WO2025118189A1

WO2025118189A1 - Method and system for wireless transmission power control in user equipment collaboration

Info

Publication number: WO2025118189A1
Application number: PCT/CN2023/136839
Authority: WO
Inventors: Shuai ZHOU; Shuaihua KOU; Xianghui HAN
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2023-12-06
Filing date: 2023-12-06
Publication date: 2025-06-12
Anticipated expiration: 2026-06-06

Abstract

This disclosure is directed generally to wireless communication networks and particularly to power control in wireless transmission by collaborating wireless terminals or user equipment (UE). For example, this disclosure describes a power control method and system. Specifically, in an application scenario of the multi-UE collaboration technology, power control is performed when a UE collaboration state is switched, when a power of an anchor UE is limited, and when a receive end powers at a base station from the collaborating UEs are mismatched, or the like. The various implementations provide improved UE transmission reliability, increased a data transmission rate, and/or enhanced system capacity.

Description

METHOD AND SYSTEM FOR WIRELESS TRANSMISSION POWER CONTROL IN USER EQUIPMENT COLLABORATION

TECHNICAL FIELD

This disclosure is directed generally to wireless communication networks and particularly to power control in wireless transmission by collaborating wireless terminals or user equipment.

BACKGROUND

In wireless access network, various radio access technologies (RATs) may be employed to achieve communications between wireless terminal devices and wireless access network nodes. It is desirable to design the wireless access network such that radio spectrum resources are efficiently allocated for such communications.

SUMMARY

This disclosure is directed generally to wireless communication networks and particularly to power control in wireless transmission by collaborating wireless terminals or user equipment (UE) . For example, this disclosure describes a power control method and system. Specifically, in an application scenario of the multi-UE collaboration technology, power control is performed when a UE collaboration state is switched, when a power of an anchor UE is limited, and when a receive end powers at a base station from the collaborating UEs are mismatched, or the like. The various implementations provide improved UE transmission reliability, increased a data transmission rate, and/or enhanced system capacity.

In some example implementations, a method performed by a first user equipment (UE) is disclosed. The method may include, comprising receiving a UE collaborative transmission indicator from a wireless base station; switching to a UE collaborative transmission state in order to perform a collaborative uplink transmission with a second UE; and performing the collaborative uplink transmission to the wireless base station with a transmission power determined using via a transmission power initiation procedure or a transmission power control procedure in response to the first UE being in the UE collaborative transmission state.

In the example implementations above, the UE collaborative transmission indicator is included in a Radio Resource Control (RRC) message or a Medial Access Control (MAC) Control Element (CE) transmitted from the wireless base station.

In any one of the example implementations above, the first UE is an assistant UE and the second UE is an anchor UE; and the collaborative uplink transmission performed by the assistant UE contains at least one transport block belonging to the anchor UE.

In any one of the example implementations above, the method may further include performing, by the assistant UE, uplink transmission of data belonging to the anchor UE in the collaborative uplink transmission; and controlling a transmission power for the collaborative uplink transmission separately from transmitting the assistant UE’s uplink transmission.

In any one of the example implementations above, the method may further include: in response to the assistant UE and the anchor UE being within a predetermined or configured geographic proximity: acquiring, by the assistant UE, a first transmission power for the anchor UE to transmit its data to the wireless base station; and initializing the assistant UE with a second transmission power based on the first transmission power for the assistant UE to transmit the collaborative uplink transmission.

In any one of the example implementations above, the method may further include: in response to determining that the collaborative uplink transmission by the assistant UE contains a duplicate or backup transmission for the anchor UE, using the first transmission power of the anchor UE as the second transmission power for the assistant UE.

In any one of the example implementations above, the method may further include: in response to determining that the collaborative uplink transmission corresponds to a split transmission of the anchor UE, determining the second transmission power based on the first transmission power and data sizes of the collaborative uplink transmission and the split transmission of the anchor UE.

In any one of the example implementations above, the method may further include in response to the assistant UE and the anchor UE being separated by more than a predetermined to configured geographic proximity, deriving an initial transmission power from a set of power control parameters for the assistant UE to perform the collaborative uplink transmission.

In any one of the example implementations above, the set of power control parameters are determined according a collaborative power control parameter set index signaled from the wireless base station.

In any one of the example implementations above, the method may further include: when the collaborative power control parameter set index is signaled, using at least a nominal Physical Uplink Shared Channel (PUSCH) power control parameter for the anchor UE to transmit its data as one of the set of power control parameters for the assistant UE to determine the initial transmission power for the assistant UE to perform the collaborative uplink transmission.

In any one of the example implementations above, the method may further include: when the collaborative power control parameter set index is signaled, using at least a UE PUSCH power control parameter for the anchor UE to transmit its data as one of the set of power control parameters for the assistant UE to determine the initial transmission power for the assistant UE to perform the collaborative uplink transmission.

In any one of the example implementations above, the method may further include: when the collaborative power control parameter set index is signaled, using at least a path loss power control parameter used by the assistant UE in a non-collaborative transmission mode as one of the set of power control parameters for the assistant UE to determine the initial transmission power for the assistant UE to perform the collaborative uplink transmission.

In any one of the example implementations above, the method may further include: when the collaborative power control parameter set index is signaled and when a Frequency Division Multiplexing (FDM) is adopted for the anchor UE and the assistant UE, using half of a frequency resource allocated to the anchor UE as one of the set of power control parameters for the assistant UE to determine the initial transmission power for the assistant UE to perform the collaborative uplink transmission.

In any one of the example implementations above, the first UE is an anchor UE and the second UE is an assistant UE; and the collaborative uplink transmission by the assistant UE contains at least one transport block belonging to the anchor UE.

In any one of the example implementations above, the method may further include: in response to a determination that the anchor UE is limited in transmission power, controlling, by the anchor UE, a transmission power of the anchor UE based on the determination during the collaborative uplink transmission.

In any one of the example implementations above, determining that the anchor UE is limited in transmission power is based on a Power Headroom Report (PHR) or on a comparison of a current transmission power of the anchor UE to a transmission power threshold.

In any one of the example implementations above, controlling the transmission power of the anchor UE during the collaborative uplink transmission based on the determination may include: in response to the collaborative uplink transmission being a duplicate or backup transmission of the anchor UE, proceeding with the collaborative uplink transmission by the anchor UE; and in response to the collaborative uplink transmission being a split transmission of the anchor UE, refraining from transmitting the collaborative uplink transmission by the anchor.

In any one of the example implementations above, the collaborative uplink transmission by the anchor UE is performed at a predetermined or configured maximum transmission power.

In any one of the example implementations above, refraining from transmitting the collaborative uplink transmission by the anchor UE is limited to a predetermined or signaled period of time.

In any one of the example implementations above, the predetermined or signaled period of time is provisioned by a timer triggered by the determination that the anchor UE is limited in transmission power.

In any one of the example implementations above, the timer is provisioned by the wireless base station or the anchor UE, and the collaborative uplink transmission by the anchor UE is resumed after an expiration of the timer.

In any one of the example implementations above, refraining from transmitting the collaborative uplink transmission by the anchor UE is achieved by an absence any Downlink Control Information (DCI) from the wireless base station for scheduling the collaborative uplink transmission in the anchor UE.

In any one of the example implementations above, refraining from transmitting the collaborative uplink transmission by the anchor UE is achieved by the anchor UE ceasing to respond to any DCI from the wireless base station intended for scheduling the collaborative uplink transmission by the anchor UE.

In any one of the example implementations above, the method may further include receiving, by the first UE: a power offset between receive powers of the collaborative uplink transmission from the first UE and the second UE by the wireless base station; and a power control command (TPC) .

In any one of the example implementations above, the method may further include adjusting transmission power associated with the collaborative uplink transmission according to the power offset and the TPC by applying one or more of: a transmission power adjustment by an amount indicated by the power offset and/or the TPC; a Modulation Coding Scheme (MSC) modification based on the power offset and/or the TPC; a path loss compensation coefficient adjustment based on the power offset and/or the TPC; a packet size adjustment based on the power offset and/or the TPC; or a number of frequency domain resources allocated to the collaborative uplink transmission based on the power offset and/or the TPC.

In any one of the example implementations above, the first UE is an anchor UE and the second UE is an assistant UE; and the power offset and the TPC are received by the first UE from wireless base station.

In any one of the example implementations above, the first UE is an assistant UE and the second UE is an anchor UE; and the power offset and the TPC are received by the assistant UE from the anchor UE.

In any one of the example implementations above, adjusting the transmission power associated with the collaborative uplink transmission according to the power offset and the TPC is partially performed by the first UE and partially performed by the second UE.

In some other example implementations, a method performed by a wireless base station is disclosed. The method may include transmitting a control message to at least one of an anchor UE and an assistant UE, the control message comprising a UE collaborative transmission indicator for switching the anchor UE and the assistant UE into a UE collaborative transmission state; and receiving a collaborative uplink transmission from the assistant UE, the collaborative uplink transmission containing data belonging to and originated from the anchor UE.

In the example implementations above, the control message comprises an RRC message or a MAC CE.

In any one of the example implementations above, the method may further include transmitting an index corresponding to a set of power control parameter for the anchor UE or the assistant UE to perform the collaborative uplink transmission.

In any one of the example implementations above, the method may further include transmitting a transmission disablement indication to the anchor UE, the transmission disablement indication indicating whether the anchor UE is disabled from transmitting data associated with the collaborative uplink transmission.

In any one of the example implementations above, the transmission disablement indication is triggered by the wireless base station in response to detecting that the anchor UE is transmission power limited and that the collaborative uplink transmission is in a triggering collaborative mode among a predetermined set of collaborative modes.

In any one of the example implementations above, the method may further include measuring a power headroom associated with the anchor UE and determining whether the anchor UE is transmission power limited based on the measured power headroom.

In any one of the example implementations above, the predetermined set of collaborative modes comprises a data duplication mode, a data split mode, and a data backup mode; and the triggering collaborative mode comprises the data split mode.

In any one of the example implementations above, the transmission disablement indication indicates that the anchor UE is disabled from transmitting the data associated with the collaborative uplink transmission during a predetermined a configurable period of time.

In any one of the example implementations above, the method may further include starting a timer initiated with the predetermined or configurable period of time when detecting that the anchor UE is transmission power limited; and refraining from scheduling, prior to an expiration of the timer, uplink transmission for the anchor UE to perform uplink transmission associated with the collaborative uplink transmission.

In any one of the example implementations above, the method may further include resuming, following the expiration of the timer, scheduling the uplink transmission for the anchor UE to perform the uplink transmission associated with the collaborative uplink transmission.

In any one of the example implementations above, the method may further include transmitting a receive power offset and/or a TPC to the anchor UE or the assistant UE, the receive power offset indicating a difference between received powers between the anchor UE and the assistant UE with respect to the collaborative uplink transmission.

The first UE or wireless base station of any one of the methods above is further disclosed. The first UE or wireless base station may include a processor and a memory, wherein the processor is configured to read computer code from the memory to cause the first UE or wireless base station to perform the method of any one of the methods above.

A non-transitory computer-readable program medium with computer code stored thereupon is further disclosed. The computer code, when executed by a processor of the first UE or wireless base station of any one of the methods above, is configured to cause the processor to implement any one of the methods above.

The above embodiments and other aspects and alternatives of their implementations are described in greater detail in the drawings, the descriptions, and the claims below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example wireless communication network including a wireless access network, a core network, and data networks.

FIG. 2 illustrates an example wireless access network including a plurality of mobile stations/terminals or User Equipments (UEs) and a wireless access network node in communication with one another via an over-the-air radio communication interface.

FIG. 3 shows an example radio access network (RAN) architecture.

FIG. 4 shows an example communication protocol stack in a wireless access network node or wireless terminal device including various network layers.

FIG. 5 shows an example core network.

FIG. 6 illustrates an example implementation of collaborative uplink transmission involving an anchor UE, an assistant UE, and a base station.

FIG. 7 illustrates another example implementation of collaborative uplink transmission involving an anchor UE, an assistant UE, and a base station.

FIG. 8 illustrates yet another example implementation of collaborative uplink transmission involving an anchor UE, an assistant UE, and a base station.

DETAILED DESCRIPTION

The technologies described in this disclosure can be used for implement inter-RAT spectrum sharing in wireless access systems. The term “over-the-air interface” is used interchangeably with “air interface” or “radio interface” in this disclosure. The term “exemplary” is used to mean “an example of” and unless otherwise stated, does not imply an ideal or preferred example, implementation, or embodiment. Section headers are used in the present disclosure to facilitate understanding of the disclosed implementations and are not intended to limit the disclosed technology in the sections only to the corresponding section. The disclosed implementations may be further embodied in a variety of different forms and, therefore, the scope of this disclosure or claimed subject matter is intended to be construed as not being limited to any of the embodiments set forth below. The various implementations may be embodied as methods, devices, components, systems, or non-transitory computer readable media. Accordingly, embodiments of this disclosure may, for example, take the form of hardware, software, firmware or any combination thereof.

In this disclosure, unified as well as specific schemes for inter-RAT spectrum utilization are described. Merely as examples, the various RATs may include but are not limited to LTE, NR, 6G, and any current and other future mobile communication technologies. Such inter-RAT spectrum sharing may be achieved via dynamic resource provisioning across RATs, across frequencies (e.g., carriers) and/or cross cells for a particular wireless terminal device or UE in forms of dual connection (DC) and/or carrier aggregation (CA) .

Wireless Communication Networks

An example wireless communication network, shown as 100 in FIG. 1, may include wireless terminal devices or user equipment (UE) 110, 111, and 112, a carrier network 102, various service applications 140, and other data networks 150. The wireless terminal devices or UEs, may be alternatively referred to as wireless terminals. The carrier network 102, for example, may include access network nodes 120 and 121, and a core network 130. The carrier network 110 may be configured to transmit voice, data, and other information (collectively referred to as data traffic) among UEs 110, 111, and 112, between the UEs and the service applications 140, or between the UEs and the other data networks 150. The access network nodes 120 and 121 may be configured as various wireless access network nodes (WANNs, alternatively referred to as wireless base stations) to interact with the UEs on one side of a communication session and the core network 130 on the other. The term “access network” may be used more broadly to refer a combination of the wireless terminal devices 110, 111, and 112 and the access network nodes 120 and 121. A wireless access network may be alternatively referred to as Radio Access Network (RAN) . The core network 130 may include various network nodes configured to control communication sessions and perform network access management and traffic routing. The service applications 140 may be hosted by various application servers deployed outside of but connected to the core network 130. Likewise, the other data networks 150 may also be connected to the core network 130.

In the example wireless communication network of 100 of FIG. 1, the UEs may communicate with one another via the wireless access network. For example, UE 110 and 112 may be connected to and communicate via the same access network node 120. The UEs may communicate with one another via both the access networks and the core network. For example, UE 110 may be connected to the access network node 120 whereas UE 111 may be connected to the access network node 121, and as such, the UE 110 and UE 111 may communicate to one another via the access network nodes 120 and 121, and the core network 130. The UEs may further communicate with the service applications 140 and the data networks 150 via the core network 130. Further, the UEs may communicate to one another directly via side link communications, as shown by 113.

FIG. 2 further shows an example system diagram of the wireless access network 120 including a WANN 202 serving UEs 110 and 112 via the over-the-air interface 204. The wireless transmission resources for the over-the-air interface 204 include a combination of frequency, time, and/or spatial resource. Each of the UEs 110 and 112 may be a mobile or fixed terminal device installed with mobile access units such as SIM/USIM modules for accessing the wireless communication network 100. The UEs 110 and 112 may each be implemented as a terminal device including but not limited to a mobile phone, a smartphone, a tablet, a laptop computer, a vehicle on-board communication equipment, a roadside communication equipment, a sensor device, a smart appliance (such as a television, a refrigerator, and an oven) , or other devices that are capable of communicating wirelessly over a network. As shown in FIG. 2, each of the UEs such as UE 112 may include transceiver circuitry 206 coupled to one or more antennas 208 to effectuate wireless communication with the WANN 120 or with another UE such as UE 110. The transceiver circuitry 206 may also be coupled to a processor 210, which may also be coupled to a memory 212 or other storage devices. The memory 212 may be transitory or non-transitory and may store therein computer instructions or code which, when read and executed by the processor 210, cause the processor 210 to implement various ones of the methods described herein.

Similarly, the WANN 120 may include a wireless base station or other wireless network access point capable of communicating wirelessly via the over-the-air interface 204 with one or more UEs and communicating with the core network 130. For example, the WANN 120 may be implemented, without being limited, in the form of a 2G base station, a 3G nodeB, an LTE eNB, a 4G LTE base station, a 5G NR base station of a 5G gNB, a 5G central-unit base station, or a 5G distributed-unit base station. Each type of these WANNs may be configured to perform a corresponding set of wireless network functions. The WANN 202 may include transceiver circuitry 214 coupled to one or more antennas 216, which may include an antenna tower 218 in various forms, to effectuate wireless communications with the UEs 110 and 112. The transceiver circuitry 214 may be coupled to one or more processors 220, which may further be coupled to a memory 222 or other storage devices. The memory 222 may be transitory or non-transitory and may store therein instructions or code that, when read and executed by the one or more processors 220, cause the one or more processors 220 to implement various functions of the WANN 120 described herein.

Data packets in a wireless access network such as the example described in FIG. 2 may be transmitted as protocol data units (PDUs) . The data included therein may be packaged as PDUs at various network layers wrapped with nested and/or hierarchical protocol headers. The PDUs may be communicated between a transmitting device or transmitting end (these two terms are used interchangeably) and a receiving device or receiving end (these two terms are also used interchangeably) once a connection (e.g., a radio link control (RRC) connection) is established between the transmitting and receiving ends. Any of the transmitting device or receiving device may be either a wireless terminal device such as device 110 and 120 of FIG. 2 or a wireless access network node such as node 202 of FIG. 2. Each device may both be a transmitting device and receiving device for bi-directional communications.

The core network 130 of FIG. 1 may include various network nodes geographically distributed and interconnected to provide network coverage of a service region of the carrier network 102. These network nodes may be implemented as dedicated hardware network nodes. Alternatively, these network nodes may be virtualized and implemented as virtual machines or as software entities. These network nodes may each be configured with one or more types of network functions which collectively provide the provisioning and routing functionalities of the core network 130.

Returning to wireless radio access network (RAN) , FIG. 3 illustrates an example RAN 340 in communication with a core network 310 and wireless terminals UE1 to UE7. The RAN 340 may include one or more various types of wireless base station or WANNs 320 and 321 which may include but are not limited to gNB, eNodeB, NodeB, or other type of base stations (for simplicity, only gNBs are illustrated in FIG. 3) . The RAN 340 may be backhauled to the core network 310 via, for example, NG interfaces.

The WANNs may of FIG. 3 may be configured to communicate with one another via inter-node interfaces. For example, the gNBs may communicate with one another via an Xn interface. For another example, 5G base stations gNBs may communicate with LTE base stations such as NodeBs or eNodeBs via an X2 interface. In some example implementations, the WANN 320, for example, may further include multiple separate access network nodes in the form of a Central Unit (CU) 322 and one or more Distributed Units (DUs) 324 and 326. In some example implementations, the CU may be a gNB Central Unit (gNB-CU) , and the DU may be a gNB Distributed Unit (gNB-DU) . The CU 322 may be connected with DU1 324 and DU2 326 via various inter-node interfaces, for example, an F1 interface. Each of the various inter-node interfaces, may further be delineated into a control-plane interface and a user-plane interface. For a specific example, the F1 interface between a CU and a DU may further include an F1-C interface and an F1-U interface, which may be used to carry control plane information and user plane data, respectively. Likewise, the Xn or X2 interfaces may include an Xn-C and Xn-U or X2-C and X2-U interfaces. For purpose of this disclosure and the claims thereof, each CU and DU are considered separate access network node. The F1 interface thus falls within a definition of inter-node communication interface. In addition, while the various implementations described below are provided in the context of a 5G cellular wireless network, the underlying principles described herein are applicable to other types of radio access networks including but not limited to other generations of cellular network, as well as Wi-Fi, Bluetooth, ZigBee, and WiMax networks.

The UEs may be connected to the network via the WANNs 320 over an air interface. The UEs may be served by at least one cell. Each cell is associated with a coverage area. These cells may be alternatively referred to as serving cells. The coverage areas between cells may partially overlap. Each UE may be actively communicating with at least one cell while may be potentially connected or connectable to more than one cell. In the example of FIG. 1, UE1, UE2, and UE3 may be served by cell1 330 of the DU1, whereas UE4 and UE5 may be served by cell2 332 of the DU1, and UE6 and UE7 may be served by cell3 associated with DU2. In some implementations, a UE may be served simultaneously by two or more cells. Each of the UE may be mobile and the signal strength and quality from the various cells at the UE may depend on the UE location and mobility.

In some example implementations, the cells shown in FIG. 3 may be alternatively referred to as serving cells. The serving cells may be grouped into serving cell groups (CGs) . A serving cell group may be either a Master CG (MCG) or Secondary CG (SCG) . Within each type of cell groups, there may be one primary cell and one or more secondary cells. A primary cell in a MSG, for example, may be referred to as a PCell, whereas a primary cell in a SCG may be referred to as PScell. Secondary cells in either an MCG or an SCG may be all referred to as SCell. The primary cells including PCell and PScell may be collectively referred to as spCell (special Cell) . All these cells may be referred to as serving cells or cells. The term “cell” and “serving cell” may be used interchangeably in a general manner unless specifically differentiated. The term “serving cell” may refer to a cell that is serving, will serve, or may serve the UE. In other words, a “serving cell” may not be currently serving the UE.While the various embodiment described below may at times be referred to one of the types of serving cells above, the underlying principles apply to all types of serving cells in both types of serving cell groups.

FIG. 4 further illustrates a simplified view of the various network layers involved in transmitting user-plane PDUs from a transmitting device 402 to a receiving device 404 in the example wireless access network of FIGs. 1-3. FIG. 4 is not intended to be inclusive of all essential device components or network layers for handling the transmission of the PDUs. FIG. 4 illustrates that the data packaged by upper network layers 420 at the transmitting device 402 may be transmitted to corresponding upper layer 430 (such as radio resource control or RRC layer) at the receiving device 304 via Packet Data Convergence Protocol layer (PDCP layer, not shown in FIG. 4) and radio link control (RLC) layer 422 and of the transmitting device, the physical (PHY) layers of the transmitting and receiving devices and the radio interface, as shown as 406, and the media access control (MAC) layer 434 and RLC layer 432 of the receiving device. Various network entities in each of these layers may be configured to handle the transmission and retransmission of the PDUs.

In FIG. 4, the upper layers 420 may be referred as layer-3 or L3, whereas the intermediate layers such as the RLC layer and/or the MAC layer and/or the PDCP layer (not shown in FIG. 4) may be collectively referred to as layer-2, or L2, and the term layer-1 is used to refer to layers such as the physical layer and the radio interface-associated layers. In some instances, the term “low layer” may be used to refer to a collection of L1 and L2, whereas the term “high layer” may be used to refer to layer-3. In some situations, the term “lower layer” may be used to refer to a layer among L1, L2, and L3 that are lower than a current reference layer. Control signaling may be initiated and triggered at each of L1 through L3 and within the various network layers therein. These signaling messages may be encapsulated and cascaded into lower layer packages and transmitted via allocated control or data over-the-air radio resources and interfaces. The term “layer” generally includes various corresponding entities thereof. For example, a MAC layer encompasses corresponding MAC entities that may be created. The layer-1, for example, encompasses PHY entities. The layer-2, for another example encompasses MAC layers/entities, RLC layers/entities, service data adaptation protocol (SDAP) layers and/or PDCP layers/entities.

FIG. 5 shows an example division of network node functions in the core network 130. While only single instances of network nodes for some functions are illustrated in FIG. 5, those having ordinary skill in the art understand that each of these network nodes may be instantiated as multiple instances that are distributed throughout the core network 130. As shown in FIG. 5, the core network 130 may include but are not limited to access management network function (AMF) nodes 530, session management function (SMF) nodes 540, user plane function (UPF) nodes 550, policy control function (PCF) nodes 520, and application data management function (AF) nodes 510.

The AMF nodes 530 may communicate with the access network 120, the SMF nodes 540, and the PCF nodes 520 respectively via communication interfaces 522, 532, and 524, and may be responsible for provisioning registration, authentication, and access by the UE to the core network 130 was well as allocation of SMF nodes 540 to support particular UE communication sessions. The SMF nodes 540 allocated by the AFM nodes 530 may in turn may be responsible for allocating UPF nodes 550 for supporting the particular UE communication session and control these allocated UPF nodes 550 via communication interface 546. Alternatively, or additionally in some implementations, the UPF nodes 550 may be directly allocated by the AMF nodes 530 via the interface 534 and controlled by the SMF nodes 540 via the communication interface 546. Access policies and session routing policies applicable to the UEs may be managed by the PCF nodes 520 which communicate the policies to the AMF nodes 530 and the SMF nodes 540 via communication interfaces 524 and 523, respectively. The PCF nodes 520 may be further responsible for managing user subscription 512 to service application 140 via the AF nodes 510. The signaling and data exchange between the various types of network nodes through various communication interfaces indicated by the various connection lines in FIG. 5, may be carried by signaling or data messages following predetermined types of format or protocols.

To support a particular end-to-end communication task requested by a UE, a communication session may be established to support a data traffic pipeline for transporting the particular end-to-end data communication traffic. The carrier network portion of the data traffic pipeline, as illustrated by 570 of FIG. 5, may involve one or more network nodes in the access network 120 and a set of UPF nodes 552, 554, and 556 in the core network 130, as selected and controlled, for example, by a set of SMF nodes 542 and 544 which may be selected and controlled by the AMF nodes 530 that are responsible for establishing and managing the communication session. Data traffic is routed among a UE at one end of the data traffic pipeline, the carrier network portion of the data traffic pipeline (including the set of network nodes in the access network 120 and the selected UPF nodes 552, 554, and 556 in the core network 130) , and another end of the data traffic pipeline including, for example, another UE, a service application or application server 140, or a data network 150, via communication interfaces such as 524, 558, and 559.

Wireless Network Generations, Wireless Spectrum Sharing, and Cross-Carrier Scheduling

Configuration and usage of wireless spectrum has always been essential to the development and progression of various generation of cellular and cell free wireless access systems. The more recent 5th Generation (5G) mobile communication technology or future 6th Generation (6G) mobile communication technology are facing high demands. Based on the current development, 5G systems are also beginning to support additional enhanced mobile broadband (eMBB) , ultra-reliable low-latency communication (URLLC) , and massive machine-type communication (mMTC) . As new access features and technologies are being developed and adopted within each generation of wireless systems or across to newer generation of wireless systems, it has become essential to reuse wireless spectrum resources used in a previous generation via new resource allocation and scheduling schemes, such that the wireless spectrum resources are shared between generations of wireless technologies in order to improve the efficiency of wireless spectrum utilization.

For example, in 5G mobile communication technology, alternatively referred to as New Radio (NR) , dynamic spectrum sharing (DSS) with 4th Generation mobile communication technology (4G) Long-Term Evolution (LTE) have been developed and employed. In some example implementations of LTE-NR spectrum sharing, part of the LTE spectral resources may be carved out for NR communications. However, the NR Physical Downlink Control Channel (PDCCH) , Physical Downlink Shared Channel (PDSCH) may not be permitted be sent on the resources of LTE PDCCH and Cell-specific Reference Signal (CRS) to avoid advertent impacts on the LTE system.

In some implementations, wireless spectrum may be utilized in units of carriers or sub-carriers for communications between wireless terminal devices and access network nodes. When multiple carriers or sub-carriers are used to support communication of a single mobile terminal device, inter-carrier resource scheduling may be implemented for reducing scheduling overhead, thereby improving resource utilization efficiency. For example, a PCell and an SCell in NR may utilized different wireless carriers. When supporting communications of a UE, NR PDCCH enhancements for intra-RAT cross-carrier scheduling including scheduling of PDSCH or PUSCH on PCell via PDCCH of SCell may be been introduced for offloading the PCell PDCCH.

In the further disclosure below, unified as well as specific schemes for inter-RAT spectrum utilization or sharing are described. Merely as examples, the various RATs may include but are not limited to LTE (4G) , NR (5G) , 6G, and any current and other future mobile communication technologies. Such inter-RAT spectrum utilization or sharing may be achieved via semi-static and/or dynamic resource provisioning across RATs, across frequencies (e.g., carriers) and/or cross cells for a particular wireless terminal device or UE in forms of dual connection (DC) and/or carrier aggregation (CA) .

In the disclosure below, the term “spectrum resource” may be used to refer to a radio spectral range predefined, pre-configured, or otherwise allocated in the over-the-air interface. As an example, A spectrum resource may include one or more predetermined, pre-configured, or allocated wireless carriers or sub carriers. As another example, a spectrum resource, for example may refer to one of frequency range 1 (FR1) and frequency range 2 (FR2) , and other wireless communication bands and/or band combinations. A spectral resource may be licensed or non-licensed. A cell may utilize a single carrier or a combination of carriers. The term “spectrum resource” may be interchangeably used with “spectral resource” , “frequency range” , and the like. Sharing of the spectrum resource by different cells or different RATs may include sharing in either or both of frequency and time at various granularity levels (e.g., resource blocks, channel, sub-carrier, carrier or other levels in frequency, or frame, subframe, slot, and symbol in time) .

Further in the disclosure below, the term “dynamic” (such as in “dynamic scheduling” , “dynamic spectrum sharing” , and the like may be used to refer to resource provisioning that occurs within a communication session, such as downlink resource scheduling via downlink control information. A resource allocation by radio resource control (RRC) information elements, for example, may be considered as static rather than dynamic provisioning.

UE Collaboration

In some application context, multiple UEs or mobile devices may be configured to perform wireless transmission or reception collaboratively. For example, a group of UEs, either located geographically in proximity of one another, or with some distances, may be configured to collaborate with one another to perform uplink transmission and downlink reception. Particularly, one UE may help another UE in the collaborative group of UEs transmit or receive data or control information to or from one or more wireless access network nodes or base stations described above. The UEs in the collaborative group may communicate with one another information needed to configure, initiate, facilitate, or effectuate such collaborative transmission or reception via any viable means, including but not limited to blue-tooth channels, wireless sidelink channels, Wi-Fi channels, free space optical channels (e.g., infrared or IR communication channels) , and the like. These channels may be referred to as collaboration channels.

Such collaborative transmission or reception of UEs may be beneficial for various application scenarios. For example, for applications utilizing virtual reality and/or augmented reality, a large number of devices may be connected and may transmit data or control information to base stations. In such situations, collaborative UE transmission may be useful in order to increase transmission bandwidth and/or transmission reliability for data of some UEs. For example, a first UE may rely on capability of one or more other UEs to enhance its uplink transmission or downlink reception to a higher level in either data rate or reliability.

UE collaboration technology for wireless data or control information transmission is reception is particularly one of the indispensable communication technologies in the current 5G and future 6G wireless access networks, where multiple UEs establish collaborative relationships and collaborate with each other such that one or multiple UEs can assist transmission and reception for another UE, thereby improving communication data quality (e.g., transmission or reception reliability) , increasing data rate, expanding cell capacity, and/or cell coverage range.

In collaborative UE transmission/reception, multiple UEs form a collaboration group so as to break through capability limitations of a single UE, including but not limited to bandwidth limitations, antenna limitations, and transmission power limitations, thereby achieving higher data transmission rates and/or higher transmission reliability for one or more UEs than what they would otherwise achieve without collaboration. In some example implementations for UE collaborative transmission/reception, UEs in the collaboration group, may be divided into anchor UE (s) and assistant UE (s) , where an assistant UE may assist an anchor UE in data transmission/reception. The various example embodiments below are provided in the context of a collaborative UE group formed by one anchor UE and one assistant UE for simplicity. However, the underlying principles of the various embodiments described below are applicable to situations where multiple anchor UEs and/or multiple assistant UEs are involved in the collaborative group. Each of the assistant UEs may assist one or more other anchor UEs in their transmission/reception. Likewise, each anchor UE may use one or more other assistant UEs to assist in its transmission/reception. A UE can be either an anchor UE or an assistant UE or both. When a UE is both an anchor UE and an assistant UE, it either use other UE to assist its transmission/reception, or assist other UEs in their transmission/reception, either at different times or simultaneously.

Further, in the various example embodiments described below, data or control information transmission of an anchor UE as assisted by an assistant UE is used as examples and for simplicity. The underlying principles described below are applicable to UE collaboration for data or control information reception.

According to manners of scheduling of the UEs by the base station, implementations of UE collaboration on transmission may be divided into transparent transmission collaboration and non-transparent transmission collaboration. In a transparent transmission collaboration, the base station does not know the existence and collaboration relationship of an assistant UE to an anchor UE, and thus only schedules the anchor UE with respect to the transmission of the anchor UE. After receiving the scheduling information for its transmission, the anchor UE may transmit or relay the scheduling information to the assistant UE through inter-user communications via, e.g., the collaboration channels described above. In non-transparent transmission collaboration, on the other hand, the base station is aware of the collaborative relationship between the assistant UE and the anchor UE, and thus can schedule the anchor UE and assistant UE simultaneously using group scheduling DCI (downlink control information) for identical scheduling, a group scheduling DCI with multiple scheduling fields separately intended for the anchor UE scheduling and assistant UE scheduling, or separate DCIs for scheduling the anchor UE for its transmission and the assistant UE for assisting the anchor UE’s transmission.

According to a collaboration relationship between the assistant UE and the anchor UE and whether the transmitted data by the assistant UE and anchor UE during collaboration is the same, implementations of UE collaboration on transmission/reception may be categorized into data duplication collaboration transmission technology, data split collaboration transmission technology, and wireless backup collaboration transmission technology (alternatively referred to as hot backup collaboration transmission technology) . These example technologies may be collectively referred to as data collaboration technologies.

The example data collaboration technologies above differ in the nature of the data of the anchor UE that the assistant UE assists with, thereby involving corresponding connecting layers between the anchor UE and the assistant UE via the collaboration channel with respect to the wireless communication network protocol stack, and involving corresponding scheduling of the collaborative transmission.

For example, as shown in FIG. 6, in the data duplication collaboration transmission technology, the MAC (medium access control) layer of the anchor UE 602 may be connected with the MAC layer or PHY (physical layer) of the assistant UE 604 via the collaboration channels, as shown by 606, making full use of physical layer capabilities of the assistant UE. The anchor UE 602 and the assistant UE 604 may transmit the same data (duplicate data) or same transport block (TB) 650 of the anchor UE 602, as shown by the two uplink transmission arrows 610 and 612 to a base station 601 having the same thickness, mainly to improve the reliability of uplink data transmission of the anchor UE 602.

For another example, as shown in FIG. 7, in the data split collaboration transmission technology, the MAC layer of the anchor UE 702 may be connected with the MAC layer or PHY layer of the assistant UE 704, making full use of the physical layer capability of the assistant UE 704 via the collaboration channel, as shown by 706. The anchor UE 702 and the assistant UE 704, however, transmit different data packets of the anchor UE, as shown by the two uplink transmission arrows 710 and 712 to a base station 701 having the different thickness, and TB1 (750) and TB2 (760) , mainly to increase a data transmission rate for the anchor UE 702.

For yet another example, as shown in FIG. 8, in the wireless backup collaboration transmission technology, the PHY layer of the anchor UE 802 may be connected with the PHY layer of the assistant UE 804 via the collaboration channels, as shown by 806. The assistant UE 804 may only provide forwarding capability. When the anchor UE 802 loses power, the assistant UE 804 forwards the data of the anchor UE 802, the same TB 850 and 860, to the base station 801, thereby improving the reliability of data transmission of the anchor UE 802.

In FIGs. 6-8, the scheduling of the transmission by the anchor UE (602, 702, 802) or assistant UE (604, 704, 804) may be provided by the base station via DCI, shown as 620, 720, and 820. For example, in the non-transparent transmission collaboration referred to above, the base station may send a group common DCI for reception by both the anchor UE and the assistant UE. The group common DCI may schedule same or different PHY resources for uplink transmission of the data of the anchor UE. The group common DCI may alternatively have different fields for scheduling the transmission of anchor UE’s data by the anchor UE and the assistant UE. Alternatively, for the non-transparent transmission collaboration, the base station may send separate UE-specific DCIs to the anchor UE and the assistant UE to schedule their transmissions of the data of the anchor UE. For another example, in the transparent transmission collaboration referred to above, the base station may only send a DCI to the anchor UE and scheduling DCI to the assistant UE may be provided to the assistant UE via the collaboration channel.

Transmission power control-general

In the wireless access network above, e.g., the 5G NR system, the transmission power of uplink data transmission may be determined by the following example formula, representing a minimum value of the maximum transmission power of the user and the power calculated by the formula.

where P_{0_PUSCH, b, f, c} (j) = P_{0_NOMINAL_PUSCH, f, c} (j) + P_{0_UE_PUSCH, b, f, c} (j) , and j is the set configuration index.

An example uplink data transmission power control particularly includes open-loop power control and closed-loop power control with respect configuration and adjustment of the various power calculation parameters above. An open-loop power control may be achieved by configuring a series of appropriate RRC parameters, whereas a closed-loop power control mainly achieves fine power control adjustment by adopting the TPC (transmit power control) value in the DCI to dynamically adjust the transmission power of the UE.

In some example implementations of user collaborative transmission above, power control of the anchor UE and the assistant UE can also be achieved via the open-loop power control and/or closed-loop power control. Various power control schemes can be performed for different collaborative transmission technologies above and in various UE collaboration transmission scenarios.

Transmission power initialization or setting in UE transmission collaboration

When a UE switches from an independent transmission mode to a collaboration transmission mode, e.g., as an assistance UE to assist an anchor UE in the transmission of the anchor UE, a transmission power for the assistance UE to transmit the data (either duplicate, split, or backup data) of the anchor UE may be first initialized. Such initialization may occur at the UE switching into the collaboration transmission role.

In some example implementations, an indicator may be introduced to indicate whether the transmission state of the UE is collaboration or non-collaboration. When two UEs transmit independently, such an indicator can be absent or may be set to “non-collaboration” or “0” for both UEs. After the two UEs establish a collaborative transmission relationship, this indicator may then be set to “collaboration” or “1” to represent a collaborative transmission state of the two UEs. This indicator, for example, can be an RRC (Radio Resource control parameters) information element configured by an RRC message or a MAC CE (control element) field.

In some example implementations, the assistant UE may both assist the anchor UE for data transmission of the anchor UE while transmitting its own data. The two different transmissions may require independent or separate or different power control. Corresponding sets of parameters for power control for assistant UE to transmit the data of the anchor UE and the data of the assistant UE may be used. These two sets of power controls of the assistant UE operate independently/separately/differently to control the transmission power at the assistant for its own data and for the data of the anchor UE.

In some example implementations, referred to as collaboration transmission power initialization/setting Method 1, the assistant UE and the anchor UE may be in geographical proximity such that the channel conditions between the two UEs and the base station can be considered as not being much different, and the transmission power of the assistant UE in collaboration state for transmitting the data of the anchor UE can be initialized or set based on the transmission power of the anchor UE.

For example, in the UE collaborative transmission system adopting the data duplication collaboration transmission mechanism or wireless backup collaboration transmission mechanism, where the assistant UE assists the anchor UE in transmitting the same data packet of the anchor UE, the transmission power of the assistant UE in the collaboration state for assisting with the data transmission of the anchor UE may be initialized or set to the transmission power of the anchor UE for the same data when the collaboration transmission relationship is established.

For another example, in the user collaborative transmission system adopting the data split collaboration transmission mechanism, where the assistant UE transmits different data packets of the anchor UE from the anchor UE’s own transmission, the transmission power of the assistant UE in the collaboration state for assisting with the data transmission of the anchor UE may be set according the data packet size via a predetermined or configured relationship between power and data size. As one example, the transmission power of the assistant UE in the collaboration state for assisting with the data transmission of the anchor UE may be set in proportionality to the data packet size.

In some specific example implementations, the data packet sizes transmitted by the assistant UE and the anchor UE may be the same in the data split collaborative transmission mode, and the transmission power of the assistant UE in collaboration state may correspondingly be initialized or set to the transmission power of the anchor UE for transmitting the data of the anchor UE.

In some other specific example implementations, the data packet sizes transmitted by the assistant UE and the anchor UE may be different, and the transmission power of the assistant UE in the data split collaboration transmission state may correspondingly be initialized proportionally or nonlinearly based on the anchor UE's transmission power according to a predetermined or configured relationship between transmission power and data size. In some other example implementations, referred to as collaboration transmission power initialization/setting Method 2, a distance between the assistant UE and the anchor UE may be relatively large such that the channel conditions between the anchor UE and the base station can be quite different from the channel conditions between the assistant UE and the base station. Power initialization may be achieved by initializing one or more power calculation parameters in Eq. (1) above and then determine the transmission power according to Eq. (1) , rather than initializing a transmit power value directly. These power control parameters may be initialized as RRC information elements or parameters.

In some example implementations of the collaboration transmission power initialization/setting Method 2 above, the set configuration index j for indexing the power control parameter configuration set for use in Eq. (1) in the collaboration state of the assistant UE may be set to j= -1. This index value may be a new value in addition to a normal set of indexes of j= (0, 1, 2, ..., J) and the RRC parameter set associated with power control are configured separately when j=-1 to initialize the collaboration transmission power control parameters for further calculation of the transmission power. For example:

1) The assistant UE's in Eq. (1) above may be configured as equal to the of anchor UE in non-collaboration state, where j_anchor represents the power control parameter set index used by the anchor UE for transmitting the corresponding data.

2) The assistant UE's in Eq. (1) above may be configured as equal to of anchor UE in non-collaboration state, where j_anchor represents the power control parameter set index used by the anchor UE for transmitting the corresponding data.

3) The assistant UE's α_b, c, f (-1) in Eq. (1) above may be configured as equal to the α_b, c, f (j_assistant) of assistant UE in non-collaboration state, where j_assistant represents the power control parameter set index used by the assistant UE for its own data. In other words, the path loss compensation factor of the assistant UE's collaboration power control is the same as that of its non-collaboration power control path loss compensation factor.

4) When FDM (frequency division multiplexing) transmission is adopted for the anchor UE and the assistant UE, the frequency domain resources allocated to both the anchor UE and the assistant UE as used in Eq. (1) for calculating transmission power may be set at half of the number of frequency domain resources allocated to the anchor UE, i.e.,

In such a manner, the power initialization for the assistant UE as calculated according the parameters above and Eq. (1) for transmitting either the duplicate, split, or backup data of the anchor UE may approximately take into consideration the differences of the channel conditions at the anchor UE and the assistant UE with respect to the base station at a relatively significant distance apart.

Anchor UE transmission control under limited power conditions

During collaborative transmission, it may occur that the maximum achievable anchor UE transmission power falls below a certain level. In such situations, because one or more assistant UE may be available for assist in the transmission of the data of the anchor UE, the anchor UE or the base station may determine whether and length of time that the anchor UE should refrain from transmitting its own data (since such transmission could be wasteful as the transmission power will not be sufficient) but rely on the assistant UE (s) instead.

Specifically, when the maximum transmission power of the anchor UE cannot meet the reception power requirements of the base station, this is the case where the power of the anchor UE is limited. The transmission of UEs with limited power presumably cannot be effectively received by the base station. In the user collaboration transmission system, it is beneficial to reasonably control the transmission power of the anchor UE and the assistant UE to save the energy consumption of the anchor UE while ensuring the reliability of data transmission of the anchor UE as much as possible. As such, in some circumstances, the UE with limited power in the collaboration transmission situation may be controlled to refrain from transmission for a certain period of time.

In some example implementations, the base station may determine whether a UE (e.g., the anchor UE) is power limited by measuring the Power Headroom Report (PHR) reported by the anchor UE. If the PHR is positive, the base station determines that the UE is not power limit, whereas if the PHR is negative, the base station determines that the UE is power limited. The base station may further introduce a new RRC parameter as an enabler to indicate whether a power-limited UE (e.g., the anchor UE) should performs transmission or should refrain from transmission.

In some example implementations, each UE may perform its own independent transmission which means the two UE are in non-collaboration state. The RRC parameter enabler above may not be set or is always set to “enable” or “1” by default. In such situation, because there the UE is not being assistant by other UEs, its transmission, even with the power limit and thus potential reception failure by the base station, should still be performed.

In some example implementations, the user collaboration transmission mechanism may be the data duplication collaboration transmission or wireless backup transmission mechanism, the RRC parameter enabler may be always set to “enable” or “1” . In other words, the power-limited UE among the collaborative UEs can still be normally scheduled by the base station for data transmission. The receiving end would then combine the transmissions from the anchor UE and the assistant UE to increase the reception power. There would be no need for the power limited UE to refrain from transmission.

In some example implementations, the user collaboration transmission mechanism may be the data split collaboration transmission, and the RRC parameter enabler of the power-limited user is set to “unable” or “0” . In such situations, because the anchor UE and the assistant UE transmit different portion of the data of the anchor UE, there is no duplicate transmission of the data that would be transmitted by the anchor UE. If the anchor UE is power limited and thus its transmission will likely fail, then it is better for the anchor UE to refrain from transmission, and allocate data to the assistant UE for transmission instead. That way, the anchor UE can save power by refrain from somewhat futile transmission.

In some example implementations, since the network condition change dynamically, a mechanism may be designed for preventing a power limited UE to refrain from transmission for a long time. In some implementations, a timer may be implemented for setting a duration of transmission refraining period for a power limited UE. The timer may be triggered when the RRC parameter enabler is set to “unable” or “0” . Once the timer expires, the UE may be taken out of the transmission refraining mode, and whether the UE reenters and trigger another transmission refraining period would depend on a new PHR measurement and whether the new PHR measurement is positive or negative.

In some example implementations, the collaborative UE may be scheduled by independent DCIs, as described above. The transmission refraining timer above may be maintained by the base station. Specifically, the base station may start the timer when the RRC parameter enabler is set to “unable” or “0” . The base station does not schedule the power-limited UE during that time period. After the timer expires, the RRC parameter enabler is set back to “enable” or “1” , and the UE transmission can be rescheduled.

In some other example implementations, collaborative users may be scheduled by a group common DCI, as described above. The transmission refraining timer above may be maintained by the power limited UE. Specifically, the power-limited user may start the transmission refraining timer when an enabler RRC parameter set to “unable” or “0” is received. During the timer period, the power-limited user may receive scheduling information for its own transmission but may ignore such scheduling by not performing the scheduled data transmission to save power. After the transmission refraining timer expires, the power-limited user resumes transmission according to the scheduling information and triggers PHR reporting for the next possible transmission refraining period.

In some other example implementations, the collaboration relationship is transparent to the base station and only anchor UE is scheduled by the base station, as described above. The transmission refraining timer above may be maintained by the power limited UE. Specifically, the power-limited UE may start the transmission refraining timer when an enabler RRC parameter set to “unable” or “0” is received. During the timer period, the power-limited user may receive scheduling information and forward it directly to the assistant UE. As for the power limited UE itself, it does not perform data transmission. After the transmission refraining timer expires, the power-limited user resumes transmission according to the scheduling information and triggers PHR reporting for the next possible transmission refraining period.

In some example implementations, the anchor UE may determine whether it is power limited according to whether the maximum transmission power has been reached. For example, if the current transmission power is equal to P_CMAX, f, c, of Eq. (1) above, it may be determined by the anchor UE that it is power limited, otherwise, if the current transmission power is less than P_CMAX, f, c, it may be determined by the anchor UE that it is not power limited. The various implementations above predefines the behavior of power-limited users in different collaboration data transmission mode (e.g., duplicate, split, or backup) .

In some other example implementations, each UE may perform its own independent transmission which means the two UE are in non-collaboration state. Then the power-limited UEs may transmit at P_CMAX, f, c in Eq. (1) .

In yet some example implementations, the user collaboration transmission mechanism may be the data duplication collaboration transmission or wireless backup transmission mechanism, and the power-limited user transmits at P_CMAX, f, c in Eq. (1) .

In some example implementations, the user collaboration transmission mechanism may be the data split collaboration transmission, the power-limited user may not transmit data, and may stars a timer described above. Prior to an expiration of the timer, the power-limited UE may not transmit data. After the timer expires, the power-limited UE may resume transmission.

Balancing of reception power at base station from collaborating UEs

In the UE collaboration transmission system above, the base station may need to combine and receive signals from the anchor UE and the assistant UE. The data from different UEs may arrive at different receiving ports at the base station. If there is a large difference in the receiving power from the different UEs, the signal may not be effective combined and received. As such, power control may be required to make the receiving signal power at different ports at the base station within the receiver sensitivity error range of the base station.

Various example implementations as described in detail below may be used for UE collaboration power control when the received power of signals from the anchor UE and the assistant UE does not match at the base station.

In some example implementations, uplink transmissions of collaborative UEs in the UE collaboration transmission system may carry UE IDs to indicate which UEs the received data at different ports of base station belong to.

In some example implementations, the base station may measure the received power from different UEs at different ports and calculates a received power difference between the different UEs, e.g.,

In some example implementations, the base station may schedule only one UE (this UE can be the anchor UE or the assistant UE, the following description takes the independent scheduling of the anchor UE merely as an example) of the collaborative transmission. The assistant UE may transmit the data of the anchor UE based on the scheduling DCI of the base station to the anchor UE. The base station cannot directly control the power of the assistant UE in such situations. The power control of collaborative transmission in such situations may be achieved by at least one of the following methods to solve the power mismatch problem above.

In a first method, referred to as single-schedule power balancing Method 1: The base station may notify the scheduled anchor UE of the power adjustment amount ΔP, and the anchor UE transmits the power adjustment amount to assistant UE by collaboration channels as described above. For example, ΔP=P_offset+f_b, f, c, where f_b, f, c is the TPC command value in the scheduling DCI, indicating the adjustment amount for the anchor UE to perform dynamic power adjustment. As such, the power adjustment is made at the assistant UE, which include power adjustment value indicated in a normal TPC as well as the power adjustment needed for compensating for the imbalance at the base station between the anchor UE and the assistant UE.

In some further example implementations of single-schedule power balancing Method 1, the assistant UE may directly adjust its power based on the transmission power P of the previous data transmission, and the transmission power after adjusted would be P-ΔP, where ΔP=P_offset+f_b, f, c.

In some other further example implementations of single-schedule power balancing Method 1, the assistant UE may achieve power control by adjusting its own Modulation and Coding Scheme (MCS) value based on the power adjustment amount ΔP and according to a predetermined or other the types of algorithms and uses the new MCS scheme.

In some other further example implementations of single-schedule power balancing Method 1, the assistant UE may achieve power adjustment by adjusting its own path loss compensation coefficient alpha value based on the power adjustment amount ΔP according to a predetermined or other the types of algorithms.

In some other further example implementations of single-schedule power balancing Method 1, when the user collaboration transmission mechanism is data split transmission, the anchor UE may adjust the packet sizes split between the anchor UE and the assistant UE according to the received power difference between the different UEs, e.g., P_offset=ΔP-f_b, f, c, according to a predetermined or other the types of algorithms so that the two UEs transmit TBs of different sizes and have the same received power measurement at the base station.

In some other further example implementations of single-schedule power balancing Method 1, when the UE collaboration transmission system may adopt FDM transmission, the anchor UE may adjust a number of frequency domain resources allocated to the two users according to the received power difference between the different UEs, e.g., P_offset=ΔP-f_b, f, c, based on a predetermined or other the types of algorithms.

In a second method, referred to as single-schedule power balancing Method 2, the base station may notify the scheduled anchor UE of the power difference P_offset between different ports. The anchor UE may forward P_offset and the TPC command value in DCI to the assistant UE. The assistant UE may perform power control based on the power adjustment amount P_offset+f_b, f, c, where f_b, f, c is the TPC command value in the scheduling DCI indicating the adjustment amount for the assistant UE to perform dynamic power adjustment.

In some further example implementations of single-schedule power balancing Method 2, the assistant UE may directly adjust its power based on the transmission power P of the previous data transmission for the anchor UE, and the transmission power after adjusted is P- (P_offset+f_b, f, c) .

In some further example implementations of single-schedule power balancing Method 2, the assistant UE may achieve power control by adjusting its own MCS value based on the power adjustment amount P_offset+f_b, f, c and uses the new modulation and coding scheme and according to a predetermined or other the types of algorithms and uses the new MCS scheme.

In some further example implementations of single-schedule power balancing Method 2, the assistant UE may achieve power adjustment by adjusting its own path loss compensation coefficient alpha value based on the power adjustment amount P_offset+f_b, f, c according to a predetermined or other the types of algorithms.

In some further example implementations of single-schedule power balancing Method 2, when the UE collaboration transmission mechanism is data split transmission. the anchor UE may adjust the packet size split between the anchor UE and the assistant UE according to P_offset so that the two UEs transmit TBs of different sizes and have the same received power measurement at the base station.

In some further example implementations of single-schedule power balancing Method 2, when the UE collaboration system adopts FDM transmission, the anchor UE may adjust the number of frequency domain resources allocated to the two UEs according to P_offset based on a predetermined or other the types of algorithms.

In some other example implementations, the base station may schedule all collaborative transmission UEs at the same time. The base station may adopt at least one of the following methods for power control of collaborative transmission to solve the power mismatch problem at the receiving end.

In a first method, referred to as multi-schedule power balancing Method 1, the base station may notify the UE of the received power difference P_offset. The UE may adjust the transmission power P directly based on P_offset.

In some further example implementations of the multi-schedule power balancing Method 1, the value of P_offset may be small, and the base station may schedule only one UE to adjust the power separately. Take the received power difference between the different UEs is derived likeas an example, when the UE that adjusts the power is UE1, UE1 may reduce P_offset on the basis of its transmission power, whereas when the UE that adjusts the power is UE2, UE2 may increase P_offset on the basis of its transmission power.

In some further example implementations of the multi-schedule power balancing Method 1, the value of P_offset may be large, and the base station may schedule the two UEs to adjust the power bidirectionally. For example, the base station may notify each UE of the power adjustment amountTake the received power difference between the different UEs is derived likeas an example, where UE1 reduces on the basis of its transmission power, and UE2 increaseson the basis of its transmission power.

In a second method, referred to as multi-schedule power balancing Method 2, the base station may treat the received power difference as a dynamic power adjustment amount, and integrate it into TPC command (s) for corresponding UE to perform dynamic power adjustment.

In some further example implementations of the multi-schedule power balancing Method 2, the value of P_offset may be small, and the base station may incorporate P_offset into the TPC command of one UE and notify the UE to adjust the power.

In some further example implementations of the multi-schedule power balancing Method 2, the value of P_offset may be relatively large, and the base station may incorporateinto the TPC command of UE1, and incorporateinto the TPC command of UE2. Then the two UEs may perform dynamic power adjustment separately.

In some further example implementations of the multi-schedule power balancing Method 2, the value of P_offset may be relatively large and may exceed the adjustment range that TPC command can adjust. In that situations, some new TPC command value may be introduced to expand the range of power adjustment based on the TPC command.

The description and accompanying drawings above provide specific example embodiments and implementations. The described subject matter may, however, be embodied in a variety of different forms and, therefore, covered or claimed subject matter is intended to be construed as not being limited to any example embodiments set forth herein. A reasonably broad scope for claimed or covered subject matter is intended. Among other things, for example, subject matter may be embodied as methods, devices, components, systems, or non-transitory computer-readable media for storing computer codes. Accordingly, embodiments may, for example, take the form of hardware, software, firmware, storage media or any combination thereof. For example, the method embodiments described above may be implemented by components, devices, or systems including memory and processors by executing computer codes stored in the memory.

Throughout the specification and claims, terms may have nuanced meanings suggested or implied in context beyond an explicitly stated meaning. Likewise, the phrase “in one embodiment/implementation” as used herein does not necessarily refer to the same embodiment and the phrase “in another embodiment/implementation” as used herein does not necessarily refer to a different embodiment. It is intended, for example, that claimed subject matter includes combinations of example embodiments in whole or in part.

In general, terminology may be understood at least in part from usage in context. For example, terms, such as “and” , “or” , or “and/or, ” as used herein may include a variety of meanings that may depend at least in part on the context in which such terms are used. Typically, “or” if used to associate a list, such as A, B or C, is intended to mean A, B, and C, here used in the inclusive sense, as well as A, B or C, here used in the exclusive sense. In addition, the term “one or more” as used herein, depending at least in part upon context, may be used to describe any feature, structure, or characteristic in a singular sense or may be used to describe combinations of features, structures or characteristics in a plural sense. Similarly, terms, such as “a, ” “an, ” or “the, ” may be understood to convey a singular usage or to convey a plural usage, depending at least in part upon context. In addition, the term “based on” may be understood as not necessarily intended to convey an exclusive set of factors and may, instead, allow for existence of additional factors not necessarily expressly described, again, depending at least in part on context.

Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present solution should be or are included in any single implementation thereof. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present solution. Thus, discussions of the features and advantages, and similar language, throughout the specification may, but do not necessarily, refer to the same embodiment.

Furthermore, the described features, advantages and characteristics of the present solution may be combined in any suitable manner in one or more embodiments. One of ordinary skill in the relevant art will recognize, in light of the description herein, that the present solution can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the present solution.

Claims

A method performed by a first user equipment (UE) , comprising:

receiving a UE collaborative transmission indicator from a wireless base station;

switching to a UE collaborative transmission state in order to perform a collaborative uplink transmission with a second UE; and

performing the collaborative uplink transmission to the wireless base station with a transmission power determined using via a transmission power initiation procedure or a transmission power control procedure in response to the first UE being in the UE collaborative transmission state.
The method of claim 1, wherein the UE collaborative transmission indicator is included in a Radio Resource Control (RRC) message or a Medial Access Control (MAC) Control Element (CE) transmitted from the wireless base station.
The method of claim 1, wherein:

the first UE is an assistant UE and the second UE is an anchor UE; and

the collaborative uplink transmission performed by the assistant UE contains at least one transport block belonging to the anchor UE.
The method of claim 3, further comprising:

performing, by the assistant UE, uplink transmission of data belonging to the anchor UE in the collaborative uplink transmission; and

controlling a transmission power for the collaborative uplink transmission separately from transmitting the assistant UE’s uplink transmission.
The method of claim 3, further comprising, in response to the assistant UE and the anchor UE being within a predetermined or configured geographic proximity:

acquiring, by the assistant UE, a first transmission power for the anchor UE to transmit its data to the wireless base station; and

initializing the assistant UE with a second transmission power based on the first transmission power for the assistant UE to transmit the collaborative uplink transmission.
The method of claim 5, further comprising, in response to determining that the collaborative uplink transmission by the assistant UE contains a duplicate or backup transmission for the anchor UE, using the first transmission power of the anchor UE as the second transmission power for the assistant UE.
The method of claim 5, further comprising in response to determining that the collaborative uplink transmission corresponds to a split transmission of the anchor UE, determining the second transmission power based on the first transmission power and data sizes of the collaborative uplink transmission and the split transmission of the anchor UE.
The method of claim 3, further comprising in response to the assistant UE and the anchor UE being separated by more than a predetermined to configured geographic proximity, deriving an initial transmission power from a set of power control parameters for the assistant UE to perform the collaborative uplink transmission.
The method of claim 8, wherein the set of power control parameters are determined according a collaborative power control parameter set index signaled from the wireless base station.
The method of claim 9, further comprising:

when the collaborative power control parameter set index is signaled, using at least a nominal Physical Uplink Shared Channel (PUSCH) power control parameter for the anchor UE to transmit its data as one of the set of power control parameters for the assistant UE to determine the initial transmission power for the assistant UE to perform the collaborative uplink transmission.
The method of claim 9, further comprising:

when the collaborative power control parameter set index is signaled, using at least a UE PUSCH power control parameter for the anchor UE to transmit its data as one of the set of power control parameters for the assistant UE to determine the initial transmission power for the assistant UE to perform the collaborative uplink transmission.
The method of claim 9, further comprising:

when the collaborative power control parameter set index is signaled, using at least a path loss power control parameter used by the assistant UE in a non-collaborative transmission mode as one of the set of power control parameters for the assistant UE to determine the initial transmission power for the assistant UE to perform the collaborative uplink transmission.
The method of claim 9, further comprising:

when the collaborative power control parameter set index is signaled and when a Frequency Division Multiplexing (FDM) is adopted for the anchor UE and the assistant UE, using half of a frequency resource allocated to the anchor UE as one of the set of power control parameters for the assistant UE to determine the initial transmission power for the assistant UE to perform the collaborative uplink transmission.
The method of claim 1, wherein:

the first UE is an anchor UE and the second UE is an assistant UE; and

the collaborative uplink transmission by the assistant UE contains at least one transport block belonging to the anchor UE.
The method of claim 14, further comprising, in response to a determination that the anchor UE is limited in transmission power, controlling, by the anchor UE, a transmission power of the anchor UE based on the determination during the collaborative uplink transmission.
The method of claim 15, wherein determining that the anchor UE is limited in transmission power is based on a Power Headroom Report (PHR) or on a comparison of a current transmission power of the anchor UE to a transmission power threshold.
The method of claim 15, wherein controlling the transmission power of the anchor UE during the collaborative uplink transmission based on the determination comprises:

in response to the collaborative uplink transmission being a duplicate or backup transmission of the anchor UE, proceeding with the collaborative uplink transmission by the anchor UE; and

in response to the collaborative uplink transmission being a split transmission of the anchor UE, refraining from transmitting the collaborative uplink transmission by the anchor UE.
The method of claim 17, wherein the collaborative uplink transmission by the anchor UE is performed at a predetermined or configured maximum transmission power.
The method of claim 17, wherein refraining from transmitting the collaborative uplink transmission by the anchor UE is limited to a predetermined or signaled period of time.
The method of claim 19, wherein the predetermined or signaled period of time is provisioned by a timer triggered by the determination that the anchor UE is limited in transmission power.
The method of claim 20, wherein the timer is provisioned by the wireless base station or the anchor UE, and the collaborative uplink transmission by the anchor UE is resumed after an expiration of the timer.
The method of claim 17, wherein refraining from transmitting the collaborative uplink transmission by the anchor UE is achieved by an absence any Downlink Control Information (DCI) from the wireless base station for scheduling the collaborative uplink transmission in the anchor UE.
The method of claim 17, wherein refraining from transmitting the collaborative uplink transmission by the anchor UE is achieved by the anchor UE ceasing to respond to any DCI from the wireless base station intended for scheduling the collaborative uplink transmission by the anchor UE.
The method of claim 1, further comprising receiving, by the first UE:

a power offset between receive powers of the collaborative uplink transmission from the first UE and the second UE by the wireless base station; and

a power control command (TPC) .
The method of claim 24, further comprising adjusting transmission power associated with the collaborative uplink transmission according to the power offset and the TPC by applying one or more of:

a transmission power adjustment by an amount indicated by the power offset and/or the TPC;

a Modulation Coding Scheme (MSC) modification based on the power offset and/or the TPC;

a path loss compensation coefficient adjustment based on the power offset and/or the TPC;

a packet size adjustment based on the power offset and/or the TPC; or

a number of frequency domain resources allocated to the collaborative uplink transmission based on the power offset and/or the TPC.
The method of claim 25, wherein:

the first UE is an anchor UE and the second UE is an assistant UE; and

the power offset and the TPC are received by the first UE from wireless base station.
The method of claim 25, wherein:

the first UE is an assistant UE and the second UE is an anchor UE; and

the power offset and the TPC are received by the assistant UE from the anchor UE.
The method of claim 25, wherein adjusting the transmission power associated with the collaborative uplink transmission according to the power offset and the TPC is partially performed by the first UE and partially performed by the second UE.
A method performed by a wireless base station, comprising

transmitting a control message to at least one of an anchor UE and an assistant UE, the control message comprising a UE collaborative transmission indicator for switching the anchor UE and the assistant UE into a UE collaborative transmission state; and

receiving a collaborative uplink transmission from the assistant UE, the collaborative uplink transmission containing data belonging to and originated from the anchor UE.
The method of claim 29, wherein the control message comprises an RRC message or a MAC CE.
The method of claim 29, further comprising transmitting an index corresponding to a set of power control parameter for the anchor UE or the assistant UE to perform the collaborative uplink transmission.
The method of claim 29, further comprising transmitting a transmission disablement indication to the anchor UE, the transmission disablement indication indicating whether the anchor UE is disabled from transmitting data associated with the collaborative uplink transmission.
The method of claim 32, wherein the transmission disablement indication is triggered by the wireless base station in response to detecting that the anchor UE is transmission power limited and that the collaborative uplink transmission is in a triggering collaborative mode among a predetermined set of collaborative modes.
The method of claim 33, further comprising measuring a power headroom associated with the anchor UE and determining whether the anchor UE is transmission power limited based on the measured power headroom.
The method of claim 33, wherein:

the predetermined set of collaborative modes comprises a data duplication mode, a data split mode, and a data backup mode; and

the triggering collaborative mode comprises the data split mode.
The method of claim 33, wherein the transmission disablement indication indicates that the anchor UE is disabled from transmitting the data associated with the collaborative uplink transmission during a predetermined a configurable period of time.
The method of claim 36, further comprising:

starting a timer initiated with the predetermined or configurable period of time when detecting that the anchor UE is transmission power limited; and

refraining from scheduling, prior to an expiration of the timer, uplink transmission for the anchor UE to perform uplink transmission associated with the collaborative uplink transmission.
The method of claim 37, further comprising resuming, following the expiration of the timer, scheduling the uplink transmission for the anchor UE to perform the uplink transmission associated with the collaborative uplink transmission.
The method of claim 29, further comprising transmitting a receive power offset and/or a TPC to the anchor UE or the assistant UE, the receive power offset indicating a difference between received powers between the anchor UE and the assistant UE with respect to the collaborative uplink transmission.
The first UE or the wireless base station of any one of claims 1-39, the first UE or the wireless base station comprising a processor and a memory, wherein the processor is configured to read computer code from the memory to cause the first UE or the wireless base station to perform the method of any one of claims 1 to 39.
A computer program product comprising a non-transitory computer-readable program medium with computer code stored thereupon, the computer code, when executed by a processor of the first UE or the wireless base station of any one of claims 1 to 39, causing the processor to implement the method of any one of claims 1 to 39.