Hybrid automatic repeat request (HARQ) retransmission

Abstract

A method comprising, by a transmitting entity: performing a first transmission over a communication channel, receiving, from a receiving entity, an indication of a channel quality for the communication channel, determining, based on the indication of the channel quality, a block error rate (BLER) floor for the communication channel, determining, based on the BLER floor, a number of bits for one or more hybrid automatic repeat request (HARQ) retransmissions associated with the first transmission, and performing, based on the determined number of bits for the one or more HARQ retransmissions, the HARQ retransmissions to the receiving entity.

Description

Technical Field

[0001] This description relates to wireless communication. Background Technology

[0002] A communication system can be a facility that enables communication between two or more nodes or devices (such as fixed or mobile communication devices). Signals can be carried on wired or wireless carrier waves.

[0003] An example of a cellular communication system is the architecture standardized by the 3rd Generation Partnership Project (3GPP). Recent developments in this area are often referred to as Long Term Evolution (LTE) of Universal Mobile Telecommunications System (UMTS) radio access technology. EUTRA (Evolved UMTS Terrestrial Radio Access) is the air interface for the 3GPP LTE upgrade path for mobile networks. In LTE, base stations or access points (APs), known as Enhanced Nodes (eNBs), provide radio access within a coverage area or cell. In LTE, mobile devices, or mobile stations, are referred to as User Equipment (UEs). LTE has included numerous improvements and developments. LTE continues to be improved.

[0004] The development of 5G New Radio (NR) is part of the ongoing evolution of mobile broadband to meet the requirements of 5G, similar to the early evolution of 3G and 4G wireless networks. In addition to mobile broadband, 5G also targets emerging use cases. The goal of 5G is to deliver significant improvements in wireless performance, which can include new levels of data rates, latency, reliability, and security. 5G NR can also be expanded to efficiently connect large numbers of Internet of Things (IoT) devices and can provide new types of mission-critical services. For example, ultra-reliable and low-latency communication (URLLC) devices can require high reliability and very low latency. 6G and other networks are also under development. Summary of the Invention

[0005] In some aspects, the technology described herein relates to an apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: perform a first transmission via a communication channel; receive from a receiving entity an indication of channel quality for the communication channel; determine a lower limit of block error rate (BLER) for the communication channel based on the channel quality indication; determine, based on the BLER lower limit, the number of bits for one or more Hybrid Automatic Repeat Request (HARQ) retransmissions associated with the first transmission; and perform a HARQ retransmission via the communication channel based on the determined number of bits for the one or more HARQ retransmissions.

[0006] In some aspects, the technology described herein relates to an apparatus comprising: means for performing a first transmission via a communication channel; means for receiving an indication of channel quality for the communication channel from a receiving entity; means for determining a lower limit of block error rate (BLER) for the communication channel based on the indication of channel quality; means for determining, based on the lower limit of BLER, the number of bits for one or more Hybrid Automatic Repeat Request (HARQ) retransmissions associated with the first transmission; and means for performing HARQ retransmissions via the communication channel based on the determined number of bits for one or more HARQ retransmissions.

[0007] In some aspects, the techniques described herein relate to a method comprising a transmitting entity: performing a first transmission via a communication channel; receiving from a receiving entity an indication of channel quality for the communication channel; determining a lower limit of block error rate (BLER) for the communication channel based on the channel quality indication; determining, based on the BLER lower limit, the number of bits to be used for one or more Hybrid Automatic Repeat Request (HARQ) retransmissions associated with the first transmission; and performing HARQ retransmissions via the communication channel based on the determined number of bits for the one or more HARQ retransmissions.

[0008] For each of the example methods, other example embodiments are provided or described, including: components for performing any of the example methods; a non-transitory computer-readable storage medium including instructions stored thereon, which, when executed by at least one processor, are configured to cause a computing system to perform any of the example methods; and an apparatus comprising: at least one processor, and at least one memory including computer program code configured, together with the at least one processor, to cause the apparatus to perform at least any of the example methods.

[0009] Details of one or more examples of embodiments are set forth in the following figures and description. Other features will be apparent from the description and figures, and from the claims. Attached Figure Description

[0010] Figure 1 This is a block diagram of wireless network 130.

[0011] Figure 2 This is a diagram illustrating an example mechanism for uplink transmission that may include one or more operations.

[0012] Figure 3 The diagram illustrates the performance of an aspect of the example embodiment.

[0013] Figure 4 This is a flowchart of an example method for sending entities.

[0014] Figure 5 This is a diagram illustrating an example embodiment.

[0015] Figure 6 This is a block diagram of a wireless station or node (e.g., UE, user equipment, AP, BS, eNB, gNB, RAN node, network node, TRP, or other node) 1300 according to an example embodiment. Detailed Implementation

[0016] It should be understood that while terms such as "first," "second," etc., preceding nouns may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another, and they do not restrict the order of the nouns. For example, without departing from the scope of the exemplary embodiments, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. As used herein, the term "and / or" includes one or more of the listed terms and any and all combinations thereof.

[0017] As used herein, unless explicitly stated otherwise, performing a "response to A" step does not indicate that the step is performed immediately after "A" appears, and one or more intermediate steps may be included.

[0018] Figure 1 This is a block diagram of wireless network 130. Figure 1 In the wireless network 130, user equipment 131, 132, 133, and 135, which may also be referred to as mobile stations (MS) or user equipment (UEs), can connect to (and communicate with) base station (BS) 134, which may also be referred to as access point (AP), enhanced node B (eNB), gNB, or RAN (radio access network) node. BS (or AP) 134 provides radio coverage within cell 136, including providing radio coverage to user equipment (or UEs) 131, 132, 133, and 135. BS 134 is also connected to core network 150 via N2 or NG interface 151. Although only four user equipment (or UEs) connected to or attached to a single BS 134 are shown, any number of user equipment and / or BSs may be provided.

[0019] At least some of the functions of a BS (e.g., NG-RAN, gNB, Access Point (AP), Base Station (BS), or (e) Node B (eNB), RAN node) can also be performed by any node, server, or host that can be operatively coupled to a transceiver such as a remote radio head. For example, some functions of a BS can be performed at least partially in a central / centralized unit (CU) and / or distributed unit (DU). Therefore, a 5G network architecture can be based on so-called CU-DU partitioning. A gNB-CU (central node) can control multiple spatially separated gNB-DUs, at least as transmit / receive (Tx / Rx) nodes. However, in some embodiments, a gNB-DU (also referred to as a DU) can include, for example, a Radio Link Control (RLC), Medium Access Control (MAC) layer, and a Physical (PHY) layer, where a gNB-CU (also referred to as a CU) can include layers above the RLC layer, such as a Packet Data Convergence Protocol (PDCP) layer, Radio Resource Control (RRC), and Internet Protocol (IP) layer. Other functional partitioning is also possible.

[0020] According to the illustrative example, a radio access network (RAN) can be part of a mobile telecommunications system. The RAN can include one or more BS or RAN nodes that implement radio access technologies, such as allowing one or more UEs to access the network or core network (CN). Thus, for example, the RAN (RAN nodes, such as BS or gNB) can reside between one or more user equipment or UEs and the core network. According to the example embodiment, each RAN node (e.g., BS, eNB, gNB, CU / DU, ...) or BS can provide one or more wireless communication services for one or more UEs or user equipments, such as allowing the UE to wirelessly access the network via the RAN node. Each RAN node or BS can perform or provide wireless communication services, such as allowing the UE or user equipment to establish a wireless connection to the RAN node and to send data to one or more UEs and / or receive data from one or more UEs. For example, after establishing a connection to the UE, the RAN node or network node (e.g., BS, eNB, gNB, CU / DU, ...) can forward data received from the network or core network to the UE and / or forward data received from the UE to the network or core network. RAN nodes or network nodes (e.g., BS, eNB, gNB, CU / DU, ...) can perform a wide variety of other radio functions or services, such as broadcasting control information to UEs (e.g., system information or system information as needed), paging UEs when data to be delivered to them is available, assisting UE handover between cells, scheduling resources for uplink data transmission from (multiple) UEs and downlink data transmission to (multiple) UEs, sending configuration information to configure one or more UEs, etc. These are just a few examples of one or more functions that a RAN node or BS can perform.

[0021] User equipment or user node (user terminal, user equipment (UE), mobile terminal, handheld wireless device, etc.) can refer to portable computing devices including wireless mobile communication devices that operate with or without a subscriber identification module (SIM), including but not limited to the following types of devices: mobile station (MS), mobile phone, cell phone, smartphone, personal digital assistant (PDA), handheld device, device using wireless modem (alarm or measuring device, etc.), laptop and / or touchscreen computer, tablet computer, tablet phone, gaming terminal, laptop, vehicle, drone, sensor, and multimedia device, or any other wireless device. It should be understood that user equipment can also be (or may include) a virtually exclusive uplink-only device, an example of which is a camera or camcorder that loads images or video clips onto the network. Furthermore, user node can include user equipment (UE), user equipment, user terminal, mobile terminal, mobile station, mobile node, subscriber equipment, subscriber node, subscriber terminal, or other user node. For example, a user node can be used for wireless communication with one or more network nodes (e.g., gNB, eNB, BS, AP, CU, DU, CU / DU) and / or with one or more other user nodes, regardless of the technology or radio access technology (RAT).

[0022] In 5G (which may be referred to as New Radio (NR)) (as an illustrative example), the core network 150 may be referred to as the 5G core network (5GC), which may include Access and Mobility Management Functions (AMF). For example, the AMF may include the following functions (e.g., some AMF functions may be supported in a single instance of the AMF): termination of the RAN Control Plane (CP) interface (N2), termination of the Non-Access Stratum (NAS) (or N1), NAS encryption and integrity protection, registration management, connection management, reachability management, mobility management, lawful eavesdropping, etc. The 5GC may also include Session Management Functions (SMF), which may include one or more of the following functions (one or more SMF functions may be supported in a single instance of the SMF): session management (e.g., session establishment, modification and release, including tunnel maintenance between the User Plane Function (UPF) and BS 134), IP address allocation and management (including optional authorization), selection and control of (multiple) UPFs, configuration of service control at the UPFs to route services to the appropriate destination, etc. In LTE (as an illustrative example), the core network 150 may be referred to as the Evolved Packet Core (EPC), which may include: a Mobility Management Entity (MME) that can handle or assist the mobility / handover of user equipment between BSs, one or more gateways that can forward data and control signals between the BS and the packet data network or the Internet, and other control functions or blocks.

[0023] Furthermore, the technologies described in this article can be applied to various types of user equipment or data service types, or to user equipment that can have multiple applications running on it, which can be different data service types. New Radio (5G) development can support multiple different applications or multiple different data service types, such as, for example: Machine Type Communication (MTC), Enhanced Machine Type Communication (eMTC), Internet of Things (IoT), and / or Narrowband IoT user equipment, Enhanced Mobile Broadband (eMBB), and Ultra Reliable and Low Latency Communication (URLLC). Many of these new 5G (NR) related applications often require higher performance than previous wireless networks.

[0024] The Internet of Things (IoT) can refer to a growing set of objects with Internet or network connectivity, enabling them to send and receive information from other network devices. For example, many sensor-type applications or devices can monitor physical conditions or states and, for instance, send reports to servers or other network devices when events occur. Machine-type communication (MTC, or machine-to-machine communication) can be characterized, for example, as the fully automated generation, exchange, processing, and actuation of data between intelligent machines, with or without human intervention. Enhanced Mobile Broadband (eMBB) can support data rates significantly higher than those currently available in LTE.

[0025] Ultra-Reliable and Low-Latency Communication (URLLC) is a new type of data service or a new use case that can be supported for New Radio (5G) systems. This enables emerging new applications and services, such as industrial automation, autonomous driving, vehicle safety, and eHealth services. Through illustrative examples, 3GPP provides [the following] with [the following] corresponding to 10 […]. -5 The goal is to achieve reliable connectivity with a low block error rate (BLER) and up to 1ms U-Plane (user / data plane) latency. Therefore, for example, URLLC user equipment / UEs may require significantly lower block error rates and lower latency than other types of user equipment / UEs (with or without requirements for simultaneous high reliability). Thus, for example, a URLLC UE (or URLLC application on a UE) may require much shorter latency compared to an eMBB UE (or eMBB applications running on a UE).

[0026] The technologies described herein can be applied to a wide variety of wireless technologies or wireless networks, such as 5G (New Radio (NR)), cmWave, and / or mmWave networks, IoT, MTC, eMTC, eMBB, URLLC, 6G, and any other wireless network or wireless technology. These example networks, technologies, or data service types are provided as illustrative examples only.

[0027] Figure 2 This is a diagram illustrating an example mechanism for an uplink transmission that may include one or more operations. The one or more operations may include at least one of the following: - Scrambling: The scrambling process can use cell-specific scrambling sequences generated based on the cell ID and scrambling identifier. The scrambling identifier can be unique for each user (UE) within the cell, thus ensuring that scrambling sequences used by different UEs are orthogonal to each other or have low cross-correlation. - Modulation mapper: can include modulation of scrambled bits to generate complex-valued modulation symbols. In other words, a modulation mapper can take binary digits 0 or 1 as input and produce complex-valued modulation symbols as output. - Layer mapper: can include mapping complex-valued modulation symbols to one or more transport layers. - Transform precoder: Transform precoding can be performed to generate complex-valued modulation symbols, such as DFT-s-OFDM (DFT extended OFDM) transform precoding. - Precoding: can include precoding of complex-valued modulation symbols, such as MIMO (Multiple-Input Multiple-Output) precoding. - Resource element mapper: can include mapping pre-encoded complex value symbols to resource elements. - Signal generation: This can include generating complex time-domain signals for the antenna port. These operations are illustrated as examples, and other mechanisms are expected to be implemented in various embodiments.

[0028] For example, transmission over a wireless channel can be affected by errors due to variations in the quality of the received signal. To some extent, such variations can be offset by link adaptation. However, receiver noise and unpredictable interference variations cannot be offset. Therefore, virtually all wireless communication systems use some form of forward error correction (FRC), adding redundancy to the transmitted signal to allow the receiver to correct errors. In NR, low-density parity check (LDPC) or polar coding can be used for error correction. Despite the error correction codes, erroneously received data units can still occur, for example, due to excessively high noise or interference levels. Hybrid Automatic Repeat Request (HARQ), which can rely on a combination of error correction coding and retransmissions with additional data and / or redundant units, is commonly used in communication systems. Despite the error correction codes, the receiver can detect erroneous data units and request a retransmission from the transmitter.

[0029] Polar codes are a family of capacity-based error-correcting codes. Polar codes, and modifications thereof using external cyclic redundancy (CRC) codes, have been adopted by 3GPP as channel coding for control channels in 5G NR. Other modifications of polar codes, such as polarized adjusted convolutional (PAC) codes or precoded polar codes (where they can be considered as polar codes with dynamically frozen bits), have shown to be highly competitive in short to medium length regimes in the case of near maximum likelihood (ML) decoding. Prominent examples of near ML decoding algorithms include Sequential Elimination List (SCL) decoding and Sequential Elimination Ordered Search (SCOS) decoding. In some cases, the information transmitted on the channel may include frozen bits (bits at frozen positions) with values ​​known to both the transmitter and receiver. These fixed-value bits are called frozen bits, and in some examples, the frozen bits are set to zero. Non-zero bits (or bits at non-zero positions) may be referred to as information bits or information positions.

[0030] This section will briefly describe an overview of polar codes and some of their drawbacks or shortcomings.

[0031] make Consider the matrix ,in yes of Fold the Kronecker product, where For example, to This is represented as a polarization transformation matrix. In the example, its generator matrix can be determined by... choose All the codes formed by the rows. These are the selected ones. Row indexes can be called information indexes, and the set containing the indexes can be represented as... For example, it can be achieved through storage. indexes To obtain Polar codes, which provide optimal performance in successive elimination (SC) decoding, for example, allow the selection of the most reliable... An index. It can be obtained from... The other code generated is the length. and dimensions of The Reed-Muller (RM) code of order , where In this case, the set Can include indexes , corresponding to having at least equal to Hamming weights The line. Assume Indicates what will be encoded Bit messages. In both cases, encoding can be performed by applying a polarization transformation after appropriately padding the message with zeros. For example, codewords. Can be used as ,in It is length A binary vector, where It has a set The index of the element subvectors, and Note that sets (therefore The polar code is known to the receiver. In the example, (e.g., in a 5G system) the polar code can be of length depending on the length of the data vector and the type of transmission, whether it is downlink or uplink. The external CRC. While this depends on how the manufacturer chooses to implement the decoding algorithm, it is generally applicable to internal... After polar codes undergo what's called SCL decoding, the external CRC code can be used for error detection. Specifically, the overall code parameters become... .

[0032] The following section briefly describes polar codes with dynamically frozen bits. This applies if the value is not always zero but depends on the preceding bits. Then freeze bits This is referred to as dynamic. At the transmitter, the encoder is designed in a way that dynamically freezes bits selected as previous information bits to obtain a certain distance profile for the resulting code. Therefore, fine-tuning for the complexity-performance tradeoff is possible for given code parameters.

[0033] In the example, aspects of uplink transmission may include error correction codes.

[0034] In the example, a channel coding and incremental redundancy hybrid automatic repeat request (IR-HARQ) scheme can be used in the communication system. In the example, block error events can be classified into two groups: undetected errors and detected errors. For the case of detected errors, the receiver can request more redundant bits for the same message, making it successful after combining the log-likelihood ratio (LLR) of the two transmissions. In the example, the lower bound of the block error rate (BLER) for any HARQ scheme can be the undetected block error rate (uBLER) of the first transmission.

[0035] Existing technologies can support various coding schemes, such as polar codes. However, when optimizing the number of bits to be sent in subsequent retransmissions, existing coding schemes (such as polar codes for IR-HARQ, for example) do not consider BLER and / or uBLER aspects. As a result, HARQ transmissions (or IR-HARQ) can be affected by the overhead of transmitting potentially unnecessary additional bits, or by not sending sufficient redundancy to achieve the target BLER (or the lower bound indicated by the uBLER of the first transmission). In the former case, the transmission of additional bits can cause overhead and lower throughput / spectral efficiency, and in the latter case, insufficient bit transmission can lead to failure to meet reliability requirements.

[0036] The example embodiment focuses on optimizing the number of bits in HARQ retransmissions used for a target BLER lower bound. In the example embodiment, a sending entity performs a first transmission via a communication channel. In the example, the sending entity may receive an indication of channel quality for the communication channel from a receiving entity. In the example, the sending entity may determine a BLER lower bound for the communication channel based on the channel quality indication. In the example, the sending entity may determine the number of bits for one or more HARQ retransmissions associated with the first transmission based on the BLER lower bound. In the example, the sending entity may perform HARQ retransmissions to the receiving entity based on the determined number of bits for one or more HARQ retransmissions.

[0037] Therefore, when implementing the example embodiment, the number of bits used for HARQ retransmissions can be reduced or increased (with higher reliability). For example, the number of bits can be determined based on a heuristic approach that takes into account the BLER and channel conditions. For example, the channel conditions can be used by the transmitting entity to determine the BLER. The heuristic approach used by the transmitting entity (or network entity, device, etc.) is based on a Gaussian function or Q function of a standard normal distribution. The heuristic approach can be based on an algorithm that can use lookup tables. In other words, given an initial transmission at the operating signal-to-noise ratio (SNR), the example embodiment targets the BLER of a polar-coded HARQ system that minimizes the BLER. According to the example embodiment, one or more HARQ retransmissions (or transmissions) can be performed based on sufficient bits (or just enough bits) from the transmitter to the receiver to achieve the lower bound of the overall error probability indicated by the uBLER of the first transmission.

[0038] In one example, the lower bound of BLER can be determined based on the probability that a cyclic redundancy check (CRC) error is not detected (e.g., an undetected CRC error). In another example, the lower bound of BLER can be determined based on unsatisfied parity checks for low-density parity check (LDPC) codes (e.g., parity checks for low-density parity check (LDPC) codes are not satisfied) or based on reliability-based rejections determined by a reliability threshold.

[0039] In the example, determining the number of bits used for one or more HARQ retransmissions can be based on a lookup table. For example, the lookup table could include at least one of the following: a mapping between a channel quality metric and the number of bits, a mapping between a Channel Quality Indicator (CQI) index and the number of bits, a mapping between the BLER lower bound and the number of bits, etc. For example, a channel quality metric can indicate how good or bad the communication channel is.

[0040] In the example, the mapping between the number of bits (or payload bits) used for one or more HARQ retransmissions and the BLER lower bound can be based on the error probability function E(R, n), where R is the code rate of the (n, k) code, k is the number of information bits (or payload bits), and n is the number of encoded bits.

[0041] In the example, E(R, n) can be calculated based on the following: Where Q is the Q-function of the standard normal distribution: C can be the capacity of the communication channel, and V can be the dispersion of the communication channel.

[0042] In the example, the sending entity can divide the number of bits used for one or more HARQ retransmissions across multiple rounds of HARQ retransmission.

[0043] In the example, the channel quality indication may be received as part of a HARQ negative acknowledgment (NACK) in response to the first transmission. In the example, the channel quality indication may indicate at least one of the following: signal-to-noise ratio (SNR), signal-to-interference-plus-noise ratio (SINR), reference signal received power (RSRP), etc. In another example, the channel quality indication may include a channel quality indicator (CQI). For example, a lookup table may include a mapping between a CQI as an index and the number of bits corresponding to that CQI for one or more HARQ retransmissions.

[0044] In the example embodiment, the communication channel can be a polar code channel, a CRC-assisted polar code channel, etc. For example, when using a polar code other than the CRC-assisted polar code, the transmitter can use an error detection mechanism different from the external CRC code.

[0045] Figure 3 This is a performance diagram illustrating an example embodiment. As depicted, the performance of the proposed example embodiment based on a just-enough-bit scheme for transmission with ΔN(-3, -2, -1, 0, 1, 2) = (544, 444, 256, 200, 144, 100) shows an enhancement over existing schemes, where ΔN represents the number of retransmitted bits, and Es / No represents the ratio of signal energy per symbol to noise power spectral density. For example, compared to a fixed-length IR-HARQ scheme, for the same reliability, BLER is improved by two orders of magnitude at an ES / No value of -3dB, while the number of bits transmitted is reduced by more than 50% at an ES / No value of 2dB.

[0046] like Figure 3 The figure illustrates the performance of a polar-coded IR-HARQ scheme (based on a design using existing technology), where the code is selected according to a 5G-based design with an 11-bit CRC. In the example, SCL decoding with a list size L=8 can be used at the receiver, as implemented by existing technology. As shown, for relatively high BLERs, the performance of the scheme in the real system does indeed approach that of longer code designs, but when the BLER of the first transmission is 10... -1 Errors can occur when the SNR is left or right or below. This is because the overall BLER lower bound of the IR HARQ scheme is the uBLER of the first transmission. In other words, sending more bits than necessary to achieve this performance in subsequent transmissions (or retransmissions) can be unnecessary. Furthermore, if the SNR is not accurately known (or estimated) before the first transmission, a significant degrade in the performance of the first transmission can occur (e.g., the first transmission is very aggressive), and therefore... ,in Indicates receiving on the channel in the first transmission Blocking events following the symbol.

[0047] Therefore, the example embodiment enhances the error correction code to achieve optimal reliability (without reducing system throughput) by sending just enough bits. According to the example embodiment, the transmitter can consider the uBLER of the polar-coded transmission in the first transmission. If an error is detected, the transmitting entity can then determine the number of (additional) bits to be used for retransmission of one or more HARQs from the transmitter to the receiver via the communication channel. Additionally, as... Figure 3 As shown, error layers can occur, which cannot be avoided due to undetected BLERs in previous transmissions (e.g., the first transmission) (unless the CRC is made longer without degrading BLER performance). In the example, according to the example embodiment, in order to send a length in the first transmission... polar codes In a bit message, the UE may send (indicate or signal) the SNR (and / or CRC for undetected errors) or any relevant noise figure along with NACK as part of the enhanced feedback to the transmitter so that the transmitter can determine the optimized number of bits for retransmission to a given polar-coded IR-HARQ system to achieve an overall BLER that matches the uBLER of the first transmission.

[0048] Therefore, the example implementation is advantageous because: 1) if the initial transmission is very aggressive, the reliability is significantly improved, which means that the code rate is much higher than the code rate that the channel can tolerate (a very low SNR mechanism); 2) in subsequent rounds of transmission or retransmission, the number of bits sent is significantly reduced.

[0049] In the example, given the SNR At this point, the throughput can be formulated as follows: (1), in This represents a block error event after the i-th transmission, as defined by... It is a universal set. yes The complement of (i.e., without block errors). Defined as a message that was not correctly decoded but was received on the channel during the previous i transmissions. An error event was detected after the symbol, and For t=2, equation (1) can be simplified as follows: (2), in Defined as a message that was not correctly decoded and received on the channel during the previous i transmissions. No error event was detected after the symbol was displayed. The increase in n² was observed to decrease as expected. However, its increase Therefore, according to the example embodiment, for the given pair and We propose a heuristic choice of n2 such that... Or equivalently, Finally, based on the example embodiment, a selection is proposed. To achieve This means that it should be done by having parameters The BLER code with parameters The initial code of uBLER is matched to select the SNR value. The number of incrementing bits transmitted. Therefore, the method of the example embodiment achieves the overall BLER approximated by the uBLER of the first transmission by using just enough bits per SNR. The channel in the first i transmissions... The symbol is shown. It is observed that increasing n² results in a decrease as expected. However, its increase Therefore, according to the example embodiment, for the given pair and We propose a heuristic choice of n2 such that... Or equivalently, Finally, based on the example embodiment, a selection is proposed. To achieve This means that it should be done by having parameters The BLER code with parameters The initial code of uBLER is matched to select the SNR value. The incremental number of bits transmitted. Therefore, the method of the example embodiment achieves the overall BLER approximated by the uBLER of the first transmission by using just enough bits per SNR.

[0050] In the example, the probability value can be obtained through simulation, and the required number of bits can be optimized through simulation. Alternative optimization schemes can be as follows. Assuming a uBLER target is given for sending a k-bit message... Therefore, a polar code corresponding to (n1, k) CRC can be selected (for 5G). If NACK is used, the additional [unclear] can be determined (or selected) by solving the following equation. Length of bit transmission: (3), For n=n2 (equivalently for) because At the transmitter location, where Set as target uBLER In equation (3), k = log2 M, for example, (M = 2^k), and Q can be the Q function of the standard normal distribution: The estimated SNR The receiver can signal to the transmitter in the form of a channel quality indicator. However, such a scheme may not necessarily maximize throughput. In the example implementation, this can be achieved by... Top Selection The mother code is selected based on its supremum, where... and An SNR range can be defined for the application under consideration, and puncturing can be used for the first transmission to have n1 bits. The transmitter can then determine... Bits are divided into multiple retransmission rounds; for example, for a given t, To further optimize the system, for example, for throughput as defined by equation (1). Some examples will be described:

[0051] Example 1. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: perform a first transmission via a communication channel; receive from a receiving entity an indication of channel quality for the communication channel; determine a lower limit of block error rate (BLER) for the communication channel based on the channel quality indication; determine, based on the BLER lower limit, a number of bits for one or more Hybrid Automatic Repeat Request (HARQ) retransmissions associated with the first transmission; and perform a HARQ retransmission via the communication channel based on the determined number of bits for the one or more HARQ retransmissions.

[0052] Example 2. The apparatus according to Example 1, wherein the lower limit of BLER is determined based on at least one of the following: the probability that an error is not detected by cyclic redundancy check (CRC); the probability that a parity check for a low-density parity check (LDPC) code is not satisfied; and the probability of a reliability-based rejection determined based on a reliability threshold.

[0053] Example 3. An apparatus according to Example 1 or 2, wherein determining the number of bits for one or more HARQ retransmissions is based on a lookup table, wherein the lookup table includes at least one of the following: a mapping between a channel quality metric and the number of bits; a mapping between a channel quality indicator (CQI) index and the number of bits; and a mapping between a BLER lower bound and the number of bits.

[0054] Example 4. According to the apparatus of Example 3, the mapping between the number of bits used for one or more HARQ retransmissions and the BLER lower bound is based on the error probability function E(R, n), where R is the code rate of the (n, k) code, k is the number of information bits, and n is the number of encoded bits.

[0055] Example 5. Based on the apparatus of Example 4, where E(R, n) is calculated based on the following terms: , where Q is the Q function of the standard normal distribution, C is the capacity of the communication channel, and V is the dispersion of the communication channel.

[0056] Example 6. An apparatus according to any one of Examples 1 to 5, wherein the apparatus is further configured to perform a division of bits for one or more HARQ retransmissions across multiple rounds of HARQ retransmission.

[0057] Example 7. An apparatus according to any one of Examples 1 to 6, wherein an indication of channel quality is received as part of a HARQ negative acknowledgment (NACK) in response to a first transmission.

[0058] Example 8. An apparatus according to any one of Examples 1 to 7, wherein the indication of channel quality indicates at least one of the following: signal-to-noise ratio (SNR); signal-to-interference-plus-noise ratio (SINR); or reference signal received power (RSRP).

[0059] Example 9. An apparatus according to any one of Examples 1 to 8, wherein the indication of channel quality includes a channel quality indicator (CQI).

[0060] Example 10. An apparatus according to any one of Examples 1 to 9, wherein the transmission through the communication channel is encoded by: CRC auxiliary polar code; polar code; or low-density parity check (LDPC) code.

[0061] Example 11. An apparatus comprising: means for performing a first transmission via a communication channel; means for receiving an indication of channel quality for the communication channel from a receiving entity; means for determining a lower limit of block error rate (BLER) for the communication channel based on the indication of channel quality; means for determining, based on the lower limit of BLER, the number of bits for one or more Hybrid Automatic Repeat Request (HARQ) retransmissions associated with the first transmission; and means for performing HARQ retransmissions via the communication channel based on the determined number of bits for one or more HARQ retransmissions.

[0062] Example 12. The apparatus according to Example 11, wherein the lower limit of BLER is determined based on at least one of the following: the probability that an error is not detected by cyclic redundancy check (CRC); the probability that a parity check for a low-density parity check (LDPC) code is not satisfied; and the probability of a reliability-based rejection determined based on a reliability threshold.

[0063] Example 13. An apparatus according to Example 11 or 12, wherein determining the number of bits for one or more HARQ retransmissions is based on a lookup table, wherein the lookup table includes at least one of the following: a mapping between a channel quality metric and the number of bits; a mapping between a channel quality indicator (CQI) index and the number of bits; and a mapping between a BLER lower bound and the number of bits.

[0064] Example 14. According to the apparatus of Example 13, the mapping between the number of bits used for one or more HARQ retransmissions and the BLER lower bound is based on the error probability function E(R, n), where R is the code rate of the (n, k) code, where k is the number of information bits and n is the number of encoded bits.

[0065] Example 15. Based on the apparatus of Example 14, where E(R, n) is calculated based on the following terms: , where Q is the Q function of the standard normal distribution, C is the capacity of the communication channel, and V is the dispersion of the communication channel.

[0066] Example 16. An apparatus according to any one of Examples 11 to 15 further includes a component for dividing the number of bits for one or more HARQ retransmissions across multiple rounds of HARQ retransmission.

[0067] Example 17. An apparatus according to any one of Examples 11 to 16, wherein an indication of channel quality is received as part of a HARQ negative acknowledgment (NACK) in response to a first transmission.

[0068] Example 18. An apparatus according to any one of Examples 11 to 17, wherein the indication of channel quality indicates at least one of the following: signal-to-noise ratio (SNR); signal-to-interference-plus-noise ratio (SINR); or reference signal received power (RSRP).

[0069] Example 19. An apparatus according to any one of Examples 11 to 18, wherein the indication of channel quality includes a channel quality indicator (CQI).

[0070] Example 20. An apparatus according to any one of Examples 11 to 19, wherein the transmission through the communication channel is encoded by: CRC auxiliary polar code; polar code; or low-density parity check (LDPC) code.

[0071] Figure 4This is a flowchart of an example method for sending an entity. The sending entity can be a network node, base station, gNB, user equipment, UE, etc.

[0072] Example 21 by Figure 4 The method is described as follows: At step 410, the method includes performing a first transmission by a sending entity through a communication channel. At step 420, the method includes receiving an indication of channel quality for the communication channel from a receiving entity. At step 430, the method includes determining a lower limit of the block error rate (BLER) for the communication channel based on the channel quality indication. At step 440, the method includes determining the number of bits for one or more Hybrid Automatic Repeat Request (HARQ) retransmissions associated with the first transmission based on the BLER lower limit. At step 450, the method includes performing a HARQ retransmission to the receiving entity based on the determined number of bits for one or more HARQ retransmissions.

[0073] Example 22. According to the method of Example 21, the lower bound of BLER is determined based on the following: the probability that an error is not detected by cyclic redundancy check (CRC), the probability that parity for a low-density parity check (LDPC) code is not satisfied; or the probability of a reliability-based rejection determined based on a reliability threshold.

[0074] Example 23. According to the method of Example 21 or 22, wherein determining the number of bits for one or more HARQ retransmissions is based on a lookup table, wherein the lookup table includes at least one of the following: a mapping between a channel quality metric and the number of bits; a mapping between a channel quality indicator (CQI) index and the number of bits; a mapping between a BLER lower bound and the number of bits.

[0075] Example 24. According to the method of Example 23, the mapping between the number of bits used for one or more HARQ retransmissions and the BLER lower bound is based on the error probability function E(R, n), where R is the code rate of the (n, k) code, k is the number of information bits, and n is the number of encoded bits.

[0076] Example 25. Following the method of Example 24, where E(R, n) is calculated based on the following terms: , where Q is the Q function of the standard normal distribution, C is the capacity of the communication channel, and V is the dispersion of the communication channel.

[0077] Example 26. According to any of Examples 21 to 25, the method further includes dividing the number of bits used for one or more HARQ retransmissions by the sending entity across multiple rounds of HARQ retransmission.

[0078] Example 27. The method according to any one of Examples 21 to 26, wherein an indication of channel quality is received as part of a HARQ negative acknowledgment (NACK) in response to a first transmission.

[0079] Example 28. A method according to any one of Examples 21 to 27, wherein the indication of channel quality indicates at least one of the following: signal-to-noise ratio (SNR); signal-to-interference-plus-noise ratio (SINR); or reference signal received power (RSRP).

[0080] Example 29. The method according to any one of Examples 21 to 28, wherein the indication of channel quality includes a channel quality indicator (CQI).

[0081] Example 30. The method of any one of Examples 21 to 29, wherein the transmission over the communication channel is encoded by: CRC auxiliary polar code; polar code; or low-density parity check (LDPC) code.

[0082] Example 31. A non-transitory computer-readable storage medium including instructions stored thereon, which, when executed by at least one processor, are configured to cause a computing system to perform a method according to any one of Examples 21 to 30.

[0083] Example 32. A computer program including instructions stored thereon for performing a method according to any one of Examples 21 to 30.

[0084] Example 33. An apparatus comprising components for performing a method according to any one of Examples 21 to 30.

[0085] Figure 5 This is a diagram illustrating an example embodiment. In step 1, the sending entity 520 can send user data to the receiving entity 510 via a communication channel as part of a first transmission. The sending entity can be a network node, base station, gNB, user equipment, UE, etc. The receiving entity can be a network node, base station, gNB, user equipment, UE, etc. In step 2, the sending entity 520 can receive a NACK in response to the first transmission from the receiving entity 510. The NACK may include an indication or information regarding the channel quality of the communication channel. In step 3, the sending entity 520 can determine a lower limit for the BLER of the communication channel based on the received indication or information. In step 4, the sending entity 520 can determine the number of bits used for one or more HARQ retransmissions associated with the first transmission. In step 5, the sending entity 520 can perform one or more new HARQ retransmissions to the receiving entity 510 based on the determined number of bits.

[0086] Figure 6This is a block diagram of a wireless station or node (e.g., UE, user equipment, AP, BS, eNB, gNB, RAN node, network node, TRP, or other node) 1300 according to an example embodiment. The wireless station 1300 may include, for example, one or more (e.g., such as...) Figure 6 The two RF (radio frequency) or wireless transceivers 1302A and 1302B shown herein include a transmitter for transmitting signals and a receiver for receiving signals. The wireless station also includes a processor or control unit / entity (controller) 1304 for transmitting and receiving instructions or software and control signals, and a memory 1306 for storing data and / or instructions.

[0087] Processor 1304 may also make decisions or determinations, generate frames, packets, or messages for transmission, decode received frames or messages for further processing, and perform other tasks or functions described herein. Processor 1304, which may be a baseband processor, may generate messages, packets, frames, or other signals for transmission via wireless transceiver 1302 (1302A or 1302B). Processor 1304 may control the transmission of signals or messages on a wireless network and may control the reception of signals or messages via a wireless network (e.g., after down-conversion, for example, by wireless transceiver 1302). Processor 1304 may be programmable and capable of executing software or other instructions stored in memory or other computer media to perform the various tasks and functions described above, such as one or more of the tasks and methods described above. Processor 1304 may be (or may include) hardware, programmable logic, a programmable processor executing software or firmware, and / or any combination of these. For example, using other terms, processor 1304 and transceiver 1302 together may be considered a wireless transmitter / receiver system.

[0088] Additionally, refer to Figure 6 The controller (or processor) 1308 can execute software and instructions, and can provide overall control for station 1300, as well as for stations not in use. Figure 6 Other systems shown provide control, such as controlling input / output devices (e.g., a display, a keyboard), and / or can execute software for one or more applications that can be provided on the wireless station 1300, such as, for example, an email program, an audio / video application, a word processor, a VoIP application, or other applications or software.

[0089] Alternatively, a storage medium may be provided that includes stored instructions, which, when executed by a controller or processor, can cause the processor 1304 or other controller or processor to perform one or more of the functions or tasks described above.

[0090] According to another example embodiment, the RF or (multiple) wireless transceivers 1302A / 1302B can receive signals or data and / or transmit or send signals or data. The processor 1304 (and possibly the transceivers 1302A / 1302B) can control the RF or wireless transceivers 1302A or 1302B to receive, transmit, broadcast, or send signals or data.

[0091] For each example method in the example methods, an example embodiment is provided or described, including: an apparatus (e.g., 1300, Figure 6 ), including components for performing any of the methods (e.g., Figure 6 The processor 1304, RF transceiver 1302A and / or 1302B, and / or memory 1306; a non-transitory computer-readable storage medium (e.g., memory 1306, ...). Figure 6 ), including instructions stored thereon, which are processed by at least one processor (processor 1304, Figure 6 When executed, it is configured to cause the computing system (e.g., 1300, Figure 6 ) execute any of the example methods; and a device (e.g., 1300, Figure 6 ), including at least one processor (e.g., processor 1304, Figure 6 ) and at least one memory including computer program code (e.g., memory 1306, Figure 6 At least one memory (1306) and computer program code are configured, together with at least one processor (1304), such that the apparatus (e.g., 1300) performs at least any one of the example methods.

[0092] Embodiments of the various technologies described herein can be implemented in digital electronic circuit systems, or in computer hardware, firmware, software, or a combination thereof. Embodiments can be implemented as computer program products, i.e., computer programs tangibly implemented in an information carrier (e.g., in a machine-readable storage device or in a propagating signal) for execution or control of their operation by a data processing device (e.g., a programmable processor, a computer, or multiple computers). Embodiments can also be provided on a computer-readable medium or a computer-readable storage medium, which may be a non-transitory medium. Embodiments of the various technologies may also include embodiments provided via transient signals or media, and / or program and / or software embodiments downloadable via the Internet or other networks(wired and / or wireless networks). Additionally, embodiments can be provided via machine-type communication, and also via the Internet of Things (IoT).

[0093] As used herein, the term "circuit system" or "circuit" refers to all of the following: (a) implementations of hardware circuitry alone, such as implementations in analog and / or digital circuit systems alone; and (b) combinations of circuitry and software (and / or firmware), such as (where applicable): (i) combinations of (multiple) processors or (ii) portions of software including (multiple) digital signal processors, software, and (multiple) memories, which work together to enable a device to perform various functions; and (c) circuitry such as (multiple) microprocessors or portions thereof, which require software or firmware for operation, even if the software or firmware is not physically present. This definition of "circuit system" applies to all uses of the term herein. As another example, as used herein, the term "circuit system" will also cover implementations of processors (or multiple processors) or portions thereof and their accompanying software and / or firmware. The term "circuit system" will also cover (for example, and if applicable to a particular element) baseband integrated circuits or application processor integrated circuits for mobile phones, or similar integrated circuits in servers, cellular network devices, or other network devices.

[0094] Computer programs can be in the form of source code, object code, or some intermediate form, and can be stored on some kind of carrier, distribution medium, or computer-readable medium, which can be any entity or device capable of carrying the program. Examples of such carriers include recording media, computer memory, read-only memory, photoelectric and / or electrical carrier signals, telecommunication signals, and software distribution packets. Depending on the required processing power, a computer program can be executed in a single electronic digital computer, or it can be distributed across multiple computers.

[0095] Furthermore, embodiments of the various technologies described herein can utilize cyber-physical systems (CPS) (systems that control collaborative computing elements of physical entities). CPS enables the implementation and development of numerous interconnected ICT devices (sensors, actuators, processors, microcontrollers, etc.) embedded in physical objects at different locations. Mobile cyber-physical systems, which possess inherent mobility, are a subclass of cyber-physical systems. Examples of mobile cyber-physical systems include mobile robots and electronic devices transported by humans or animals. The increasing prevalence of smartphones has fueled interest in the field of mobile cyber-physical systems. Therefore, various embodiments of the technologies described herein can be provided via one or more of these technologies.

[0096] Computer programs such as the aforementioned computer programs can be written in any programming language, including compiled or interpreted languages, and can be deployed in any form, including as standalone programs or as modules, components, subroutines, or other units or parts thereof suitable for a computing environment. Computer programs can be deployed to execute on a single computer or multiple computers at a single location, or distributed across multiple locations and interconnected by a communication network.

[0097] The method steps can be executed by one or more programmable processors that execute a computer program or a portion thereof to perform a function by manipulating input data and generating output. The method steps can also be executed by a device, and the device can be implemented as a special-purpose logic circuit system, such as an FPGA (Field-Programmable Gate Array) or an ASIC (Application-Specific Integrated Circuit).

[0098] Processors suitable for executing computer programs include, by way of example, both general-purpose and special-purpose microprocessors, and any kind of digital computer, chip, or chipset, and any one or more processors. Typically, a processor receives instructions and data from read-only memory or random access memory, or both. Components of a computer may include at least one processor for executing instructions, and one or more memory devices for storing instructions and data. Typically, a computer may also include, or be operatively coupled to, receive data from, transfer data to, or both of one or more mass storage devices (e.g., magnetic disks, magneto-optical disks, or optical disks) for storing data. Information carriers suitable for implementing computer program instructions and data include all forms of non-volatile memory, including, by way of example, semiconductor memory devices (e.g., EPROM, EEPROM, and flash memory devices); magnetic disks (e.g., internal hard disks or removable disks); magneto-optical disks; and CD-ROM and DVD-ROM disks. Processors and memory may be supplemented by, or incorporated into, a system of dedicated logic circuitry.

[0099] To provide interaction with a user, embodiments can be implemented on a computer having a display device (e.g., a cathode ray tube (CRT) or liquid crystal display (LCD) monitor) for displaying information to the user and a user interface (such as a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback, such as visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including auditory, voice, or tactile input.

[0100] The embodiments can be implemented in a computing system, which can be: a computing system including back-end components (e.g., as a data server), or a computing system including middleware components (e.g., an application server), or a computing system including front-end components (e.g., a client computer with a graphical user interface web browser through which a user can interact with the embodiments), or any combination of such back-end, middleware, or front-end components. Components can be interconnected via digital data communication (e.g., a communication network) of any form or medium. Examples of communication networks include local area networks (LANs) and wide area networks (WANs), such as the Internet.

[0101] While certain features of the embodiments have been described herein, many modifications, substitutions, alterations, and equivalents will now occur to those skilled in the art. Therefore, it should be understood that the appended claims are intended to cover all such modifications and alterations falling within the true spirit of the various embodiments.

Claims

1. A device for communication, comprising: At least one processor; as well as At least one memory for storing instructions When the instructions are executed by the at least one processor, the device causes the following to be performed: The first transmission is performed via the communication channel; Receive an indication of channel quality for the communication channel from the receiving entity; Based on the indication of the channel quality, a lower limit for the block error rate (BLER) for the communication channel is determined; Based on the BLER lower bound, determine the number of bits to be used for retransmission of one or more Hybrid Automatic Repeat Request (HARQ) requests associated with the first transmission; as well as HARQ retransmission is performed through the communication channel based on the determined number of bits used for the one or more HARQ retransmissions.

2. The apparatus of claim 1, wherein the lower limit of BLER is determined based on at least one of the following: The probability that an error will not be detected by Cyclic Redundancy Check (CRC); The probability that the parity check of a low-density parity-check (LDPC) code is not satisfied; The probability of rejection based on reliability threshold.

3. The apparatus of claim 1, wherein determining the number of bits used for the one or more HARQ retransmissions is based on a lookup table, wherein the lookup table includes at least one of the following: The mapping between the channel quality metric and the number of bits; Mapping between the Channel Quality Indicator (CQI) index and the number of bits; or The mapping between the BLER lower limit and the number of bits.

4. The apparatus of claim 3, wherein the mapping between the number of bits used for the one or more HARQ retransmissions and the lower bound of BLER is based on an error probability function E(R, n), where R is the code rate of the (n, k) code, k is the number of information bits, and n is the number of encoded bits.

5. The apparatus of claim 4, wherein E(R,n) is calculated based on: ， Where Q is the Q-function of the standard normal distribution, C is the capacity of the communication channel, and V is the dispersion of the communication channel.

6. The apparatus according to any one of claims 1 to 5, wherein the apparatus is further configured to perform the division of the number of bits for the one or more HARQ retransmissions across multiple rounds of HARQ retransmission.

7. The apparatus according to any one of claims 1 to 5, wherein the indication of channel quality is received as part of a HARQ negative acknowledgment (NACK) in response to the first transmission.

8. The apparatus according to any one of claims 1 to 5, wherein the indication of channel quality indicates at least one of the following: Signal-to-noise ratio (SNR); Signal-to-interference-plus-noise ratio (SINR); or Reference signal received power (RSRP).

9. The apparatus according to any one of claims 1 to 5, wherein the indication of channel quality includes a channel quality indicator (CQI).

10. The apparatus according to any one of claims 1 to 5, wherein the transmission through the communication channel is encoded in the following manner: CRC auxiliary polar code; Polar codes; or Low-density parity-check (LDPC) code.

11. An apparatus for communication, comprising: Components for performing a first transmission via a communication channel; A component for receiving an indication of channel quality for the communication channel from a receiving entity; Components for determining a lower limit of the block error rate (BLER) for the communication channel based on the indication of the channel quality; A component for determining, based on the BLER lower limit, the number of bits to be retransmitted for one or more Hybrid Automatic Repeat Request (HARQ) retransmissions associated with the first transmission; as well as A component for performing HARQ retransmission via the communication channel based on the determined number of bits used for the one or more HARQ retransmissions.

12. The apparatus of claim 11, wherein the lower limit of BLER is determined based on at least one of the following: The probability that an error will not be detected by Cyclic Redundancy Check (CRC); The probability that the parity check of a low-density parity-check (LDPC) code is not satisfied; The probability of rejection based on reliability threshold.

13. The apparatus of claim 11, wherein determining the number of bits used for the one or more HARQ retransmissions is based on a lookup table, wherein the lookup table includes at least one of the following: The mapping between the channel quality metric and the number of bits; Mapping between the Channel Quality Indicator (CQI) index and the number of bits; or The mapping between the BLER lower limit and the number of bits.

14. The apparatus of claim 13, wherein the mapping between the number of bits used for the one or more HARQ retransmissions and the lower bound of the BLER is based on an error probability function E(R, n), where R is the code rate of the (n, k) code, k is the number of information bits, and n is the number of encoded bits.

15. The apparatus of claim 14, wherein E(R,n) is calculated based on: ， Where Q is the Q-function of the standard normal distribution, C is the capacity of the communication channel, and V is the dispersion of the communication channel.

16. The apparatus according to any one of claims 11 to 15, further comprising a component for dividing the number of bits for the one or more HARQ retransmissions across multiple rounds of HARQ retransmission.

17. The apparatus according to any one of claims 11 to 15, wherein the indication of channel quality is received as part of a HARQ negative acknowledgment (NACK) in response to the first transmission.

18. The apparatus according to any one of claims 11 to 15, wherein the indication of channel quality indicates at least one of the following: Signal-to-noise ratio (SNR); Signal-to-interference-plus-noise ratio (SINR); or Reference signal received power (RSRP).

19. The apparatus according to any one of claims 11 to 15, wherein the indication of channel quality includes a channel quality indicator (CQI).

20. The apparatus according to any one of claims 11 to 15, wherein the transmission through the communication channel is encoded in the following manner: CRC auxiliary polar code; Polar codes; or Low-density parity-check (LDPC) code.

21. A method for communication, comprising a sending entity: The first transmission is performed via the communication channel; Receive an indication of channel quality for the communication channel from the receiving entity; Based on the indication of the channel quality, a lower limit for the block error rate (BLER) for the communication channel is determined; Based on the BLER lower bound, determine the number of bits to be used for retransmission of one or more Hybrid Automatic Repeat Request (HARQ) requests associated with the first transmission; as well as HARQ retransmission is performed through the communication channel based on the determined number of bits used for the one or more HARQ retransmissions.

22. The method of claim 21, wherein the lower limit of BLER is determined based on the following: The probability that an error will not be detected by Cyclic Redundancy Check (CRC); The probability that the parity check of a low-density parity-check (LDPC) code is not satisfied; or The probability of rejection based on reliability threshold.

23. The method of claim 21, wherein determining the number of bits used for the one or more HARQ retransmissions is based on a lookup table, wherein the lookup table includes at least one of the following: The mapping between the channel quality metric and the number of bits; Mapping between the Channel Quality Indicator (CQI) index and the number of bits; or The mapping between the BLER lower limit and the number of bits.

24. The method of claim 23, wherein the mapping between the number of bits used for the one or more HARQ retransmissions and the lower bound of BLER is based on an error probability function E(R, n), where R is the code rate of the (n, k) code, k is the number of information bits, and n is the number of encoded bits.

25. The method of claim 24, wherein E(R,n) is calculated based on: ， Where Q is the Q-function of the standard normal distribution, C is the capacity of the communication channel, and V is the dispersion of the communication channel.

26. The method according to any one of claims 21 to 25, further comprising: The sending entity divides the number of bits used for the one or more HARQ retransmissions across multiple rounds of HARQ retransmission.

27. The method according to any one of claims 21 to 25, wherein the indication of channel quality is received as part of a HARQ negative acknowledgment (NACK) in response to the first transmission.

28. The method according to any one of claims 21 to 25, wherein the indication of channel quality indicates at least one of the following: Signal-to-noise ratio (SNR); Signal-to-interference-plus-noise ratio (SINR); or Reference signal received power (RSRP).

29. The method according to any one of claims 21 to 25, wherein the indication of channel quality includes a channel quality indicator (CQI).

30. The method according to any one of claims 21 to 25, wherein the transmission through the communication channel is encoded in the following manner: CRC auxiliary polar code; Polar codes; or Low-density parity-check (LDPC) code.

31. A computer-readable storage medium comprising instructions stored thereon, the instructions being configured, when executed by at least one processor, to cause a computing system to perform the method according to any one of claims 21 to 30.

32. A computer program product comprising instructions stored thereon for performing the method according to any one of claims 21 to 30.

Images