WO2021119677A2

WO2021119677A2 - Methods and apparatus for dynamic indication of rate matching

Info

Publication number: WO2021119677A2
Application number: PCT/US2021/026459
Authority: WO
Inventors: Diana MAAMARI; Brian Classon; Vipul Desai
Original assignee: FutureWei Technologies Inc
Current assignee: FutureWei Technologies Inc
Priority date: 2020-04-09
Filing date: 2021-04-08
Publication date: 2021-06-17
Anticipated expiration: 2022-10-09
Also published as: WO2021119677A3

Abstract

A method implemented by an access node includes transmitting, by the access node to a user equipment (UE), a rate matching indicator indicating a rate matching buffer mode to set a size of a rate matching buffer; encoding, by the access node, data thereby producing encoded data; rate matching, by the access node, the encoded data in accordance with the size of the rate matching buffer; and transmitting, by the access node to the UE, the rate matched data.

Description

Methods and Apparatus for Dynamic Indication of Rate

Matching

This application claims the benefit of U.S. Provisional Application No. 63/007,811, filed on April 9, 2020, entitled "Apparatus and Method for Dynamic Indication of Rate Matching," which application is hereby incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to methods and apparatus for digital communications, and, in particular embodiments, to methods and apparatus for dynamic indication of rate matching. BACKGROUND

The channel coding used for Fifth Generation (5G) New Radio (NR) compliant communication systems uses low density parity check (LDPC) codes for both downlink (DL) and uplink (UL) transmissions of shared channels, e.g., the physical downlink shared channel (PDSCH) and the physical uplink shared channel (PUSCH). Furthermore, LDPC codes are also used for the physical sidelink shared channel (PSSCH).

5G NR supports LDPC codes with a mother code rate of 1/3 for base graph 1 and 1/5 for base graph 2. For a rate k/n code, each k input bits generate n output bits. An implication of the code rate is the amount of storage needed at a receiving device. With hybrid automatic repeat request (HARQ) procedures, a commonly used practice is to store some or all of the representations of the received bits. An example representation is a log- likelihood ratio (LLR) which provides information about the most likely value of a bit and the reliability of the estimated bit, with the LLRs being the ratio of the probabilities of the two different hypotheses (i.e., the probability that the bit is either a 'o' or a T'). LLRs can be combined. For example, in a first transmission, the LLR of a particular received bit can be stored. In a retransmission, the LLR of the received bit can be added to the stored LLR.

An issue with storing LLRs (or equivalently, soft bits) is the size of the storage buffer at the receiving device has to grow as a function of factors, such as, the mother code rate, the number of simultaneous HARQ processes supported, the number of carriers supported, the maximum number of transport blocks (TBs) supported, and so on. A TB, e.g., packets, data, etc., is encoded and transmitted on the PDSCH, PUSCH, PSSCH, and so on. With a rate k/ n code, n words of storage may be necessary for each bit of the TB. This issue also arises when storing hard bits (i.e., 'o' or 'i'), but because soft bits require more than t bit per value, the storage buffer size issue is more severe with soft bits.

SUMMARY

According to a first aspect, a method implemented by an access node is provided. The method comprising: transmitting, by the access node to a user equipment (UE), a rate matching indicator indicating a rate matching buffer mode to set a size of a rate matching buffer; encoding, by the access node, data thereby producing encoded data; rate matching, by the access node, the encoded data in accordance with the size of the rate matching buffer thereby producing rate matched data; and transmitting, by the access node to the UE, the rate matched data.

In a first implementation form of the method according to the first aspect, the rate matching buffer mode comprising a full buffer rate matching (FBRM) mode a or limited buffer rate matching (LBRM) mode.

In a second implementation form of the method according to the first aspect or any preceding implementation form of the first aspect, the rate matching indicator comprising a field of a downlink control information (DCI) message.

In a third implementation form of the method according to the first aspect or any preceding implementation form of the first aspect, the rate matching indicator being transmitted in a DCI message.

In a fourth implementation form of the method according to the first aspect or any preceding implementation form of the first aspect, the rate matching indicator comprising an unused bit of a plurality of bits used to indicate hybrid automatic repeat request (HARQ) processes.

In a fifth implementation form of the method according to the first aspect or any preceding implementation form of the first aspect, further comprising configuring, by the access node, the rate matching buffer mode.

In a sixth implementation form of the method according to the first aspect or any preceding implementation form of the first aspect, further comprising configuring, by the access node, a number of HARQ processes. In a seventh implementation form of the method according to the first aspect or any preceding implementation form of the first aspect, the rate matching indicator updates a previous rate matching indicator.

According to a second aspect, a method implemented by a UE is provided. The method comprising: receiving, by the UE from an access node, a rate matching indicator indicating a rate matching buffer mode; setting, by the UE, a buffer size of a buffer in accordance with the rate matching indicator; placing, by the UE in the buffer in accordance with the buffer size, data received on a physical downlink shared channel (PDSCH); and decoding, by the UE, the data placed in the buffer.

In a first implementation form of the method according to the second aspect, the rate matching buffer mode comprising a FBRM mode or a LBRM mode.

In a second implementation form of the method according to the second aspect or any preceding implementation form of the second aspect, the rate matching indicator comprising a field of a DCI message.

In a third implementation form of the method according to the second aspect or any preceding implementation form of the second aspect, the rate matching indicator being transmitted in a DCI message.

In a fourth implementation form of the method according to the second aspect or any preceding implementation form of the second aspect, the rate matching indicator comprising an unused bit of a plurality of bits used to indicate HARQ processes.

In a fifth implementation form of the method according to the second aspect or any preceding implementation form of the second aspect, further comprising receiving, by the UE from the access node, the rate matching buffer mode.

In a sixth implementation form of the method according to the second aspect or any preceding implementation form of the second aspect, further comprising receiving, by the UE from the access node, a number of HARQ processes.

According to a third aspect, a method implemented by a UE is provided. The method comprising: determining, by the UE, a rate matching buffer mode in accordance with a base graph used by an access node; setting, by the UE, a buffer size of a buffer in accordance with the rate matching indicator; placing, by the UE in the buffer in accordance with the buffer size, data received on a PDSCH; and decoding, by the UE, the data placed in the buffer.

In a first implementation form of the method according to the third aspect, the base graph comprising a first base graph or a second base graph.

In a second implementation form of the method according to the third aspect or any preceding implementation form of the third aspect, the rate matching buffer mode comprising a FBRM mode when the base graph comprises the second base graph, and the rate matching buffer mode comprising a LBRM mode when the base graph comprises the first base graph.

According to a fourth aspect, an access node is provided. The access node comprising: one or more processors; and a non-transitory memory storage comprising instructions that, when executed by the one or more processors, cause the access node to: transmit, to a UE, a rate matching indicator indicating a rate matching buffer mode to set a size of a rate matching buffer; encode data to produce encoded data; rate matching the encoded data in accordance with the size of the rate matching buffer to produce rate matched data; and transmit, to the UE, the rate matched data.

In a first implementation form of the access node according to the fourth aspect, the rate matching buffer mode comprising a FBRM mode or a LBRM mode.

In a second implementation form of the access node according to the fourth aspect or any preceding implementation form of the fourth aspect, the rate matching indicator comprising a field of a DCI message.

In a third implementation form of the access node according to the fourth aspect or any preceding implementation form of the fourth aspect, the rate matching indicator being transmitted in a DCI message.

In a fourth implementation form of the access node according to the fourth aspect or any preceding implementation form of the fourth aspect, the rate matching indicator comprising an unused bit of a plurality of bits used to indicate HARQ processes.

In a fifth implementation form of the access node according to the fourth aspect or any preceding implementation form of the fourth aspect, the instructions causing the access node to configure the rate matching buffer mode. In a sixth implementation form of the access node according to the fourth aspect or any preceding implementation form of the fourth aspect, the instructions causing the access node to configure a number of HARQ processes.

According to a fifth aspect, a UE is provided. The UE comprising: one or more processors; and a non-transitory memory storage comprising instructions that, when executed by the one or more processors, cause the UE to: receive, from an access node, a rate matching indicator indicating a rate matching buffer mode; set a buffer size of a buffer in accordance with the rate matching indicator; place, in the buffer in accordance with the buffer size, data received on a PDSCH; and decode the data placed in the buffer.

In a first implementation form of the UE according to the fifth aspect, the rate matching buffer mode comprising a FBRM mode or a LBRM mode.

In a second implementation form of the UE according to the fifth aspect or any preceding implementation form of the fifth aspect, the rate matching indicator comprising a field of a DCI message.

In a third implementation form of the UE according to the fifth aspect or any preceding implementation form of the fifth aspect, the rate matching indicator being transmitted in a DCI message.

In a fourth implementation form of the UE according to the fifth aspect or any preceding implementation form of the fifth aspect, the rate matching indicator comprising an unused bit of a plurality of bits used to indicate HARQ processes.

In a fifth implementation form of the UE according to the fifth aspect or any preceding implementation form of the fifth aspect, further comprising receiving, by the UE from the access node, the rate matching buffer mode.

In a sixth implementation form of the UE according to the fifth aspect or any preceding implementation form of the fifth aspect, further comprising receiving, by the UE from the access node, a number of HARQ processes.

An advantage of a preferred embodiment is that the power consumption associated with monitoring reference signals is reduced, thereby reducing the overall power consumption of a communications device. Yet another advantage of a preferred embodiment is that the number of reference signal monitoring occasions is reduced, further reducing the overall power consumption of the communications device.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

Figure t illustrates a first example communications system;

Figure 2 illustrates a diagram of a prior art technique involving rate matching for a shared channel;

Figure 3A illustrates a prior art transmission buffer for a rate 1/3 code with FBRM;

Figure 3B illustrates a prior art transmission buffer for a rate 1/3 code with LBRM;

Figure 4A illustrates a flow diagram of example operations occurring in an access node making a downlink transmission with rate matching being selected based on the TB size according to example embodiments presented herein;

Figure 4B illustrates a flow diagram of example operations occurring in a UE receiving a downlink transmission with rate matching being selected based on the TB size according to example embodiments presented herein;

Figure 5A illustrates a flow diagram of example operations occurring in an access node making a downlink transmission with rate matching where a rate matching indicator is included in unused bits of a HARQ processes field according to example embodiments presented herein;

Figure 5B illustrates a flow diagram of example operations occurring in a UE receiving a downlink transmission with rate matching where a rate matching indicator is included in unused bits of a HARQ processes field according to example embodiments presented herein;

Figure 6A illustrates a flow diagram of example operations occurring in an access node making a downlink transmission with rate matching where a rate matching indicator is included in the DCI according to example embodiments presented herein; Figure 6B illustrates a flow diagram of example operations occurring in a UE receiving a downlink transmission with rate matching where a rate matching indicator is included in the DCI according to example embodiments presented herein;

Figure 7A illustrates a flow diagram of example operations occurring in an access node making a downlink transmission with rate matching being selected based on the base graph used according to example embodiments presented herein;

Figure 7B illustrates a flow diagram of example operations occurring in u UE receiving a downlink transmission with rate matching being selected based on the base graph used according to example embodiments presented herein;

Figure 8A illustrates a flow diagram of example operations occurring in an access node making a downlink transmission where rate matching using FBRM is a capability of the UE according to example embodiments presented herein;

Figure 8B illustrates a flow diagram of example operations occurring in a UE receiving a downlink transmission where rate matching using FBRM is a capability of the UE according to example embodiments presented herein;

Figure 9 illustrates a flow diagram of example operations occurring in a UE making an uplink transmission with rate matching in the uplink being selected based on a rate matching indicator included in a DCI according to example embodiments presented herein;

Figure to illustrates a flow diagram of example operations occurring in a UE making an uplink transmission with rate matching in the uplink being indicated in an existing field according to example embodiments presented herein;

Figure 11 illustrates a flow diagram of example operations occurring in a UE making an uplink transmission with rate matching in the uplink being indicated by the indication indicating rate matching in the downlink according to example embodiments presented herein;

Figure 12 illustrates a flow diagram of example operations occurring in a UE making an uplink transmission with rate matching in the uplink being set in accordance with a size of the TB being transmitted

Figure 13 illustrates a block diagram of an embodiment processing system for performing methods described herein; Figure 14 illustrates a block diagram of a transceiver adapted to transmit and receive signaling over a telecommunications network according to example embodiments presented herein;

Figure 15 illustrates an example communication system according to example embodiments presented herein;

Figures 16A and 16 B illustrate example devices that may implement the methods and teachings according to this disclosure

Figure 17 is a block diagram of a computing system that may be used for implementing the devices and methods disclosed herein.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The structure and use of disclosed embodiments are discussed in detail below. It should be appreciated, however, that the present disclosure provides many applicable concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific structure and use of embodiments, and do not limit the scope of the disclosure.

Figure 1 illustrates a first example communications system too. Communications system too includes an access node 110, with coverage area 101, serving user equipments (UEs), such as UEs 120. Access node 110 is connected to a backhaul network 115 that provides connectivity to services and the Internet. In a first operating mode, communications to and from a UE passes through access node 110. In a second operating mode, communications to and from a UE do not pass through access node 110, however, access node 110 typically allocates resources used by the UE to communicate when specific conditions are met. Communication between a UE pair in the second operating mode occurs over sidelinks 125, comprising uni-directional communication links. Communication between a UE and access node pair also occur over uni-directional communication links, where the communication links between the UE and the access node are referred to as uplinks 130, and the communication links between the access node and UE is referred to as downlinks 135.

Access nodes may also be commonly referred to as Node Bs, evolved Node Bs (eNBs), next generation (NG) Node Bs (gNBs), master eNBs (MeNBs), secondary eNBs (SeNBs), master gNBs (MgNBs), secondary gNBs (SgNBs), network controllers, control nodes, base stations, access points, transmission points (TPs), transmission-reception points (TRPs), cells, carriers, macro cells, femtocells, pico cells, and so on, while UEs may also be commonly referred to as mobile stations, mobiles, terminals, users, subscribers, stations, and the like. Access nodes may provide wireless access in accordance with one or more wireless communication protocols, e.g., the Third Generation Partnership Project (3GPP) long term evolution (LTE), LTE advanced (LTE-A), 5G, 5G LTE, 5G NR, sixth generation (6G), High Speed Packet Access (HSPA), the IEEE 802.11 family of standards, such as 802.na/b/g/n/ac/ad/ax/ay/be, etc. As used herein, the term “mobile device” refers to any component (or collection of components) capable of establishing a wireless connection with a base station, such as a user equipment (UE), a mobile station (STA), and other wirelessly enabled devices. In some embodiments, the network too may comprise various other wireless devices, such as relays, low power nodes, etc. While it is understood that communications systems may employ multiple access nodes capable of communicating with a number of UEs, only one access node and two UEs are illustrated for simplicity.

As discussed previously, a significant contributor to communication device (e.g., UE or access node) complexity is the hybrid automatic repeat request (HARQ) soft buffer size. The storage of soft bits to support the HARQ operation is a major factor to the total memory over all of the HARQ processes. This is referred to as the HARQ soft buffer size. One technique used to reduce the amount of buffer memory needed is to use rate matching. Rate matching may involve mapping the number of bits in a transport block (TB) to the number of bits that can be transmitted. Rate matching involves many parameters, including sub-block interleaving, bit collecting, and pruning. As an example, in a physical downlink shared channel (PDSCH) TB of a 3GPP LTE compliant communication system, rate matching is performed over code blocks and occurs after the code blocks have undergone turbo encoding.

Figure 2 illustrates a diagram 200 of a prior art technique involving rate matching for a shared channel. Data being transmitted is low density parity check (LDPC) encoded (block 205) to produce encoded bits, which are then rate matched (block 207). The rate matched bits are transmitted over the shared channel (block 209).

A commonly used rate matching technique is referred to as full buffer rate matching (FBRM). In FBRM, usage of a rate k/n code results in n bits being transmitted. A communicating device (e.g., UE, access node, etc.) can store the n soft bits. Figure 3A illustrates a prior art transmission buffer 300 for a rate 1/3 code with FBRM. Transmission buffer 300 can be a circular buffer, where the size of the circular buffer is related to the rate matching mode (e.g., FBRM or limited buffer rate matching (LBRM)). Transmission buffer 300 includes systematic bits 305 (original bits from which parity bits are determined), and parity bits 307 and 309. Bit selection is a function of the redundancy version. As an example, assume that the redundancy version indicates the bit selection starts at the beginning of transmission buffer 300. Systematic bits 305 may be transmitted first, followed by parity bits 307 and 309. Wraparound (wrap 311) occurs when parity bits 307 and 309 are transmitted, then bits starting from systematic bits 305 are selected for transmission.

Another commonly used rate matching technique is referred to as LBRM. In LBRM, a rate k/ n mother code is transmitted as a rate k'/ n' mode, where k'/ n' > k/ n. Figure 3B illustrates a prior art transmission buffer 350 for a rate 1/3 code with LBRM. In practice, transmission buffer 350 is filled in a manner similar to transmission buffer 300 (for FBRM), with systematic bits 305 and parity bits 307 and 309. However, during selection of bits for transmission when LBRM is being used, a subset of transmission buffer 350 is utilized. As an example, for rate 1/2 LBRM (rate 2/3 FBRM), bits from systematic bits 305 and parity bits 307 are used for transmission, and bits from parity bits 309 are not used for transmission, even in the case of retransmissions occurring in a HARQ process. In LBRM, wraparound (wrap 355) occurs after parity bits 307, with parity bits 309 not being transmitted.

When LBRM is used, it is possible to implement HARQ operation with reduced requirements for soft buffer size while maintaining the peak data rates. In LBRM, the length of a circular buffer used to store the code block segments is shortened for some transport blocks (TBs). Therefore, LBRM operation sets a lower bound on the code rate. The aim of LBRM may be to reduce the required HARQ soft buffer size while minimizing impact on system performance. With LBRM, the effective mother code rate for a TB is a function of the TBs and the allocated soft buffer size of the communicating device. Because the system knows the soft buffer size of the communicating device, the system places a limit on the code bits transmitted so that only the code bits that can be placed in the soft buffer of the communicating device are transmitted for all transmissions or retransmissions of a TB. Placing the code bits comprises storing the code bits in the soft buffer if the soft buffer is empty or combining the code bits with corresponding values in the soft buffer if the soft buffer is not empty.

The difference between LBRM and FBRM involves the occurrence of the wraparound (e.g., wrap 311 for FBRM vs. wrap 355 for LBRM). The smaller number of bits being transmitted in LBRM provides LBRM an advantage in a reduction in the memory requirement associated with buffering bits (e.g., soft bits) at a communicating device. As an example, if the TBs are 3000 bits in size and with a mother code rate of 1/3 and FBRM, then 9000 unique bits are available for transmission. Hence a communicating device would need to buffer up to 9000 bits. However, with rate 1/2 LBRM (rate 2/3 FBRM), only 6000 unique bits are available for transmission, reducing the buffer size requirement at the communicating device to 6000 bits. However, LBRM may lead to a performance loss. As an example, consider the case presented above where 9000 unique bits are transmitted with FBRM, the decoding performance is better than with 6000 unique bits being transmitted with LBRM because the entire code structure of the rate 1/3 code is used. However, with LBRM, although 3000 bits are repeated (and added in some manner at the communicating device), the effective rate at the communicating device is a 1/2 code. The absence of some parity bits may have a greater negative impact on decoding performance than the benefits associated with bit repetition. The performance loss may be observed at low signal-to- noise ratio (SNR) conditions or with small TBs.

In 5G NR, only LBRM is supported for downlink transmission. While for uplink transmissions, LBRM is optional (based on UE capability) and is applicable for frequency range 1 (FRt) and frequency range 2 (FR2). FBRM is the default operation for uplink transmissions. If the UE supports LBRM, the system can enable LBRM by utilizing radio resource control (RRC) configuration. Although enabling LBRM using RRC configuration is good, RRC configuration is not optimal because RRC configuration is not dynamic in nature. Furthermore, RRC configuration applies to every uplink transmission by the RRC configured UE, not supporting configuration based on TB size. The table presents a summary of LBRM and FBRM utilization in 5G NR.

Table: Summary of LBRM and FBRM utilization in 5G NR. As 5G NR evolves to support a greater number of applications and services, the current utilization of LBRM may limit performance. As an example, FBRM may be more favorable where increased reliability is desired. Examples of evolved usage may include reduced capability UEs, coverage enhancement, ultra-reliable low latency communications (URLLC), extended range (XR). Advantages of FBRM support include:

- If the number of HARQ processes used is less than the number of HARQ processes supported, the extra memory available may be used to support FBRM.

- Downlink receptions may utilize FBRM instead of LBRM. Current 5G NR supports only LBRM.

- For small packet (small TBs) transmission, FBRM may be better than LBRM, especially if buffers are allocated for large TBs.

- For reliable transmission, FBRM may be better than LBRM due to the improved decoding performance, which may lead to fewer retransmissions.

However, under good environmental conditions, LBRM may be better than FBRM due to reduced storage requirements. Therefore, there is a need for methods and apparatus that support LBRM and FBRM operation, as well as dynamic indication of rate matching technique being utilized.

According to an example embodiment, methods and apparatus supporting LBRM and FBRM operation with dynamic indication thereof are provided. Supporting both LBRM and FBRM operation enables the matching of the rate matching technique to the application supported. As an example, FBRM may be used when URLLC is needed or small TB transmissions are used. As another example, LBRM may be used for large TB transmissions or high reliability is not needed. The inclusion of dynamic indication enables the switching of the rate matching for different transmission classes, types, priorities, sizes, etc.

In an embodiment, in the situation when a UE supports reception in the downlink for both LBRM and FBRM, a transmission size threshold is used to determine which rate matching technique to use. As an example, if a TB is smaller than the transmission size threshold, then FBRM is used. The transmission size threshold may be specified in a technical standard or specified by an operator of the communication system. Alternatively, the UE and the access node may collaborate to determine the transmission size threshold. As an example, the UE may calculate the size of the TB based on the number of RBs, and code rate for both rate matching cases (LBRM and FBRM). Example values of the transmission size threshold include 500 bits, 1000 bits, 1500 bits, and so on. Other values are possible. The UE may use hypothesis testing to support determining the rate matching technique used for a particular TB. As an example, the UE may attempt to decode a received TB with a hypothesis that LBRM is used for rate matching, as well decode the received TB with a hypothesis that FBRM is used for rate matching. One of the two hypotheses will result in successful decoding of the TB, and the UE can use the correct hypothesis for subsequent receptions of TBs of the same transmission type, priority, etc.

Figure 4A illustrates a flow diagram of example operations 400 occurring in an access node making a downlink transmission with rate matching being selected based on the TB size.

Operations 400 begin with the access node determining the size of the TB (block 405). As discussed previously, the size of the TB may be based on the number of RBs in the TB, as well as the code rate. The access node performs rate matching on the data (block 407). The access node performs rate matching (either FBRM or LBRM) on the data. The access node transmits the rate matched data (block 409).

Figure 4B illustrates a flow diagram of example operations 450 occurring in a UE receiving a downlink transmission with rate matching being selected based on the TB size.

Operations 450 begin with the UE determining the size of the TB (block 455). As an example, the UE may determine the TB size based on the number of RBs, and a code rate for both rate matching cases. The TB performs a check to determine if the size of the TB meets the transmission size threshold (block 457). If the size of the TB is less than the transmission size threshold, the UE decodes the TB using FBRM (block 459). If the size of the TB is greater than or equal to the transmission size threshold, the UE decodes the TB using LBRM (block 461). In general, the rate matching mode (either FBRM or LBRM) alters which of the received data used to decode the received transmission. As an example, the UE sets the size of the buffer to a first size if FBRM is used, while if LBRM is used, the size of the buffer is set to a second size. Furthermore, the UE also places the received data into the buffer. As used herein, placing the received data into the buffer comprises storing the received data in the buffer if the buffer is empty, and combining the received data with data already present in the particular portions of the buffer where the received data is to be inserted if the buffer is not empty.

Alternatives to the meaning of meeting the transmission size threshold are possible. As an example, FBRM may be used if the size of the TB is less than or equal to the transmission size threshold, while LBRM may be used if the size of the TB is greater than the transmission size. The transmission size threshold may be specified by a technical standard or by an operator of the communication system. Alternatively, the UE and the access node collaborate to determine the transmission size threshold.

In an alternative, the UE uses hypothesis testing to determine if FBRM or LBRM is being used. As discussed previously, the UE attempts to decode the received bits with a hypothesis that FBRM is being used. If the decoding is successful, the UE knows that FBRM is being used and will assume FBRM for similar transmissions in the future. If the decoding is unsuccessful, the UE attempts to decode the received bits with a hypothesis that LBRM is being used. If the decoding is successful, the UE knows that LBRM is being used and will assume LBRM for similar transmissions in the future. If both hypotheses are unsuccessful, the UE may attempt a different hypothesis or request a retransmission from the access node.

In general, when the configured number of HARQ process is smaller than the maximum number of HARQ processes, more memory is available than needed, hence it is possible to increase the average memory per process. In such a situation, FBRM may be used to take advantage of the excess memory.

In situations where the UE implements soft buffer management based on the maximum number of HARQ processes, then when a smaller number of HARQ processes is configured, the average memory per HARQ process can be increased. In such situations, FBRM may be utilized to reuse the additional memory. As an example, consider a situation where there is a maximum of 16 HARQ processes (corresponding to a 4-bit HARQ processes downlink control information (DCI) field), but with only 8 configured HARQ processes (corresponding to 3 bits of the HARQ processes DCI field). If the maximum TB size is 3000 bits, then with LBRM and the 16 maximum HARQ processes, the number of soft bits needing storage =

TB_size * #_HARQ processes / LBRM code rate =

3000 * 2 * 16 = 96000.

Then, with 8 configured HARQ processes, the number of soft bits needing storage =

TB_size * #_HARQ processes / LBRM code rate =

3000 * 3 * 8 = 72000.

Therefore, the memory storage allocated for 16 HARQ processes with LBRM is sufficient for 8 HARQ processes with FBRM.

In an embodiment, in the situation when a UE supports reception in the downlink for both LBRM and FBRM, a rate matching indicator is used to specify the rate matching technique used. The rate matching indicator indicates the use of either LBRM or FBRM techniques.

In an embodiment, the rate matching indicator is conveyed in an existing field. The usage of FBRM may be indicated in an existing field, such as the HARQ processes field. Although the discussion focuses on the HARQ processes field, other existing fields may be used. The HARQ processes field may have a configurable size, with possible sizes being o, l, 2, 3, or 4 bits. The size of the HARQ processes field may be determined by a higher layer parameter (e.g., using RRC configuration). When the number of HARQ processes is less than the maximum number (e.g., 16 HARQ processes), one or more bits may be used to indicate whether LBRM or FBRM is used. As an example, with a maximum of 16 HARQ processes, 4 bits are used to indicate the HARQ processes and LBRM is used. However, if 8 HARQ processes are configured, only 3 bits are used to indicate the HARQ processes and 1 bit may be used to indicate whether FBRM or LBRM is used. An example is as follows:

Enable FBRM: o or 1 bits used as rate matching indicator, as configured by the higher layer parameter.

The higher layer parameter determines whether the existing field is used for the rate matching indicator (LBRM or FBRM). The number of bits that remain in the HARQ processes field that are not used to indicate HARQ processes may be signaled in the HARQ processes field and may be used to signal the rate matching indicator. As an example, if 2 bits of the HARQ processes field are used for 4 HARQ processes, the remaining 2 bits may be used as the rate matching indicator. In an embodiment, the first remaining bit is used to indicate either FBRM or LBRM (depending on value) for the first two HARQ processes, while the second remaining bit is used to indicate either FBRM or LBRM (depending on value) for the second two HARQ processes.

In an embodiment, a higher layer parameter determines whether the new DCI field is used or not. The DCI field may have a configurable size. In an embodiment, the DCI field size is equal to the size of the HARQ processes field. In an embodiment, the DCI field size is smaller than the size of the HARQ processes field because some HARQ processes may be indicated using common bits.

Figure 5A illustrates a flow diagram of example operations 500 occurring in an access node making a downlink transmission with rate matching where a rate matching indicator is included in unused bits of a HARQ processes field. Operations 500 begin with the access node configuring a number of HARQ processes for the UE (block 505). The number of configured HARQ processes is less than or equal to the maximum number of HARQ processes. The number of configured HARQ processes is typically a power of 2 number, such as 2, 4, 8, 16, etc. In The Third Generation Partnership Project (3GPP) Release 16 technical standards, the number of configured HARQ processes is configured as a higher layer parameter. As an example, in the situation where the number of configured HARQ processes is significantly smaller than the maximum number of HARQ processes to enable FBRM operation without requiring the UE to have an excessively large amount of memory allocated to buffer soft bits.

The access node configures FBRM option (block 507). In general, if the UE has FBRM capability, the access node may configure FBRM operation so that the UE can expect to receive data using FBRM. Configuring the FBRM option enables FBRM operation and informs the UE that some transmissions may be rate matched using FBRM.

The access node transmits a rate matching indicator in the HARQ processes field (block 509). As an example, the access node transmits the rate matching indicator to indicate that FBRM is being used. As another example, the access node transmits the rate matching indicator to indicate that LBRM is being used. The rate matching indicator may be transmitted in unused bits of the HARQ processes field, for example. In addition to the rate matching indicator, the access node may transmit redundancy version (RV), modulation and coding scheme (MCS), number of RBs, HARQ process ID, new data indicator (NDI), and so on. The access node performs rate matching on data bits (block 511). The data bits may be rate matched using FBRM or LBRM, depending on the rate matching process selected. The access node transmits the encoded data bits (block 513).

Figure 5B illustrates a flow diagram of example operations 550 occurring in a UE receiving a downlink transmission with rate matching where a rate matching indicator is included in unused bits of a HARQ processes field.

Operations 550 begin with the UE receiving a configuration of a number of HARQ processes for the UE (block 555). The number of configured HARQ processes is less than or equal to the maximum number of HARQ processes. As an example, the number of configured HARQ processes is significantly smaller than the maximum number of HARQ processes to enable FBRM operation without requiring the UE to have an excessively large amount of memory allocated to buffer soft bits. The UE receives a configuration of FBRM option (block 557). The configuration of the FBRM option enables FBRM operation and informs the UE that some transmissions may be rate matched using FBRM. The UE receives a rate matching indicator in the HARQ processes field (block 559). As an example, the UE receives the rate matching indicator to indicate that FBRM is being used. As another example, the UE receives the rate matching indicator to indicate that LBRM is being used. The rate matching indicator may be received in unused bits of the HARQ processes field, for example.

As discussed previously, the rate matching indicator indicates the rate matching mode used, e.g., FBRM or LBRM. The rate matching mode used by the access node in the transmission may be used to set the size of the buffer of the UE. As an example, the UE sets the size of the buffer to a first size if FBRM is used, while if LBRM is used, the size of the buffer is set to a second size.

The UE performs a check to determine if FBRM is used (block 561). The UE may process the rate matching indicator to determine if FBRM is used. As an example, if the rate matching indicator is "o", then FBRM is used, while if it is "1", then LBRM is used. Alternatively, if the rate matching indicator is "1", then FBRM is used, while if it is "o", then LBRM is used. If FBRM is used, the UE decodes received data bits (which are placed in the buffer) using FBRM (block 563). The decoding of the received data bits using FBRM may include combining received soft information with previously placed soft information associated with the HARQ process. If the decoding is successful, the TB may be provided to higher layers of the UE for additional processing. If LBRM is used, the UE decodes the received data bits (which are placed in the buffer) using LBRM (block 565).

In an embodiment, the rate matching indicator is conveyed in the DCI, which is carried in the physical downlink control channel (PDCCH). The signaling of the rate matching indicator in the DCI is a dynamic signaling approach. As an example, an indicator is added to each HARQ process. The indicator may be a single bit indicator, although a multi-bit indicator may be used. As an example, a "o" may indicate the use of LBRM for transmissions associated with the HARQ process, while a "1" may indicate the use of FBRM for transmissions associated with the HARQ process. Alternatively, a "1" may indicate the use of LBRM for transmissions associated with the HARQ process, while a "o" may indicate the use of FBRM for transmissions associated with the HARQ process.

In a communication system supporting multiple input multiple output (MIMO) operation, there are 2 HARQ processes in the DCI. An example DCI field is as follows (when the field is present, it can be either "o" or "1"):

Enable FBRM: o or 1 bit determined by higher layer parameter.

The embodiments include DCI for different 5G NR releases. In an embodiment, the DCI may override or set the FBRM configuration. As an example, a DCI intended for URLLC operation may always use FBRM.

A higher layer parameter may determine whether the new field is used or not. The field may have a configurable size. In an embodiment, the field size may be equal to the size of the HARQ processes field. In another embodiment, the field size may be smaller than the size of the HARQ processes field because some HARQ processes may be indicated using common bits.

Figure 6A illustrates a flow diagram of example operations 6oo occurring in an access node making a downlink transmission with rate matching where a rate matching indicator is included in the DCI.

Operations 6oo begin with the access node configuring a number of HARQ processes for the UE (block 605). The number of configured HARQ processes is less than or equal to the maximum number of HARQ processes. As an example, the number of configured HARQ processes is significantly smaller than the maximum number of HARQ processes to enable FBRM operation without requiring the UE to have an excessively large amount of memory allocated to buffer soft bits. The access node configures FBRM option (block 607). Configuring the FBRM option enables FBRM operation and informs the UE that some transmissions may be rate matched using FBRM.

The access node transmits a rate matching indicator in the DCI (block 609). As an example, the access node transmits the rate matching indicator to indicate that FBRM is being used. As another example, the access node transmits the rate matching indicator to indicate that LBRM is being used. The rate matching indicator may be transmitted in the DCI, for example. The access node performs rate matching on data bits (block 611). The data bits may be rate matched using FBRM or LBRM, depending on the rate matching process selected. The access node transmits the encoded data bits (block 613).

Figure 6B illustrates a flow diagram of example operations 650 occurring in a UE receiving a downlink transmission with rate matching where a rate matching indicator is included in the DCI.

Operations 650 begin with the UE receiving a configuration of a number of HARQ processes for the UE (block 655). The number of configured HARQ processes is less than or equal to the maximum number of HARQ processes. As an example, the number of configured HARQ processes is significantly smaller than the maximum number of HARQ processes to enable FBRM operation without requiring the UE to have an excessively large amount of memory allocated to buffer soft bits. The UE receives a configuration of FBRM option (block 657). The configuration of the FBRM option enables FBRM operation and informs the UE that some transmissions may be rate matched using FBRM.

The UE receives a rate matching indicator in the DCI (block 659). As an example, the UE receives the rate matching indicator to indicate that FBRM is being used. As another example, the UE receives the rate matching indicator to indicate that LBRM is being used. The rate matching indicator may be received in unused bits of a field of the DCI, for example.

The UE performs a check to determine if FBRM is used (block 661). The UE may process the rate matching indicator to determine if FBRM is used. As an example, if the rate matching indicator is "o", then FBRM is used, while if it is "1", then LBRM is used. Alternatively, if the rate matching indicator is "1", then FBRM is used, while if it is "o", then LBRM is used. If FBRM is used, the UE decodes received data bits using FBRM (block 663). If LBRM is used, the UE decodes the received data bits using LBRM (block 665). Decoding the received data includes receiving the data and placing the received data bits into the buffer.

In an embodiment, in the situation when a UE supports reception in the downlink for both LBRM and FBRM, the base graph is used to determine which rate matching technique to use. As an example, if base graph 2 (BG2) is used as the base graph of the LDPC used to encode the data bits, then FBRM is used, while base graph 1 (BGt) uses LBRM. Alternatively, if BG2 is used as the base graph of the LDPC used to encode the data bits, then LBRM is used, while BGt uses FBRM. The mapping of base graph to rate matching technique may be specified in a technical standard or specified by an operator of the communication system.

Figure 7A illustrates a flow diagram of example operations 700 occurring in an access node making a downlink transmission with rate matching being selected based on the base graph used. Operations 700 begin with the access node determining the base graph of the LDPC (block 705). The base graph of the LDPC is used to encode the data bits, where the base graph is typically selected based on the size of the TBs. The access node performs rate matching (either FBRM or LBRM) on the encoded data bits (block 707). The rate matching performed on the encoded data bits is in accordance with the base graph used in the LDPC. As an example, if BG2 is used, FBRM is used for rate matching, while if BGt is used, LBRM is used for rate matching. As another example, if BG2 is used, LBRM is used for rate matching, while if BGt is used, FBRM is used for rate matching. The access node transmits the rate matched data (block 709).

Figure 7B illustrates a flow diagram of example operations 750 occurring in u UE receiving a downlink transmission with rate matching being selected based on the base graph used.

Operations 750 begin with the UE determining the base graph of the LDPC (block 755). The base graph is the base graph of the LDPC used by the access node to encode the data bits. The UE performs a check to determine if the base graph is BG2 (block 757). If the base graph is BG2, the UE decodes the received data using FBRM (block 759). If the base graph is BGt, the UE decodes the received data using LBRM (block 761). In general, the rate matching mode (either FBRM or LBRM) alters which of the received data is used to decode the received transmission. As an example, the UE sets the size of the buffer to a first size if FBRM is used, while if LBRM is used, the size of the buffer is set to a second size. Furthermore, the UE also places the received data into the buffer, where, if the buffer is empty the received data is stored in the buffer, and where, if the buffer is not empty, the received data is combined with data already present in the particular portions of the buffer where the received data is to be inserted. Additionally, if the base graph is BGt, the UE decodes the received data using FBRM, and if the base graph is BG2, the UE decodes the received data using LBRM.

In an embodiment, in the situation when a UE supports reception in the downlink for both LBRM and FBRM, a capability for the downlink is added. With the added capability is enabled by RRC signaling, the UE receives downlink transmissions assuming FBRM, for example. The enabling of the added capability by RRC signaling and the dynamic signaling indicating FBRM for a particular transmission may be combined. As an example, a change to accommodate reception using FBRM may be achieved by setting an internal flag LLBR to o. Hence if the RRC signaling or dynamic signaling indicate to use FBRM, then the internal flag 7LBR =O to indicate FBRM, while if the RRC signaling or dynamic signaling indicate to use LBRM, then the internal flag 7LBRM=I to indicate LBRM.

Figure 8A illustrates a flow diagram of example operations 8oo occurring in an access node making a downlink transmission where rate matching using FBRM is a capability of the UE.

Operations 8oo begin with the access node enabling the UE capability supporting FBRM (block 805). The access node may enable the UE capability supporting FBRM using RRC signaling, for example. The access node performs rate matching using FBRM (block 807). The data bits, after encoding, are rate matched by the access node using FBRM.

The access node transmits the rate matched data (block 809).

Figure 8B illustrates a flow diagram of example operations 850 occurring in a UE receiving a downlink transmission where rate matching using FBRM is a capability of the UE.

Operations 850 begin with the UE performing a check to determine if the UE capability supporting FBRM has been enabled (block 855). The enabling of the UE capability supporting FBRM may be accomplished by the access node using RRC signaling. If the UE capability supporting FBRM has been enabled, the UE sets the buffer size in accordance with FBRM and receives the downlink transmission and places data from the downlink transmission into the buffer (block 857) and decodes the received transmission using FBRM (block 859). If the UE capability supporting FBRM has not been enabled, the UE sets the buffer size in accordance with LBRM and receives the downlink transmission and places data from the downlink transmission into the buffer (block 861) and decodes the received transmission using LBRM (block 863).

In an embodiment, in the situation when a UE supports reception in the downlink for both LBRM and FBRM, the use of FBRM (or LBRM) is dependent upon a configuration of a reliability or coverage enhancement parameter. An example of a reliability or coverage enhancement parameter is a MCS table configured with high reliability entries. The presence and use of such a parameter is used to enable (or disable) the use of FBRM.

In an embodiment, in the situation when a UE supports reception in the downlink for both LBRM and FBRM, the use of FBRM (or LBRM) is dependent on the number of retransmissions. The number of retransmissions may be related to coverage enhancement or reliability. As an example, if a low number of retransmissions are permitted, FBRM may be used to increase reliability while reducing the likelihood of retransmissions. Conversely, if a large number of retransmissions are permitted, LBRM may be used to reduce buffering requirements without negatively impacting reliability.

In general, the access node is responsible for managing its own buffer for storing soft bits, the access node may want control regarding the use of FBRM or LBRM in uplink transmissions. As in the situation with downlink transmissions, it may be advantageous to have the UE transmit in the uplink using FBRM for a smaller number of HARQ processes (which would free up extra memory that would be used to store soft bits to support FBRM). Alternatively, it may be favorable to have the UE transmit in the uplink using LBRM when the number of HARQ processes is about equal to the maximum number of HARQ processes, due to the shortage of memory to buffer soft bits.

A variety of cases may be considered depending on the capability of the UE:

Case l: Having a UE that is capable of supporting LBRM by enabling higher layer parameter rate matching.

- In cases where FBRM is expected to provide better performance (e.g., cases with a smaller number of configured HARQ processes), the higher layer configuration set to LBRM may be suboptimal for performance considerations. As a contrast, using FBRM may result in superior performance.

- In cases where LBRM is expected to provide better performance (e.g., cases with the number of configured HARQ processes being about equal to the maximum number of HARQ processes), the higher layer configuration set to FBRM is suboptimal for storage reasons. Alternatively, it may be possible to use RRC configuration to configure the choice of LBRM, although such a solution remains suboptimal.

Case 2: Having a UE that is capable of supporting LBRM while having the network configure the HARQ processes field in the DCI so that the maximum number of bits is used, but fewer HARQ processes (than the maximum number of HARQ processes) are used.

- In such situations where FBRM is expected to provide better performance, if the access node sends retransmissions using bits that correspond to the redundancy version that the UE does not store, the UE is unable to utilize those bits for effective decoding.

Case 3: Having a UE that is incapable of supporting LBRM. In such a situation, FBRM is always supported.

In an embodiment, in the situation when a UE supports transmission in the uplink for both LBRM and FBRM, a rate matching indicator is used to signal the use of LBRM or FBRM. In this situation, the rate matching indicator overrides the RRC configuration. It may be possible to dynamically signal the usage of FBRM or LBRM in the DCI, which is carried in the PDCCH. As an example, the rate matching indicator comprises a t bit value, and there is one rate matching indicator for each HARQ processes. As an example, the rate matching indicator associated with a HARQ process being equal to "o" indicates LBRM for the process, while the rate matching indicator being equal to "l" indicates FBRM for the process. Alternatively, the rate matching indicator associated with a HARQ process being equal to "l" indicates LBRM for the process, while the rate matching indicator being equal to "o" indicates FBRM for the process. The use of rate matching indicators may result in increased DCI size, especially for the situation where MIMO is supported, which results in two HARQ processes fields in the DCI.

In an embodiment, a higher layer parameter indicates whether the new field (containing the rate matching indicators) is used or not. The new field may be configurable in size. In an embodiment, the size of the new field is equal to the size of the HARQ processes field, e.g., one rate matching indicator per HARQ process. In another embodiment, the size of the new field is smaller than the size of the HARQ processes field because some HARQ processes may be indicated using common bits.

Figure 9 illustrates a flow diagram of example operations 900 occurring in a UE making an uplink transmission with rate matching in the uplink being selected based on a rate matching indicator included in a DCI.

Operations 900 begin with the UE performing a check to determine if the DCI overrides a RRC configuration (block 905). As an example, the UE checks to determine if it has received a DCI with rate matching indicators that overrides the RRC configuration for the rate matching of uplink transmissions. If the UE has received a DCI that overrides the RRC configuration, the UE performs the rate matching in accordance with the rate matching indicators (block 907) and transmits the rate matched data (block 909). If the UE has not received a DCI that overrides the RRC configuration, the UE performs the rate matching in accordance with the RRC configuration (block 911) and transmits the rate matched data (block 913). Performing rate matching includes setting the size of the buffer used to store the data and placing the data in the buffer, where the size of the buffer is set in accordance with the rate matching mode.

In an embodiment, in the situation when a UE supports transmission in the uplink for both LBRM and FBRM, an existing field of the DCI is used to indicate the use of FBRM or LBRM. The usage of FBRM or LBRM may be indicated in an existing field, such as the HARQ processes field of the DCI. As discussed previously, the HARQ processes field may have a configurable size, with possible sizes being o, 1, 2, 3, or 4 bits. The size of the HARQ processes field may be determined by a higher layer parameter (e.g., using RRC configuration). When the number of HARQ processes is less than the maximum number (e.g., i6 HARQ processes), one or more bits may be used to indicate whether LBRM or FBRM is used in the uplink.

A separate configuration may be used to indicate if the new field is used for LBRM or FBRM or the existing field is used for LBRM or FBRM indication is used for uplink or downlink indication. In an embodiment, the configuration may simultaneously signal the indication for both the downlink and the uplink. In an embodiment, a RRC configuration specific to the configured HARQ processes are provided.

Figure to illustrates a flow diagram of example operations tooo occurring in a UE making an uplink transmission with rate matching in the uplink being indicated in an existing field.

Operations tooo begin with the UE performing a check to determine if the rate matching indicator indicates FBRM operation (block 1005). The rate matching indicator may be received in an existing field of the DCI, such as the HARQ processes field of the DCI, for example. If the rate matching indicator indicates FBRM operation, the UE performs the rate matching in accordance with the FBRM (block 1007) and transmits the rate matched data (block 1009). If the rate matching indicator indicates LBRM operation, the UE performs the rate matching in accordance with the LBRM (block ton) and transmits the rate matched data (block 1013). Performing rate matching includes setting the size of the buffer used to store the data and placing the data in the buffer, where the size of the buffer is set in accordance with the rate matching mode.

In an embodiment, in the situation when a UE supports transmission in the uplink for both LBRM and FBRM, the rate matching technique (either LBRM or FBRM) used for the downlink is also used for the uplink. As an example, a rate matching indicator for the downlink (as described previously) is also used to set the rate matching configuration for the uplink. In another embodiment, the technique discussed previously enabling the overriding of the RRC configuration of the rate matching in the downlink is also used to override the RRC configuration of the rate matching in the uplink. In yet another embodiment, configuration signaling to change the number of bits of the HARQ processes field simultaneously changes the uplink and downlink FBRM or LBRM choice, depending on the type of traffic, for example. A single message may be used to signal such a configuration. Figure n illustrates a flow diagram of example operations ltoo occurring in a UE making an uplink transmission with rate matching in the uplink being indicated by the indication indicating rate matching in the downlink.

Operations ltoo begin with the UE receiving specification of the rate matching technique for the downlink (block 1105). The specification of the rate matching technique for the downlink may be received in a RRC message, a DCI, and so on. The UE performs rate matching for an uplink transmission in accordance with the specification of the rate matching technique for the downlink (block 1107). In other words, the UE uses the same rate matching technique for the uplink transmission as for received downlink transmissions. Performing rate matching includes setting the size of the buffer used to store the data and placing the data in the buffer, where the size of the buffer is set in accordance with the rate matching mode. The UE transmits the rate matched data (block 1109).

In an embodiment, in the situation when a UE supports transmission in the uplink for both LBRM and FBRM, the rate matching technique is selected in accordance with the size of the TB of the uplink transmission. The rate matching technique may be selected solely in accordance with the size of the TB, independent with the HARQ channels. The rate matching technique may be selected by comparing the TB size with a transmission size threshold, where the transmission size threshold may be configured through higher layer configuration. Alternatively, the transmission size threshold is specified by a technical standard or operator of the communication system. In an embodiment, additional RRC parameters may be permitted, one per bandwidth part (BWP) or at least one BWP has a different RRC configuration parameter. In the case where the rate matching technique in the uplink and the downlink are set in accordance with the size of the TBs, the transmission size threshold may be the same for both the uplink and the downlink, or the transmission size threshold may be different in the uplink and the downlink.

In should be clear that the example embodiments presented herein are operable with sidelink transmissions, as well as downlink and uplink transmissions. In general, the example embodiments presented herein are operable in situations where transmissions are encoded with LDPC codes.

Figure 12 illustrates a flow diagram of example operations 1200 occurring in a UE making an uplink transmission with rate matching in the uplink being set in accordance with a size of the TB being transmitted. Operations 1200 begin with the UE determining the size of the TB (block 1205). As discussed previously, the size of the TB may be based on the number of RBs in the TB, as well as the code rate. The UE performs a comparison of the size of the TB with the transmission size threshold (block 1207). As shown in Figure 12, if the size of the TB is less than the transmission size threshold, FBRM is used for uplink transmissions. However, it is possible to use LBRM if the size of the TB is less than the transmission size threshold. Additionally, the comparison condition may differ. As an example, if the size of the TB is less than or equal to the transmission size threshold, FBRM is used for uplink transmissions.

If the size of the TB is less than the transmission size threshold, the UE performs the rate matching in accordance with the FBRM (block 1209) and transmits the rate matched data (block 1211). If the size of the TB is not less than the transmission size threshold, the UE performs the rate matching in accordance with the LBRM (block 1213) and transmits the rate matched data (block 1215). Performing rate matching includes setting the size of the buffer used to store the data and placing the data in the buffer, where the size of the buffer is set in accordance with the rate matching mode.

Figure 13 illustrates a block diagram of an embodiment processing system 1300 for performing methods described herein, which may be installed in a host device. As shown, the processing system 1300 includes a processor 1304, a memory 1306, and interfaces 1310-1314, which may (or may not) be arranged as shown in Figure 13. The processor 1304 may be any component or collection of components adapted to perform computations and/or other processing related tasks, and the memory 1306 may be any component or collection of components adapted to store programming and/or instructions for execution by the processor 1304. In an embodiment, the memory 1306 includes a non-transitory computer readable medium. The interfaces 1310, 1312, 1314 may be any component or collection of components that allow the processing system 1300 to communicate with other devices/components and/or a user. For example, one or more of the interfaces 1310, 1312, 1314 may be adapted to communicate data, control, or management messages from the processor 1304 to applications installed on the host device and/or a remote device. As another example, one or more of the interfaces 1310, 1312, 1314 may be adapted to allow a user or user device (e.g., personal computer (PC), etc.) to interact/communicate with the processing system 1300. The processing system 1300 may include additional components not depicted in Figure 13, such as long term storage (e.g., non-volatile memory, etc.). In some embodiments, the processing system 1300 is included in a network device that is accessing, or part otherwise of, a telecommunications network. In one example, the processing system 1300 is in a network-side device in a wireless or wireline telecommunications network, such as a base station, a relay station, a scheduler, a controller, a gateway, a router, an applications server, or any other device in the telecommunications network. In other embodiments, the processing system 1300 is in a user-side device accessing a wireless or wireline telecommunications network, such as a mobile station, a user equipment (UE), a personal computer (PC), a tablet, a wearable communications device (e.g., a smartwatch, etc.), or any other device adapted to access a telecommunications network.

In some embodiments, one or more of the interfaces 1310, 1312, 1314 connects the processing system 1300 to a transceiver adapted to transmit and receive signaling over the telecommunications network. Figure 14 illustrates a block diagram of a transceiver 1400 adapted to transmit and receive signaling over a telecommunications network. The transceiver 1400 may be installed in a host device. As shown, the transceiver 1400 comprises a network-side interface 1402, a coupler 1404, a transmitter 1406, a receiver 1408, a signal processor 1410, and a device-side interface 1412. The network-side interface 1402 may include any component or collection of components adapted to transmit or receive signaling over a wireless or wireline telecommunications network.

The coupler 1404 may include any component or collection of components adapted to facilitate bi-directional communication over the network-side interface 1402. The transmitter 1406 may include any component or collection of components (e.g., up- converter, power amplifier, etc.) adapted to convert a baseband signal into a modulated carrier signal suitable for transmission over the network-side interface 1402. The receiver 1408 may include any component or collection of components (e.g., down -converter, low noise amplifier, etc.) adapted to convert a carrier signal received over the network-side interface 1402 into a baseband signal. The signal processor 1410 may include any component or collection of components adapted to convert a baseband signal into a data signal suitable for communication over the device-side interface(s) 1412, or vice-versa. The device-side interface(s) 1412 may include any component or collection of components adapted to communicate data-signals between the signal processor 1410 and components within the host device (e.g., the processing system 1300, local area network (LAN) ports, etc.).

The transceiver 1400 may transmit and receive signaling over any type of communications medium. In some embodiments, the transceiver 1400 transmits and receives signaling over a wireless medium. For example, the transceiver 1400 may be a wireless transceiver adapted to communicate in accordance with a wireless telecommunications protocol, such as a cellular protocol (e.g., long-term evolution (LTE), etc.), a wireless local area network (WLAN) protocol (e.g., Wi-Fi, etc.), or any other type of wireless protocol (e.g., Bluetooth, near field communication (NFC), etc.). In such embodiments, the network-side interface 1402 comprises one or more antenna/radiating elements. For example, the network-side interface 1402 may include a single antenna, multiple separate antennas, or a multi-antenna array configured for multi-layer communication, e.g., single input multiple output (SIMO), multiple input single output (MISO), multiple input multiple output (MIMO), etc. In other embodiments, the transceiver 1400 transmits and receives signaling over a wireline medium, e.g., twisted-pair cable, coaxial cable, optical fiber, etc.

Figure 15 illustrates an example communication system 1500. In general, the system 1500 enables multiple wireless or wired users to transmit and receive data and other content. The system 1500 may implement one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), or non-orthogonal multiple access (NOMA).

In this example, the communication system 1500 includes electronic devices (ED) 1510a- 1510c, radio access networks (RANs) 1520a- 1520b, a core network 1530, a public switched telephone network (PSTN) 1540, the Internet 1550, and other networks 1560. While certain numbers of these components or elements are shown in Figure 15, any number of these components or elements may be included in the system 1500.

The EDs i5ioa-i5toc are configured to operate or communicate in the system 1500. For example, the EDs i5ioa-i5ioc are configured to transmit or receive via wireless or wired communication channels. Each ED i5ioa-i5ioc represents any suitable end user device and may include such devices (or may be referred to) as a user equipment or device (UE), wireless transmit or receive unit (WTRU), mobile station, fixed or mobile subscriber unit, cellular telephone, personal digital assistant (PDA), smartphone, laptop, computer, touchpad, wireless sensor, or consumer electronics device.

The RANs i52oa-t52ob here include base stations I570a-t570b, respectively. Each base station I570a-t570b is configured to wirelessly interface with one or more of the EDs i5ioa-i5toc to enable access to the core network 1530, the PSTN 1540, the Internet 1550, or the other networks 1560. For example, the base stations I570a-t570b may include (or be) one or more of several well-known devices, such as a base transceiver station (BTS), a Node-B (NodeB), an evolved NodeB (eNodeB), a Next Generation (NG) NodeB (gNB), a Home NodeB, a Home eNodeB, a site controller, an access point (AP), or a wireless router. The EDs i5ioa-i5ioc are configured to interface and communicate with the Internet 1550 and may access the core network 1530, the PSTN 1540, or the other networks 1560.

In the embodiment shown in Figure 15, the base station 1570a forms part of the RAN 1520a, which may include other base stations, elements, or devices. Also, the base station 1570b forms part of the RAN 1520b, which may include other base stations, elements, or devices. Each base station I570a-t570b operates to transmit or receive wireless signals within a particular geographic region or area, sometimes referred to as a “cell.” In some embodiments, multiple-input multiple-output (MIMO) technology maybe employed having multiple transceivers for each cell.

The base stations I570a-t570b communicate with one or more of the EDs i5ioa-i5ioc over one or more air interfaces 1590 using wireless communication links. The air interfaces 1590 may utilize any suitable radio access technology.

It is contemplated that the system 1500 may use multiple channel access functionality, including such schemes as described above. In particular embodiments, the base stations and EDs implement 5G New Radio (NR), LTE, LTE-A, or LTE-B. Of course, other multiple access schemes and wireless protocols may be utilized.

The RANs I520a-t520b are in communication with the core network 1530 to provide the EDs 1510a- 1510c with voice, data, application, Voice over Internet Protocol (VoIP), or other services. Understandably, the RANs I520a-t520b or the core network 1530 may be in direct or indirect communication with one or more other RANs (not shown). The core network 1530 may also serve as a gateway access for other networks (such as the PSTN 1540, the Internet 1550, and the other networks 1560). In addition, some or all of the EDs i5ioa-i5toc may include functionality for communicating with different wireless networks over different wireless links using different wireless technologies or protocols. Instead of wireless communication (or in addition thereto), the EDs may communicate via wired communication channels to a service provider or switch (not shown), and to the Internet 1550.

Although Figure 15 illustrates one example of a communication system, various changes may be made to Figure 15. For example, the communication system 1500 could include any number of EDs, base stations, networks, or other components in any suitable configuration. Figures i6A and i6B illustrate example devices that may implement the methods and teachings according to this disclosure. In particular, Figure i6A illustrates an example ED 1610, and Figure i6B illustrates an example base station 1670. These components could be used in the system 1500 or in any other suitable system.

As shown in Figure 16A, the ED 1610 includes at least one processing unit 1600. The processing unit 1600 implements various processing operations of the ED 1610. For example, the processing unit 1600 could perform signal coding, data processing, power control, input/output processing, or any other functionality enabling the ED 1610 to operate in the system 1500. The processing unit 1600 also supports the methods and teachings described in more detail above. Each processing unit 1600 includes any suitable processing or computing device configured to perform one or more operations. Each processing unit 1600 could, for example, include a microprocessor, microcontroller, digital signal processor, field programmable gate array, or application specific integrated circuit.

The ED 1610 also includes at least one transceiver 1602. The transceiver 1602 is configured to modulate data or other content for transmission by at least one antenna or NIC (Network Interface Controller) 1604. The transceiver 1602 is also configured to demodulate data or other content received by the at least one antenna 1604. Each transceiver 1602 includes any suitable structure for generating signals for wireless or wired transmission or processing signals received wirelessly or by wire. Each antenna 1604 includes any suitable structure for transmitting or receiving wireless or wired signals. One or multiple transceivers 1602 could be used in the ED 1610, and one or multiple antennas 1604 could be used in the ED 1610. Although shown as a single functional unit, a transceiver 1602 could also be implemented using at least one transmitter and at least one separate receiver.

The ED 1610 further includes one or more input/output devices 1606 or interfaces (such as a wired interface to the Internet 1550). The input/output devices 1606 facilitate interaction with a user or other devices (network communications) in the network. Each input/output device 1606 includes any suitable structure for providing information to or receiving information from a user, such as a speaker, microphone, keypad, keyboard, display, or touch screen, including network interface communications.

In addition, the ED 1610 includes at least one memory 1608. The memory 1608 stores instructions and data used, generated, or collected by the ED 1610. For example, the memory 1608 could store software or firmware instructions executed by the processing unit(s) 1600 and data used to reduce or eliminate interference in incoming signals. Each memory 1608 includes any suitable volatile or non-volatile storage and retrieval device(s). Any suitable type of memory may be used, such as random access memory (RAM), read only memory (ROM), hard disk, optical disc, subscriber identity module (SIM) card, memory stick, secure digital (SD) memory card, and the like.

As shown in Figure i6B, the base station 1670 includes at least one processing unit 1650, at least one transceiver 1652, which includes functionality for a transmitter and a receiver, one or more antennas 1656, at least one memory 1658, and one or more input/output devices or interfaces 1666. A scheduler, which would be understood by one skilled in the art, is coupled to the processing unit 1650. The scheduler could be included within or operated separately from the base station 1670. The processing unit 1650 implements various processing operations of the base station 1670, such as signal coding, data processing, power control, input/output processing, or any other functionality. The processing unit 1650 can also support the methods and teachings described in more detail above. Each processing unit 1650 includes any suitable processing or computing device configured to perform one or more operations. Each processing unit 1650 could, for example, include a microprocessor, microcontroller, digital signal processor, field programmable gate array, or application specific integrated circuit.

Each transceiver 1652 includes any suitable structure for generating signals for wireless or wired transmission to one or more EDs or other devices. Each transceiver 1652 further includes any suitable structure for processing signals received wirelessly or by wire from one or more EDs or other devices. Although shown combined as a transceiver 1652, a transmitter and a receiver could be separate components. Each antenna 1656 includes any suitable structure for transmitting or receiving wireless or wired signals. While a common antenna 1656 is shown here as being coupled to the transceiver 1652, one or more antennas 1656 could be coupled to the transceiver(s) 1652, allowing separate antennas 1656 to be coupled to the transmitter and the receiver if equipped as separate components. Each memory 1658 includes any suitable volatile or non-volatile storage and retrieval device(s). Each input/output device 1666 facilitates interaction with a user or other devices (network communications) in the network. Each input/output device 1666 includes any suitable structure for providing information to or receiving/providing information from a user, including network interface communications.

Figure 17 is a block diagram of a computing system 1700 that may be used for implementing the devices and methods disclosed herein. For example, the computing system can be any entity of UE, access network (AN), mobility management (MM), session management (SM), user plane gateway (UPGW), or access stratum (AS). Specific devices may utilize all of the components shown or only a subset of the components, and levels of integration may vary from device to device. Furthermore, a device may contain multiple instances of a component, such as multiple processing units, processors, memories, transmitters, receivers, etc. The computing system 1700 includes a processing unit 1702. The processing unit includes a central processing unit (CPU) 1714, memory 1708, and may further include a mass storage device 1704, a video adapter 1710, and an I/O interface 1712 connected to a bus 1720.

The bus 1720 may be one or more of any type of several bus architectures including a memory bus or memory controller, a peripheral bus, or a video bus. The CPU 1714 may comprise any type of electronic data processor. The memory 1708 may comprise any type of non-transitory system memory such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), read-only memory (ROM), or a combination thereof. In an embodiment, the memory 1708 may include ROM for use at boot-up, and DRAM for program and data storage for use while executing programs.

The mass storage 1704 may comprise any type of non-transitory storage device configured to store data, programs, and other information and to make the data, programs, and other information accessible via the bus 1720. The mass storage 1704 may comprise, for example, one or more of a solid state drive, hard disk drive, a magnetic disk drive, or an optical disk drive.

The video adapter 1710 and the I/O interface 1712 provide interfaces to couple external input and output devices to the processing unit 1702. As illustrated, examples of input and output devices include a display 1718 coupled to the video adapter 1710 and a mouse, keyboard, or printer 1716 coupled to the I/O interface 1712. Other devices may be coupled to the processing unit 1702, and additional or fewer interface cards may be utilized. For example, a serial interface such as Universal Serial Bus (USB) (not shown) may be used to provide an interface for an external device.

The processing unit 1702 also includes one or more network interfaces 1706, which may comprise wired links, such as an Ethernet cable, or wireless links to access nodes or different networks. The network interfaces 1706 allow the processing unit 1702 to communicate with remote units via the networks. For example, the network interfaces 1706 may provide wireless communication via one or more transmitters/transmit antennas and one or more receivers/ receive antennas. In an embodiment, the processing unit 1702 is coupled to a local-area network 1722 or a wide-area network for data processing and communications with remote devices, such as other processing units, the Internet, or remote storage facilities.

It should be appreciated that one or more steps of the embodiment methods provided herein may be performed by corresponding units or modules. For example, a signal may be transmitted by a transmitting unit or a transmitting module. A signal may be received by a receiving unit or a receiving module. A signal may be processed by a processing unit or a processing module. Other steps may be performed by an encoding unit or module, a rate matching unit or module, a decoding unit or module, or a configuring unit or module. The respective units or modules may be hardware, software, or a combination thereof. For instance, one or more of the units or modules may be an integrated circuit, such as field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs).

Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the scope of the disclosure as defined by the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A method implemented by an access node, the method comprising: transmitting, by the access node to a user equipment (UE), a rate matching indicator indicating a rate matching buffer mode to set a size of a rate matching buffer; encoding, by the access node, data thereby producing encoded data; rate matching, by the access node, the encoded data in accordance with the size of the rate matching buffer thereby producing rate matched data; and transmitting, by the access node to the UE, the rate matched data.

2. The method of claim t, the rate matching buffer mode comprising a full buffer rate matching (FBRM) mode or a limited buffer rate matching (LBRM) mode.

3. The method of any one of claims t-2, the rate matching indicator comprising a field of a downlink control information (DCI) message.

4. The method of claim 3, the rate matching indicator being transmitted in a DCI message.

5. The method of any one of claims 1-2, the rate matching indicator comprising an unused bit of a plurality of bits used to indicate hybrid automatic repeat request (HARQ) processes.

6. The method of any one of claims 1-5, further comprising configuring, by the access node, the rate matching buffer mode.

7. The method of any one of claims 1-6, further comprising configuring, by the access node, a number of HARQ processes.

8. The method of any one of claims 1-6, the rate matching indicator updates a previous rate matching indicator.

9. A method implemented by a user equipment (UE), the method comprising: receiving, by the UE from an access node, a rate matching indicator indicating a rate matching buffer mode; setting, by the UE, a buffer size of a buffer in accordance with the rate matching indicator; placing, by the UE in the buffer in accordance with the buffer size, data received on a physical downlink shared channel (PDSCH); and decoding, by the UE, the data placed in the buffer.

10. The method of claim 9, the rate matching buffer mode comprising a full buffer rate matching (FBRM) mode or a limited buffer rate matching (LBRM) mode.

11. The method of any one of claims 9-10, the rate matching indicator comprising a field of a downlink control information (DCI) message.

12. The method of claim 11, the rate matching indicator being transmitted in a DCI message.

13. The method of any one of claims 9-10, the rate matching indicator comprising an unused bit of a plurality of bits used to indicate hybrid automatic repeat request (HARQ) processes.

14. The method of any one of claims 9-13, further comprising receiving, by the UE from the access node, the rate matching buffer mode.

15. The method of any one of claims 9-14, further comprising receiving, by the UE from the access node, a number of HARQ processes.

16. A method implemented by a user equipment (UE), the method comprising: determining, by the UE, a rate matching buffer mode in accordance with a base graph used by an access node; setting, by the UE, a buffer size of a buffer in accordance with the rate matching indicator; placing, by the UE in the buffer in accordance with the buffer size, data received on a physical downlink shared channel (PDSCH); and decoding, by the UE, the data placed in the buffer.

17. The method of claim 16, the base graph comprising a first base graph or a second base graph.

18. The method of claim 17, the rate matching buffer mode comprising a full buffer rate (FBRM) mode when the base graph comprises the second base graph, and the rate matching buffer mode comprising a limited buffer rate matching (LBRM) mode when the base graph comprises the first base graph.

19. An access node comprising: one or more processors; and a non-transitory memory storage comprising instructions that, when executed by the one or more processors, cause the access node to: transmit, to a user equipment (UE), a rate matching indicator indicating a rate matching buffer mode to set a size of a rate matching buffer; encode data to produce encoded data; rate matching the encoded data in accordance with the size of the rate matching buffer to produce rate matched data; and transmit, to the UE, the rate matched data.

20. The access node of claim 19, the rate matching buffer mode comprising a full buffer rate matching (FBRM) mode or a limited buffer rate matching (LBRM) mode.

21. The access node of any one of claims 19-20, the rate matching indicator comprising a field of a downlink control information (DCI) message.

22. The access node of claim 21, the rate matching indicator being transmitted in a DCI message.

23. The access node of any one of claims 19-20, the rate matching indicator comprising an unused bit of a plurality of bits used to indicate hybrid automatic repeat request (HARQ) processes.

24. The access node of any one of claims 19-23, the instructions causing the access node to configure the rate matching buffer mode.

25. The access node of any one of claims 19-24, the instructions causing the access node to configure a number of HARQ processes.

26. A user equipment (UE) comprising: one or more processors; and a non-transitory memory storage comprising instructions that, when executed by the one or more processors, cause the UE to: receive, from an access node, a rate matching indicator indicating a rate matching buffer mode; set a buffer size of a buffer in accordance with the rate matching indicator; place, in the buffer in accordance with the buffer size, data received on a physical downlink shared channel (PDSCH); and decode the data placed in the buffer.

27. The UE of claim 26, the rate matching buffer mode comprising a full buffer rate matching (FBRM) mode or a limited buffer rate matching (LBRM) mode.

28. The UE of any one of claims 26-27, the rate matching indicator comprising a field of a downlink control information (DCI) message.

29. The UE of claim 28, the rate matching indicator being transmitted in a DCI message.

30. The UE of any one of claims 26-27, the rate matching indicator comprising an unused bit of a plurality of bits used to indicate hybrid automatic repeat request (HARQ) processes.

31. The UE of any one of claims 26-30, further comprising receiving, by the UE from the access node, the rate matching buffer mode.

32. The UE of any one of claims 26-31, further comprising receiving, by the UE from the access node, a number of HARQ processes.