or more computer-readable storage media (CRSMs) include instructions, where the instructions are executed by one or more processors to cause a user equipment (UE) to: control reception of control information from a first transmission point or a second transmission point, wherein the control information includes an indication indicating a parameter set for determining quasi co-location (QCL); determine, based on the indicated parameter set, a QCL hypothesis to be used to estimate channel characteristics for receiving a first plurality of layers in a downlink channel from the first transmission point and a second plurality of layers in a downlink channel from the second transmission point; estimate channel characteristics for receiving the first plurality of layers and for receiving the second plurality of layers based on the QCL hypothesis; and control reception of the first plurality of layers using a first receive antenna and reception of the second plurality of layers using a second receive antenna based on the estimated channel characteristics.

In a second aspect, an apparatus implemented in a user equipment (UE) includes: an antenna array including at least a first receiving antenna and a second receiving antenna; a processor circuit operably coupled to the antenna array, the processor circuit being configured to: control the first receiving antenna to receive a first set of multiple layers in a downlink channel of a first cell; control the second receiving antenna to receive a second set of multiple layers in a downlink channel of a second cell; control the first receiving antenna or the second receiving antenna to receive control information from the first cell or the second cell, wherein the control information includes an indication of at least one parameter set for determining a quasi-co-location (QCL) hypothesis; determine a QCL hypothesis based on the parameter set, wherein the QCL hypothesis will be used to estimate channel characteristics for reception of the first set of multiple layers and for reception of the second set of multiple layers; use the QCL hypothesis to estimate first channel characteristics for reception of the first set of multiple layers and second channel characteristics for reception of the second set of multiple layers, respectively; and based on the estimated first channel characteristics and second channel characteristics, control the first receiving antenna to receive the first set of multiple layers, and control the second receiving antenna to receive the second set of multiple layers.

In a third aspect, one or more computer-readable storage media (CRSMs) include instructions, wherein the instructions are executed by one or more processors to cause a base station to: control transmission of a first group of one or more independent data streams in a downlink channel from a first transmission point associated with the base station, wherein the first transmission point corresponds to a downlink cell and a second transmission point is another base station or a small cell base station; generate control information, the control information including an indication of a parameter set to be used to determine a quasi co-location (QCL) hypothesis for receiving at least one of the first group of one or more independent data streams or the second group of one or more independent data streams to be sent by the second transmission point in the downlink channel of the second transmission point, wherein the control information indicates the parameter set to be used to determine a quasi co-location (QCL) hypothesis for receiving at least one of the first group of one or more independent data streams or the second group of one or more independent data streams to be sent by the second transmission point in the downlink channel of the second transmission point. A first CSI feedback process for a link reports channel state information (CSI)-reference information (RS) of CSI, and antenna ports associated with the CSI-RS are not assumed to be quasi-co-located; controlling transmission of the control information; obtaining CSI for the first CSI feedback process, the CSI including a channel quality indicator (CQI), a precoding matrix indicator (PMI), and a rank indicator (RI), wherein the RI is assumed to be used for the first CSI feedback process based on the RI of a second CSI feedback process corresponding to the second transmission point, and the PMI and CQI of the first CSI feedback process are determined independently of the PMI and CQI of the second CSI feedback process; and using the obtained CSI to assist transmission of the first group of one or more independent data streams.

In a fourth aspect, an apparatus implemented in a base station includes: a device for identifying control information related to a parameter set, wherein the parameter set is to be used to determine a quasi-co-location (QCL) hypothesis, wherein the QCL hypothesis is used to receive a first independent data stream to be sent by a downlink cell or a second independent data stream to be sent by another downlink cell, wherein the control information indicates a channel state information (CSI)-reference information (RS) to be used to report CSI according to a first CSI feedback process for each link of a first transmission point, and an antenna port associated with the CSI-RS is not assumed to be quasi-co-located. bits; a device for sending the first independent data stream and the control information; a device for receiving CSI of the first CSI feedback process, the CSI including a channel quality indicator (CQI), a precoding matrix indicator (PMI) and a rank indicator (RI), wherein the CQI is based on an indication about inheriting the RI from the second CSI feedback process, and the CQI is an average CQI measured at different stages between CSI-reference signal (RS) resources including aggregated CSI-RS resources; and a device for using the received CSI to assist the transmission of the first independent data stream.

In a fifth aspect, an apparatus to be used as a base station includes: a processor circuit configured to: generate control information including an indication of a parameter set to be used to determine a quasi co-location (QCL) assumption for receiving at least one of a first set of one or more independent data streams or a second set of one or more independent data streams to be sent by a second transmission point in a downlink channel of the second transmission point, wherein the control information indicates channel state information (CSI)-reference information (RS) to be used for reporting CSI according to a first CSI feedback process for respective links of a first transmission point associated with the base station, and antenna ports associated with the CSI-RS are not assumed to be quasi co-located, wherein the first transmission point corresponds to a downlink cell and the second transmission point is another base station. or a small cell base station and using the obtained CSI of the first CSI feedback process to assist transmission of the first group of one or more independent data streams; and a communication circuit communicatively coupled to the processor circuit, the communication circuit being configured to: transmit the first group of one or more independent data streams in a downlink channel from the first transmission point, transmit control information, and obtain CSI of the first CSI feedback process, the obtained CSI comprising a channel quality indicator (CQI), a precoding matrix indicator (PMI), and a rank indicator (RI), wherein the RI is assumed for the first CSI feedback process based on the RI of a second CSI feedback process corresponding to the second transmission point, and the PMI and CQI of the first CSI feedback process are determined independently of the PMI and CQI of the second CSI feedback process.

In a sixth aspect, an apparatus to be used by a user equipment (UE) includes: means for receiving control information from a first transmission point or a second transmission point, wherein the control information includes an indication of a parameter set for determining quasi co-location (QCL); means for determining, based on the indicated parameter set, a QCL hypothesis to be used to estimate channel characteristics for receiving a first plurality of layers in a downlink channel from the first transmission point and a second plurality of layers in a downlink channel from the second transmission point; means for estimating channel characteristics for receiving the first plurality of layers and for receiving the second plurality of layers based on the QCL hypothesis; and means for receiving the first plurality of layers using a first receive antenna and controlling reception of the second plurality of layers using a second receive antenna based on the estimated channel characteristics, wherein: one or more first independent data streams correspond to the first plurality of layers and are to be transmitted by at least one of a plurality of antenna ports associated with one or more UE-specific reference signals (RSs) of the first transmission point, and one or more second independent data streams correspond to the second plurality of layers and are to be transmitted by at least one of a plurality of antenna ports associated with one or more UE-specific RSs of the second transmission point.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings. For ease of description, similar reference numerals denote similar structural elements. The embodiments are illustrated by way of example and not by way of limitation in the illustrations of the accompanying drawings.

FIG1 illustrates a broadband wireless access (BWA) network according to various example embodiments;

FIG2 illustrates components of electronic device circuitry, such as user equipment (UE) circuitry and/or evolved Node B (eNB) circuitry, according to various example embodiments;

FIG3 illustrates example components of a UE device according to various example embodiments;

4 illustrates a process that may be performed by a UE to determine a quasi co-location (QCL) hypothesis for multi-cell multi-point single-user (SU) multiple-input multiple-output (MIMO) transmission according to various embodiments;

FIG5 illustrates another process that may be performed by a UE to determine a QCL hypothesis for multi-cell multi-point SU-MIMO transmission according to various embodiments;

FIG6 illustrates another process that may be performed by a UE to determine a QCL hypothesis for multi-cell multi-point SU-MIMO transmission according to various embodiments;

FIG7 illustrates a process that may be performed by an eNB to assist multi-cell multi-point SU-MIMO transmissions according to various embodiments; and

FIG8 illustrates another process that may be performed by an eNB to assist multi-cell multi-point SU-MIMO transmissions according to various embodiments.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings. The same reference numerals may be used in different figures to identify the same or similar elements. In the following description, specific details such as specific structures, architectures, interfaces, technologies, etc. are described for illustrative and non-limiting purposes in order to provide a thorough understanding of various aspects of the claimed invention. However, it will be apparent to those skilled in the art who have the benefit of this disclosure that various aspects of the claimed invention may be practiced in other examples that depart from these specific details. In some cases, descriptions of well-known devices, circuits, and methods are omitted to avoid obscuring the description of the present invention with unnecessary detail.

The various aspects of the illustrative embodiments will be described using the terms commonly used by those skilled in the art to convey the essence of their work to those skilled in the art. However, it will be apparent to those skilled in the art that alternative embodiments may be practiced using only some of the described aspects. For illustrative purposes, specific numbers, materials, and configurations have been set forth to provide a thorough understanding of the illustrative embodiments. However, it will be apparent to those skilled in the art that alternative embodiments may be practiced without these specific details. In other cases, well-known features have been omitted or simplified to avoid blurring the illustrated embodiments.

Furthermore, various operations will be described as multiple discrete operations in a manner that is most helpful for understanding the illustrative embodiments; however, the order of description should not be construed as implying that these operations are necessarily order-dependent. In particular, these operations do not need to be performed in the order presented.

The phrases "in various embodiments," "in some embodiments," etc. are used repeatedly. The phrases generally do not refer to the same embodiment; however, it may also refer to the same embodiment. Unless the context dictates otherwise, the terms "comprising," "having," and "including" are synonymous. The phrases "A or B," "A/B," and "A and/or B" mean (A), (B), or (A and B). Similar to the phrase "A and/or B," the phrases "A/B" and "A or B" mean (A), (B), or (A and B). For the purposes of this disclosure, the phrase "at least one of A and B" means (A), (B), or (A and B). The description may use the phrases "in an embodiment," "in some embodiments," and/or "in various embodiments," which phrases may each refer to one or more of the same or different embodiments. In addition, the terms "comprising," "including," "having," and the like used with respect to the embodiments of the present disclosure are synonymous.

The exemplary embodiments can be described as processes depicted in the form of flow charts, flow diagrams, data flow diagrams, structure diagrams, or block diagrams. Although a flow chart can describe operations as sequential processes, many operations can be performed in parallel or simultaneously. In addition, the order of operations can be rearranged. A process can be terminated when its operations are completed, but can also have additional steps not included in (one or more) figures. A process can correspond to a method, function, procedure, subroutine, subroutine, etc. When a process corresponds to a function, its termination can correspond to the function returning to the calling function and/or main function.

As used herein, the term "circuit" refers to a hardware component configured to provide the functionality, as part of, or including such hardware components, such as an application specific integrated circuit (ASIC), an electronic circuit, a logic circuit, a (shared, dedicated, or combined) processor, and/or a (shared, dedicated, or combined) memory. In some embodiments, a circuit may execute one or more software or firmware programs to provide at least some of the functionality. The exemplary embodiments may be described in the general context of computer executable instructions (e.g., program code, software modules, and/or functional processes) executed by the one or more circuits described above. Program code, software modules, and/or functional processes may include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific data types. Existing hardware in existing communication networks may be used to implement the program code, software modules, and/or functional processes discussed herein. For example, existing hardware at existing network elements or control nodes may be used to implement the program code, software modules, and/or functional processes discussed herein.

As used herein, the term "user device" may be considered synonymous with or may sometimes refer hereinafter to a client, mobile phone, mobile device, mobile terminal, user terminal, mobile unit, mobile station, mobile user, UE, subscriber, user, remote station, access agent, user agent, receiver, etc., and may describe a remote user of network resources in a communication network. In addition, the term "user device" may include any type of wireless/wired device, such as a consumer electronic device, a cellular phone, a smart phone, a tablet computer, a wearable computing device, a personal digital assistant (PDA), a desktop computer, and a laptop computer.

As used herein, the term "network element" may be considered synonymous with or refer to a networked computer, network hardware, network device, router, switch, hub, bridge, radio network controller, radio access network device, gateway, server, and/or any other similar device. The term "network element" may describe a physical computing device of a wired or wireless communication network and may be configured to host a virtual machine. Additionally, the term "network element" may describe a device that provides a radio baseband function for data and/or voice connectivity between a network and one or more users. The term "network element" may be considered synonymous with and/or referred to as a "base station." As used herein, the term "base station" may be considered synonymous with or referred to as a node B, enhanced node B or evolved node B (eNB), base transceiver station (BTS), access point (AP), etc., and may describe a device that provides a radio baseband function for data and/or voice connectivity between a network and one or more users.

It should also be noted that the term "channel" as used herein may refer to any tangible or intangible transmission medium for transmitting data or data streams. Furthermore, the term "channel" may be synonymous with or equivalent to "communication channel," "data communication channel," "transmission channel," "data transmission channel," "access channel," "data access channel," "link," "data link," "carrier," "radio frequency carrier," and/or any other similar term representing a path or medium through which data is transmitted.

Embodiments herein relate to assisted multi-cell multi-point single-user (SU) multiple-input multiple-output (MIMO) transmission, in which multiple transmission layers are provided to a UE via a neighboring cell or non-serving cell or transmission point. Example embodiments provide the following advantages: the multi-cell multi-point SU MIMO transmission scheme can improve throughput or data rate in dense deployment areas such as indoor environments or relatively large urban environments; the multi-cell multi-point SU MIMO transmission scheme can provide load balancing by allocating additional transmission resources to the UE from less loaded or low-loaded transmission points; and currently deployed base stations (e.g., eNBs) may not need to be upgraded to include additional transmission antenna elements, thereby saving costs for network operators.

FIG1 illustrates an example of a broadband wireless access (BWA) network 100 according to an example embodiment. BWA network 100 includes two UEs 105, three eNBs 110 (eNB 110-1, eNB 110-2, and eNB 110-3 are collectively referred to as "eNB 110"), and three cells 115 (cell 115-1, cell 115-2, cell 115-3 are collectively referred to as "cell 115"). The following description is provided for an example BWA network 100 operating in conjunction with the Long Term Evolution (LTE) standard provided by the Third Generation Partnership Project (3GPP) technical specifications. However, the example embodiments are not limited in this respect, and the described embodiments may be applied to other networks that benefit from the principles described herein.

1 , each of the UEs 105 (collectively referred to as “UE 105”) may be a physical hardware device capable of running one or more applications and accessing network services via a radio link (“link”) with the eNB 110. The UE 105 may include a transmitter/receiver (or alternatively, a transceiver), memory, one or more processors, and/or other similar components. According to various embodiments, the UE 105 (referred to as a “4Rx UE 105”) may include four receive antenna elements. The UE 105 may be configured to transmit/receive data to/from the eNB 110 via the link. The UE 105 may be designed to sequentially and automatically perform a series of arithmetic or logical operations; be equipped to record/store digital data on a machine-readable medium; and transmit and receive digital data via the eNB 110. The wireless transmitter/receiver (or alternatively, transceiver) included in the UE 105 may be configured to operate according to one or more wireless communication protocols and/or one or more cellular telephone communication protocols, such as 3GPP LTE, 3GPP LTE-Advanced (LTE-A), and/or any other wireless communication protocols including those based on radio frequency (RF), optical (visible/invisible), etc. In various embodiments, the UE 105 may include a wireless telephone or smartphone, a laptop personal computer (PC), a tablet PC, a wearable computing device, an autonomous sensor, or other similar machine type communication (MTC) device, and/or any other physical or logical device capable of recording, storing, and/or transmitting digital data to/from the eNB 110 and/or any other similar network element.

An eNB 110 is a hardware computing device configured to provide wireless communication services to mobile devices (e.g., UEs 105) within a geographic area or cell 115 associated with the eNB 110 (e.g., cell 115-1 associated with eNB 110-1). A cell 115 may also be referred to as a "serving cell," "cell coverage area," or the like. The eNB 110 may provide wireless communication services to the UEs 105 via one or more links 120 for each UE 105. As shown in FIG1 , the links 120 between the eNB 110 and the UEs 105 may include one or more downlink (or forward) channels for transmitting information from the eNB 110 to the UEs 105. Although not shown in FIG1 , the links 120 may also include one or more uplink (or reverse) channels for transmitting information from the UEs 105 to the eNB 110. These channels may include a physical downlink shared channel (PDSCH), a physical downlink control channel (PDCCH), a physical hybrid automatic repeat request (HARQ) indicator channel (PHICH), a physical control format indicator channel (PCFICH), a physical broadcast channel (PBCH), a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), a physical random access channel (PRACH), and/or any other similar communication channels or links for transmitting/receiving data.

In various embodiments, the eNB 110 includes a transmitter/receiver (or alternatively, a transceiver) connected to one or more antennas, one or more memory devices, one or more processors, and/or other similar components. The one or more transmitters/receivers may be configured to transmit/receive data signals to/from one or more UEs 105 within its cell 115 via one or more links that may be associated with the transmitter and receiver. The eNB 110 or a transmitter of the eNB 110 may be referred to as a "transmission point." In various embodiments, when the BWA network 100 employs the LTE or LTE-A standard, the eNB 110 may utilize the Evolved Universal Terrestrial Radio Access (E-UTRA) protocol, such as Orthogonal Frequency Division Multiple Access (OFDMA) for downlink communications and Single Carrier Frequency Division Multiple Access (SC-FDMA) for uplink communications.

In many deployment scenarios, such as BWA network 100, one or more of the eNBs 110 may include only two transmit antenna elements (referred to as a "2Tx eNB"), in part due to the prohibitive costs associated with upgrading the eNBs 110 to include more than two transmit antennas. In conventional systems, each eNB 110 may only be able to provide single-point, single-cell MIMO coverage to a UE 105, where only one serving cell 115 (e.g., eNB 110-3 serving a single UE 105, as shown in FIG1 ) is able to provide downlink transmissions to the UE 105. According to various example embodiments, the UE 105 may receive transmission layers not only from the serving cell 115, but also from one or more neighboring cells 115 with available downlink resources. For example, as shown in FIG1 , the serving 2Tx eNB 110-1 may transmit two transmission layers, and the neighboring 2Tx eNB 110-2, which has available downlink resources, may also provide two transmission layers, resulting in a total of four transmission layers being received by the 4Rx UE 105. By performing such transmissions, the UE 105 can increase the peak data rate by decoding up to four transmission layers at the same or similar times, with some layers transmitted by the first serving cell (e.g., serving cell 115-1) and other layers transmitted by a neighboring cell (e.g., serving cell 115-2). To spatially separate multiple layers on the same frequency, the 4Rx UE 105 can use four receive antenna elements with a receiver capable of suppressing interference from the interfering layers. Such a receiver can be a minimum mean square error interference rejection combining (MMSE-IRC) receiver, a reduced complexity maximum likelihood (R-ML) receiver, a symbol layer interference cancellation (SLIC) or codeword interference cancellation (CWIC) receiver, and/or other similar receivers. In addition, in some deployment scenarios, the number of layers from a single eNB 110 may be limited by the propagation characteristics of the channel (e.g., line of sight), which may limit the number of MIMO layers transmitted to two MIMO layers. For example, in the BWA network 100 , due to various propagation characteristics, the serving eNB 110 - 1 having more than two antenna elements can only transmit two transmission layers, while the neighboring eNB 110 - 2 having available downlink resources can also provide two transmission layers, so that a total transmission of four transmission layers is received by the 4Rx UE 105 .

In other embodiments, the number of transmission layers may be different across different transmission points or cells 115. For example, eNB 110-1 may transmit two (spatial) transmission layers, and eNB 110-2 may transmit one transmission layer (not shown). In another example, when UE 105 is within an area covered by all three cells 115 (not shown), eNB 110-1 may transmit two spatial transmission layers, eNB 110-2 may transmit one transmission layer, and eNB 110-3 may transmit one transmission layer. Furthermore, while FIG1 shows three eNBs 110, example embodiments provide that neighboring cells may be provided by small cells such as femtocells, picocells, or any other suitable network element. The above-described transmission scheme may be referred to as a multi-cell multi-point SU-MIMO transmission scheme.

Multipoint transmission may refer to transmissions performed by multiple transmission points or cells 115. When multiple transmission points coordinate with each other to provide multipoint transmission, the transmission points are considered to be part of a coordinated multipoint (CoMP) transmission scheme. Current CoMP transmission schemes include dynamic point selection and joint transmission. Dynamic point selection includes transmissions from a single transmission point, where the transmission point can change dynamically. Joint transmission (also known as "joint processing" and "cooperative MIMO") includes simultaneous transmissions from multiple transmission points, where each transmission point transmits at the same frequency within the same subframe based on relatively extensive backhaul communications between the transmission points. For most CoMP transmission schemes, it is generally assumed that the UE 105 receives all MIMO layers using quasi-colocated UE-dedicated RS antenna ports, which means that precoding is performed jointly by all transmission points.

An antenna port is a logical entity distinguished by a reference signal sequence. Multiple antenna port signals may be transmitted on a single physical transmit antenna element, and/or a single antenna port may be distributed across multiple physical transmit antenna elements. Antenna ports 0-3 are indicated by or otherwise associated with a cell-specific reference signal (CRS), antenna ports 5 and 7-14 are indicated by or otherwise associated with a UE-specific reference signal (UE-specific RS) also known as a demodulation reference signal (DMRS), and antenna ports 15-22 are indicated by or otherwise associated with a channel state information reference signal (CSI-RS). The current specification describes that the UE-specific antenna ports for transmitting spatial layers are assumed to be quasi-co-located with each other.

The term "quasi-co-located" means that two or more antenna ports are considered to be quasi-co-located if the large-scale characteristics of the channel over which symbols on one antenna port are transmitted can be inferred from the channel over which symbols on another antenna port are transmitted. Large-scale channel characteristics include one or more of delay spread, Doppler spread, Doppler shift, average gain, average delay, receive timing, etc. When two antenna ports are quasi-co-located, the UE 105 can assume that the large-scale channel characteristics of the signal received from the first antenna port can be inferred from the signal received from the second antenna port. For example, when the UE 105 decodes a received PDSCH transmission, the UE 105 can use the associated UE-specific RS to perform channel estimation operations. To perform the channel estimation operations, the UE 105 may need to know the large-scale channel characteristics of the channel. Using the current standard quasi-co-location (QCL) assumption, a UE 105 configured for transmission modes 1-9 can assume that the CRS antenna port, CSI-RS antenna port, and UE-specific RS antenna port are quasi-co-located for the serving cell.

A UE 105 configured for transmission mode 10 may operate according to two QCL types, e.g., Type A and Type B. When the UE 105 is configured as a Type A UE, the UE 105 may assume that the CRS, UE-specific RS, and CSI-RS antenna ports are quasi-co-located, which is the QCL assumption for transmission modes 1-9. When the UE 105 is configured as a Type B UE, the UE 105 may assume that the CSI-RS antenna ports corresponding to the CSI-RS resource configuration identified by higher layer signaling (e.g., radio resource control (RRC) signaling) and the UE-specific RS antenna ports associated with the PDSCH are quasi-co-located. For a UE 105 configured for transmission mode 10, the QCL type may be signaled to the UE 105 by higher layer signaling (e.g., RRC signaling). The QCL assumption of the current standard means that all transmission layers are transmitted from the same transmission point, which indicates that only single-point single-cell SU-MIMO is supported by the current standard.

To provide multi-cell multi-point SU-MIMO, example embodiments provide for adjusting (or removing) the current QCL assumptions used for UE-specific RSs to accommodate the channel characteristics of different transmission layers transmitted from different transmission points. In some embodiments, the QCL assumptions are adjusted only for UEs configured for transmission mode 10. Example embodiments provide for QCL assumption adjustment because channels associated with different transmission points may have different channel characteristics. Therefore, if UE 105 infers channel characteristics derived from antenna ports used for transmission from a first transmission point, then antenna ports used for transmission from a second transmission point, time and frequency synchronization errors may occur.

Although not shown in FIG1 , each eNB 110 may be part of a radio access network (RAN) or associated with a radio access technology (RAT). In an embodiment where the communication network 100 adopts the LTE standard, the RAN may be referred to as an evolved universal terrestrial radio access network (E-UTRAN). The RAN and its typical functions are generally well known, and therefore a further detailed description of the typical functions of the RAN is omitted. In addition, although not shown in FIG1 , the BWA network 100 may include a core network (CN), which may include one or more hardware devices, such as one or more servers. These servers may provide various telecommunication services to the UE 105. In an embodiment where the BWA network 100 adopts the LTE standard, one or more servers of the CN may include components of a system architecture evolution (SAE) having an evolved packet core (EPC) as described in the 3GPP technical specifications. In this embodiment, one or more servers of the CN may include components such as a Mobility Management Entity (MME) and/or a Serving General Packet Radio Service Support Node (SGSN) (which may be referred to as "SGSN/MME"), a Serving Gateway (SGW), a Packet Data Network (PDN) Gateway (PGW), a Home Subscriber Server (HSS), an Access Network Discovery and Selection Function (ANDSF), an Evolved Packet Data Gateway (ePDG), a MTC Interworking Function (IWF), or other similar components known in the art. Because the components of the SAE core network and their functions are generally well known, further detailed description of the SAE core network is omitted. It should also be noted that the above functions may be provided by the same physical hardware device or by separate components and/or devices.

Although FIG1 illustrates three cell coverage areas (e.g., cell 115), three base stations (e.g., eNB 110), and two mobile devices (e.g., UE 105), it should be noted that in various example embodiments, BWA network 100 may include more eNBs serving more UEs than shown in FIG1. However, not all of these generally conventional components need be shown in order to understand the example embodiments described herein.

FIG2 illustrates components of electronic device circuitry 200, which may be eNB circuitry, UE circuitry, or some other type of circuitry, according to various embodiments. In embodiments, the electronic device circuitry may be, or may be incorporated into or otherwise be part of, a UE 105, an eNB 110, or some other type of electronic device. As shown, the electronic device circuitry 200 includes control circuitry 205, transmit circuitry 210, and receive circuitry 215.

According to various embodiments, transmit circuitry 210 and receive circuitry 215 may be coupled to one or more antennas to facilitate over-the-air transmissions, for example, with eNB 110. For example, transmit circuitry 210 may be configured to receive digital data from one or more components of eNB 110 and convert the received digital data into an analog signal for transmission over an air interface using one or more antennas. Receive circuitry 215 may be any type of hardware device that can receive a signal modulated on a radio wave and convert it into usable information, such as digital data. Receive circuitry 215 may be coupled to one or more antennas to capture the radio waves. Receive circuitry 215 may be configured to transmit the digital data converted from the captured radio waves to one or more other components of UE 105. It should be noted that transmit circuitry 210 and receive circuitry 215 may be collectively referred to as "signal circuitry," "signaling circuitry," or the like. In embodiments, transmit circuitry 210 and receive circuitry 215 may be coupled to control circuitry 205. In some embodiments where the electronic device circuitry 200 is a UE 105 or is otherwise part of a UE 105, the receive circuitry 215 may be a receiver or portion of a receiver, such as an MMSE-IRC receiver, an R-ML receiver, a SLIC or CWIC receiver, and/or any other similarly suitable receiver. The control circuitry 205 may be configured to perform the control operations described herein with respect to the UE 105 and/or the eNB 110. Components of the UE 105 circuitry may be configured to perform operations similar to those described elsewhere in this disclosure with respect to the UE 105.

In an embodiment where the electronic device circuit 200 is a UE 105 or is incorporated into the UE 105 or is otherwise part of the UE 105, the antenna array may include at least a first receive antenna and a second receive antenna. For example, the one or more antennas may be an antenna array including a first receive antenna, a second receive antenna, a third receive antenna, and a fourth receive antenna. The receiving circuit 215 may be configured to receive a first group of one or more independent data streams in a downlink channel of a first cell (e.g., cell 115-1). The receiving circuit 215 may also be configured to receive a second group of one or more independent data streams in a downlink channel of a second cell (e.g., cell 115-2). The receiving circuit 215 may also be configured to receive control information including an indication of parameters of the first or second group of one or more independent data streams from the first cell and/or the second cell. The indication may indicate a QCL assumption for determining channel characteristics for reception of the independent data streams. In addition, the control circuit 205 may be configured to perform the processing described herein, such as the processing 400-600 described with respect to Figures 4-6.

In embodiments where the electronic device circuitry 200 is a transmission point and/or a downlink cell (e.g., eNB 110-1 associated with cell 115-1), is incorporated therein, or is otherwise part thereof, the control circuitry 205 may be configured to identify control information related to parameters of a first independent data stream transmitted by the downlink cell or a second independent data stream transmitted by another downlink cell (e.g., eNB 110-2 associated with cell 115-2). In this embodiment, the transmit circuitry 210 may be configured to transmit the first independent data stream and the control information to the UE 105. The parameters may indicate a QCL assumption used to determine channel characteristics for reception of the first independent data stream and/or the second independent data stream. The indication may indicate the QCL assumption used to determine channel characteristics for reception of the independent data streams. Furthermore, the control circuitry 205 may be configured to perform the processes described herein, such as processes 700-800 described with respect to FIG. 7-8.

FIG3 illustrates components of an example electronic device 300 for one embodiment. In various embodiments, the electronic device 300 may be the same as or similar to the UE 105 previously described with respect to FIG1 and FIG2. In some embodiments, the electronic device 300 may include at least application circuitry 302, baseband circuitry 304, radio frequency (RF) circuitry 306, front-end module (FEM) circuitry 308, and one or more antennas 310 coupled together as shown.

The application circuitry 302 may include one or more application processors. For example, the application circuitry 302 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and specialized processors (e.g., graphics processors, application processors, etc.). The processor(s) may be coupled to a memory/storage device and/or may include a memory/storage device and may be configured to execute instructions stored in the memory/storage device to enable various applications and/or operating systems to run on the system.

The baseband circuitry 304 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry 304 may include one or more baseband processors and/or control logic to process baseband signals received from the receive signal path of the RF circuitry 306 and generate baseband signals for the transmit signal path of the RF circuitry 306. The baseband circuitry 304 may interface with the application circuitry 302 to generate and process baseband signals and to control the operation of the RF circuitry 306. For example, in some embodiments, the baseband circuitry 304 may include a second generation (2G) baseband processor 304a, a third generation (3G) baseband processor 304b, a fourth generation (4G) baseband processor 304c, and/or other baseband processor(s) 304d for other existing, developing, or future generations (e.g., fifth generation (5G), 6G, etc.). The baseband circuitry 304 (e.g., one or more of the baseband processors 304a-d) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry 306. Radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, and the like. In some embodiments, the modulation/demodulation circuitry of baseband circuitry 304 may include fast Fourier transform (FFT), precoding, and/or constellation mapping/demapping functions. In some embodiments, the encoding/decoding circuitry of baseband circuitry 304 may include convolution, tail-biting convolution, turbo, Viterbi, and/or low-density parity check (LDPC) encoder/decoder functions. The embodiments of the modulation/demodulation and encoder/decoder functions are not limited to these examples and may include other suitable functions in other embodiments.

In some embodiments, the baseband circuit 304 may include elements of a protocol stack, such as elements of the Evolved Universal Terrestrial Radio Access Network (E-UTRAN) protocol including physical (PHY), medium access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), and/or radio resource control (RRC) elements. The central processing unit (CPU) 304e of the baseband circuit 304 may be configured to run elements of the protocol stack for signaling at the PHY, MAC, RLC, PDCP, and/or RRC layers. In some embodiments, the baseband circuit may include one or more audio digital signal processors (DSPs) 304f. The audio DSP(s) 304f may include elements for compression/decompression and echo cancellation, and may include other suitable processing elements in other embodiments. In some embodiments, the components of the baseband circuit 304 may be appropriately combined in a single chip, a single chipset, or placed on the same circuit board. In some embodiments, some or all of the components of the baseband circuit 304 and the application circuit 302 may be implemented together, for example, on a system on a chip (SOC).

In some embodiments, baseband circuitry 304 may provide communications compatible with one or more radio technologies. For example, in some embodiments, baseband circuitry 304 may support communications with E-UTRAN and/or other wireless metropolitan area networks (WMANs), wireless local area networks (WLANs), and wireless personal area networks (WPANs). Embodiments in which baseband circuitry 304 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

RF circuitry 306 can enable communication with a wireless network using modulated electromagnetic radiation through a non-solid medium. In various embodiments, RF circuitry 306 can include switches, filters, amplifiers, and the like to facilitate communication with the wireless network. RF circuitry 306 can include a receive signal path that can include circuitry for down-converting RF signals received from FEM circuitry 308 and providing baseband signals to baseband circuitry 304. RF circuitry 306 can also include a transmit signal path that can include circuitry for up-converting baseband signals provided by baseband circuitry 304 and providing an RF output signal to FEM circuitry 308 for transmission.

In some embodiments, RF circuitry 306 may include a receive signal path and a transmit signal path. The receive signal path of RF circuitry 306 may include mixer circuitry 306a, amplifier circuitry 306b, and filter circuitry 306c. The transmit signal path of RF circuitry 306 may include filter circuitry 306c and mixer circuitry 306a. RF circuitry 306 may also include synthesizer circuitry 306d for synthesizing frequencies for use by mixer circuitry 306a in both the receive and transmit signal paths. In some embodiments, mixer circuitry 306a in the receive signal path may be configured to downconvert the RF signal received from FEM circuitry 308 based on the synthesized frequency provided by synthesizer circuitry 306d. Amplifier circuitry 306b may be configured to amplify the downconverted signal, and filter circuitry 306c may be a low-pass filter (LPF) or a band-pass filter (BPF) configured to remove unwanted signals from the downconverted signal to generate an output baseband signal. The output baseband signal may be provided to baseband circuitry 304 for further processing. In some embodiments, the output baseband signal may be a zero-frequency baseband signal, but this is not required.In some embodiments, the mixer circuit 306a of the receive signal path may include a passive mixer, although the scope of the embodiments is not limited in this respect.

In some embodiments, mixer circuit 306a of the transmit signal path can be configured to upconvert an input baseband signal based on a synthesized frequency provided by synthesizer circuit 306d to generate an RF output signal for FEM circuit 308. The baseband signal can be provided by baseband circuit 304 and can be filtered by filter circuit 306c. Filter circuit 306c can include a low-pass filter (LPF), but the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuit 306a of the receive signal path and the mixer circuit 306a of the transmit signal path may include two or more mixers and may be arranged for quadrature down-conversion and/or quadrature or up-conversion, respectively. In some embodiments, the mixer circuit 306a of the receive signal path and the mixer circuit 306a of the transmit signal path may include two or more mixers and may be arranged for image suppression (e.g., Hartley image suppression). In some embodiments, the mixer circuit 306a of the receive signal path and the mixer circuit 306a of the transmit signal path may be arranged for direct down-conversion and/or direct up-conversion, respectively. In some embodiments, the mixer circuit 306a of the receive signal path and the mixer circuit 306a of the transmit signal path may be configured for superheterodyne operation.

In some embodiments, the output baseband signal and the input baseband signal may be analog baseband signals, but the scope of the embodiments is not limited in this respect. In some alternative embodiments, the output baseband signal and the input baseband signal may be digital baseband signals. In these alternative embodiments, RF circuitry 306 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry, and baseband circuitry 304 may include a digital baseband interface for communicating with RF circuitry 306.

In some dual-mode embodiments, separate radio IC circuitry may be provided to process signals for each spectrum, although the scope of the embodiments is not limited in this respect.

In some embodiments, synthesizer circuit 306 d may be a fractional-N synthesizer or a fractional N/N+1 synthesizer, but the scope of the embodiments is not limited in this respect, as other types of frequency synthesizers may also be suitable. For example, synthesizer circuit 306 d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer including a phase-locked loop with a frequency divider. Synthesizer circuit 306 d may be configured to synthesize an output frequency for use by mixer circuit 306 a of RF circuit 306 based on a frequency input and a frequency divider control input. In some embodiments, synthesizer circuit 306 d may be a fractional N/N+1 synthesizer.

In some embodiments, the frequency input may be provided by a voltage-controlled oscillator (VCO), but this is not required. Depending on the desired output frequency, the divider control input may be provided by baseband circuitry 304 or application circuitry 302. In some embodiments, the divider control input (e.g., N) may be determined from a lookup table based on the channel indicated by application circuitry 302.

The synthesizer circuit 306d of the RF circuit 306 may include a frequency divider, a delay-locked loop (DLL), a multiplexer, and a phase accumulator. In some embodiments, the frequency divider may be a dual-modulus frequency divider (DMD), and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by N or N+1 (e.g., based on a carry output) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable delay elements, a phase detector, a charge pump, and a D-type flip-flop. In these embodiments, the delay elements may be configured to split the VCO cycle into Nd equal-phase groups, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

In some embodiments, synthesizer circuit 306d can be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency can be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with a quadrature generator and divider circuit to generate multiple signals at the carrier frequency with multiple different phases relative to each other. In some embodiments, the output frequency can be the LO frequency (fLO). In some embodiments, RF circuit 306 can include an IQ/polarity converter.

FEM circuitry 308 may include a receive signal path, which may include circuitry configured to operate on RF signals received from one or more antennas 310, amplify the received signals, and provide an amplified version of the received signals to RF circuitry 306 for further processing. FEM circuitry 308 may also include a transmit signal path, which may include circuitry configured to amplify signals provided by RF circuitry 306 for transmission to one or more of the one or more antennas 310. In some embodiments, FEM circuitry 308 may include a TX/RX switch to switch between transmit and receive modes of operation. FEM circuitry 308 may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include a low-noise amplifier (LNA) to amplify received RF signals and provide the amplified received RF signals as output (e.g., to RF circuitry 306). The transmit signal path of the FEM circuitry 308 may include a power amplifier (PA) to amplify input RF signals (e.g., provided by RF circuitry 306) and one or more filters to generate RF signals for subsequent transmission (e.g., via one or more of the one or more antennas 310).

In some embodiments, the electronic device 300 may include additional elements, such as memory/storage devices, displays, cameras, sensors, and/or input/output (I/O) interfaces (not shown).

In some embodiments, RF circuitry 306 may be, or otherwise be included in, a receiver such as an MMSE-IRC receiver, an R-ML receiver, a SLIC or CWIC receiver, and/or any other suitable receiver.

In an embodiment where the electronic device 300 is a UE 105 or is incorporated into the UE 105 or otherwise serves as part of the UE 105, the one or more antennas 310 may include at least a first receive antenna and a second receive antenna. For example, the one or more antennas 310 may be an antenna array including a first receive antenna, a second receive antenna, a third receive antenna, and a fourth receive antenna. The RF circuitry 306 may be configured to receive a first set of one or more independent data streams in a downlink channel of a first downlink cell (e.g., cell 115-1). The RF circuitry 306 may also be configured to receive a second set of one or more independent data streams in a downlink channel of a second downlink cell (e.g., cell 115-2). The RF circuitry 306 may also be configured to receive control information from the first and/or second downlink cells that indicates parameters of the first or second set of one or more independent data streams. The indication (or parameter) may indicate a QCL assumption used to determine channel characteristics for reception of the independent data streams. In addition, the baseband circuitry 304 may be configured to perform the processing described herein, such as the processing 400-600 described with respect to Figures 4-6.

In an embodiment where electronic device 300 is a transmission point and/or downlink cell (e.g., eNB 110-1 associated with cell 115-1), or is incorporated into or otherwise part of a transmission point and/or downlink cell, baseband circuitry 304 may be configured to identify control information related to parameters of a first independent data stream to be transmitted by the downlink cell or a second independent data stream to be transmitted by another downlink cell (e.g., eNB 110-2 associated with cell 115-2). In this embodiment, RF circuitry 306 may be configured to transmit the first independent data stream and the control information to UE 105. The indication (or parameter) may indicate a QCL assumption used to determine channel characteristics for reception of the independent data stream. Furthermore, baseband circuitry 304 may be configured to perform the processes described herein, such as processes 700-800 described with respect to FIG. 7-8.

FIG4 illustrates a process 400 that may be performed by a UE 105 to determine a QCL hypothesis for a multi-cell multi-point SU-MTMO transmission in accordance with various embodiments. In some embodiments, the UE 105 may include one or more non-transitory computer-readable media having instructions stored thereon that, when executed by the UE 105, cause the UE 105 to perform the process 400. For purposes of illustration, the process 400 will be described as being performed by the UE 105 described with respect to FIG1-3. However, it should be noted that other similar devices may perform the process 400. Although a specific example and order of operations are shown in FIG4, in various embodiments, these operations may be reordered, split into additional operations, combined, and/or omitted altogether. In some embodiments, the operations shown in FIG4 may be combined with operations described with respect to other embodiments, such as those shown by one or more of FIG5-8 or one or more operations described with respect to the non-limiting examples provided herein.

4 , at operation 405, UE 105 may process a first set of one or more independent data streams received from a first transmission point in a downlink channel. At operation 410, UE 105 may process a second set of one or more independent data streams received from a second transmission point in a downlink channel. Each independent data stream may correspond to a transmission layer (also referred to herein as a "layer"). In some embodiments, at least one independent data stream may be transmitted by at least one antenna port of a plurality of antenna ports associated with one or more reference signals (e.g., UE-specific RSs of the first transmission point or the second transmission point).

At operation 415, UE 105 may process control information received from the first transmission point or the second transmission point. At operation 420, UE 105 may determine a QCL assumption to be used to estimate channel characteristics for reception of the first set of one or more independent data streams or for reception of the second set of one or more independent data streams. The control information may include an indication of a QCL assumption to be used to estimate channel characteristics for reception of the first set of one or more independent data streams or for reception of the second set of one or more independent data streams. According to various embodiments, UE 105 may not assume that the multiple antenna ports are quasi-co-located with respect to at least one of Doppler shift, Doppler spread, average delay, or delay spread. In some embodiments, the indication may indicate that a QCL assumption is not to be used, while in other embodiments, the indication may indicate that an appropriate QCL assumption is to be used. At operation 425, UE 105 may estimate channel characteristics for reception of the first set of one or more independent data streams or for reception of the second set of one or more independent data streams based on the quasi-co-located assumption.

When the indication indicates that the QCL assumption will not be used, the UE 105 may assume the same channel characteristics (e.g., the same Doppler shift, Doppler spread, average delay, and delay spread) on a predefined set of physical resource blocks (PRBS). In this embodiment, the UE 105 may perform channel estimation for the downlink channel from each transmission point separately on a predefined set of PRBs. The predefined set of PRBs may be a PRB bundle set. A PRB bundle set may include two or more PRB bundles. Each PRB bundle may include multiple consecutive or contiguous PRBs scheduled for the UE 105. The UE 105 may assume that consecutive PRBs in a PRB bundle use the same precoder for corresponding PDSCH transmissions from the serving eNB 110. Each PRB bundle may have multiple associated UE-specific RSs (e.g., each PRB bundle may be associated with 12 UE-specific RSs). In this embodiment, the UE 105 may perform time-frequency tracking operations using the UE-specific RSs transmitted separately on each antenna port. The time-frequency operation may be used to determine the time-frequency offset for each UE-specific RS antenna port for each transmission point. In some embodiments, the time-frequency offset for each UE-specific RS antenna port and/or transmission point can be calculated by jointly processing the bundled PRBs in the PRB bundling set. Using the time-frequency offset, the UE 105 can determine the UE-specific RS for a set of PRBs sent from the transmission point.

When the indication indicates a suitable QCL assumption to be used, the indication may indicate quasi-co-location of each UE-specific RS antenna port (e.g., antenna ports 7-14) being transmitted and one or more antenna ports associated with one or more other RSs. The other RSs may include one or more CRSs (e.g., antenna ports 0-3), one or more CSI-RS antenna ports (e.g., antenna ports 15-22), and/or one or more discovery RS antenna ports (which may be used to discover signals broadcast by small base stations). In this embodiment, the eNB 110 may configure the UE 105 with the suitable QCL assumption. For example, the eNB 110 may provide the configuration information through RRC signaling or through physical layer signaling. For example, the QCL assumption may be indicated to the UE 105 using a "PDSCH Resource Element (RE) Mapping and Quasi-Co-location" indicator field included in a DCI format 2D message or a new DCI format message (e.g., a DCI format 2E message). Furthermore, in some embodiments, two or more "PDSCH RE mapping and quasi co-location indicator" fields may be used in a DCI format 2D message to indicate two or more QCL assumptions between a subset of scheduled UE-specific RS antenna ports and CSI-RS antenna ports and/or CRS antenna ports. In other embodiments, two or more DCI messages may be sent to the UE 105, each of which may indicate one or more parameters associated with a transmission from a corresponding transmission point. In this embodiment, the one or more parameters may include QCL assumptions between one or more UE-specific RS antenna ports and higher-layer configured CRS resources and/or CSI-RS resources associated with a transmission point.

As an example, at operation 415, the UE 105 may receive one or more DCI format 2D messages, each of which may include a "PDSCH RE Mapping and Quasi Co-location Indicator" field. At operation 420, the UE 105 may use the information contained in two or more "PDSCH RE Mapping and Quasi Co-location Indicator" fields to determine resource element mapping. For example, when the UE 105 is configured in transmission mode 10 for a given serving cell 115, the UE 105 may be configured by higher layer signaling with up to four parameter sets to decode (one or more) PDSCH transmissions based on a detected PDSCH/enhanced physical downlink control channel (EPDCCH) with a DCI format 2D message intended for the UE 105 and the given serving cell 115. The UE 105 may determine the PDSCH RE mapping using a parameter set based on the value of the "PDSCH RE Mapping and Quasi Co-location Indicator" field in the detected DCI format 2D message. The value of the "PDSCH RE Mapping and Quasi Co-location Indicator" field may be as follows.

Table 1: PDSCH RE mapping and quasi co-location indicator field in DCI format 2D

Parameters used to determine PDSCH RE mapping and PDSCH antenna port quasi-co-location are configured through higher-layer signaling. Each parameter set includes "crs-PortsCount-r11", "crs-FreqShift-r11", "mbsfn-SubframeConfigList-r11", "csi-RS-ConfigZPId-r11", "pdsch-Start-r11" and "qcl-CSI-RS-ConfigNZPId-r11".

In addition to determining the PDSCH RE mapping using a parameter set according to the value of the "PDSCH RE mapping and quasi co-location indicator" field, the UE 105 may use the value contained in the "PDSCH RE mapping and quasi co-location indicator" field to determine one or more other RSs that are quasi co-located with one or more UE-specific RSs. For example, if the UE 105 is configured for a "Type B" quasi co-location type, the UE 105 may use the indicated parameter set to determine PDSCH antenna port quasi co-location. For example, according to current standards, a UE configured in transmission mode 10 for a serving cell is configured by a higher layer parameter "qcl-Operation" to have one of two quasi co-location types (e.g., Type A and Type B) for the serving cell to decode PDSCH transmissions according to a transmission scheme associated with antenna ports 7-14. When the UE 105 is configured as a Type A UE, the UE 105 may assume that antenna ports 0-3 and/or 7-22 of the serving cell are quasi co-located with respect to delay spread, Doppler spread, Doppler shift, and average delay. When UE 105 is configured as a Type B UE, UE 105 may assume that antenna ports 15-22 corresponding to the CSI-RS resource configuration identified by the higher layer parameter “qcl-CSI-RS-ConfigNZPId-r11” and antenna ports 7-14 associated with the PDSCH are quasi-co-located in terms of Doppler shift, Doppler spread, average delay, and delay spread.

According to various embodiments, the value of the "PDSCH RE mapping and quasi-co-location indicator" field may also be used to indicate the PDSCH RE mapping mode of the transmitting cell. For example, the resource elements used by the CRS antenna port may depend on the physical cell ID or the multicast/broadcast based single frequency network (MBSFN) subframe configuration. In these cases, the PDSCH RE mapping may be determined by the number of CRS antenna ports, the CRS frequency offset, and/or the MBSFN subframe configuration. The PDSCH RE may also depend on the number of orthogonal frequency division multiplexing (OFDM) symbols used for control channel transmission. In addition, the CSI-RS transmission may also be different for different cells and/or transmission points, so the CSI-RS resource configuration may also be used to determine the PDSCH RE. As part of the PDSCH RE mapping, a set of quasi-co-located CRS and CSI-RS antenna ports may be provided to indicate one or more reference signals that may be used to estimate the time-frequency offset corresponding to the transmission point. The received PDSCH and UE-specific RS may be compensated for the estimated offset using appropriate timing and frequency offset compensation functions.

FIG5 illustrates a process 500 that may be performed by a UE 105 to determine a QCL hypothesis for multi-cell multi-point SU-MFMO transmission, according to various embodiments. In some embodiments, the UE 105 may include one or more non-transitory computer-readable media having instructions stored thereon that, when executed by the UE 105, cause the UE 105 to perform the process 500. For illustrative purposes, the operations of the process 500 will be described as being performed by the UE 105 described with respect to FIG1-3. However, it should be noted that other similar devices may operate the process 500. Although FIG5 illustrates a specific example and order of operations, in various embodiments, these operations may be reordered, split into additional operations, combined, and/or omitted entirely. In some embodiments, the operations illustrated in FIG5 may be combined with operations described with respect to other embodiments, such as those illustrated by one or more of FIG4 and FIG6-8 and/or described with respect to the non-limiting examples herein.

5 , at operation 505, UE 105 may control reception of a first set of one or more independent data streams in a downlink channel of a first transmission point associated with serving cell 115. At operation 510, UE 105 may control reception of a second set of one or more independent data streams in a downlink channel of a second transmission point associated with non-serving cell 115. At least one independent data stream in the first set of one or more independent data streams may correspond to a separate layer, and the independent data stream may be transmitted by at least one UE-specific RS antenna port (e.g., one or more of antenna ports 7-14) of the first transmission point.

At operation 515, UE 105 may control the use of one or more receive antenna elements to receive control information from the first transmission point and/or the second transmission point. At operation 520, UE 105 may determine a QCL assumption to be used to estimate channel characteristics for reception of the first set of one or more independent data streams or for reception of the second set of one or more independent data streams. In various embodiments, the control information may include an indication of a parameter for the first or second set of one or more independent data streams. The parameter may indicate a QCL assumption to be used to estimate channel characteristics of a downlink channel providing the first or second set of one or more independent data streams. At operation 525, UE 105 may use a quasi-co-location assumption to estimate channel characteristics for reception of the first set of one or more independent data streams or for reception of the second set of one or more independent data streams. Channel characteristics may include Doppler shift, Doppler spread, average delay, and/or delay spread. In some embodiments, the parameter may indicate that a QCL assumption is not used, and UE 105 may assume the same channel characteristics across a defined set of PRBs (as discussed with respect to FIG. 4 ).

According to various embodiments, the indication (or parameter) may indicate the appropriate QCL assumption to be used. For example, the indication (or parameter) may indicate that one or more UE-specific RS antenna ports may be quasi-co-located with antenna ports associated with one or more other reference signals. Other reference signals may include one or more CRS antenna ports (e.g., antenna ports 0-3), one or more CSI-RS antenna ports (e.g., antenna ports 15-22), and/or one or more discovery RSs.

In some embodiments, two or more PDSCH RE mapping sets may be provided to the UE 105 so that the UE 105 can determine the PDSCH RE mapping hypothesis for each MIMO layer transmitted by the corresponding transmission point. For example, the location of the PDSCH RE within a subframe may depend on the REs occupied by one or more CRSs, which may be based on the cell ID of the transmission point or cell 115. In some cases, if the transmission of PDSCH on a MIMO layer is performed from multiple transmission points, each with a different cell ID, the PDSCH RE positions may not be aligned for each of the multiple transmission points. Therefore, in some embodiments, two or more PDSCH RE mapping sets may be signaled to the UE 105 to determine the PDSCH RE mapping hypothesis associated with each of the (one or more) MIMO layers transmitted by the transmission point. In some embodiments, the two or more PDSCH RE mapping sets may be used to determine the PDSCH RE hypothesis for the MIMO layer associated with the UE-specific RS antenna port. In this embodiment, two or more "PDSCH RE mapping and quasi co-location indicator" fields in two or more DCI messages may be used to provide two or more PDSCH RE mapping sets to UE 105. In this embodiment, each "PDSCH RE mapping and quasi co-location indicator" field may provide an association of a scheduled MIMO layer (UE-specific RS antenna port) with a PDSCH RE mapping. In other embodiments, two or more DCI format 2D messages may be sent to UE 105 to indicate transmission parameters for a scheduled layer, including its UE-specific RS antenna port and its PDSCH RE mapping.

FIG6 illustrates a process 600 that may be performed by a UE 105 to determine a QCL hypothesis for a multi-cell multi-point SU-MFMO transmission, according to various embodiments. In some embodiments, the UE 105 may include one or more non-transitory computer-readable media having stored thereon instructions that, when executed by the UE 105, cause the UE 105 to perform the process 600. For illustrative purposes, the operations of process 600 will be described as being performed by the UE 105 described with respect to FIG1-3. However, it should be noted that other similar devices may also perform the process 600. Although a specific example and order of operations are shown in FIG6, in various embodiments, these operations may be reordered, split into additional operations, combined, and/or omitted altogether. In some embodiments, the operations illustrated in FIG6 may be combined with operations described with respect to other embodiments, such as the operations illustrated in one or more of FIG4-5 and FIG7-8 and/or with respect to one or more of the non-limiting embodiments provided herein.

6 , at operation 605, UE 105 may receive two or more sets of parameters associated with a PDSCH transmission, where each set of parameters corresponds to a single transmission point. At operation 610, UE 105 may receive an indication of one or more transmission layers and an association of the transmission layers with one or more sets of parameters. At operation 615, UE 105 may receive a PDSCH transmission based on the parameter sets.

The PDSCH parameter group may be used to derive the PDSCH REs that are used by the transmission point to send the PDSCH transmission. In some embodiments, the PDSCH parameter group may include CRS parameters such as CRS offset, cell identifier, and the number of CRS antenna ports. In some embodiments, the PDSCH parameter group may include parameters of a non-zero power channel state information reference signal (NZP CSI-RS), such as the number of NZP CSI-RS antenna ports, a scrambling identifier, a pattern index, and the like. In some embodiments, the PDSCH parameter group may be used to establish a QCL assumption for the CRS antenna port and/or the NZP CSI-RS antenna port and the UE-specific RS antenna port. In this embodiment, the QCL assumption may be used to derive channel characteristics such as delay spread, Doppler spread, time offset, frequency offset, and/or average channel gain.

Each set of parameters may be signaled to the UE 105 using higher layer signaling (e.g., using RRC signaling). Furthermore, each PDSCH parameter set may be provided to the UE 105 on a per transport block basis. In some embodiments, transport blocks may be transmitted from different transmission points, and in some cases, may be transmitted from the same transmission point. Since different transmission points may have different PDSCH REs, the parameters may be included in a "PDSCH RE Mapping and Quasi Co-Location Indicator" field of one or more DCI messages for each transport block. The "PDSCH RE Mapping and Quasi Co-Location Indicator" field may comprise 2 bits in a DCI format 2D message, as discussed above with respect to FIG. 4 . In other embodiments, a new DCI format (e.g., DCI format 2E) message may be used to indicate the QCL assumption. The new DCI format may also include a "PDSCH RE Mapping and Quasi Co-Location Indicator" field to indicate the QCL assumption, or the new DCI format may include another suitable field for indicating the QCL assumption(s).

The per-transport-block indication can allow the UE-specific RS antenna port to be associated with the QCLs of different CSI-RS and/or CRS transmitted by different transmission points. This QCL association can be used for time offset measurement and compensation based on an appropriate time offset estimation function. An example of the association between the layer and the first and second "PDSCH RE Mapping and Quasi Co-location Indicator" fields is shown below for a total of layers 2-8.

Table 2: Association between layers and first and second antenna ports

Table 2 shows the quasi-co-location of CRS antenna ports and/or CSI-RS antenna ports for layers to be transmitted on a specified antenna port. For example, if a total of 8 layers of PDSCH transmission are scheduled for transmission, a set of first layers sent on antenna ports 7-10 can be quasi-co-located with a first CRS antenna port and/or CSI-RS antenna port, and a set of second layers sent on antenna ports 11-14 can be quasi-co-located with a second CRS antenna port and/or CSI-RS antenna port. In order to simplify the processing of received PDSCH transmissions, in some embodiments, some parameters associated with the "PDSCH RE mapping and quasi-co-location indicator" field can be the same across two or more transport blocks. For example, in such an embodiment, the UE105 can assume the same PDSCH start symbol for both transport blocks, which can be set according to the first (or second) "PDSCH RE mapping and quasi-co-location indicator" field.

In other embodiments, the "PDSCH RE Mapping and Quasi-Co-location Indicator" field may provide information about PDSCH RE mapping on different layers and may not provide QCL information for layers associated with UE-specific RS antenna ports. In this case, UE-specific RS antenna ports for layers transmitting different transport blocks may not be assumed to be quasi-co-located. Instead, UE 105 may assume that UE-specific RS antenna ports for layers transmitting one transport block are quasi-co-located. Time-frequency tracking in this case should be performed independently by UE 105 on different groups of UE-specific RS. For example, according to Table 2, if PDSCH transmission of 4 layers is scheduled, UE 105 may assume QCL for antenna ports 7 and 8 or QCL for antenna ports 9 and 10, but not assume QCL between antenna ports 7-8 and 9-10. This embodiment is based on the assumption that UE-specific RS antenna ports are not quasi-co-located with each other. This assumption may correspond to a new QCL behavior that can be configured to UE 105 via higher layer signaling, such as RRC signaling. In this embodiment, the UE 105 may assume that there is no QCL assumption only when the size of the resource allocation is greater than N resource blocks (where N = 2 or N = 3). In other embodiments, the UE 105 may assume QCL between UE-specific reference signals and other reference signals such as CRS and/or CSI-RS, e.g., corresponding to the serving cell.

FIG7 illustrates a process 700 that may be performed by an eNB 110 to determine and provide QCL hypotheses for multi-cell, multi-point SU-MIMO transmissions, according to various embodiments. In some embodiments, the eNB 110 may include one or more non-transitory computer-readable media having instructions stored thereon that, when executed by the eNB 110, cause the eNB 110 to perform the process 700. For illustrative purposes, the operations of process 700 will be described as being performed by the eNB 110 as described with respect to FIG1-3. However, it should be noted that other similar devices and/or network elements may perform the process 700. Although FIG7 illustrates a specific example and order of operations, in various embodiments, these operations may be reordered, split into additional operations, combined, and/or omitted altogether. In some embodiments, the operations illustrated in FIG7 may be combined with operations described with respect to other embodiments, such as the operations illustrated in FIG4-6 and FIG8 and/or one or more operations described with respect to the non-limiting examples provided herein.

7 , at operation 705 , eNB 110 may identify control information related to parameters of a first independent data stream to be transmitted by a downlink cell associated with eNB 110 or a second independent data stream to be transmitted by another downlink cell associated with another eNB 110 . At operation 710 , eNB 110 may send control information including an indication of the parameters to UE 105 , enabling UE 105 to determine the parameters for the downlink transmission. In various embodiments, the parameters may indicate a QCL assumption to be used to determine channel characteristics for obtaining the first independent data stream or the second independent data stream. For example, in some embodiments, CSI-RS antenna ports may not be assumed to be quasi-co-located with each other, and eNB 110 may use channel state information (CSI) to assist in the transmission of the first set of one or more independent data streams. In this embodiment, the control information may configure UE 105 using one of two CSI processes, a transmission point-specific CSI feedback process, or an aggregated CSI feedback process.

In a transmission point-specific CSI feedback process, CSI feedback for multi-point multi-cell SU-MIMO operation may include configuring the UE 105 with two or more CSI reporting processes, where each CSI reporting process contains one NZP CSI-RS resource for channel measurement associated with one transmission point. Each CSI process may represent the CSI for one link 120 between the UE 105 and the transmission point. In this embodiment, for each link 120, the UE 105 may provide CSI feedback (e.g., channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), etc.) to the corresponding transmission point. In some embodiments, CQI reports may be provided for aggregated CSI-RS resources, which are composed of a set of CSI-RS resources configured for the UE 105. CSI-RS resource aggregation may be provided by signaling a CSI-RS resource index to the UE 105. Furthermore, each CSI feedback process may generate a different RI value, and under current standards, a first CSI feedback process may inherit the RI value from a second CSI feedback process. In this embodiment, the RI value of the second CSI feedback can be assumed to be used for the first CSI feedback process, while the PMI and CQI will be determined independently in multiple CSI feedback processes. In various embodiments, an indication of inheriting the RI from the corresponding CSI feedback process can be provided to another CSI feedback process to calculate the CQI based on the assumption that the precoding using the PMI is calculated for the CSI feedback process. The CQI with aggregated CSI-RS resources can be obtained as an average CQI, where the average is performed over different stages between the CSI-RS resources including the aggregated CSI-RS resources.

In the aggregate CSI feedback process, one CSI reporting process is used, where the CSI process contains CSI-RS resources with antenna ports transmitted from all antenna elements of two or more transmission points. In this case, the existing QCL assumptions for the CSI-RS resources should be relaxed, and the UE should not assume quasi-co-location between the antenna ports of one CSI-RS resource. In another embodiment, higher layer signaling can be used to indicate whether the QCL assumption is valid for a given CSI-RS resource. The eNB 110 can identify and send an indication to the UE 105 regarding the aggregation of CSI-RS antenna ports to be used for CSI reporting in higher layer signaling (e.g., RRC signaling).

According to various embodiments, generating control information may include a mapping of codewords to layers to help control the data rate allocation for each transmission layer. For example, one or more transport blocks may be converted into codewords, which may be used to obtain one or more modulation symbols. These modulation symbols may then be mapped to one or more antenna ports. In some embodiments, where two or more DCI messages are used to schedule PDSCH transmissions, the eNB 110 may map each codeword to a separate transmission layer such that there is a one-to-one correspondence between each codeword and each layer. In other embodiments, the eNB 110 may map multiple layers to each codeword, which may reduce the signaling overhead associated with indicating the modulation and coding scheme.

7 , once the control information is identified and sent to the UE 105 , at operation 715 , the eNB 110 may transmit a first set of one or more independent data streams in a downlink channel.

FIG8 illustrates a process 800 that may be performed by an eNB 110 to determine and provide QCL hypotheses for multi-cell, multi-point SU-MIMO transmissions, according to various embodiments. In some embodiments, the eNB 110 may include one or more non-transitory computer-readable media having instructions stored thereon that, when executed by the eNB 110, cause the eNB 110 to perform process 800. For illustrative purposes, the operations of process 800 will be described as being performed by the eNB 110 described with respect to FIG1-3. However, it should be noted that other similar devices and/or network elements may operate process 800. Although FIG8 illustrates a specific example and order of operations, in various embodiments, these operations may be reordered, split into additional operations, combined, and/or omitted altogether. In some embodiments, the operations illustrated in FIG8 may be combined with operations described with respect to other embodiments, such as the operations illustrated by one or more of FIG4-7 and/or one or more operations described with respect to the non-limiting embodiments provided herein.

Referring to FIG. 8 , at operation 805, eNB 110 may generate a set of independent data streams to be transmitted from associated transmission points in a downlink channel. In various embodiments, the transmission points associated with eNB 110 may correspond to downlink cells 115 or one or more physical transmission antenna elements. At operation 810, eNB 110 may control transmission of the set of independent data streams to UE 105 using one or more transmission antenna elements. Each independent data stream may correspond to a single layer and may be transmitted using at least one antenna port associated with one or more UE-specific RSs (e.g., one or more of antenna ports 7-14). eNB 110 may receive CSI feedback from UE 105, which may be used by eNB 110 to generate and transmit the independent data streams. In such embodiments, eNB 110 may configure UE 105 with one of two CSI processes, such as the transmission point-specific CSI feedback process or the aggregated CSI feedback process discussed previously with respect to FIG. 7 .

At operation 815, eNB 110 may generate control information associated with the transmission point or another transmission point, the control information indicating parameters for the set of independent data streams. At operation 820, eNB 110 may cause the control information to be transmitted using one or more transmit antenna elements. These parameters may indicate a quasi-co-location assumption for reception of the set of independent data streams. In various embodiments, transmitting the control information may include signaling the quasi-co-location of the UE-specific RS antenna port with one or more other reference signals using two or more "PDSCH RE Mapping and Quasi-Co-location Indicator" fields according to the various example embodiments described above. Furthermore, in some embodiments, when two or more DCI messages are to be used to schedule PDSCH transmissions, eNB 110 may generate the control information by mapping one codeword to one transmission layer. In other embodiments, eNB 110 may map one codeword to two or more transmission layers associated with one or more independent data streams in the first set of one or more independent data streams, or map one codeword to two or more layers associated with one or more independent data streams in the second set of one or more independent data streams. In any embodiment, the control information may indicate whether there is a one-to-one correspondence between each codeword and each transmission layer, or whether there is a one-to-many correspondence between each codeword and two or more transmission layers.

The above description of the implementation provides an illustration and description of example embodiments and is not intended to be exhaustive or to limit the scope of the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings and/or may be acquired from practice of various implementations of the invention. For example, the example embodiments described relate to auxiliary multi-cell multi-point SU-MIMO transmission. However, the example embodiments can be extended to apply to auxiliary multi-cell multi-point multi-user (MU)-MIMO transmission, for example.

The following are some non-limiting examples:

Example 1 may include at least one computer-readable medium including instructions that, when executed by one or more processors, cause a user equipment (UE) to: process a first group of one or more independent data streams received from a first transmission point in a downlink channel; process a second group of one or more independent data streams received from a second transmission point in a downlink channel; process control information received from the first transmission point or the second transmission point; determine a quasi-co-location hypothesis for estimating channel characteristics for receiving the first group of one or more independent data streams or for receiving the second group of one or more independent data streams, wherein the quasi-co-location hypothesis to be used is based on an indication within the control information; and estimate the channel characteristics for receiving the first group of one or more independent data streams or for receiving the second group of one or more independent data streams based on the quasi-co-location hypothesis. The at least one computer-readable medium may be a non-transitory computer-readable medium.

Example 2 may include at least one computer-readable medium of Example 1 and/or any other one or more examples disclosed herein, wherein at least one independent data stream in the first group of one or more independent data streams corresponds to a first layer, and the at least one independent data stream is to be transmitted by at least one antenna port in a plurality of antenna ports associated with one or more UE-specific reference signals (RSs) of a first transmission point.

Example 3 may include at least one computer-readable medium of Example 2 and/or any other one or more examples disclosed herein, wherein the indication indicates that the multiple antenna ports are not assumed to be quasi-co-located with respect to at least one of Doppler shift, Doppler spread, average delay, or delay spread.

Example 4 may include at least one computer-readable medium of Example 3 and/or any other one or more examples disclosed herein, wherein the same Doppler shift, Doppler spread, average delay, and delay spread are assumed over a predefined set of physical resource blocks (PRBs).

Example 5 may include at least one computer-readable medium of Example 3 and/or any other one or more examples disclosed herein, wherein the indication is used to indicate quasi-co-location of an antenna port among a plurality of antenna ports associated with one or more UE-specific RSs and one or more antenna ports associated with one or more other RSs.

Example 6 may include at least one computer-readable medium of Example 5 and/or any other one or more examples disclosed herein, wherein the one or more other RSs include one of a cell-specific RS (CRS), a channel state information reference signal (CSI-RS), or a discovery RS.

Example 7 may include at least one computer-readable medium of Example 2 and/or any other one or more examples disclosed herein, wherein the indication indicates quasi-co-location of an antenna port among a plurality of antenna ports associated with one or more UE-specific RSs with other RSs, and wherein, when the instructions are executed by one or more processors, causes the UE to: determine one or more other RSs using two or more physical downlink shared channel (PDSCH) resource element (RE) mappings and a quasi-co-location indicator field.

Example 8 may include at least one computer-readable medium of Example 2 and/or any other one or more examples disclosed herein, wherein the instruction indicates quasi-co-location of an antenna port in a plurality of antenna ports associated with one or more UE-specific RSs with other RSs, and wherein, when the instruction is executed by one or more processors, causes the UE to: determine the one or more other RSs using two or more downlink control information (DCI) format 2D messages, wherein each of the two or more DCI format 2D messages includes at least one PDSCH RE mapping and a quasi-co-location indicator field.

Example 9 may include at least one computer-readable medium of Example 2 and/or any other one or more examples disclosed herein, wherein the indication indicates RE mappings for one or more independent data streams in the first group of one or more independent data streams and one or more independent data streams in the second group of one or more independent data streams, and wherein, when the instructions are executed by one or more processors, causes the UE to: determine the RE mapping using two or more PDSCH RE mappings and a quasi-co-location indicator field.

Example 10 may include an apparatus to be implemented in a user equipment (UE), comprising: an antenna array including at least a first receiving antenna and a second receiving antenna; one or more computer-readable storage media having instructions; and one or more processors coupled to the antenna array and the one or more computer-readable storage media, wherein at least one of the one or more processors will execute the instructions to: control the use of the first receiving antenna to receive a first group of one or more independent data streams in a downlink channel of a first cell; control the use of the second receiving antenna to receive a second group of one or more independent data streams in a downlink channel of a second cell; control the use of the first receiving antenna to receive control information from the first downlink cell or the use of the second receiving antenna from the second downlink cell; based on an indication of the control information, determine a quasi-co-location hypothesis, wherein the quasi-co-location hypothesis will be used to estimate channel characteristics for the reception of the first group of one or more independent data streams or for the reception of the second group of one or more independent data streams; and use the quasi-co-location hypothesis to estimate channel characteristics for the reception of the first group of one or more independent data streams or for the reception of the second group of one or more independent data streams.

Example 11 may include the apparatus of Example 10 and/or any other one or more examples disclosed herein, wherein at least one independent data stream in the first group of one or more independent data streams corresponds to a layer, and the at least one independent data stream is transmitted by at least one antenna port in a plurality of antenna ports associated with one or more UE-specific reference signals of a first downlink cell, wherein the plurality of antenna ports include antenna ports 7-14.

Example 12 may include the apparatus of Example 11 and/or any other one or more examples disclosed herein, wherein the indication indicates that multiple antenna ports are not assumed to be quasi-co-located with respect to Doppler shift, Doppler spread, average delay, and/or delay spread, and are assumed to have the same Doppler shift, Doppler spread, average delay, and delay spread over a predefined set of physical resource blocks (PRBs).

Example 13 may include the apparatus of Example 12, wherein an antenna port in one or more UE-specific RS antenna ports and an antenna port associated with one or more other RSs are quasi-co-located, wherein the one or more other RSs include at least one of a cell-specific RS including antenna ports 0-3, a channel state information RS (CSI-RS) including antenna ports 15-21, or a discovery RS.

Example 14 may include an apparatus of Example 11 and/or any other one or more examples disclosed herein, wherein the control information includes an indication of quasi-co-location of multiple antenna ports associated with one or more UE-specific reference signals and antenna ports associated with other reference signals using two or more physical downlink shared channel (PDSCH) resource element (RE) mappings and a quasi-co-location indicator field.

Example 15 may include the apparatus of Example 11 and/or any other one or more examples disclosed herein, wherein the indication indicates quasi-co-location of multiple antenna ports associated with one or more UE-specific RSs with other RSs, and at least one of the one or more processors executes the instructions to: determine the other RSs using two or more downlink control information formats 2D including a PDSCH RE mapping and a quasi-co-location indicator field.

Example 16 may include the apparatus of Example 11 and/or any other one or more examples disclosed herein, wherein the indication indicates RE mappings for one or more independent data streams in the first group of one or more independent data streams and one or more independent data streams in the second group of one or more independent data streams, and at least one of the one or more processors executes the instructions to: determine the RE mapping using two or more PDSCH RE mappings and the quasi-co-location indicator field.

Example 17 may include the apparatus of Example 10 and/or any other one or more examples disclosed herein, wherein channel state information (CSI) is used by a first downlink cell or a second downlink cell to assist transmission of a first set of one or more independent data streams or a second set of one or more independent data streams, and antenna ports associated with CSI reference signals (CSI-RS) are not assumed to be quasi-co-located, and wherein at least one processor executes instructions to: control reception of an indication in higher layer signaling related to an aggregation of antenna ports of configured CSI-RS that should be used for CSI reporting.

Example 18 may include at least one computer-readable medium including instructions that cause an evolved Node B (eNB) to, in response to execution of the instructions by the eNB, cause a first set of one or more independent data streams to be transmitted in a downlink channel from a first transmission point associated with the eNB, wherein the first transmission point corresponds to a downlink cell and a second transmission point is one of another eNB or a small cell base station; generate control information including an indication of parameters of at least one of the first set of one or more independent data streams or a second set of one or more independent data streams to be transmitted by the second transmission point in a downlink channel of the second transmission point; and implement transmission of the control information. The at least one computer-readable medium may be a non-transitory computer-readable medium.

Example 19 may include at least one computer-readable medium of Example 18 and/or any other one or more examples disclosed herein, wherein antenna ports associated with a CSI reference signal (CSI-RS) are not assumed to be quasi-co-located, and wherein the instructions further cause the eNB, in response to execution of the instructions by the eNB, to: use channel state information (CSI) to assist transmission of a first set of one or more independent data streams; and send an indication in higher layer signaling related to the aggregation of antenna ports of the configured CSI-RS for CSI reporting.

Example 20 may include at least one computer-readable medium of Example 18 and/or any other one or more examples disclosed herein, wherein the instructions further cause the eNB, in response to execution of the instructions by the eNB, to: map a codeword to a transport layer when two or more downlink control information (DCI) messages are to be used to schedule a physical downlink shared channel (PDSCH).

Example 21 may include at least one computer-readable medium of Example 18 and/or any other one or more examples disclosed herein, wherein the instructions further cause the eNB to perform the following operations in response to execution of the instructions by the eNB: mapping a codeword to two or more transport layers associated with one or more independent data streams in the first group of one or more independent data streams, or mapping a codeword to two or more layers associated with one or more independent data streams in the second group of one or more independent data streams.

Example 22 may include an apparatus to be implemented in an evolved Node B (eNB), comprising: one or more computer-readable storage media having instructions; and one or more processors coupled to an antenna array and the one or more computer-readable storage media, wherein at least one of the one or more processors executes the instructions to: identify control information related to parameters of a first independent data stream to be sent by a downlink cell or a second independent data stream to be sent by another downlink cell; and enable transmission of the first independent data stream and the control information.

Example 23 may include the apparatus of Example 22 and/or any other one or more examples disclosed herein, wherein antenna ports associated with a CSI reference signal (CSI-RS) are not assumed to be quasi-co-located, and wherein at least one processor executes instructions to: use channel state information (CSI) to assist in transmission of a first independent data stream; and send an indication in higher layer signaling related to an aggregation of antenna ports of the configured CSI-RS to be used for CSI reporting.

Example 24 may include an apparatus of Example 22 and/or any other one or more examples disclosed herein, wherein the at least one processor executes instructions to: map a codeword to a transport layer when two or more downlink control information (DCI) messages are to be used to schedule a physical downlink shared channel (PDSCH).

Example 25 may include the apparatus of Example 22 and/or any other one or more examples disclosed herein, wherein at least one processor executes instructions to: map a codeword to two or more layers associated with one or more independent data streams comprising a first independent data stream, or map a codeword to two or more layers associated with one or more independent data streams comprising a second independent data stream.

Example 26 may include an apparatus to be implemented in a user equipment (UE), comprising: radio frequency (RF) circuitry to receive a first set of one or more independent data streams received from a first transmission point in a first downlink channel; receive a second set of one or more independent data streams from a second transmission point in a second downlink channel; and receive control information from the first transmission point or the second transmission point, and baseband circuitry to process the first set of one or more independent data streams; process the second set of one or more independent data streams; process the control information to determine a quasi-co-location hypothesis for estimating channel characteristics for reception of the first set of one or more independent data streams or for reception of the second set of one or more independent data streams, wherein the quasi-co-location hypothesis to be used is based on an indication within the control information; and estimating channel characteristics for reception of the first set of one or more independent data streams or for reception of the second set of one or more independent data streams based on the quasi-co-location hypothesis.

Example 27 may include the apparatus of Example 26 and/or any other one or more examples disclosed herein, wherein at least one independent data stream in the first group of one or more independent data streams corresponds to a first layer, and the at least one independent data stream is to be transmitted by at least one antenna port in a plurality of antenna ports associated with one or more UE-specific reference signals (RSs) of the first transmission point.

Example 28 may include the apparatus of Example 27 and/or any other one or more examples disclosed herein, wherein the indication indicates that the multiple antenna ports are not assumed to be quasi-co-located with respect to Doppler shift, Doppler spread, average delay, or delay spread.

Example 29 may include an apparatus of Example 28 and/or any other one or more examples disclosed herein, wherein the same Doppler shift, Doppler spread, average delay, and delay spread are assumed over a predefined set of physical resource blocks (PRBs).

Example 30 may include an apparatus of Example 28 and/or any other one or more examples disclosed herein, wherein the indication indicates quasi-co-location of an antenna port among a plurality of antenna ports associated with one or more UE-specified RSs and one or more antenna ports associated with one or more other RSs.

Example 31 may include an apparatus of Example 30 and/or any other one or more examples disclosed herein, wherein the one or more other RSs include one of a cell-specific RS (CRS), a channel state information reference signal (CSI-RS), or a discovery RS.

Example 32 may include an apparatus of Example 27 and/or any other one or more examples disclosed herein, wherein the indication indicates quasi-co-location of an antenna port from a plurality of antenna ports associated with one or more UE-specified RSs and antenna ports associated with other RSs, and wherein the baseband circuitry determines the one or more other RSs using two or more physical downlink shared channel (PDSCH) resource element (RE) mappings and a quasi-co-location indicator field.

Example 33 may include the apparatus of Example 27 and/or any other one or more examples disclosed herein, wherein the indication indicates quasi-co-location of antenna ports of a plurality of antenna ports associated with one or more UE-specific RSs and antenna ports associated with other RSs, and wherein the baseband circuitry is to determine the one or more other RSs using two or more downlink control information (DCI) format 2D messages, wherein each of the two or more DCI format 2D messages includes at least one PDSCH RE mapping and a quasi-co-location indicator field.

Example 34 may include the apparatus of Example 27 and/or any other one or more examples disclosed herein, wherein the indication indicates RE mappings for one or more independent data streams in the first group of one or more independent data streams and one or more independent data streams in the second group of one or more independent data streams, and wherein the baseband circuitry determines the RE mapping using two or more PDSCH RE mappings and a quasi-co-location indicator field.

Example 35 may include a computer-implemented method for providing multi-cell multi-point single-user (SU) multiple-input multiple-output (MIMO) transmission, the method comprising: receiving and processing, by a user equipment (UE), a first set of one or more independent data streams received in a downlink channel from a first transmission point; receiving and processing, by the UE, a second set of one or more independent data streams received in a downlink channel from a second transmission point; receiving and processing, by the UE, control information received from the first transmission point or the second transmission point; determining, by the UE, a quasi-co-location hypothesis to be used for estimating channel characteristics for reception of the first set of one or more independent data streams or for reception of the second set of one or more independent data streams, wherein the quasi-co-location hypothesis to be used is based on an indication within the control information; and estimating, by the UE, channel characteristics for reception of the first set of one or more independent data streams or for reception of the second set of one or more independent data streams based on the quasi-co-location hypothesis.

Example 36 may include the method of Example 35 and/or any other one or more examples disclosed herein, wherein at least one independent data stream in the first group of one or more independent data streams corresponds to a first layer, and the at least one independent data stream is to be transmitted by at least one antenna port in a plurality of antenna ports associated with one or more UE-specific reference signals (RS) of the first transmission point.

Example 37 may include the method of Example 36 and/or any other one or more examples disclosed herein, wherein the indication indicates that the multiple antenna ports are not assumed to be quasi-co-located with respect to at least one of Doppler shift, Doppler spread, average delay, or delay spread.

Example 38 may include the method of Example 37 and/or any other one or more examples disclosed herein, wherein the same Doppler shift, Doppler spread, average delay, and delay spread are assumed over a predefined set of physical resource blocks (PRBs).

Example 39 may include the method of Example 37 and/or any other one or more examples disclosed herein, wherein the indication indicates quasi-co-location of antenna ports of multiple antenna ports associated with one or more UE-specific RSs and one or more antenna ports associated with one or more other RSs.

Example 40 may include the method of Example 39, wherein the one or more other RSs include one of a cell-specific RS (CRS), a channel state information reference signal (CSI-RS), or a discovery RS.

Example 41 may include the method of Example 36 and/or any other one or more examples disclosed herein, wherein the indication indicates that an antenna port among a plurality of antenna ports associated with one or more UE-specific RSs and an antenna port associated with other RSs are quasi-co-located, and the method further includes: determining, by the UE, one or more other RSs using two or more physical downlink shared channel (PDSCH) resource element (RE) mappings and a quasi-co-location indicator field.

Example 42 may include the method of Example 36 and/or any other one or more examples disclosed herein, wherein the indication indicates quasi-co-location of an antenna port among a plurality of antenna ports associated with one or more UE-specific RSs and an antenna port associated with other RSs, and the method further comprises: determining, by the UE, one or more other RSs using two or more downlink control information (DCI) format 2D messages, wherein each of the two or more DCI format 2D messages includes at least one PDSCH RE mapping and a quasi-co-location indicator field.

Example 43 may include the method of Example 36 and/or any other one or more examples disclosed herein, wherein the indication indicates RE mappings for one or more independent data streams in the first group of one or more independent data streams and one or more independent data streams in the second group of one or more independent data streams, and the method further includes: determining the RE mapping by the UE using two or more PDSCH RE mappings and a quasi-co-location indicator field.

Example 44 may include at least one computer-readable medium including instructions, wherein the instructions, in response to execution of the instructions by the UE, cause the user equipment (UE) to perform the method of Examples 35-43 and/or any other one or more examples disclosed herein. The at least one computer-readable medium may be a non-transitory computer-readable medium.

Example 45 may include an apparatus to be implemented in a user equipment (UE), comprising: an antenna array including at least a first receive antenna and a second receive antenna; a radio frequency (RF) circuit coupled to the antenna array, the RF circuit using the first receive antenna to receive a first group of one or more independent data streams in a downlink channel of a first cell, using the second receive antenna to receive a second group of one or more independent data streams in a downlink channel of a second cell, and using the first receive antenna to receive control information from the first downlink cell or from the second downlink cell using the second receive antenna; and a baseband circuit coupled to the RF circuit, the baseband circuit determining a quasi-co-location hypothesis based on an indication of the control information, wherein the quasi-co-location hypothesis is used to estimate channel characteristics for reception of the first group of one or more independent data streams or reception of the second group of one or more independent data streams; and using the quasi-co-location hypothesis, estimating channel characteristics for reception of the first group of one or more independent data streams or reception of the second group of one or more independent data streams.

Example 46 may include the apparatus of Example 45 and/or any other one or more examples disclosed herein, wherein at least one independent data stream in the first group of one or more independent data streams corresponds to a layer, and the at least one independent data stream is transmitted by at least one antenna port in a plurality of antenna ports associated with one or more UE-specific reference signals of the first downlink cell, wherein the plurality of antenna ports include antenna ports 7-14.

Example 47 may include the apparatus of Example 46 and/or any other one or more examples disclosed herein, wherein the indication indicates that multiple antenna ports are not assumed to be quasi-co-located with respect to Doppler shift, Doppler spread, average delay, and/or delay spread, and that the same Doppler shift, Doppler spread, average delay, and delay spread are assumed on a predefined set of physical resource blocks (PRBs).

Example 48 may include an apparatus of Example 47 and/or any other one or more examples disclosed herein, wherein antenna ports of one or more UE-specific RS antenna ports and antenna ports associated with one or more other RSs are quasi-co-located, wherein the one or more other RSs include at least one of a cell-specific RS including antenna ports 0-3, a channel state information RS (CSI-RS) including antenna ports 15-21, or a discovery RS.

Example 49 may include an apparatus of Example 46 and/or any other one or more examples disclosed herein, wherein the control information includes an indication of quasi-co-location of multiple antenna ports associated with one or more UE-specific reference signals and antenna ports associated with other reference signals using two or more physical downlink shared channel (PDSCH) resource element (RE) mappings and a quasi-co-location indicator field.

Example 50 may include the apparatus of Example 46 and/or any other one or more examples disclosed herein, wherein the indication indicates quasi-co-location of multiple antenna ports associated with one or more UE-specific RSs and antenna ports associated with other RSs, and the baseband circuitry uses two or more downlink control information formats 2D including a PDSCH RE mapping and a quasi-co-location indicator field to determine the other RSs.

Example 51 may include an apparatus of Example 46 and/or any other one or more examples disclosed herein, wherein the indication indicates RE mappings for one or more independent data streams in the first group of one or more independent data streams and one or more independent data streams in the second group of one or more independent data streams, and the baseband circuit uses two or more PDSCH RE mappings and a quasi-co-location indicator field to determine the RE mapping.

Example 52 may include the apparatus of Example 45 and/or any other one or more examples disclosed herein, wherein channel state information (CSI) is used by the first downlink cell or the second downlink cell to assist in transmission of a first set of one or more independent data streams or a second set of one or more independent data streams, and antenna ports associated with CSI reference signals (CSI-RS) are not assumed to be quasi-co-located, and the baseband circuit controls reception in higher layer signaling of an indication related to the aggregation of antenna ports of the configured CSI-RS that should be used for CSI reporting.

Example 53 may include a computer-implemented method for providing multi-cell multi-point single-user (SU) multiple-input multiple-output (MIMO) transmission, the method comprising: receiving, by a user equipment (UE) using a first receive antenna, a first group of one or more independent data streams in a downlink channel of a first cell; receiving, by the UE using a second receive antenna, a second group of one or more independent data streams in a downlink channel of a second cell; receiving, by the UE, control information from the first downlink cell using the first receive antenna or from the second downlink cell using the second receive antenna; determining, by the UE, a quasi-co-location hypothesis based on an indication of the control information, wherein the quasi-co-location hypothesis is to be used to estimate channel characteristics for reception of the first group of one or more independent data streams or for reception of the second group of one or more independent data streams; and using the quasi-co-location hypothesis by the UE to estimate channel characteristics for reception of the first group of one or more independent data streams or for reception of the second group of one or more independent data streams.

Example 54 may include the method of Example 53 and/or any other one or more examples disclosed herein, wherein at least one independent data stream in the first group of one or more independent data streams corresponds to a layer, and the at least one independent data stream is transmitted by at least one antenna port in a plurality of antenna ports associated with one or more UE-specific reference signals of the first downlink cell, wherein the plurality of antenna ports include antenna ports 7-14.

Example 55 may include the method of Example 54 and/or any other one or more examples disclosed herein, wherein the indication indicates that multiple antenna ports are not assumed to be quasi-co-located with respect to Doppler shift, Doppler spread, average delay and/or delay spread, and are assumed to have the same Doppler shift, Doppler spread, average delay and delay spread over a predefined set of physical resource blocks (PRBs).

Example 56 may include the method of Example 55 and/or any other one or more examples disclosed herein, wherein an antenna port in one or more UE-specific RS antenna ports and an antenna port associated with one or more other RSs are quasi-co-located, wherein the one or more other RSs include at least one of a cell-specific RS including antenna ports 0-3, a channel state information RS (CSI-RS) including antenna ports 15-21, or a discovery RS.

Example 57 may include the method of Example 54 and/or any other one or more examples disclosed herein, wherein the control information includes an indication of quasi-co-location of multiple antenna ports associated with one or more UE-specific reference signals and antenna ports associated with other reference signals using two or more physical downlink shared channel (PDSCH) resource element (RE) mappings and a quasi-co-location indicator field.

Example 58 may include the method of Example 54 and/or any other one or more examples disclosed herein, wherein the indication indicates quasi-co-location of multiple antenna ports associated with one or more UE-specific RSs with antenna ports associated with other RSs, and at least one processor of the one or more processors is to execute instructions to: use two or more downlink control information formats 2D including a PDSCH RE mapping and a quasi-co-location indicator field to determine the other RSs.

Example 59 may include the method of Example 54 and/or any other one or more examples disclosed herein, wherein the indication will indicate RE mappings for one or more independent data streams in the first group of one or more independent data streams and one or more independent data streams in the second group of one or more independent data streams, and at least one of the one or more processors will execute instructions to: determine the RE mapping using two or more PDSCH RE mappings and the quasi-co-location indication field.

Example 60 may include the method of Example 53 and/or any other one or more examples disclosed herein, wherein channel state information (CSI) is used by the first downlink cell or the second downlink cell to assist in the transmission of a first group or a second group of one or more independent data streams of one or more independent data streams.

Example 61 may include at least one computer-readable medium including instructions, causing a user equipment (UE) to perform any one of Examples 53-60 and/or any other one or more examples disclosed herein in response to the instructions being executed by the UE. The at least one computer-readable medium may be a non-transitory computer-readable medium.

Example 62 may include an apparatus implemented by an evolved Node B (eNB), comprising: one or more computer-readable storage media having instructions; and one or more processors coupled to an antenna array and the one or more computer-readable storage media, wherein at least one of the one or more processors executes the instructions to: cause transmission of a first set of one or more independent data streams in a downlink channel from a first transmission point associated with the eNB, wherein the first transmission point corresponds to a downlink cell and the second transmission point is one of another eNB or a small cell base station; generate control information including an indication of a parameter of at least one of the first set of one or more independent data streams or a second set of one or more independent data streams sent by the second transmission point in a downlink channel of the second transmission point; and effectuate transmission of the control information.

Example 63 may include the apparatus of Example 62 and/or any other one or more examples disclosed herein, wherein antenna ports associated with a CSI reference signal (CSI-RS) are not assumed to be quasi co-located, and wherein the instructions further cause the eNB, in response to execution by the eNB of the instructions, to: use channel state information (CSI) to assist transmission of a first set of one or more independent data streams; and send, in higher layer signaling, an indication related to an aggregation of antenna ports of the configured CSI-RS to be used for CSI reporting.

Example 64 may include the device of Example 62 and/or any other one or more examples disclosed herein, wherein the instructions further cause the eNB to, in response to execution of the instructions by the eNB, map a codeword to a transport layer when two or more downlink control information (DCI) messages are to be used to schedule a physical downlink shared channel (PDSCH).

Example 65 may include the apparatus of Example 62 and/or any other one or more examples disclosed herein, wherein the instructions further cause the eNB, in response to execution of the instructions by the eNB, to: map a codeword to two or more transport layers associated with one or more independent data streams in the first group of one or more independent data streams, or map a codeword to two or more layers associated with one or more independent data streams in the second group of one or more independent data streams.

Example 66 may include an apparatus implemented by an evolved Node B (eNB), comprising: radio frequency (RF) circuitry for transmitting a first set of one or more independent data streams in a downlink channel from a first transmission point associated with the eNB, wherein the first transmission point corresponds to a downlink cell and the second transmission point is one of another eNB or a small cell base station; and baseband circuitry coupled to the RF circuitry, the baseband circuitry generating control information including an indication of a parameter of at least one of the first set of one or more independent data streams or a second set of one or more independent data streams to be transmitted by the second transmission point in the downlink channel of the second transmission point, and wherein the RF circuitry is to transmit the control information.

Example 67 may include the apparatus of Example 66 and/or any other one or more examples disclosed herein, wherein antenna ports associated with a CSI reference signal (CSI-RS) are not assumed to be quasi-co-located, and wherein baseband circuitry uses channel state information (CSI) to assist in the transmission of a first set of one or more independent data streams; and transmission of an indication related to the aggregation of antenna ports of the configured CSI-RS to be used for CSI reporting is implemented in higher layer signaling.

Example 68 may include an apparatus of Example 66 and/or any other one or more examples disclosed herein, wherein the baseband circuit maps a codeword to a transport layer when two or more downlink control information (DCI) messages are to be used to schedule a physical downlink shared channel (PDSCH).

Example 69 may include the apparatus of Example 66 and/or any other one or more examples disclosed herein, wherein the baseband circuit maps a codeword to two or more transport layers associated with one or more independent data streams in the first group of one or more independent data streams, or maps a codeword to two or more layers associated with one or more independent data streams in the second group of one or more independent data streams.

Example 70 may include an apparatus to be implemented in an evolved Node B (eNB), comprising: a baseband circuit for identifying control information, the control information being related to parameters of a first independent data stream to be sent by a downlink cell or a second independent data stream to be sent by another downlink cell; and implementing transmission of the first independent data stream and the control information; and a radio frequency (RF) circuit coupled to the baseband circuit, the RF circuit to send the first independent data stream and the control information.

Example 71 may include the apparatus of Example 70 and/or any other one or more examples disclosed herein, wherein antenna ports associated with a CSI reference signal (CSI-RS) are not assumed to be quasi-co-located, and wherein the baseband circuitry is to use channel state information (CSI) to assist in transmission of a first independent data stream; and the RF circuitry is to send in higher layer signaling an indication regarding an aggregation of antenna ports for configured CSI-RS to be used for CSI reporting.

Example 72 may include an apparatus of Example 70 and/or any other one or more examples disclosed herein, wherein the baseband circuit maps a codeword to a transport layer when two or more downlink control information (DCI) messages are used to schedule a physical downlink shared channel (PDSCH).

Example 73 may include the apparatus of Example 70 and/or any other one or more examples disclosed herein, wherein the baseband circuit maps a codeword to two or more layers associated with one or more independent data streams comprising a first independent data stream, or maps a codeword to two or more layers associated with one or more independent data streams comprising a second independent data stream.

Example 74 may include at least one computer-readable medium having instructions, the instructions causing an evolved Node B (eNB) to, in response to execution of the instructions by the eNB, identify control information related to parameters of a first independent data stream to be transmitted by a downlink cell or a second independent data stream to be transmitted by another downlink cell; and enable transmission of the first independent data stream and the control information. The at least one computer-readable medium may be a non-transitory computer-readable medium.

Example 75 may include at least one computer-readable medium of example 74 and/or any other one or more examples disclosed herein, wherein antenna ports associated with a CSI reference signal (CSI-RS) are not assumed to be quasi-co-located, and wherein at least one processor executes instructions to: use channel state information (CSI) to assist in transmission of a first independent data stream; and send an indication in higher layer signaling related to an aggregation of antenna ports of the configured CSI-RS to be used for CSI reporting.

Example 76 may include at least one computer-readable medium of Example 74 and/or any other one or more examples disclosed herein, wherein at least one processor executes instructions to: map a codeword to a transport layer when two or more downlink control information (DCI) messages are to be used to schedule a physical downlink shared channel (PDSCH).

Example 77 may include at least one computer-readable medium of Example 74 and/or any other one or more examples disclosed herein, wherein the at least one processor executes instructions to: map a codeword to two or more layers associated with one or more independent data streams comprising a first independent data stream, or map a codeword to two or more layers associated with one or more independent data streams comprising a second independent data stream.

Example 78 may include a computer-implemented method for providing multi-cell multi-point single-user (SU) multiple-input multiple-output (MIMO) transmission, the method comprising: transmitting, by an evolved Node B (eNB), a first set of one or more independent data streams in a downlink channel from a first transmission point associated with the eNB, wherein the first transmission point corresponds to a downlink cell and a second transmission point is one of another eNB or a small cell base station; generating, by the eNB, control information including an indication of parameters of at least one of the first set of one or more independent data streams or a second set of one or more independent data streams transmitted by the second transmission point in a downlink channel of the second transmission point; and transmitting, by the eNB, the control information.

Example 79 may include the method of Example 78 and/or any other one or more examples disclosed herein, wherein antenna ports associated with a CSI reference signal (CSI-RS) are not assumed to be quasi-co-located, and further comprising: using channel state information (CSI) by the eNB to assist in transmission of the first set of one or more independent data streams; and sending, by the eNB in higher layer signaling, an indication regarding an aggregation of antenna ports of the configured CSI-RS to be used for CSI reporting.

Example 80 may include the method of Example 78 and/or any other one or more examples disclosed herein, further including: mapping a codeword to a transport layer by the eNB when two or more downlink control information (DCI) messages are to be used to schedule a physical downlink shared channel (PDSCH).

Example 81 may include the method of Example 78 and/or any other one or more examples disclosed herein, further comprising: mapping, by the eNB, a codeword to two or more transport layers associated with one or more independent data streams in the first group of one or more independent data streams, or mapping a codeword to two or more layers associated with one or more independent data streams in the second group of one or more independent data streams.

Example 82 may include at least one computer-readable medium having instructions, causing an evolved Node B (eNB) to perform the method of any of Examples 78-81 and/or any other one or more examples disclosed herein in response to execution of the instructions by the eNB. The at least one computer-readable medium may be a non-transitory computer-readable medium.

Example 83 may include a computer-implemented method for providing multi-cell multi-point single-user (SU) multiple-input multiple-output (MIMO) transmission, the method comprising: identifying, by an evolved Node B (eNB), control information related to parameters of a first independent data stream to be sent by a downlink cell or a second independent data stream to be sent by another downlink cell; and sending, by the eNB, the first independent data stream and the control information.

Example 84 may include the method of Example 82 and/or any other one or more examples disclosed herein, wherein antenna ports associated with a CSI reference signal (CSI-RS) are not assumed to be quasi co-located, and the method further includes: using channel state information (CSI) by the eNB to assist in transmission of the first independent data stream; and sending, by the eNB in higher layer signaling, an indication related to an aggregation of antenna ports of the configured CSI-RS to be used for CSI reporting.

Example 85 may include the method of Example 82 and/or any other one or more examples disclosed herein, further including: mapping a codeword to a transport layer by the eNB when two or more downlink control information (DCI) messages are to be used to schedule a physical downlink shared channel (PDSCH).

Example 86 may include the method of Example 82 and/or any other one or more examples disclosed herein, further comprising: mapping, by the eNB, a codeword to two or more layers associated with one or more independent data streams comprising the first independent data stream, or mapping a codeword stream to two or more layers associated with one or more independent data streams comprising the second independent data stream.

Example 87 may include at least one computer-readable medium including instructions causing an evolved Node B (eNB) to perform the method of any one of Examples 83-86 and/or any other one or more examples disclosed herein in response to execution of the instructions by the eNB. The at least one computer-readable medium may be a non-transitory computer-readable medium.

The foregoing description of the above examples provides an illustration and description of the exemplary embodiments disclosed herein, but the above examples are not intended to be exhaustive or to limit the scope of the invention to the precise forms disclosed. Modifications and variations are possible in light of the above teachings and/or can be obtained from practice of various implementations of the invention.

Claims (37)

1. One or more computer-readable storage media (CRSM) including instructions, wherein the instructions are executed by one or more processors to cause a user equipment (UE) to: The control receives control information from a first transmission point or a second transmission point, wherein the control information includes an indication of a parameter set for determining quasi-cooperative positioning (QCL); Based on the indicated set of parameters, QCL assumptions are determined to be used to estimate channel characteristics for a first set of multiple layers in a downlink channel received from the first transmission point and a second set of multiple layers in a downlink channel received from the second transmission point. Estimate the channel characteristics for reception of the first group of multiple layers and for reception of the second group of multiple layers based on the QCL assumptions; and Based on the estimated channel characteristics, control is set to use a first receiving antenna to receive the first group of multiple layers and control is set to use a second receiving antenna to receive the second group of multiple layers. 2. One or more CRSMs according to claim 1, wherein: One or more first independent data streams correspond to the first group of multiple layers, and the one or more first independent data streams will be transmitted by at least one of a plurality of antenna ports associated with one or more UE-specific reference signals (RS) of the first transmission point; and One or more second independent data streams correspond to the second group of multiple layers, and the one or more second independent data streams will be transmitted by at least one of the multiple antenna ports associated with one or more UE-dedicated RSs of the second transmission point. 3. One or more CRSMs according to claim 2, wherein the indication indicates that the plurality of antenna ports are not assumed to be quasi-cooperatively located with respect to at least one of Doppler shift, Doppler spread, average delay, or delay spread, and wherein the same Doppler shift, Doppler spread, average delay, and delay spread are assumed on a predefined set of physical resource blocks (PRBs). 4. One or more CRSMs according to claim 2, wherein the parameter set includes crs-PortsCount-r11, crs-FreqShift-r11, mbsfn-SubframeConfigList-r11, csi-RS-ConfigZPId-r11, pdsch-Start-r11, and qcl-CSI-RS-ConfigNZPId-r11. 5. One or more CRSMs according to claim 2, wherein the indication indicates quasi-co-location of the UE-dedicated RS antenna port and one or more antenna ports associated with one or more other RSs for the first set of multiple layers to be transmitted on the first transport block and for the second set of multiple layers to be transmitted on the second transport block. 6. The one or more CRSMs according to claim 5, wherein the one or more other RSs include one of a cell-specific RS (CRS), a channel state information reference signal (CSI-RS), or a discovery RS. 7. One or more CRSMs according to claim 2, wherein the instruction indicates quasi-co-location of antenna ports among the plurality of antenna ports associated with the one or more UE-dedicated RSs and other RSs, and wherein execution of the instruction causes the UE to: One or more other RSs are identified using two or more Physical Downlink Shared Channel (PDSCH) Resource Element (RE) mappings and Quasi-Cooperative Positioning Indicator fields. 8. One or more CRSMs according to claim 2, wherein the instruction indicates quasi-co-location of antenna ports among the plurality of antenna ports associated with the one or more UE-dedicated RSs and other RSs, and wherein execution of the instruction causes the UE to: One or more other RSs are determined using two or more Downlink Control Information (DCI) format 2D messages, wherein each of the two or more DCI format 2D messages includes at least one PDSCH RE mapping and quasi-cooperative positioning indicator field. 9. One or more CRSMs according to claim 2, wherein the instruction indicates RE mapping for the one or more first independent data streams of the first group of multiple layers and the one or more second independent data streams of the second group of multiple layers, and wherein execution of the instruction causes the UE to: The RE mapping is determined using two or more PDSCH RE mapping and quasi-co-location indicator fields. 10. An apparatus implemented in a user equipment (UE), comprising: An antenna array, comprising at least a first receiving antenna and a second receiving antenna; A processor circuit operatively coupled to the antenna array, the processor circuit being configured to: Control the first receiving antenna to receive the first group of multiple layers in the downlink channel of the first cell; Control the second receiving antenna to receive the second group of multiple layers in the downlink channel of the second cell; Controlling the first receiving antenna or the second receiving antenna to receive control information from the first cell or the second cell, wherein the control information includes an indication of at least one set of parameters for determining a quasi-cooperative positioning (QCL) hypothesis; Based on the parameter set, QCL assumptions are determined, wherein the QCL assumptions will be used to estimate the channel characteristics for reception of the first set of multiple layers and for reception of the second set of multiple layers; The QCL assumptions are used to estimate the first channel characteristics for reception of the first group of multiple layers and the second channel characteristics for reception of the second group of multiple layers, respectively; and Based on the estimated first and second channel characteristics Control the first receiving antenna to receive the first group of multiple layers, and Control the second receiving antenna to receive the second group of multiple layers. 11. The apparatus according to claim 10, wherein: The first group of multiple layers corresponds to one or more first independent data streams, and the one or more first independent data streams are transmitted by at least one antenna port from a plurality of antenna ports associated with one or more UE-specific reference signals (RS) of the first cell. The second group of multiple layers corresponds to one or more second independent data streams, and the one or more second independent data streams are transmitted by at least one antenna port of a plurality of antenna ports associated with one or more UE-dedicated RSs of the second cell. The plurality of antenna ports include antenna ports 7-14. 12. The apparatus of claim 11, wherein the indication indicates that the plurality of antenna ports are not assumed to be quasi-coordinated in terms of Doppler shift, Doppler spread, average delay, and/or delay spread, and that they are assumed to have the same Doppler shift, Doppler spread, average delay, and delay spread on a predefined set of physical resource blocks (PRBs). 13. The apparatus of claim 12, wherein a plurality of antenna ports in the one or more UE-dedicated RS antenna ports and antenna ports associated with one or more other RSs are quasi-cooperatively located, wherein the one or more other RSs include at least one of a cell-dedicated RS containing antenna ports 0-3, a channel state information RS (CSI-RS) containing antenna ports 15-21, or a discovery RS. 14. The apparatus according to any one of claims 11-13, wherein the control information includes indications for quasi-cooperative positioning of the plurality of antenna ports and other reference signals associated with the one or more Physical Downlink Shared Channel (PDSCH) Resource Element (RE) mappings and quasi-cooperative positioning indicator fields using two or more Physical Downlink Shared Channel (PDSCH) Resource Element (RE) fields and associated with the one or more UE-specific reference information numbers. 15. The apparatus according to any one of claims 11-13, wherein the indication indicates quasi-cooperative positioning of the plurality of antenna ports and other RSs associated with the one or more UE-dedicated RSs, and the processor circuitry is configured to: The other RSs are determined using two or more downlink control information format 2D fields, including a PDSCH RE mapping and a quasi-cooperative positioning indicator field. 16. The apparatus according to any one of claims 11-13, wherein the indication indicates RE mapping for the one or more first independent data streams of the first set of multiple layers and the one or more second independent data streams of the second set of multiple layers, and the processor circuitry is configured to: The RE mapping is determined using two or more PDSCH RE mapping and quasi-co-location indicator fields. 17. The apparatus according to any one of claims 11-13, wherein channel state information (CSI) is used by a first downlink cell or a second downlink cell to assist the transmission of one or more first independent data streams of the first set of multiple layers or one or more second independent data streams of the second set of multiple layers, and the antenna port associated with the CSI reference signal (CSI-RS) is not assumed to be quasi-cooperatively localized, and wherein the processor circuitry is configured to: Controls the reception of indications related to the aggregation of the antenna ports of the configured CSI-RS that should be used for CSI reporting in higher-level signaling. 18. One or more computer-readable storage media (CRSM) including instructions, wherein the instructions are executed by one or more processors to cause a base station to: Control the transmission of a first set of one or more independent data streams in a downlink channel from a first transmission point associated with the base station, wherein the first transmission point corresponds to a downlink cell and the second transmission point is another base station or a small cell base station; Generate control information including an indication of a set of parameters to be used to determine a quasi-cooperative localization (QCL) hypothesis for receiving at least one of a first set of one or more independent data streams or a second set of one or more independent data streams to be transmitted by the second transmission point in the downlink channel of the second transmission point, wherein the control information indicates that channel state information (CSI)-reference information (RS) to be used to report CSI according to a first CSI feedback procedure for each link of the first transmission point, and the antenna port associated with the CSI-RS is not assumed to be quasi-cooperative localization; Control the transmission of the control information; The CSI of the first CSI feedback procedure is obtained, the CSI including a Channel Quality Indicator (CQI), a Precoding Matrix Indicator (PMI), and a Rank Indicator (RI), wherein the RI is assumed to be used for the first CSI feedback procedure based on the RI of the second CSI feedback procedure corresponding to the second transmission point, and the PMI and CQI of the first CSI feedback procedure are determined independently of the PMI and CQI of the second CSI feedback procedure; and The obtained CSI is used to assist in the transmission of one or more independent data streams in the first group. 19. One or more CRSMs of claim 18, wherein the antenna port associated with the CSI-RS is not assumed to be quasi-cooperative positioning, the control information instructs respective CSI feedback procedures for each link of the first transmission point and the second transmission point, and wherein execution of the instructions causes the base station to: Send instructions related to the aggregation of the antenna ports of the configured CSI-RS that will be used for CSI reporting using higher-layer signaling. 20. One or more CRSMs according to claim 18 or 19, wherein, in order to generate the control information, the execution of the instructions causes the base station to: When two or more downlink control information (DCI) messages are used to schedule the physical downlink shared channel (PDCSH), a codeword is mapped to a transport layer. 21. One or more CRSMs according to claim 18 or 19, wherein, in order to generate the control information, the execution of the instructions causes the base station to: Mapping a codeword to two or more transport layers associated with one or more independent data streams in the first group of one or more independent data streams, or mapping a codeword to two or more layers associated with one or more independent data streams in the second group of one or more independent data streams. 22. An apparatus implemented in a base station, comprising: A means for identifying control information associated with a parameter set, which will be used to determine a quasi-cooperative positioning (QCL) assumption for receiving a first independent data stream to be transmitted by a downlink cell or a second independent data stream to be transmitted by another downlink cell, wherein the control information indicates that the channel state information (CSI)-reference information (RS) will be used to report the CSI according to the first CSI feedback process for each link of the first transmission point, and the antenna port associated with the CSI-RS is not assumed to be quasi-cooperatively positioned; A means for transmitting the first independent data stream and the control information; A means for receiving CSI from the first CSI feedback process, the CSI including a channel quality indicator (CQI), a precoding matrix indicator (PMI), and a rank indicator (RI), wherein the CQI is based on an indication of RI inherited from the second CSI feedback process, and the CQI is an average CQI measured at different stages between CSI-reference signal (RS) resources including aggregated CSI-RS resources; and A means for using the received CSI to assist in the transmission of the first independent data stream. 23. The apparatus of claim 22, wherein the control information indicates respective CSI feedback procedures for each link of the first transmission point and the second transmission point, and wherein the means for transmitting is used for: Send instructions related to the aggregation of the antenna ports of the configured CSI-RS that will be used for CSI reporting using higher-layer signaling. 24. The device according to claim 22 or 23, further comprising: A means for mapping a codeword to a transport layer when two or more downlink control information (DCI) messages will be used to schedule a physical downlink shared channel (PDCSH). 25. The device according to claim 22 or 23, further comprising: A means for mapping a codeword to two or more layers associated with one or more independent data streams including the first independent data stream, or for mapping a codeword to two or more layers associated with one or more independent data streams including the second independent data stream. 26. An apparatus for use as a base station, the apparatus comprising: The processor circuit is configured as follows: Generate control information including an indication of a set of parameters to be used to determine a quasi-cooperative positioning (QCL) assumption, the QCL assumption being used to receive at least one of a first set of one or more independent data streams or a second set of one or more independent data streams to be transmitted by a second transmission point in the downlink channel of the second transmission point, wherein the control information indicates that channel state information (CSI)-reference information (RS) to be used to report CSI according to a first CSI feedback procedure for each link of the first transmission point associated with the base station, and the antenna port associated with the CSI-RS is not assumed to be quasi-cooperatively positioned, wherein the first transmission point corresponds to a downlink cell and the second transmission point is another base station or a small cell base station. The CSI obtained from the first CSI feedback process is used to assist the transmission of the first group of one or more independent data streams; and A communication circuit communicatively coupled to the processor circuitry, the communication circuitry being used for: Send one or more independent data streams from the first transmission point in the downlink channel. Send control information, and The CSI of the first CSI feedback process is obtained, and the obtained CSI includes a channel quality indicator (CQI), a precoding matrix indicator (PMI), and a rank indicator (RI), wherein the RI is assumed to be used for the first CSI feedback process based on the RI of the second CSI feedback process corresponding to the second transmission point, and the PMI and CQI of the first CSI feedback process are determined independently of the PMI and CQI of the second CSI feedback process. 27. The apparatus of claim 26, wherein the antenna port associated with CSI-RS is not assumed to be quasi-cooperative positioning, the control information indicates respective CSI feedback procedures for each link of the first transmission point and the second transmission point, and the communication circuitry is configured to: Send instructions related to the aggregation of the antenna ports of the configured CSI-RS that will be used for CSI reporting using higher-layer signaling. 28. The apparatus of claim 26 or 27, wherein, in order to generate the control information, the processor circuitry is configured to: When two or more downlink control information (DCI) messages are used to schedule the physical downlink shared channel (PDCSH), a codeword is mapped to a transport layer. 29. The apparatus of claim 26 or 27, wherein, in order to generate the control information, the processor circuitry is configured to: Mapping a codeword to two or more transport layers associated with one or more independent data streams in the first group of one or more independent data streams, or mapping a codeword to two or more layers associated with one or more independent data streams in the second group of one or more independent data streams. 30. An apparatus for use by a user equipment (UE), the apparatus comprising: A means for receiving control information from a first transmission point or a second transmission point, wherein the control information includes an indication of a set of parameters for determining quasi-cooperative positioning (QCL). A means for determining, based on an indicated set of parameters, QCL assumptions to be used to estimate channel characteristics for receiving a first set of multiple layers in a downlink channel from a first transmission point and a second set of multiple layers in a downlink channel from a second transmission point. A means for estimating channel characteristics for reception of the first set of multiple layers and for reception of the second set of multiple layers based on the QCL assumptions; and A means for receiving a first group of multiple layers using a first receiving antenna based on estimated channel characteristics and controlling the receiving of a second group of multiple layers using a second receiving antenna, wherein: One or more first independent data streams correspond to the first group of multiple layers, and the one or more first independent data streams will be transmitted by at least one of a plurality of antenna ports associated with one or more UE-specific reference signals (RS) of the first transmission point, and One or more second independent data streams correspond to the second group of multiple layers, and the one or more second independent data streams will be transmitted by at least one of the multiple antenna ports associated with one or more UE-dedicated RSs of the second transmission point. 31. The device of claim 30, wherein the indication indicates that the plurality of antenna ports are not assumed to be quasi-cooperatively located with respect to at least one of Doppler shift, Doppler spread, average delay, or delay spread, and wherein the same Doppler shift, Doppler spread, average delay, and delay spread are assumed on a predefined set of physical resource blocks (PRBs). 32. The device of claim 30, wherein the parameter set includes crs-PortsCount-r11, crs-FreqShift-r11, mbsfn-SubframeConfigList-r11, csi-RS-ConfigZPId-r11, pdsch-Start-r11, and qcl-CSI-RS-ConfigNZPId-r11. 33. The device of claim 30, wherein the indication indicates quasi-cooperative positioning of the UE-dedicated RS antenna port and one or more antenna ports associated with one or more other RSs for the first set of multiple layers to be transmitted on a first transport block and for the second set of multiple layers to be transmitted on a second transport block. 34. The device of claim 33, wherein the one or more other RSs include one of a cell-specific RS (CRS), a channel state information reference signal (CSI-RS), or a discovery RS. 35. The device according to any one of claims 30-34, wherein the indication indicates quasi-cooperative positioning of antenna ports among the plurality of antenna ports associated with the one or more UE-dedicated RSs and other RSs, and the device comprises: A means for determining one or more other RSs using two or more Physical Downlink Shared Channel (PDSCH) Resource Element (RE) mappings and Quasi-Cooperative Location Indicator fields. 36. The device according to any one of claims 30-34, wherein the indication indicates quasi-cooperative positioning of antenna ports among the plurality of antenna ports associated with the one or more UE-dedicated RSs and other RSs, and the device comprises: A means for determining one or more other RSs using two or more downlink control information (DCI) format 2D messages, wherein each of the two or more DCI format 2D messages includes at least one PDSCH RE mapping and quasi-cooperative positioning indicator field. 37. The device according to any one of claims 30-34, wherein the indication indicates RE mapping for the one or more first independent data streams of the first set of multiple layers and the one or more second independent data streams of the second set of multiple layers, and the device comprises: A means for determining the RE mapping using two or more PDSCH RE mapping and quasi-co-location indicator fields.