HK1235601B - Device and method of supporting reduced data transmission bandwidth - Google Patents

Description

Device and method supporting reduced data transmission bandwidth

Priority Declaration

This application claims the benefit of priority to U.S. patent application serial number 14/718,750, filed on May 21, 2015, which claims the benefit of priority to U.S. provisional patent application serial number 62/052,253, filed on September 18, 2014, and entitled “SUPPORT FOR DATATRANSMISSION BANDWIDTH LESS THAN 1PRB FOR MTC UES,” each of which is incorporated herein by reference in its entirety.

Technical Field

Embodiments relate to wireless communications. Some embodiments relate to cellular communication networks, including 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) networks and LTE Advanced (LTE-A) networks, as well as fourth generation (4G) networks and fifth generation (5G) networks. Some embodiments relate to enhanced coverage communications.

Background Art

With the increase in different types of devices communicating with servers and other computing devices over networks, the use of third-generation long-term evolution (3GPP LTE) systems has increased. Specifically, conventional user equipment (UE), such as cellular phones, and machine-type communication (MTC) UEs currently utilize 3GPP LTE systems. MTC UEs present particular challenges due to the low energy consumption involved in such communications. Specifically, MTC UEs are computationally inefficient and have low communication power requirements, and many are configured to remain in a single location essentially indefinitely. Examples of such MTC UEs include sensors (e.g., sensing environmental conditions) or microcontrollers in appliances or vending machines. In some cases, MTC UEs may be located in areas with little to no coverage, such as inside buildings or in isolated geographic areas. Unfortunately, in many cases, MTC UEs lack sufficient power to communicate with their nearest serving base station (enhanced Node B (eNB)). Similar issues can arise for non-fixed wireless UEs (e.g., mobile phones) located in network areas with poor coverage, i.e., where the link budget is several dB lower than typical network values.

In the case where the UE is in such an area, the transmission power cannot be increased by either the UE or the eNB. In order to achieve coverage extension and obtain additional dB in the link budget, a signal can be repeatedly transmitted from the transmitting device (either the UE or the eNB) over an extended period spanning multiple subframes and multiple physical channels to accumulate energy at the receiving device (the other of the UE and the eNB). In the current LTE standard, the minimum uplink or downlink resource that can be scheduled is 1 physical resource block (PRB). Compared to conventional UEs, the message size used by MTC UEs may be limited, and the message size may use much less than 1 PRB. Therefore, it may be desirable to allocate resources for uplink or downlink data transmission to MTC UEs with a granularity smaller than 1 PRB.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like reference numerals may describe similar components in different views. Like reference numerals with different letter suffixes may represent different instances of similar components. These figures generally illustrate various embodiments discussed in this document by way of example and not limitation.

FIG1 is a functional diagram of a 3GPP network according to some embodiments.

FIG2 is a block diagram of a 3GPP device according to some embodiments.

3A and 3B illustrate downlink allocations in a subframe according to some embodiments.

4A and 4B illustrate downlink allocations in subframes with frequency hopping according to some embodiments.

FIG5 illustrates a flow chart of a method for employing reduced data transmission bandwidth according to some embodiments.

DETAILED DESCRIPTION

The following description and accompanying drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, portions and features of other embodiments. The embodiments set forth in the claims include all available equivalents of those claims.

Figure 1 is a functional diagram of a 3GPP network according to some embodiments. The network may include a radio access network (RAN) (e.g., E-UTRAN or Evolved Universal Terrestrial Radio Access Network, as shown) 100 and a core network 120 (e.g., shown as an Evolved Packet Core (EPC)) coupled together via an S1 interface 115. For convenience and brevity, only a portion of the core network 120 and the RAN 100 are shown.

The core network 120 includes a mobility management entity (MME) 122, a serving gateway (serving GW) 124, and a packet data network gateway (PDN GW) 126. The RAN 100 includes an evolved Node-B (eNB) 104 (which may function as a base station) for communicating with the UE 102. The eNB 104 may include a macro eNB and a low power (LP) eNB.

The MME is functionally similar to the control plane of a traditional Serving GPRS Support Node (SGSN). The MME manages mobility aspects of access, such as gateway selection and tracking area list management. The Serving GW 124 terminates the interface toward the RAN 100 and routes traffic packets (such as data or voice packets) between the RAN 100 and the core network 120. Additionally, it can be the local mobility anchor for inter-eNB handovers and can also provide an anchor for inter-3GPP mobility. Other responsibilities may include lawful interception, charging, and some policy enforcement. The Serving GW 124 and MME 122 can be implemented in one physical node or in separate physical nodes. The PDN GW 126 terminates the SGi interface toward the Packet Data Network (PDN). The PDN GW 126 routes traffic packets between the EPC 120 and external PDNs and can be a key node for policy enforcement and charging data collection. It can also provide an anchor for mobility with non-LTE access. External PDNs can be any type of IP network as well as an IP Multimedia Subsystem (IMS) domain. The PDN GW 126 and the Serving GW 124 may be implemented in one physical node or in separate physical nodes.

The eNB 104 (macro and micro) terminates the air interface protocol and can be the first point of contact for the UE 102. The eNB 104 can communicate with the UE 102 in normal coverage mode and with the UE 104 in one or more enhanced coverage modes. In some embodiments, the eNB 104 can implement various logical functions for the RAN 100, including but not limited to RNC (Radio Network Controller) functions such as radio bearer management, uplink and downlink dynamic radio resource management and traffic packet scheduling, and mobility management. According to an embodiment, the UE 102 can be configured to communicate orthogonal frequency division multiplexing (OFDM) communication signals with the eNB 104 over a multi-carrier communication channel according to OFDMA communication technology. OFDM signals can include multiple orthogonal subcarriers. Other technologies such as non-orthogonal multiple access (NOMA), code division multiple access (CDMA), and orthogonal frequency division multiple access (OFDMA) can also be used.

The S1 interface 115 is an interface that separates the RAN 100 and the EPC 120. It is divided into two parts: S1-U, which carries traffic packets between the eNB 104 and the Serving GW 124, and S1-MME, which is a signaling interface between the eNB 104 and the MME 122.

For cellular networks, LP cells are typically used to extend coverage to indoor areas where outdoor signals don't reach well, or to increase network capacity in areas with very dense phone usage, such as train stations. As used herein, the term low-power (LP) eNB refers to any suitable relatively low-power eNB for implementing narrower cells (narrower than macrocells), such as femtocells, picocells, or microcells. Femtocell eNBs are typically provided by mobile network operators to their residential or enterprise customers. Femtocells are typically the size of a residential gateway or smaller and are typically connected to a user's broadband line. Once plugged in, the femtocell connects to the mobile operator's mobile network and, for residential femtocells, typically provides additional coverage within a range of 30 to 50 meters. Therefore, since the LP eNB is coupled via the PDN GW 126, the LP eNB can be a femtocell eNB. Similarly, a picocell is a wireless communication system that typically covers a small area, such as within a building (office, shopping mall, train station, etc.), or more recently, within an airplane. A picocell eNB can typically connect to another eNB, such as a macro eNB, via its base station controller (BSC) functionality via an X2 link. Therefore, an LPeNB can be implemented with a picocell eNB because it is coupled to a macro eNB via an X2 interface. A picocell eNB or other LP eNB can incorporate some or all of the functionality of a macro eNB. In some cases, this can be referred to as an access point base station or enterprise femtocell.

Communications over the LTE network can be divided into 10ms frames, each of which can contain ten 1ms subframes. Each subframe of the frame can then contain two time slots of 0.5ms. Each subframe can be used for uplink (UL) communication from the UE to the eNB or downlink (DL) communication from the eNB to the UE. The eNB can allocate a larger number of DL communications than UL communications in a particular frame. The eNB can schedule uplink and downlink transmissions over various frequency bands. The allocation of resources in a subframe used in one frequency band can be different from those in another frequency band. Depending on the system used, each time slot of a subframe can contain 6-7 symbols. In some embodiments, a subframe can contain 12 or 24 subcarriers. A downlink resource grid can be used for downlink transmissions from the eNB to the UE, while an uplink resource grid can be used for uplink transmissions from the UE to the eNB or from the UE to another UE. The resource grid can be a time-frequency grid, which is the physical resource in each time slot. The smallest time-frequency unit in the resource grid can be represented as a resource element (RE). Each column and row of the resource grid may correspond to an OFDM symbol and an OFDM subcarrier, respectively. The resource grid may contain resource blocks (RBs) that describe the mapping of physical channels to resource elements and physical RBs (PRBs). A PRB may be the smallest resource unit that can be allocated to a UE in the current 3GPP standard. A resource block may be 180kHz wide in frequency and 1 slot long in time. In frequency, a resource block may be 12×15kHz subcarriers or 24×7.5kHz subcarriers wide. For most channels and signals, 12 subcarriers may be used for each resource block, depending on the system bandwidth. The duration of the resource grid in the time domain corresponds to one subframe or two resource blocks. For the conventional cyclic prefix (CP) case, each resource grid may include 12 (subcarriers)*14 (symbols)=168 resource elements.

In addition to physical resource blocks, the LTE system can also define virtual resource blocks (VRBs). VRBs can have the same structure and size as PRBs. VRBs can be of different types: distributed and localized. In resource allocation, VRB pairs located in two time slots in a subframe can be distributed together, and a pair of VRBs can have an index of n _VRB . Localized VRBs can be mapped to PRBs, that is, n _PRB = n _VRB ; the mapping from localized VRBs to PRBs can be the same in both time slots in a subframe. Distributed VRBs can be mapped to PRBs according to a frequency hopping rule, where n _PRB = f(n _VRB , _ns ), where _ns = 0-19 (the time slot number of the radio frame). The mapping from distributed VRN to PRBs can be different between time slots in a subframe.

There may be several different physical channels transmitted using such resource blocks, including the Physical Downlink Control Channel (PDCCH) and Physical Downlink Shared Channel (PDSCH) in downlink transmissions, and the Physical Uplink Control Channel (PUCCH) and Physical Uplink Shared Channel (PUSCH) in uplink transmissions. Each downlink subframe may be divided into PDCCH and PDSCH, while each uplink subframe may contain PUCCH and PUSCH. The PDCCH may typically occupy the first two symbols of each subframe and carry, among other things, information about the transport format and resource allocation associated with the PDCCH, as well as H-ARQ information associated with the uplink or downlink shared channel. The PDSCH or PUSCH may carry user data and higher layer signaling to the UE or eNB and occupy the remainder of the subframe.

Typically, downlink scheduling (assigning control and shared channel resource blocks to UEs within a cell) can be performed at the eNB based on channel quality information provided from the UE to the eNB, and downlink resource assignment information can then be sent to each UE on the PDCCH assigned to the UE. The PDCCH can contain downlink control information (DCI) in one of several formats, which tells the UE how to find and decode data sent on the PDSCH in the same subframe from the resource grid. Thus, the UE can receive the downlink transmission, detect the PDCCH, and decode the DCI based on the PDCCH before decoding the PDSCH. The DCI format can provide details such as the number of resource blocks, resource allocation type, modulation scheme, transport block, redundancy version, coding rate, etc. Each DCI format can have a 16-bit cyclic redundancy code (CRC) and is scrambled with a radio network temporary identifier (RNTI) that identifies the target UE for which the PDSCH is intended. The use of a UE-specific RNTI can limit the decoding of the DCI format (and therefore the corresponding PDSCH) to only the intended UE.

FIG2 is a functional diagram of a 3GPP device according to some embodiments. For example, the device may be a UE or an eNB. In some embodiments, the eNB may be a fixed, non-mobile device. 3GPP device 200 may include physical layer circuitry 202 for transmitting and receiving signals using one or more antennas 201. 3GPP device 200 may also include medium access control (MAC) layer circuitry 204 for controlling access to a wireless medium. 3GPP device 200 may also include processing circuitry 206 and memory 208 configured to perform the operations described herein.

In some embodiments, the mobile device or other device described herein may be part of a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capabilities, a web tablet, a wireless phone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), or other device that can wirelessly receive and/or send information. In some embodiments, the mobile device or other device may be a UE 102 or eNB 104 configured to operate according to a 3GPP standard. In some embodiments, the mobile device or other device may be configured to operate according to other protocols or standards, including IEEE 802.11 or other IEEE standards. In some embodiments, the mobile device or other device may include one or more of a keyboard, a display, a non-volatile memory port, multiple antennas, a graphics processor, an application processor, a speaker, and other mobile device elements. The display may be an LCD screen including a touch screen.

Antenna 201 may include one or more directional or omnidirectional antennas, such as dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other types of antennas suitable for transmitting RF signals. In some multiple-input multiple-output (MIMO) embodiments, antennas 201 may be effectively separated to exploit spatial diversity and the resulting different channel characteristics.

Although the 3GPP device 200 is shown as having several separate functional elements, one or more of the functional elements may be combined and may be implemented by a combination of software-configured elements (such as a processing element including a digital signal processor (DSP)) and/or other hardware elements. For example, some elements may include one or more microprocessors, DSPs, field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), radio frequency integrated circuits (RFICs), and combinations of various hardware and logic circuits for performing at least the functions described herein. In some embodiments, a functional element may refer to one or more processes operating on one or more processing elements.

The embodiments may be implemented in one of hardware, firmware, and software, or in a combination of hardware, firmware, and software. The embodiments may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transitory mechanism for storing information in a machine (e.g., computer) readable form. For example, a computer-readable storage device may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk storage medium, an optical storage medium, a flash memory device, and other storage devices and media. Some embodiments may include one or more processors and may be configured with instructions stored on a computer-readable storage device.

The term "machine-readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store one or more instructions. The term "machine-readable medium" may include any medium that is capable of storing, encoding, or carrying instructions for execution by the 3GPPP device 200 and causing it to perform any one or more of the techniques of the present disclosure, or capable of storing, encoding, or carrying data structures used by or associated with such instructions. The term "transmission medium" should be considered to include any intangible medium capable of storing, encoding, or carrying instructions for execution, and includes digital or analog communication signals or other intangible media that facilitate the communication of such software.

As mentioned above, the minimum scheduling granularity of the current 3GPP standard is 1PRB. In some embodiments, the granularity can be reduced to provide a smaller effective PRB (hereinafter referred to as PRB _min ). PRB _min can be limited in frequency and/or time. Similar to the resources of 1PRB, resources less than 1PRB can be allocated to the UE, allowing the UE to communicate with the eNB using a smaller resource set. In some embodiments, allocation information can be provided in the control signaling before the UE receives the PDCCH signal. In some embodiments, the allocation of PRBs to the PRB _min component can be explicitly indicated by DCI for downlink assignments or uplink grants. Among other things, DCI can indicate which resource block carries data and the demodulation scheme to be used to decode the data. The receiver can first decode the DCI using blind decoding and decode the data (contained in the PDSCH for downlink transmission and the PUSCH for uplink transmission) based on the information in the DCI. The reduced PRBs may allow MTC UEs to transmit messages of reduced size used by MTC UEs (compared to regular UEs) and apply increased or maximum transmit power over a smaller bandwidth in uplink transmissions, thereby improving power spectral density (PSD) to enhance coverage for MTC UEs.

There are several DCI formats that can currently exist in TS 36.212, which can differ between uplink and downlink transmissions. Downlink DCI formats can include formats 1, 1A, 1B, 1C, 1D, 2, and 2A, as well as uplink DCI formats such as formats 0, 3, and 3A. Formats 1, 1A, 1B, 1C, and 1D can be used to schedule PDSCH codewords for single-input single-output (SISO) or MIMO applications, while formats 2 and 2A can be used to schedule PDSCHs using different multiplexing. Format 0 can be used to schedule uplink data (on the PUSCH), while formats 3 and 3A can be used to indicate uplink transmit power control. Whether used for uplink or downlink, the DCI format can each include multiple fields. The fields can include a resource allocation header, resource block assignment, modulation and coding scheme, HARQ process number, new data indicator, redundancy version, transmit power control (TPC) command, and downlink assignment index (DAI). The resource allocation header may indicate the type of resource allocation used for PDSCH/PUSCH resource mapping. There may be two bitmap-based resource allocation types (type 0 and type 1), where each bit addresses a single resource block or a group of resource blocks. Resource block assignments may be used by the UE to interpret resource allocations for PDSCHs allocated with type 0 or type 1. Resource block assignments may include the number of resource allocation bits and, depending on the allocation type and bandwidth, may include other information for allocation and indication. The modulation and coding scheme field may indicate the coding rate and modulation scheme used to encode the PDSCH codeword. Currently supported modulation schemes may be QPSK, 16QAM, and 64QAM. The HARQ process number field may indicate the HARQ process number used by higher layers for the current PDSCH codeword. The HARQ process number may be associated with a new data indicator and a redundancy version field. The new data indicator may indicate whether the codeword is a new transmission or a retransmission. The redundancy version may indicate the redundancy version of the codeword corresponding to the four different versions of the codeword added to the codeword during turbo encoding, which may specify the amount of redundancy. The TPC command may specify the power used by the UE in transmitting the PUCCH.DAI is a TDD-specific field that may indicate the count of downlink assignments scheduled for the UE within a subframe.

In some embodiments, the resource allocation header can be adjusted to reduce granularity to PRB _min . Furthermore, since multiple PRB _{min s} can be allocated within a PRB, the PRB _{min s} of different UEs can be combined in various ways, allowing the UE's PRB _{min s} to be allocated in any of several ways. Figures 3A and 3B illustrate downlink allocations within a subframe according to some embodiments. Specifically, Figures 3A and 3B illustrate different embodiments of centralized allocation and distributed allocation, respectively. Although not shown, similar methods can be applied to uplink communications in other embodiments.

As shown in Figure 3A, subframe 300 includes PDCCH 302 and PDSCH 304 as well as centralized PRB _min allocation for first UE 306 and second UE 308. It can be seen that the minimum bandwidth granularity can be 6 resource elements, that is, for example, the granularity can be reduced to 1/2PRB of the current PRB. In some embodiments, PRB _min can be limited in frequency and can be, for example, 90kHz wide (6×15kHz subcarriers or 12×7.5kHz subcarriers wide) in frequency and 1 time slot long in time. In other embodiments, the granularity can be different. In some embodiments, the granularity of each UE in the PRB can be the same (that is, the PRB _min is the same), while in other embodiments, the granularity can be different. For example, the PRB _min for two UEs can be 1/4PRB, while for a third UE, the PRB _min can be 1/2PRB. The granularity can be set according to the type of UE, the type of traffic provided by the UE, time/day, etc. For centralized resource allocation, MTC UEs can be assigned a contiguous set of subcarriers to transmit and receive data in the PRB _min . As shown in Figure 3A, all subcarriers assigned to a particular UE can be contiguous. In the example shown in Figure 3A, UE #1 is assigned subcarrier indices {0, 1, 2, 3, 4, 5}, while UE #2 is assigned subcarrier indices {6, 7, 8, 9, 10, 11}.

Figure 3B shows a subframe 320 with a distributed resource allocation scheme, where the PRB _min is the same as in Figure 3A. The PRBs of the distributed centralized allocation scheme provide non-contiguous subcarriers for UE1 326 and UE2 328. As can be seen in Figure 3B, UE1 is assigned subcarrier indices {0, 2, 4, 6, 8, 10}, while UE2 is assigned subcarrier indices {1, 3, 5, 7, 9, 11}. Therefore, in the example shown, each adjacent subcarrier is assigned to a different UE - alternating subcarrier assignment in the case of PRB _min = 1/2PRB. In other embodiments, the subcarrier indices for one or more of the UEs may include a combination of centralized and distributed resource allocation, that is, some adjacent subcarriers may be assigned to the same UE, while other adjacent subcarriers are assigned to different UEs. In one such example, UE1 may be assigned subcarrier indices {0, 2, 3, 4, 8, 10}, while UE2 may be assigned subcarrier indices {1, 5, 6, 7, 9, 11}.

In some embodiments, the resource allocation scheme (whether centralized or distributed) can be explicitly indicated in the DCI format for DL assignments or UL grants. In some embodiments, the resource allocation scheme can be predefined by a standard or configured via control signaling such as radio resource control (RRC) signaling when the UE is in RRC connected mode or in a system information block (SIB). Thus, resource allocation can be statically or dynamically assigned. In some embodiments, if the network determines that the UE is an MTC UE, signaling overhead can be reduced and system design can be simplified by only allowing centralized resource allocation within the PRBs to be defined for MTC UEs.

The DCI format can be adjusted so that the DCI format can define a PRB _min with a bandwidth granularity smaller than 1 PRB. For bandwidths of 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz, the number of PRBs allowed in each band can be 6, 15, 25, 50, 75, and 100, respectively. Currently, the PRB index and the total number of PRBs can be used to indicate which of the above PRBs are assigned to the UE. In order to enable the DCI format to assign PRB _min , the DCI format can replace the PRB index and the total number of PRBs with the subcarrier block index and the total number of subcarrier blocks, respectively. In one example, if the minimum bandwidth granularity is defined as P _SC , assuming a 15 kHz subcarrier, the number of subcarrier blocks can be given by B = 12 / P _SC . In this case, in DL resource allocation types 0 and 1, the resource block group size (P) as defined in ETSI TS 136 213 Section 7.1.6.1 can be changed to P*B. Note that in type 0 resource allocation, the resource block assignment information includes a bitmap indicating the resource block groups (contiguous PRBs) allocated to the UE, while in type 1 resource allocation, the resource block assignment information of size N _RBG indicates to the UE the PRBs in a PRB set from one of the P resource block group subsets. In type 2 resource allocation, where the resource block assignment information indicates to the UE a set of contiguously allocated localized or distributed virtual resource blocks, the step value as defined in ETSI TS 136 213 Section 7.1.6.3 can be changed depending on the downlink system bandwidth.

In some embodiments, additional bits may be provided in the DCI format to indicate the subcarrier index within a PRB. In one such embodiment, when the minimum bandwidth granularity allows resource allocation of less than 1 PRB, a bitmap (hereinafter referred to as each bitmap) may be used for resource assignment of all subcarriers. Each bitmap may indicate whether each subcarrier within a PRB is assigned. In one embodiment, each bitmap may indicate that a particular subcarrier is assigned using "1" and that a particular subcarrier is not assigned using "0". For example, to indicate that the first four subcarriers are assigned to the UE for data transmission, each bitmap may specify "111100000000". Therefore, the number of additional bits used in the DCI format may be equal to the number of subcarriers, which may increase the signaling overhead of the DCI format by an excessive amount.

In some embodiments, different types of bitmaps (hereinafter referred to as block bitmaps) can be used to reduce the amount of signaling overhead. In a block bitmap, instead of indicating individual subcarriers used to transmit data, blocks of subcarriers used to transmit data can be indicated in the block bitmap. For example, the block size can be set by a specification or communicated through other types of dynamic control signaling. In some embodiments, the block size can be the minimum bandwidth granularity, while in other embodiments, the block size can be larger than the minimum bandwidth granularity but smaller than 1 PRB. For example, assuming the minimum bandwidth granularity is _PSC and the number of subcarrier blocks is 12/ _PSC , a subcarrier block can be indicated as being used to transmit data using fewer bits. In one embodiment, each block in the block bitmap can indicate that a specific subcarrier block is assigned for transmission using a "1" and that a specific subcarrier block is not assigned for transmission using a "0." For example, if the minimum bandwidth granularity is four 15kHz subcarrier blocks, three additional bits can be used to indicate the three blocks that form the PRB. In this case, a block bitmap of "010" can indicate that only the second block is assigned to the UE for transmission. One or more of the blocks can be assigned to a specific UE for transmission. In one specific example thereof, the first block may indicate the assignment of subcarriers [0, 1, 2, 3], the second block may indicate the assignment of subcarriers [4, 5, 6, 7], and the third block may indicate the assignment of subcarriers [8, 9, 10, 11]. Although in this example, each of the blocks contains contiguous subcarriers, in other embodiments, some or all of the blocks may contain non-contiguous subcarriers. Thus, in another specific example, the first block may indicate the assignment of subcarriers [0, 1, 4, 7], the second block may indicate the assignment of subcarriers [2, 3, 5, 6], and the third block may indicate the assignment of subcarriers [8, 9, 10, 11].

In some embodiments, to further reduce signaling overhead, instead of using a single bit indicating whether a particular subcarrier block has been assigned, only a single subcarrier or subcarrier block index in the DCI format can be used for resource assignment. Such an embodiment can save signaling overhead in situations where more than two blocks are available for assignment. In the above example where three subcarrier blocks can be assigned, two bits can be used to signal three values. For example, "00," "01," and "10" can indicate the assignment of subcarrier blocks 1, 2, and 3, respectively. Thus, in this example, the binary indication "01" can indicate that only the second subcarrier block is assigned to a particular UE for transmission, rather than "010" using bits of the bitmap to indicate a particular block to indicate that only the second subcarrier block is assigned to a particular UE for transmission. In other embodiments, any of the four available values can be mapped to the three subcarrier blocks as needed. For example, each of the additional values can indicate a specific, predetermined combination of multiple subcarrier blocks assigned to a particular UE or an alternative arrangement of subcarriers assigned to a particular UE. For example, assuming that the values "00," "01," and "10" above each indicate that different subcarrier blocks that are consistent with each other (i.e., contain non-overlapping subcarriers) are assigned to the UE, the value "11" may be assigned to a subcarrier block that is inconsistent with the other values assigned to the UE. For example, the eNB may determine that the UE is able to communicate more efficiently via a particular subcarrier block (e.g., the block includes only those subcarriers with less interference), and assign an additional block if there are no other UEs to be assigned inconsistent subcarrier blocks. In such an example, for example, UEs may have different priorities such that a high-priority UE (or user or transmission) may transmit via such a block, while a block containing a consistent set of subcarriers is assigned to a lower-priority UE regardless of the presence of other UEs in the cell.

In some embodiments, the eNB may signal a list of cell RNTIs (C-RNTIs) in an order for the UE group in a manner similar to DCI format 3/3A (which describes the transmission of transmission control protocol commands for PUCCH and PUSCH with 2-bit or 1-bit power adjustment). Thus, the C-RNTI may be a unique identifier that signals to the UE which block it is assigned based on the order of assignment. Thus, m C-RNTIs may be used for m blocks, each containing n subcarriers. Additionally, a common RNTI may be predefined or provided by higher layers for scrambling of the PDCCH, such that the same common RNTI may be provided to multiple UEs, and the assignments further provided based on the order of assignment. The provision of the common RNTI by higher layers may be provided via RRC or SIB signaling. Thus, the common RNTI may be associated with a resource allocation with a granularity of 1 PRB. In one embodiment, the UE may receive the PDCCH from the eNB using the common RNTI and derive the dedicated subcarrier blocks based on the order of the C-RNTIs. Continuing with the above example, assuming there are four subcarriers in each block, such that there are three blocks in each PRB, the eNB can use three C-RNTIs that are signaled sequentially to the first UE, the third UE, and the second UE. In this case, when the eNB assigns PRBs to the group of UEs, all within the PRB, the first UE can be assigned a first subcarrier block (e.g., subcarriers [0, 1, 2, 3]), the second UE can be assigned a third subcarrier block (e.g., subcarriers [8, 9, 10, 11]), and the third UE can be assigned a second subcarrier block (e.g., subcarriers [4, 5, 6, 7]). As mentioned above, the above examples are merely exemplary, and a block can contain contiguous subcarriers and/or non-contiguous subcarriers within a PRB indicated by a common RNTI. Unlike previous embodiments, the use of group-based scheduling allows the UE and the eNB to reuse DCI formats in the existing LTE specification, thereby minimizing implementation effort.

Figures 3A and 3B illustrate different approaches in which PRBs can be subdivided to provide smaller granularity allocations for a single subframe. Although the subframes in Figures 3A and 3B illustrate continuous time allocations of resource elements across all time slots of each subframe, other embodiments are possible. Figures 4A and 4B illustrate downlink allocations in subframes with frequency hopping according to some embodiments. Similar to the above, although not shown, in other embodiments, similar methods can be applied to uplink communications. In frequency hopping, the assigned frequency resource allocation can be changed from one time period to another in a controlled manner. The UE's frequency hopping can be based on explicit frequency hopping information in a scheduling grant from the eNB. Frequency hopping can be inter-subframe hopping or intra-subframe hopping. As shown in Figures 4A and 4B, intra-subframe frequency hopping can occur between time slots. Several different embodiments can be applied to provide frequency hopping.

In one process, the eNB may send a scheduling grant to the UE in a DCI message. The uplink scheduling grant in the DCI message may include a flag indicating whether frequency hopping is on or off. The UE may receive a scheduling grant with a virtual resource allocation. The virtual resource allocation may then be mapped by the UE to a physical resource allocation in the first time slot and to another physical resource allocation in the second time slot based on the frequency hopping type. That is, each distributed type virtual resource block in a subframe may be mapped to a different PRB, i.e., the same distributed type virtual resource block of two time slots may be mapped to different PRBs, and there may be a gap value between them. Depending on the number of PRBs in the system (system bandwidth), there may be 1 or 2 gap values. The resource allocation signaling from the eNB may indicate the sequence number of the starting virtual resource block and the number of consecutive virtual resource blocks.

In one embodiment, the currently used downlink and uplink frequency hopping schemes can be extended to bandwidth granularity less than 1 PRB. As described above, in some embodiments, the PRB index and the total number of PRBs can be used to indicate the assignment of resources for communicating with a specific UE (whether uplink or downlink). In a manner similar to the above, when the granularity is reduced, the PRB index and the total number of PRBs can be replaced by the subcarrier block index and the total number of subcarrier blocks, respectively. As described above, assuming that the minimum bandwidth granularity is P _SC and the number of subcarrier blocks is B = 12 / P _SC (for 15kHz subcarriers), for distributed type virtual resource blocks, the resource block gap value (N _gap ) as defined in 3GPP TS 36.211 Section 6.2.3.2 can be adjusted to N _gap * B.

In some embodiments, a downlink and uplink frequency hopping scheme with a bandwidth granularity of 1 PRB can be used. In this case, the relative position of the UE allocation within 1 PRB can be specified for each frequency hopping. As shown in Figure 4A, in some embodiments, to provide frequency hopping, the frequency position within 1 PRB can remain the same as in the centralized frequency hopping resource block. For intra-subframe hopping, in time slot 0, a first PRB index (e.g., PRB index 3) can be assigned and a first subcarrier index (e.g., subcarrier index {0-5}) can be allocated. Using the frequency hopping mechanism, in time slot 1, a second PRB index (e.g., PRB index 10) can be obtained according to the existing LTE specification, and within the second PRB, the same subcarrier index (e.g., subcarrier index {0-5}) can be allocated. Figure 4A shows a downlink subframe 402 across the system bandwidth. The subframe 402 can include allocation sets 402 and 404 within the PRB. Although only one allocation set is shown in each time slot in Figure 4A, more allocation sets can exist across the system bandwidth. In FIG4A , each allocation set 402, 404 contains allocations to two UEs (UE1 406 and UE2 408), resulting in a minimum bandwidth granularity of six subcarriers. Frequency hopping occurs in FIG4A because the PRBs assigned to UE1 406 and UE2 408 differ between the time slots of subframe 400. Note that MTC UEs can perform frequency hopping as long as they are able to utilize allocations provided by the eNB in different frequency hopping domains. As can be seen in FIG4A , the relative subcarrier positions of the allocations to UE1 406 and UE2 408 within each PRB can remain constant across different frequency hopping domains in different time slots.

However, in some embodiments, the frequency positions within 1PRB can be swapped as in a frequency hopping resource block. In a specific example, if the subcarrier set within 1PRB is defined as Ω, then in the hopping resource block, the subcarrier set can be obtained as 11-Ω. In this case, data mapping can start from the lowest subcarrier index within the hopping resource block to simplify the design of resource mapping. For example, similar to the above for intra-subframe hopping, in time slot 0, a first PRB index (e.g., PRB index 3) can be assigned and a first subcarrier index (e.g., subcarrier index {0-5}) can be allocated. Using the frequency hopping mechanism, in time slot 1, a second PRB index (e.g., PRB index 10) can be obtained according to the existing LTE specification, and within the second PRB, the same subcarrier index (e.g., subcarrier index {6-11}) can be allocated. The starting subcarrier for data mapping is still subcarrier 6.

FIG4B illustrates an example in which the frequency positions within one PRB differ in a centralized frequency hopping resource block. In FIG4B , a subframe 422 may include allocation sets 422 and 424 within a PRB. As described above, although only one allocation set is shown in each time slot in FIG4B , more allocation sets may exist across the system bandwidth. Each allocation set 422 and 424 contains allocations directed to two UEs (UE1 426 and UE2 428), forming a minimum bandwidth granularity of 6 subcarriers. The PRBs assigned to UE1 426 and UE2 428 differ between the time slots of subframe 420. Although both UE1 426 and UE2 428 are allocated within the same PRB, unlike the embodiment shown in FIG4A , the relative subcarrier positions allocated within UE1 426 and UE2 428 within each PRB may be swapped between different frequency hopping domains in different time slots. As described above, the frequency hopping mechanism of FIG4A and FIG4B may be predefined or configured via SIB or RRC signaling. Alternatively, the frequency hopping schemes of Figures 4A and 4B may be explicitly signaled in the DCI format for downlink assignments and uplink grants.In some embodiments, to simplify the design, only one frequency hopping scheme may be supported, such as Figure 4A.

In some embodiments, the allocation distribution within the PRBs of each time slot can be independent of each other. That is, in two sets of figures: Figures 3A and 3B and Figures 4A and 4B, embodiments are shown in which the allocation of PRBs in two UEs is centralized, so that in each time slot, each subcarrier in the PRBs allocated to the UE is adjacent to another subcarrier in the PRBs allocated to the UE. In other embodiments, the PRBs can be allocated in a distributed manner for the two time slots, so that each subcarrier in the PRBs allocated to the UE is adjacent only to subcarriers in PRBs allocated to one or more different UEs, or the PRBs can be allocated in a hybrid manner where some subcarriers are distributed and some subcarriers are centralized. In other embodiments, the PRBs can be allocated differently between the time slots of a single subframe (or between subframes), so that the allocation of PRBs to UEs within each time slot can be centralized, distributed, or some combination thereof, and can be independent of the allocation in other time slots.

The same design principles can be extended and applied to distributed resource allocation schemes and inter-subframe hopping schemes. The design principles can be extended to downlink frequency hopping for data transmission of less than 1 PRB. Further, the frequency hopping mechanism can be applied to MTC UEs with reduced bandwidth (e.g., 1.4 MHz). Frequency resources can be hopped within the MTC range as predefined or configured by high-layer signaling. In addition, frequency hopping can be applied to conventional UEs with support for delay-tolerant MTC applications. In this case, frequency resources can hop within the entire system bandwidth. Regardless of whether the allocation is centralized or distributed, how the allocation is provided to the UE and/or whether frequency hopping exists (and how frequency hopping is provided) may depend on the type of UE, the type of traffic provided by the UE, the time/day, and/or other factors.

When modifying the communication between the UE and the eNB to support a reduced bandwidth of less than 1 PRB, the demodulation reference signal (DM-RS) may also be modified. The DM-RS is a reference signal (also known as an LTE pilot signal) specific to a particular UE. The DM-RS can be used by the UE to demodulate the PDSCH and to estimate channel quality (e.g., interference from other eNBs). To support a large number of UEs, a large number of DM-RS sequences can be used. Different DM-RS sequences are achieved by cyclic shifts of the base sequence. The UE can perform measurements based on the DM-RS and send the measurement results to the eNB for analysis and network control. The DM-RS can be sent in every resource block allocated to the UE. If, for some reason, the DM-RS is not correctly decoded by the eNB, the PUSCH or PUCCH may also not be decoded by the eNB. The DM-RS can be generated using a Zadoff-Chu sequence as indicated in TS 36.211 section 5.5.1 and can be located in the center symbols of the time slots of the uplink subframe, such as symbol 3 (in time slot 0) and symbol 10 (in time slot 1). To support a large number of UEs, a large number of DM-RS sequences can be generated by using cyclic shifts of a base sequence. In some embodiments, after generating the DM-RS sequence, the UE can puncture the subcarriers not assigned to itself within the PRB.

In some embodiments, as specified in TS 36.211 section 5.5.1, the reference signal sequence is defined by a cyclic shift α of the base sequence according to the following formula:

Where m is the length of the reference signal sequence, and multiple reference signal sequences can be defined from a single base sequence by different values of α. In embodiments where less than a single resource block can be allocated to a particular UE, m can take values different from those above—i.e., 0<m<1, in which case the DM-RS sequence becomes:

Where Ω may be the set of assigned resource elements within one resource block, and Ω = {0, 1, ..., 11}.

In some embodiments, a DM-RS sequence can be generated based on a base sequence with a length less than 12 (1/subcarrier). In this case, the base sequence can be given by the following formula:

Where is the minimum number of resource elements assigned to a UE. The phase value can be generated to have a constant modulus in the frequency domain, low CM, low memory/complexity requirements, and good cross-correlation properties. In one embodiment, similar to the existing LTE specification for sequence lengths less than 6 resource blocks, sequence hopping can be disabled for sequence lengths less than 1 resource block. In one example, when, the phase value can be defined as shown in Table 1:

Table 1

FIG5 illustrates a flow diagram of a method for employing a reduced data transmission bandwidth according to some embodiments. For example, the method 500 illustrated in FIG5 may be employed by the UE described above with respect to FIG2 . At operation 502 of method 500 , the UE may receive a downlink assignment or an uplink grant from the eNB. The assignment or grant may be provided in a PDCCH signal.

At operation 504, the UE may determine whether a resource allocation has been provided via control signaling prior to receiving the PDCCH signal. The resource allocation may be predefined, such as provided by a system specification, or configured, for example, specifically for the UE via SIB or RRC signaling. The control signaling may indicate whether the resource allocation is a centralized resource allocation or a distributed resource allocation.

If the resource allocation is provided by the PDCCH, then at operation 506, the UE may decode the PDCCH and extract the resource allocation from the decoded PDCCH. The PDCCH may include a DCI format that includes the resource allocation. The UE may be able to determine from the DCI format whether the resource allocation is less than one PRB. For example, the DCI format may include a subcarrier block index and the total number of subcarrier blocks that specify the resources within the PRB allocated to the UE. In other examples, the DCI format may include a bitmap for all subcarriers. In this case, each individual bit of the bitmap may correspond to a unique subcarrier or block of different subcarriers. Alternatively, the bitmap may instead indicate a subcarrier block index whose value corresponds to a different subcarrier block. Although not shown, the UE may instead derive the resource allocation using the received C-RNTI associated with the ordered list of C-RNTIs and a public RNTI previously provided to the UE.

At operation 508, the UE may determine the distribution of the resource allocation. The UE may determine whether the resource allocation is centralized (adjacent subcarriers other than the edge subcarriers are allocated to the UE) or distributed (at least one adjacent subcarrier other than the edge subcarriers is allocated to different UEs). The frequency of the resource allocation and the timing of the resource allocation may be determined. For example, the same set of subcarriers may be allocated for the entire subframe, or different sets of subcarriers may be allocated. In the latter case, the resource allocation may include frequency hopping within the subframe. If the UE determines that the resource allocation includes frequency hopping, the frequency hopping information may be provided by the UE in the scheduling grant and include a subcarrier block index and a total number of subcarrier blocks. Within a particular PRB, the relative position of the UE's resource allocation may remain constant or may change.

At operation 510, the UE may also generate a DM-RS sequence. The UE may extract the DM-RS sequence from subcarriers not assigned to the UE, where the DM-RS sequence has been generated by puncturing the subcarriers not assigned to the UE. Additionally or alternatively, the DM-RS sequence may be generated using a base sequence having a length less than the number of subcarriers in 1 PRB (12).

At operation 512, the UE may transmit the DM-RS and information to the eNB using the allocated resources. The UE may transmit during the PUSCH, which may then be received by the eNB. The transmission may use any format described herein, including, for example, inter-subframe or intra-subframe frequency hopping.

Various examples of the present disclosure are provided below. These examples are not intended to limit the present disclosure in any way. In Example 1, a UE includes a transceiver and processing circuitry configured to communicate with an eNB. The processing circuitry is configured to receive downlink control information (DCI) from the eNB. The DCI is configured to provide a resource allocation in a PRB of a subframe, the resource allocation including a reduced physical resource block (PRB _min ) of less than one PRB for at least one of downlink (DL) and uplink (UL) communications. The PRB includes 12 wide subcarriers or 24 narrow subcarriers in frequency, and the PRB _min includes less than 12 wide subcarriers or less than 24 narrow subcarriers. The processing circuitry is configured to configure the transceiver to communicate with the eNB using the resource allocation.

In Example 2, the subject matter of Example 1 can optionally include that resource allocation for the UE within the PRB comprises a centralized allocation across time slots of the subframe such that each subcarrier in PRB _min is adjacent to another subcarrier in PRB _min .

In Example 3, the subject matter of Example 2 can optionally include that resource allocation for the UE within the PRB comprises a centralized allocation across two slots of the subframe such that each subcarrier in PRB _min is adjacent to another subcarrier in PRB _min throughout the subframe.

In Example 4, the subject matter of one or any combination of Examples 1 to 3 may optionally include: resource allocation for the UE within the PRB includes a distributed allocation throughout the time slots of the subframe such that each subcarrier in the PRB _min is adjacent to a subcarrier in another PRB _min in a PRB allocated to a different UE.

In Example 5, the subject matter of Example 4 can optionally include that the resource allocation for the UE within the PRB comprises a distributed allocation across two slots of the subframe such that each subcarrier in a PRB _min is adjacent to a subcarrier in another PRB _min throughout the subframe.

In Example 6, the subject matter of one or any combination of Examples 1 to 5 may optionally include resource allocation for the UE within the time slot PRB _min throughout the subframe, the resource allocation including at least one of centralized allocation throughout the time slots of the subframe and distributed allocation throughout the time slots of the subframe, the centralized allocation throughout the time slots of the subframe making each subcarrier in PRB _min adjacent to another subcarrier in PRB _min , the distributed allocation throughout the time slots of the subframe making each subcarrier in PRB _min adjacent to a subcarrier in another PRB _min in PRBs allocated to different UEs, and the resource allocation for the UE within the PRB throughout each time slot of the subframe is independent of each other.

In Example 7, the subject matter of one or any combination of Examples 1 to 6 may optionally include whether the resource allocation comprises centralized resource allocation or distributed resource allocation being predefined or configured via system information blocks or radio resource control signaling.

In Example 8, the subject matter of one or any combination of Examples 1 to 7 may optionally include indicating, in a DCI format for a downlink assignment or an uplink grant, whether the resource allocation comprises localized resource allocation or distributed resource allocation.

In Example 9, the subject matter of one or any combination of Examples 1 to 8 may optionally include: the DCI format includes a subcarrier block index and a total number of subcarrier blocks configured to specify resources within a PRB allocated to the UE.

In Example 10, the subject matter of one or any combination of Examples 1 to 9 may optionally include: the DCI format includes a subcarrier bitmap configured to specify resources within a PRB allocated to the UE, and each individual bit of the subcarrier bitmap corresponds to: a unique one of the subcarriers, or a unique subcarrier block, each subcarrier block including different subcarriers, or a subcarrier block index whose values correspond to different subcarrier blocks, each subcarrier block including different subcarriers.

In Example 11, the subject matter of one or any combination of Examples 1 to 10 may optionally include: the processing circuit is further configured to: configure the transceiver to receive a list of cell RNTIs (C-RNTIs) from the eNB in an order including multiple UEs of the UE, configure the transceiver to receive a first resource allocation with a granularity of 1PRB based on a common RNTI, where the common RNTI is one of the following: predefined or provided by a higher layer, for scrambling of a physical downlink control channel, and derive dedicated subcarrier blocks from the first resource allocation based on the order of the received C-RNTIs to obtain a resource allocation of less than 1PRB.

In Example 12, the subject matter of one or any combination of Examples 1 to 11 may optionally include: the processing circuit is further configured to: configure the transceiver to receive frequency hopping information in a scheduling grant from the eNB, the frequency hopping information including a subcarrier block index and a total number of subcarrier blocks.

In Example 13, the subject matter of one or any combination of Examples 1 to 12 may optionally include: the processing circuit is further configured to at least one of the following: receive a DM-RS sequence generated by puncturing subcarriers not allocated to the UE, and receive a DM-RS sequence generated using a base sequence with a length less than 12.

In Example 14, the subject matter of one or any combination of Examples 1 to 13 may optionally include: the processing circuit is further configured to: the PRB includes 6-7 orthogonal frequency division multiplexing (OFDM) symbols in time, the wider and narrower subcarriers are 15kHz and 7.5kHz respectively, the UE is a machine type communication (MTC) UE, and the machine type communication (MTC) UE is restricted to communicating with the eNB through a limited set of subcarriers of the bandwidth spectrum over which the eNB can communicate, and the MTC UE is configured to send reduced size messages through the limited set of subcarriers in uplink transmissions.

In Example 15, the subject matter of one or any combination of Examples 1 to 14 may optionally include an antenna configured to send and receive communications between the transceiver and the eNB.

In Example 16, an apparatus of an eNB includes processing circuitry configured to: configure a transceiver to send downlink control information (DCI) configured to provide resource allocations in PRBs of a subframe to a plurality of machine type communication user equipments (MTC UEs), the resource allocations for each of the MTC UEs including a reduced physical resource block (PRB _min ) of less than one PRB in the PRB for at least one of downlink and uplink communications, wherein the PRB includes 12 wider subcarriers or 24 narrower subcarriers in frequency, the PRB _min includes less than 12 wider subcarriers or less than 24 narrower subcarriers, and wherein the eNB is configured to communicate with the MTC UEs using a reduced size message over the subcarriers of the PRB _min .

In Example 17, the subject matter of Example 16 may optionally include: resource allocation for each UE within a PRB is one of the following: centralized allocation throughout the time slots of the subframe, so that each subcarrier in PRB _min is adjacent to another subcarrier in PRB _min , and distributed allocation throughout the time slots of the subframe, so that each subcarrier in PRB _min is adjacent to a subcarrier in another PRB _min in PRBs allocated to different UEs among multiple UEs, and the resource allocation includes centralized resource allocation or distributed resource allocation is one of the following: predefined or configured via system information block or radio resource control signaling, or indicated in DCI format.

In Example 18, the subject matter of one or any combination of Examples 16 to 17 may optionally include: the DCI format includes a subcarrier bitmap configured to specify resources within a PRB allocated to the UE, and one of the following situations exists: each individual bit of the subcarrier bitmap corresponds to: a unique subcarrier in the subcarrier, or a unique subcarrier block, each subcarrier block including different subcarriers, or a subcarrier block index whose values correspond to different subcarrier blocks, each subcarrier block including different subcarriers.

In Example 19, the subject matter of one or any combination of Examples 16 to 18 may optionally include: configuring the transceiver to send a list of cell RNTIs (C-RNTIs) to the UE in an order for the UE, and configuring the transceiver to send a first resource allocation with a granularity of 1PRB to the UE based on a common RNTI, the common RNTI being one of the following: predefined or provided by a higher layer, for scrambling of a physical downlink control channel, wherein dedicated subcarrier blocks can be derived by the UE from the first resource allocation based on the order of the received C-RNTIs to obtain a resource allocation of less than 1PRB.

In Example 20, the subject matter of one or any combination of Examples 16 to 19 may optionally include: the processing circuit is further configured to: configure the transceiver to send frequency hopping information in a scheduling grant to the UE, and one of the following: the frequency hopping information includes a subcarrier block index and a total number of subcarrier blocks, and wherein, whether the relative position of the resource allocation of each UE within a PRB between time slots of a subframe remains the same or differs between time slots is one of the following: predefined or configured via system information block or radio resource control signaling, or indicated in DCI format.

In Example 21, the subject matter of one or any combination of Examples 16 to 20 may optionally include a transceiver configured to transmit signals through a network and receive signals from a UE.

In Example 22, a non-transitory computer-readable storage medium is disclosed that stores instructions for execution by one or more processors of a user equipment (UE) to configure the UE to communicate with an enhanced NodeB (eNB), the one or more processors configuring the UE to: receive downlink control information (DCI) from the eNB, the DCI configured to provide a localized resource allocation or a distributed resource allocation, wherein the localized resource allocation or the distributed resource allocation includes a reduced physical resource block (PRB _min ) of less than 1 PRB for at least one of downlink (DL) communication and uplink (DL) communication in a PRB of a subframe, wherein the PRB includes 6-7 orthogonal frequency division multiplexing (OFDM) symbols in time and 12 15 kHz subcarriers or 24 7.5 kHz subcarriers in frequency, wherein the PRB _min includes less than 12 15 kHz subcarriers or less than 24 7.5 kHz subcarriers, and wherein whether the resource allocation includes a localized resource allocation or a distributed resource allocation is indicated in a DCI format.

In Example 23, the subject matter of Example 22 may optionally include: the DCI format includes a subcarrier block index configured to specify resources within a PRB allocated to the UE and a total number of subcarrier blocks, or the DCI format includes a bitmap for all subcarriers, wherein one of the following conditions exists: each individual bit of the bitmap corresponds to a unique subcarrier block, each subcarrier block includes different subcarriers, and the bitmap is configured to specify resources within the PRB allocated to the UE, or a subcarrier block index whose values correspond to different subcarrier blocks, each subcarrier block includes different subcarriers, and the bitmap is configured to specify resources within the PRB allocated to the UE.

Although the embodiments have been described with reference to specific example embodiments, it will be apparent that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of protection of the present disclosure. Accordingly, the description and drawings are to be considered illustrative and not restrictive. The drawings forming a part thereof show, by way of illustration and not limitation, specific embodiments in which the subject matter may be practiced. The illustrated embodiments are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be utilized and derived therefrom so that structural and logical substitutions and changes may be made without departing from the scope of protection of the present disclosure. Therefore, this detailed description should not be construed as limiting, and the scope of protection of the various embodiments is limited only by the appended claims and the full scope of equivalents to which such claims are entitled.

Such embodiments of the subject matter of the present invention may be referred to herein, individually and/or collectively, by the term "invention" merely for convenience and are not intended to actively limit the scope of protection of the present application to any single invention or inventive concept, if more than one is actually disclosed. Thus, although specific embodiments have been shown and described herein, it should be understood that any arrangement for achieving the same purpose may replace the specific embodiments shown. This disclosure is intended to cover any and all modifications or variations of the various embodiments. Combinations of the above embodiments, as well as other embodiments not specifically described herein, will be apparent to those skilled in the art upon reading the above description.

In this document, as is common in patent documents, the terms "a" or "an" are used to include one or more than one, independent of any other instance or usage of "at least one" or "one or more." In this document, unless otherwise indicated, the term "or" is used to refer to a non-exclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B." In this document, the terms "include" and "in which" are used as the plain English equivalents of the respective terms "comprise" and "wherein." In addition, in the following claims, the terms "include" and "comprising" are open-ended, that is, systems, UEs, articles, compositions, formulas, or processes that include elements in addition to those elements listed after such terms in the claim are still considered to fall within the scope of protection of the claim. In addition, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels and are not intended to impose numerical requirements on their objects.

An Abstract of the present disclosure is provided to comply with 37 C.F.R. §1.72(b), which requires that the abstract will allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it is not intended to interpret or limit the scope or meaning of the claims. Additionally, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This approach of disclosure should not be interpreted to reflect an intention that the claimed embodiments require more features than are expressly recited in each claim. On the contrary, as reflected in the claims that follow, the inventive subject matter lies in less than all the features of a single disclosed embodiment. Accordingly, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.

Claims (11)

1. A user equipment (UE), the user equipment comprising: A transceiver configured to send signals to and receive signals from an enhanced node B (eNB) in a network; and The processing circuit is configured as follows: The eNB receives downlink control information (DCI) configured to provide resource allocation in a physical resource block (PRB) of a subframe, the resource allocation including a reduced physical resource block (PRB _min ) of less than one PRB for at least one of downlink (DL) and uplink (UL) communication, wherein the PRB comprises 12 wider subcarriers or 24 narrower subcarriers in frequency, and wherein the PRB _min comprises fewer than 12 wider subcarriers or fewer than 24 narrower subcarriers; and Configure the transceiver to communicate with the eNB using the resource allocation. Wherein, the wider subcarrier and the narrower subcarrier are 15kHz and 7.5kHz, respectively. The resource allocation for the UE within the PRB includes a distributed allocation of time slots throughout the subframe, such that each subcarrier in the PRB _min is adjacent to a subcarrier in another PRB _min allocated to a different UE, and the resource allocation for the UE within the PRB for each time slot throughout the subframe is independent of each other. 2. The UE according to claim 1, wherein: The DCI format includes a subcarrier block index and the total number of subcarrier blocks configured to specify resources within the PRB allocated to the UE. 3. The UE according to claim 1, wherein: The DCI format includes a subcarrier bitmap, which is configured to specify resources within the PRB allocated to the UE, and includes one of the following conditions: Each individual bit of the subcarrier bitmap corresponds to: The only subcarrier among the subcarriers, or A unique subcarrier block, each subcarrier block comprising different subcarriers, or Subcarrier block index, whose value corresponds to a different subcarrier block, each subcarrier block including different subcarriers. 4. The UE according to claim 1, wherein the processing circuit is further configured as follows: The transceiver is configured to receive a list of cell RNTIs (C-RNTIs) from the eNB in the order of multiple UEs including the UE. The transceiver is configured to receive a first resource allocation with a granularity of 1 PRB based on a common RNTI, wherein the common RNTI is one of the following: predefined or provided by a higher layer, used for scrambling the physical downlink control channel, and Dedicated subcarrier blocks are derived from the first resource allocation based on the order of the received C-RNTIs to obtain a resource allocation of less than 1 PRB. 5. The UE according to claim 1, wherein the processing circuit is further configured as follows: The transceiver is configured to receive frequency hopping information from the eNB in the scheduling permission, the frequency hopping information including the subcarrier block index and the total number of subcarrier blocks. 6. The UE according to claim 1, wherein the processing circuit is further configured in at least one of the following ways: Receive a DM-RS sequence generated by puncturing subcarriers not assigned to the UE, and Receive DM-RS sequences generated using base sequences of length less than 12. 7. The UE according to claim 1, wherein: The PRB consists of 6-7 orthogonal frequency division multiplexing (OFDM) symbols in time. The UE is a Machine Type Communication (MTC) UE, which is restricted to communicating with the eNB via a limited set of subcarriers in the bandwidth spectrum that the eNB can communicate with. The MTC UE is configured to send reduced-size messages via the limited set of subcarriers during uplink transmission. 8. An eNode B (eNB) device, the device comprising: The processing circuit is configured as follows: The transceiver is configured to send downlink control information (DCI) to multiple machine type communication user equipments (MTC UEs). The DCI is configured to provide resource allocation in a physical resource block (PRB) of a subframe. The resource allocation for each MTC UE includes a reduced physical resource block (PRB _min ) of less than one PRB for at least one downlink and uplink communication within the PRB. The PRB comprises either 12 wider subcarriers or 24 narrower subcarriers in frequency, and the PRB _min comprises less than 12 wider subcarriers or less than 24 narrower subcarriers. The eNB is configured to communicate with the MTC UE using reduced-size messages via the subcarrier of the PRB _min . Wherein, the wider subcarrier and the narrower subcarrier are 15kHz and 7.5kHz, respectively. The resource allocation for each UE within the PRB is a distributed allocation across the time slots of the subframe, such that each subcarrier in the PRB _min is adjacent to a subcarrier in another PRB _min allocated to a different UE among the plurality of UEs, and the resource allocation for the UE within the PRB of each time slot is independent of each other. 9. The apparatus of claim 8, wherein the processing circuit is further configured as follows: Configure the transceiver to send a list of cell RNTIs (C-RNTIs) to the UE in order for the UE, and The transceiver is configured to send a first resource allocation with a granularity of 1 PRB to the UE based on a common RNTI, wherein the common RNTI is one of the following: predefined or provided by a higher layer, used for scrambling the physical downlink control channel. The dedicated subcarrier block can be derived by the UE from the first resource allocation based on the order of the received C-RNTI to obtain a resource allocation of less than 1 PRB. 10. A non-transitory computer-readable storage medium storing instructions that are executed by one or more processors of a user equipment (UE) to configure the UE: Sending signals to and receiving signals from augmentation node B (eNB) in the network; The eNB receives downlink control information (DCI) configured to provide resource allocation in a physical resource block (PRB) of a subframe, the resource allocation including a reduced physical resource block (PRB _min ) of less than one PRB for at least one of downlink (DL) and uplink (UL) communication, wherein the PRB comprises 12 wider subcarriers or 24 narrower subcarriers in frequency, and wherein the PRB _min comprises fewer than 12 wider subcarriers or fewer than 24 narrower subcarriers; and Use the resource allocation to communicate with the eNB. Wherein, the wider subcarrier and the narrower subcarrier are 15kHz and 7.5kHz, respectively. The resource allocation for the UE within the PRB includes a distributed allocation of time slots throughout the subframe, such that each subcarrier in the PRB _min is adjacent to a subcarrier in another PRB _min allocated to a different UE, and the resource allocation for the UE within the PRB for each time slot throughout the subframe is independent of each other. 11. A non-transitory computer-readable storage medium storing instructions that are executed by one or more processors of an enhanced NodeB (eNB) device to configure the eNB: Downlink control information (DCI) is sent to multiple machine type communication user equipments (MTC UEs). The DCI is configured to provide resource allocation in a physical resource block (PRB) of a subframe. The resource allocation for each MTC UE includes a reduced physical resource block (PRB _min ) of less than one PRB for at least one downlink and uplink communication within the PRB. The PRB comprises either 12 wider subcarriers or 24 narrower subcarriers in frequency, and the PRB _min comprises less than 12 wider subcarriers or less than 24 narrower subcarriers. The PRB _min subcarrier communicates with the MTC UE using reduced-size messages. Wherein, the wide subcarrier and the narrow subcarrier are 15kHz and 7.5kHz, respectively. The resource allocation for each UE within the PRB is a distributed allocation across the time slots of the subframe, such that each subcarrier in the PRB _min is adjacent to a subcarrier in another PRB _min allocated to a different UE among the plurality of UEs, and the resource allocation for the UE within the PRB of each time slot is independent of each other.