CN114175541A

CN114175541A - Integrated signaling of HARQ acknowledgements

Info

Publication number: CN114175541A
Application number: CN201980098506.1A
Authority: CN
Inventors: 郭海友
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Priority date: 2019-07-17
Filing date: 2019-07-17
Publication date: 2022-03-11
Also published as: WO2021007796A1

Abstract

Embodiments of the present disclosure relate to integrated signaling of hybrid automatic repeat request acknowledgements. The first device determines a reception status of a plurality of transport blocks received from at least one second device. The first device generates a bit sequence based on the reception status of the plurality of transport blocks such that each of the plurality of transport blocks corresponds to one or more bits in the sequence. The first device transmits the bit sequence to the at least one second device as an indication of the reception status.

Description

Integrated signaling of HARQ acknowledgements

Technical Field

Embodiments of the present disclosure relate generally to the field of telecommunications, and more particularly, to methods, apparatuses, devices, and computer-readable storage media for integrated signaling of hybrid automatic repeat request (HARQ) acknowledgements.

Background

HARQ acknowledgement signalling is an indispensable component in the retransmission protocol. Most wireless systems, including 3GPP Long Term Evolution (LTE) and New Radio (NR), rely on a combination of error correction coding and retransmission of erroneous data units, employing HARQ with soft combining. HARQ provides robustness to transmission errors and maintains multiple parallel stop-and-wait processes. Upon receiving the transport block, the receiving device attempts to decode the transport block and informs the transmitting device of the result of the decoding operation by a single acknowledgement bit indicating whether the decoding was successful or whether retransmission of the transport block is required.

In Medium Access Control (MAC) of LTE and NR, a large transport block is split into multiple code blocks before encoding. Each code block is configured with its own 24-bit CRC, except for the Cyclic Redundancy Check (CRC) of the entire transport block. Since each code block has its own CRC, errors can be detected on a single code block as well as the entire transport block, positive Acknowledgements (ACK) in case of successful decoding and Negative Acknowledgements (NACK) in case of failed decoding. As part of the control information, the receiving device feeds back a single bit indicating a positive or negative acknowledgement for each transport block, code block or group of code blocks. In case of an erroneous reception of a data unit, a retransmission is requested from the respective transmitting device.

BRIEF SUMMARY OF THE PRESENT DISCLOSURE

In general, example embodiments of the present disclosure provide solutions for integrated signaling for HARQ acknowledgements.

In a first aspect, a first apparatus is provided. The first device comprises at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the first apparatus at least to: determining a reception status of a plurality of transport blocks received from at least one second device; generating a bit sequence based on the reception status of the plurality of transport blocks such that each transport block of the plurality of transport blocks corresponds to one or more bits in the sequence; and transmitting the sequence of bits to the at least one second device as an indication of the reception status.

In a second aspect, a second apparatus is provided. The second device comprises at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the second apparatus at least to: transmitting a transport block to a first device, the first device receiving at least a plurality of transport blocks from the second device; receiving at least a portion of a sequence of bits from the first device, each transport block of the plurality of transport blocks corresponding to one or more bits in the sequence; and determining a reception status of the transport block based on at least a portion of the bit sequence.

In a third aspect, a method is provided. The method includes determining a reception status of a plurality of transport blocks received from at least one second device; generating a bit sequence based on the reception status of the plurality of transport blocks such that each transport block of the plurality of transport blocks corresponds to one or more bits in the sequence; and transmitting the sequence of bits to the at least one second device as an indication of the reception status.

In a fourth aspect, a method is provided. The method includes transmitting a transport block to a first device, the first device receiving at least a plurality of transport blocks from the second device; receiving a sequence of bits from the first device, each transport block of the plurality of transport blocks corresponding to one or more bits in the sequence; and determining a reception status of the transport block based on the bit sequence.

In a fifth aspect, an apparatus is provided that comprises means for determining a reception status of a plurality of transport blocks received from at least one second device; means for generating a sequence of bits based on reception states of the plurality of transport blocks such that each transport block of the plurality of transport blocks corresponds to one or more bits in the sequence; and means for transmitting the sequence of bits to the at least one second device as an indication of the reception status.

In a sixth aspect, an apparatus is provided that includes means for transmitting a transport block to a first device, the first device receiving a plurality of transport blocks from at least a second device; means for receiving a sequence of bits from the first device, each transport block of the plurality of transport blocks corresponding to one or more bits in the sequence; and means for determining a reception status of the transport block based on the bit sequence.

In a seventh aspect, there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method according to the above third aspect.

In an eighth aspect, there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least a method according to the fourth aspect described above.

It should be understood that this disclosure is not intended to identify key or essential features of the embodiments of the disclosure, nor is it intended to be used to limit the scope of the disclosure. Other features of the present disclosure will become readily apparent from the following description.

Drawings

Some example embodiments will now be described with reference to the accompanying drawings, in which:

FIG. 1 illustrates an example communication network in which embodiments of the present disclosure may be implemented;

figure 2 shows a diagram illustrating the separate signaling of HARQ acknowledgements;

fig. 3 illustrates a flow diagram of an example process for integrated signaling for HARQ acknowledgements in accordance with some embodiments of the present disclosure;

figure 4 is a diagram illustrating integrated signaling of HARQ acknowledgements according to some embodiments of the present disclosure;

fig. 5 is a diagram illustrating an example process of HARQ-related information according to some embodiments of the present disclosure;

6A, 6B, and 6C illustrate examples of generating a bit sequence according to some embodiments of the present disclosure;

fig. 7 is a diagram illustrating transmission of a bit sequence according to some embodiments of the present disclosure;

FIGS. 8A and 8B illustrate examples of query bit sequences according to some embodiments of the present disclosure;

FIG. 9 shows a graph of the performance of a proposed solution according to some embodiments of the present disclosure;

FIG. 10 illustrates a flow diagram of a method according to some embodiments of the present disclosure;

FIG. 11 shows a flow diagram of a method according to some other embodiments of the present disclosure;

FIG. 12 shows a simplified block diagram of an apparatus suitable for implementing embodiments of the present disclosure; and

FIG. 13 illustrates a block diagram of an example computer-readable medium in accordance with some embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals denote the same or similar elements.

Detailed Description

The principles of the present disclosure will now be described with reference to a few exemplary embodiments. It is to be understood that these examples are described solely for the purpose of illustration and to assist those skilled in the art in understanding and practicing the disclosure, and are not intended to suggest any limitation as to the scope of the disclosure. The disclosure described herein may be implemented in a variety of ways other than those described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

References in the disclosure to "one embodiment," "an example embodiment," etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term "and/or" includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "has," "having," "includes" and/or "including," when used herein, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof.

In this application, the term "circuitry" may refer to one or more or all of the following:

(a) hardware-only circuit implementations (e.g., implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuit(s) and software, for example (as applicable):

(i) a combination of analog and/or digital hardware circuit(s) and software/firmware, and

(ii) a hardware processor with software (including digital signal processor (s)), software and any portion of memory(s) that work together to cause a device (such as a mobile phone or server) to perform various functions, and

(c) hardware circuit(s) and/or processor(s), such as microprocessor(s) or a portion of microprocessor(s), that require software (e.g., firmware) for operation, but which may not be present when software is not required for operation.

The definition of circuit applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or its) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in a server, a cellular network device, or other computing or network device.

As used herein, the term "communication network" refers to a network that conforms to any suitable communication standard, such as Long Term Evolution (LTE), LTE-advanced (LTE-a), Wideband Code Division Multiple Access (WCDMA), High Speed Packet Access (HSPA), narrowband internet of things (NB-IoT), and so forth. Further, communication between terminal devices and network devices in a communication network may be performed according to any suitable generation of communication protocols, including, but not limited to, a first generation (1G) communication protocol, a second generation (2G) communication protocol, a 2.5G communication protocol, a 2.75G communication protocol, a third generation (3G) communication protocol, a fourth generation (4G) communication protocol, a 4.5G communication protocol, a fifth generation (5G) communication protocol in the future, and/or any other protocol currently known or to be developed in the future. Embodiments of the present disclosure may be applied to various communication systems. In view of the rapid development of communications, there will of course be future types of communication technologies and systems with which the present disclosure may be implemented. And should not be construed as limiting the scope of the disclosure to only the above-described systems.

As used herein, the term "network device" refers to a node in a communication network through which a terminal device accesses the network and receives services therefrom. A network device may refer to a Base Station (BS) or an Access Point (AP), e.g., a node B (NodeB or NB), an evolved node B (eNodeB or eNB), an NR-NB (also known as a gNB), a Remote Radio Unit (RRU), a Radio Header (RH), a Remote Radio Header (RRH), a relay, a low power node such as a femto node (femto), a pico node (pico), etc., depending on the terminology and technology of the application.

The term "terminal device" refers to any terminal device capable of wireless communication. By way of example, and not limitation, a terminal device may also be referred to as a communication device, User Equipment (UE), Subscriber Station (SS), portable subscriber station, Mobile Station (MS), or Access Terminal (AT). The end devices may include, but are not limited to, mobile phones, cellular phones, smart phones, voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable end devices, Personal Digital Assistants (PDAs), portable computers, desktop computers, image capture end devices such as digital cameras, gaming end devices, music storage and playback devices, in-vehicle wireless end devices, wireless terminals, mobile stations, notebook embedded devices (LEEs), notebook installed devices (LMEs), USB dongles, smart devices, wireless Customer Premises Equipment (CPE), internet of things (loT) devices, watches or other wearable devices, Head Mounted Displays (HMDs), vehicles, drones, medical devices and applications (such as tele-surgery), industrial devices and applications (such as robots and/or other wireless devices operating in industrial and/or automated processing chain environments), or other devices, Consumer electronics devices, devices operating on commercial and/or industrial wireless networks, and the like. In the following description, the terms "terminal device", "communication device", "terminal", "user equipment" and "UE" may be used interchangeably.

In NR, an asynchronous HARQ protocol is used for downlink and uplink. In the asynchronous HARQ protocol, the scheduling of retransmissions is in principle similar to the initial transmission. Without fixed uplink/downlink allocations, it is necessary to support dynamic Time Division Duplexing (TDD) using asynchronous uplink protocols instead of synchronous protocols in LTE. It also provides greater flexibility in terms of prioritization between data streams and devices, and facilitates extension to unlicensed spectrum operation. For such asynchronous operation, an explicit HARQ process number is also required to signal to indicate the process being addressed. NR supports 16 HARQ processes at most, taking 4 bits extra to distinguish HARQ processes. The larger maximum number of HARQ processes compared to LTE is driven by the possibility of a remote radio head causing some pre-delay and shorter slot duration at high frequencies. Importantly, a larger maximum number of HARQ processes does not mean a longer round trip time, since not all processes need to be used, which is only an upper limit on the number of possible processes.

Another feature of the HARQ mechanism in NR compared to LTE is the possibility of retransmission of code block groups. This function is beneficial for very large transport blocks or when a transport block is partially disturbed by another preemptive transmission. As part of the channel coding operation in the physical layer, the transport block is partitioned into one or more code blocks, and error correction coding is applied to each of the code blocks of up to 8448 bits to keep the channel coding complexity reasonable. Thus, even at medium data rates, there may be multiple code blocks per transport block, and at Gbps data rates, there may be hundreds of code blocks per transport block.

In many cases, especially if the interference is bursty and hits a small number of Orthogonal Frequency Division Multiplexing (OFDM) symbols in a slot, only a few of these code blocks in the transport block may be corrupted, while most of these code blocks are received correctly. For correct reception of the transport block it is sufficient to retransmit the erroneous code block instead of the entire transport block. However, if all individual code blocks are addressed by the HARQ mechanism, the control signaling overhead will be too large. The signaling overhead of HARQ becomes non-persistent, which will deteriorate large-scale connections. Therefore, future developments of NR require a complex and economical HARQ acknowledgement signaling method that can achieve per code block retransmissions.

In the asynchronous HARQ protocol, the receiving device feeds back ACK/NACK to the transmitting device. First, the transmitting device must determine which HARQ process and which code block the returned acknowledgement relates to. This can be solved directly by using explicit HARQ process numbers and code block numbers, using acknowledgement timing associated with a particular HARQ process, in case a small number of code blocks are to be indicated, or using acknowledgement positions in the HARQ codebook, in case multiple acknowledgements are transmitted simultaneously.

However, the above direct approach is not applicable to NR in view of unsustainable signaling costs. This is because NR allows one UE to maintain up to 16 HARQ processes on each carrier, and each process typically handles hundreds of code blocks. For this reason, in NR, the HARQ protocol makes some trade-offs between performance and signaling cost by configuring per-Code Block Group (CBG) retransmissions. The HARQ acknowledgement indicates only the group of code blocks instead of a single code block. Therefore, the entire CBG, including the corrupted code block and the correct code block, needs to be retransmitted, resulting in an inevitable bandwidth efficiency performance loss.

The other partyThe HARQ mechanism in the MAC layer targets very fast retransmissions. If low latency is important, a large number of HARQ acknowledgements need to be fed back quickly after the end of the downlink and uplink slots, which presents a challenge to the control channel design. Regardless of the decoding state, a positive or negative acknowledgement must be sent for the transport block or code block. With the strong forward error correction codes employed, the probability of receiving erroneous code blocks is very low, especially for ultra-reliable low-delay communications (URLLC). The minimum reliability requirement of URLLC is that in the channel quality at the edge of coverage, the probability of success for transmitting a 32-byte layer 2 protocol data unit within 1ms is 1-10^-5. This means that the receiving device mostly feeds back messages on positive acknowledgements and transmits NACKs infrequently.

In view of the above, signaling overhead can be saved by deliberately utilizing such asymmetric feedback of ACK and NACK by appropriate design. However, the conventional method does not pay much attention to this point. Embodiments of the present disclosure indicate and send HARQ acknowledgements in an integrated manner for multiple transmissions. The disclosed signaling method takes advantage of the sporadic nature of NACK signaling and allows for an efficient HARQ protocol that does not trade off between performance and cost.

The principles and embodiments of the present disclosure will be described in detail below with reference to the drawings. Referring initially to fig. 1, fig. 1 illustrates an example communication network in which embodiments of the present disclosure may be implemented. Communication network 100 includes network device 110 and terminal devices 120-1, 120-2 …, and 120-N (where N is an integer), which may be collectively referred to as "terminal devices" 120 or individually as "terminal devices" 120.

Network 100 may provide one or more cells 102 to serve terminal devices 120. It should be understood that the number of network devices, terminal devices, and/or cells are given for illustrative purposes and are not intended to suggest any limitation to the present disclosure. Communication network 100 may include any suitable number of network devices, terminal devices, and/or cells suitable for implementing the present disclosure.

In communication network 100 as shown in fig. 1, network device 110 may transmit data and control information to terminal device 120, and terminal device 120 may also transmit data and control information to network device 110. The link from network device 110 to terminal device 120 is referred to as the Downlink (DL) and the link from terminal device 120 to network device 110 is referred to as the Uplink (UL). In the DL, the network device 110 is a Transmitting (TX) device (or transmitter) and the terminal device 120 is a Receiving (RX) device (or receiver). In the UL, the terminal device 120 is a TX device (or transmitter) and the network device 110 is an RX device (or receiver).

Communications in communication network 100 may be implemented in accordance with any suitable communication protocol, including, but not limited to, cellular communication protocols (first generation (1G), second generation (2G), third generation (3G), fourth generation (4G), and fifth generation (5G), etc.), wireless local network communication protocols (e.g., Institute of Electrical and Electronics Engineers (IEEE)802.11, etc.), and/or any other protocol now known or later developed in the future. Further, the communication may utilize any suitable wireless communication technology, including but not limited to: code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple Input Multiple Output (MIMO), Orthogonal Frequency Division Multiplexing (OFDM), discrete Fourier transform spread OFDM (DFT-s-OFDM), and/or any other technique now known or later developed.

In communication, a TX device may transmit a transport block including a plurality of code blocks or CBGs to an RX device. For example, in the UL, network device 110 may receive transport blocks from terminal devices 120-1, 120-2, …, 120-N. In the DL, terminal device 120 (e.g., terminal device 120-1) may receive transport blocks from network device 110. A reception status for each code block and/or CBG may be determined by the RX device, and an indication of the reception status may be sent to the TX device to indicate whether the TX device retransmits the corresponding code block and/or CBG.

Traditionally, almost all HARQ protocols employ separate signaling of HARQ acknowledgements for uplink transmissions. Referring now to fig. 2, a diagram 200 illustrating split signaling of HARQ acknowledgements is shown. As shown in fig. 2, a network device, such as the gNB 210, maintains a plurality of independent HARQ entities 230-1, 230-2, …, 230-N for UEs 220-1, 220-2, …, 220-N, respectively. The HARQ entity decodes the UL transport block (or code block) and informs the corresponding UE of the result of the decoding operation through a separate DL control channel on the radio interface. HARQ acknowledgements for different UEs 220-1, 220-2, …, 220-N are indicated and signaled separately with respect to each other. Thus, the signaling cost increases with the number of UEs and the number of carrier components and the total number of HARQ processes and code blocks.

For example, in the NR standard, HARQ related information is included in a user specific uplink scheduling grant, dedicated to each of the UEs 220-1, 220-2, …, 220-N, respectively. The scheduling assignment contains necessary HARQ related control signaling and transport block related information, including: HARQ process number (4 bits), which informs the device of the HARQ process used for soft combining; CBG transmission indicator (CBGTI, 0, 2, 4, 6 or 8 bits) indicating the retransmitted code block group (present only in DCI format 1-1, and present only when CBG retransmission is configured); a new data indicator (1 bit) indicating whether the grant relates to a retransmission of a transport block or to a transmission of a new transport block.

Based on this signaling, the so-called CBG is defined by an explicit indication. If every CBG retransmission is configured, every CBG provides feedback and only erroneously received code block groups are retransmitted. This may consume less resources than retransmitting the entire transport block, thereby achieving a trade-off between performance and cost.

Furthermore, the split signaling method as shown in fig. 2 has less flexibility. Control channel resources should be reserved for the HARQ related and transport block related information regardless of the decoding state of the code block. To support retransmission per code block, the minimum signaling overhead (bits) required for the separate signaling is equal to the total number of UL code blocks from all UEs 220-1, 220-2, …, 220-N.

Accordingly, embodiments of the present disclosure propose a solution for integrated signaling for HARQ acknowledgement. In this solution, a bit sequence is generated by the RX device indicating HARQ related information on multiple code blocks or CBGs in a joint and implicit way. The RX device may transmit a bit sequence to one or more TX devices, from which the one or more TX devices may determine HARQ related information for a code block or CBG. When the RX device is a network device and the one or more TX devices comprise a plurality of terminal devices, the bit sequence may be broadcast over the radio interface. In this way, per-code block retransmission or per-CBG retransmission is achieved with less signaling overhead.

Referring now to fig. 3, shown is a flow diagram illustrating an example process 300 for integrated signaling for HARQ acknowledgements in accordance with some embodiments of the present disclosure. For purposes of discussion, process 300 will be described with reference to FIG. 1. As shown in fig. 1, process 300 may involve network device 110 and one or more terminal devices 120.

In process 300, terminal device 120 sends 305 a transport block to network device 110. For example, terminal device 120 may send a transport block comprising a plurality of transport blocks to network device 110 during a HARQ process. As used herein, the term "transport block" refers to a data unit whose reception status can be determined by the RX device (e.g., based on CRC). In some example embodiments, a transport block may refer to a code block. In some other example embodiments, the transport block may be referred to as a CBG. It should be understood that embodiments of the present disclosure may be applied to data units having other sizes or granularities, as long as the receipt status of the data units may be determined separately.

Although only one terminal device 120 is shown in fig. 3, it should be understood that process 300 may involve multiple terminal devices, such as all or portions of terminal devices 120-1, 120-2, …, 120-N. Thus, network device 110 receives at least a plurality of transport blocks from terminal device 120. In some example embodiments, multiple transport blocks may be received from a single terminal device 120. In some example embodiments, multiple transport blocks may be received from multiple terminal devices, e.g., all or a portion of terminal devices 120-1, 120-2 … 120-N.

The network device 110 determines 310 a reception status of a plurality of transport blocks received from at least one terminal device 120. For example, network device 110 may detect whether there is an error in decoding each transport block in the transport block. Network device 110 then generates 315 bit sequence based on the reception status of the plurality of transport blocks such that each of the plurality of transport blocks corresponds to one or more bits in the sequence. That is, the bit sequence indicates the reception status of the plurality of transport blocks in an integrated manner.

For a better understanding of the manner of integration proposed in this disclosure, reference is now made to fig. 4. Fig. 4 is a diagram 400 illustrating integrated signaling of HARQ acknowledgements, in accordance with some embodiments of the present disclosure. In the example architecture shown in fig. 4, a randomized data structure based on Bloom filter 450 is introduced and optimized. Network device 110 serves terminal devices 120-1, 120-2, …, 120-N with UL transmissions and maintains HARQ entities 430-1, 430-2, …, 430-N, each of which handles HARQ processes for a corresponding one of terminal devices 120-1, 120-2, …, 120-N.

In contrast to the split signaling shown in fig. 2, all HARQ entities 430-1, 430-2, …, 430-N share the same bloom filter 450. In some example embodiments, the bloom filter may be designed as a NACK filter configured to represent a set of NACK information from all or part of the HARQ entities 430-1, 430-2, …, 430-N. The bloom filter 450 may generate a bit sequence indicating the synthesis information of the NACKs corresponding to a plurality of transport blocks (e.g., a plurality of code blocks).

In the example shown in fig. 4, network device 110 maintains only one bloom filter 450 for a plurality of terminal devices 120-1, 120-2, …, 120-N to generate a bit sequence. Alternatively or additionally, network device 110 may maintain bloom filters for each of the plurality of terminal devices 120-1, 120-2, …, 120-N. In this case, a bit sequence may be generated for each terminal device 120 and the reception status of the plurality of transport blocks from the corresponding terminal device 120 may be indicated as a whole.

To understand the mapping of a particular transport block to one or more bits in a sequence, reference is now made to fig. 5. Fig. 5 is a diagram 500 illustrating an example process of HARQ-related information according to some embodiments of the present disclosure. As shown in fig. 5, bit sequence 550 generated by network device 110 (e.g., by bloom filter 450) may have m bits. All m bits are initially assigned a first value, e.g. "0".

To map the transport block 501, an identification generator 510 may be used. Identification generator 510 may perform bijective mapping such that transport blocks associated with HARQ processes for a particular terminal device 120 may be indexed by a unique identification (e.g., a global ID number).

In the case where one bloom filter is maintained for multiple terminal devices 120 (e.g., the example shown in fig. 4), the identification generator 510 may generate the unique identification 520 of the transport block 501 based on the identification of the terminal device 120 from which the transport block 501 was received, the identification of the HARQ process during which the transport block 501 was received, and the identification of the transport block 501 used to distinguish the transport block 501 from other transport blocks of the terminal device 120. In other words, the unique identification 520 of the transport block 501 is generated based on the set of local identifications associated with the transport block 501. For example, if transport block 501 is a code block received from terminal device 120-1 during a HARQ process, the identity of terminal device 120-1, the local number of the HARQ process, and the local number of the code block for terminal device 120-1 may be used to generate unique identity 520.

In the case where each HARQ entity maintains a bloom filter for the respective terminal device 120, the identification generator 510 may generate the unique identification 520 of the transport block 501 based on the identification of the HARQ process during which the transport block 501 was received and the identification of the transport block 501 used to distinguish the transport block 501 from other transport blocks of the terminal device 120.

In the example shown in fig. 4, for each of the HARQ entities 430-1, 430-2, …, 430-N, if the transport block (e.g., code block) does not pass the CRC, the unique identification of the erroneous transport block may be fed into the bloom filter 450 for the NACK. It should be appreciated that both the network device 110 and the terminal device 120 employ the same identification generator 510 or apply the same generation rules to generate the unique identification of the transport block. Identification generator 510 may be implemented in a variety of ways, and the scope of the present disclosure is not limited in this respect.

The position of one or more bits in sequence 550 corresponding to transport block 501 may then be determined by hashing unique identification 520. For example, k independent consistent random hash functions { f } may be used_i(·) | i ═ 1,2, …, k }. Each of the hash functions 530-1, 530-2, …, 530-k maps a unique identification to a

range

0,1,2,…, m-1 }. Each element of the range indicates a position in bit sequence 550. It should be understood that the hash function should be known to both the network device 110 and all terminal devices 120.

For the example shown in FIG. 5, assuming that the unique identification 520 of the transport block 501 is x, the computation of the hash functions 530-1, 530-2, …, 530-k may generate a set { f ] indicating k positions in the sequence 550_i(x) I |, 1,2, …, k }. If x indexes the wrong transport block, then for

i

1,2, …, k, the f-th in sequence 550_i(x) A bit may be assigned a second value, e.g., "1". It should be understood that a particular bit may be set to "1" multiple times, but only the first change is valid. After performing the same operation on all erroneous transport blocks, the resulting sequence 550 may indicate all NACK information in an integrated manner.

Reference is now made to fig. 3. After generating the bit sequence, e.g. after mapping all transport blocks with NACKs, the network device 110 sends 320 the resulting bit sequence to the terminal device 120 as an indication of the reception status of the plurality of transport blocks. In an example embodiment where one bloom filter is maintained for multiple terminal devices 120 (as in the example shown in fig. 4), network device 110 may broadcast the bit sequence over the DL control channel so that each terminal device 120 in serving cell 102 may receive at least a portion of the bit sequence. In an example embodiment where each HARQ entity maintains a bloom filter for a respective terminal device 120, the bit sequence may be transmitted to the respective terminal device 120 over a dedicated DL control channel.

Upon receiving at least a part of the bit sequence, the terminal device 120 may determine 325 a reception status of a previously transmitted transport block. For example, terminal device 120 may first generate a unique identification (e.g., denoted as y) for a particular transport block using identification generator 510 as described above. The hash function f may then be applied_i(·) | i ═ 1,2, …, k } applies to the unique identity y, and f can be generated indicating k positions in the sequence_i(y), wherein i is 1,2, …, k.

For example, if for i ═ 1,2, …, k, all bit sets f_i(y) has a second value, e.g. a value of "1", then the terminal is enabledDevice 120 may determine that a failure occurred in receiving the transport block with index y, otherwise terminal device 120 may determine that network device 110 correctly received the transport block with index y. If the terminal device 120 determines that a failure occurs in receiving the transport block with index y, the terminal device 120 may retransmit the transport block, for example, in the next slot.

In some example embodiments, terminal device 120 may determine a duration T since transmission of transport block 305 and determine whether the duration exceeds a time threshold T for receiving an indication of a status_max. If the duration T is below a time threshold T_maxThe terminal device 120 may determine the reception status of the transport block based on the received bit sequence.

An example of a general process for integrated signaling of HARQ acknowledgements is described with reference to fig. 3. Although the example process 300 is described with respect to UL transmissions, integrated signaling may also be applied to DL transmissions. In this case, the terminal device 120 may generate a bit sequence indicating the reception status of the plurality of DL transport blocks and transmit it to the network device 110.

In example embodiments of the present disclosure, HARQ acknowledgements for a large number of transport blocks (e.g., code blocks) may be fed back to the TX device in an integrated manner, and thus signaling overhead may be significantly reduced. In this way, every code block or every CBG retransmission can be done.

Specific example implementations are now described with reference to fig. 6A, 6B, 6C, 7, 8A, and 8B. Fig. 6A, 6B, and 6C illustrate examples of generating a bit sequence according to some embodiments of the present disclosure. As shown in FIG. 6A, the sequence 650 consists of m bits, which are indexed 0,1,2, …, m-1, respectively. Each bit in sequence 650 is initially assigned a value of "0" by network device 110.

As shown in fig. 6B, network device 110 may determine that a failure occurred when code block 601 was received and generate a unique identification ID1 for code block 601, e.g., as described above with reference to fig. 5. The hash functions 530-1, 530-2, …, 530-k are then applied to the unique identification ID₁. As shown in fig. 6B, due to f₁(ID₁)＝2、f₂(ID₁)＝m-6、f_k(ID₁) Network device 110 may assign a value of "1" to

bits

2, 4, and m-6.

As shown in fig. 6C, network device 110 may determine that a failure occurred when code block 602 was received and generate a unique identification ID for code block 602₂. The hash function 530-1, 530-2, …, 530-k is then applied to the unique identification ID₂. As shown in fig. 6B, due to f₁(ID₂)＝0、f₂(ID₂) M-5 and f_k(ID₂) Network device 110 may assign a value of "1" to

bits

0, 2, and m-5. It should be noted that in this example, the value of bit 2 is set to "1" twice and is valid only for the first time.

After generating bit sequence 650, network device 110 may transmit sequence 650 to terminal device 120. Reference is now made to fig. 7, which is a diagram 700 illustrating transmission of a bit sequence in accordance with some embodiments of the present disclosure. As shown in fig. 7, network device 110 may broadcast bit sequence 750 over a DL broadcast control channel. In order to quickly feed back NACK information of all error code blocks received in the current slot, a DL broadcast control channel is configured at the end of each slot. As shown in fig. 7, dedicated resources 710 may be configured for a DL broadcast control channel to transmit a bit sequence 750.

In this way, each terminal device 120 can obtain the bit sequence 750 by decoding the DL control channel and determine whether the transmitted code block was successfully received. Alternatively, each terminal device 120 may decode only a portion of the DL control channel that is allocated to a subset of bits in the sequence 750 that correspond to one or more of the code blocks it transmits. In this case, the terminal device 120 may first determine a subset of bits corresponding to one or more code blocks and decode only the portion allocated to the subset of bits.

Fig. 8A and 8B illustrate examples of a query bit sequence 750 according to some embodiments of the present disclosure. It should be understood that the sequence 750 shown in fig. 7, 8A, and 8B is shaded and has a different reference number than the sequence 650 shown in fig. 6A, 6B, and 6C. This takes into account potential errors in the transmit or receive sequence 650, which do not affect the principles of the present disclosure.

As shown in FIG. 8A, for a code block 601, the terminal device 120 may generate a unique identification ID for the code block 601, for example, by using the generator 510 as discussed with reference to FIG. 5₁. The hash function 530-1, 530-2, …, 530-k is then applied to the unique identification ID₁. Similar to that shown in FIG. 6B, the unique identification ID is hashed₁Result of (a) is f₁(ID₁)＝2、f₂(ID₁)＝m-6、f_k(ID₁) 4. Terminal device 120 checks the value of

bits

2, 4, m-6. Since all

bits

2, 4, m-6 have a value of "1", the terminal device 120 may determine that a failure occurred when the code block 601 was received by the network device 110 and retransmit the code block 601 to the network device 110.

As shown in FIG. 8B, for a code block 803, the terminal device 120 may generate a unique identification ID for the code block 803, for example, by using the generator 510₃. The hash function 530-1, 530-2, …, 530-k is then applied to the unique identification ID₃. Hashing a unique identification ID₃Result of (a) is f₁(ID₃)＝2,f₂(ID₃)＝3,f_k(ID₃) 4. The terminal device 120 checks the values of

bits

2, 3, 4. Since the value of bit 3 is "0", terminal device 120 may determine that network device 110 successfully received code block 803 and therefore no retransmission is required.

It should be understood that the example implementations are presented for purposes of illustration and not limitation. In addition, the network device 110 and the terminal device 120 are aware of the identity generator, the hash function and the size of the bit sequence and the DL broadcast control channel.

In some example embodiments, the number of bits in the sequence and the number of hash functions used to hash the unique identification may be fixed. In some example embodiments, the number of bits in the sequence and the number of hash functions used to hash the unique identification may be signaled. Such example embodiments are now described in detail.

The above solution for integrated signaling of HARQ NACK suffers from only single-sided errors. Specifically, the probability of a false ACK (a transport block declared correct when incorrect) is zero. This means that any erroneous transport blocks cannot be ignored. This robust feature facilitates retransmission design.

False NACKs (transmission blocks declared as errors when there are no errors) are sometimes encountered. All k bits corresponding to one correct transport block may be set to "1" by other erroneous transport blocks. It is noted that by noting the bloom filter for NACKs, e.g., noting the number of bits in the sequence and the number of hash functions, the probability of false NACKs can be reduced to an acceptable (approximately zero) ratio.

Assuming that the hash function is random, the probability of false NACK for the correct transport block (referred to as false NACK probability) can be calculated in a simple manner. Assume that network device 110 receives a total of N transport blocks from one or more terminal devices 120 in a time slot, where each terminal device 120 independently suffers from an error with a probability P_e. After hashing the unique identities of all M erroneous transport blocks into a bit sequence, the probability, denoted by P, that a particular bit still has a value of "0" can be calculated by the following equation:

wherein P (M) is randomly dependent on a binomial random variable M such that

Let q be the fraction of bits that are set to "0" after all erroneous transport blocks have been hashed to the bloom filter. It can be shown that this value q is very concentrated around its expected value, i.e.,

in practical engineering, it is difficult to apply direct calculations to optimize the bloom filter for NACKs. Hereinafter, the followingThe lower limit of q is used for simplifying the actual optimization. It can be shown that the function e^-kM/mWith respect to M, it is convex. According to the Jensen (Jensen) inequality, the following equation applies:

thus, the false NACK probability can be expressed approximately as:

it should be noted that for a position in the sequence given by any of the k hash functions, it is tested whether a NACK associated with the correct transport block is sent, with a probability of 1-q for the bit being assigned a "1". Thus, all bits corresponding to the k hash functions are assigned a probability of "1" of (1-q)^k。

By setting to a given value NP_eThe upper bound on the probability of false NACKs can be minimized by choosing an appropriate number of hash functions. It can be easily shown that as long as k is mln2/NP_eA minimum false NACK may be achieved

This also means that the probability of false NACKs can be reduced to less than a given tolerance epsilon if the required size of the bit sequence meets the following requirement

Considering P_eAt 10^-5Order of magnitude, so the overhead required for integrated signaling increases only linearly by a very small amount of 1.44P_elog₂(1/. epsilon.). Thus, the optimal number of hash functions can be represented by k ═ log₂(1/epsilon) was determined.

Thus, canThe length of the bit sequence and the number of hash functions are indicated. Network device 110 may determine a failure rate P of transport blocks_e. Failure rate P_eMay be predetermined, for example, at the system design level. The failure rate P may be determined based on the reception status of transport blocks that have been received by the network device 110_e。

Network device 110 may determine an error rate tolerance, e.g., a tolerance epsilon for false NACK probabilities, for indicating the reception status. For example, the error rate tolerance ε may be predetermined at the system design level. Network device 110 may then base on the failure rate P_eThe error rate tolerance epsilon and the number of transport blocks to determine the length of the bit sequence. For example, the length of the bit sequence may be determined as

Wherein

Representing the smallest integer greater than x.

Network device 110 may also determine the number of hash functions to hash the unique identification based on error rate tolerance. For example, the number of hash functions may be determined as

Wherein

Representing the largest integer less than x.

In some example embodiments, network device 110 may further send the length of the bit sequence and the number of hash functions to terminal device 120. For example, the network device 110 may broadcast an indication of the length of the bit sequence and the number of hash functions so that all terminal devices 120 in the serving cell 102 may know to have information about the length of the bit sequence and the number of hash functions.

The proposed integrated signaling solution has zero false ACK probability and negligible false NACK probability (10)^-10～10^-15) And signaling overhead is minimal. On the upper partThe analysis has shown that for a failure rate P to be handled by a HARQ process_eGiven a total number N of transport blocks, only one needs to be assigned

The signaling overhead of the bits to achieve an error probability less than epsilon. In other words, the amount of signaling overhead for HARQ acknowledgement may be reduced by 1.44P_elog₂(1/epsilon) times.

Fig. 9 is a graph 900 illustrating the performance of a proposed solution according to some embodiments of the present disclosure. As shown in FIG. 9, the reduction factor is a function of the failure rate P_eAnd error rate tolerance epsilon. It can be seen that at a false NACK probability of 10^-10～10^-15Under the condition of (3), the scheme can reduce signaling overhead by 2-3 orders of magnitude. This means that the proposed solution can be used for large scale access with per code block request HARQ.

Further details of example embodiments according to the present disclosure will be described with reference to fig. 10 to 11.

Fig. 10 illustrates a flow diagram of an example method 1000 in accordance with some example embodiments of the present disclosure. As shown in fig. 1, method 1000 may be implemented on a device, such as network device 110. For purposes of discussion, the method 1000 will be described with reference to fig. 1.

At block 1010, the network device 110 determines a reception status of a plurality of transport blocks received from at least one terminal device 120. At block 1020, the network device 110 generates a bit sequence based on the reception status of the plurality of transport blocks such that each of the plurality of transport blocks corresponds to one or more bits in the sequence. In block 1040, the network device 110 transmits the bit sequence to the at least one terminal device 120 as an indication of the reception status.

In some example embodiments, generating the bit sequence comprises: assigning a first value to a bit in the sequence; and in response to a failure in receiving a first transport block of the plurality of transport blocks, assigning a second value to a first subset of bits in the sequence corresponding to the first transport block, the second value being different from the first value.

In some example embodiments, the method 1000 further comprises: in response to a failure in receiving a second transport block of the plurality of transport blocks, a second value is assigned to a second subset of bits in the sequence corresponding to the second transport block, the second subset of bits being at least partially different from the first subset of bits.

In some example embodiments, assigning the second value to the first subset of bits corresponding to the first transport block comprises: obtaining a unique identifier of a first transport block; and determining the position of the first subset of bits in the sequence by hashing the unique identification.

In some example embodiments, obtaining the unique identification of the first transport block comprises determining the unique identification of the first transport block based on at least one of: an identification of the terminal device 120 from which the first transport block was received; an identification of a hybrid automatic repeat request process during which the first transport block was received; and an identification of the first transport block used to distinguish the first transport block from other transport blocks of terminal device 120.

In some example embodiments, the method 1000 further comprises: determining a failure rate of transport blocks that have been received by network device 110; determining an error rate tolerance for the indication of the reception status; determining a length of the bit sequence based on the failure rate, the error rate tolerance, and the number of the plurality of transport blocks; and determining a number of hash functions for hashing the unique identification based on the error rate tolerance.

In some example embodiments, the method 1000 further comprises: the length of the bit sequence and the number of hash functions are transmitted to the at least one terminal device 120.

In some example embodiments, the at least one terminal device 120 comprises a plurality of terminal devices.

Fig. 11 illustrates a flow diagram of an example method 1100 according to some example embodiments of the present disclosure. Method 1100 may be implemented at a device such as terminal device 120 shown in fig. 1. For discussion purposes, the method 1100 will be described with reference to fig. 1.

At block 1110, terminal device 120 sends transport blocks to network device 110, and network device 110 receives at least a plurality of transport blocks from terminal device 120. At block 1120, the terminal device 120 receives at least a portion of a bit sequence from the network device 110, each of a plurality of transport blocks corresponding to one or more bits in the sequence. At block 1130, the terminal device 120 determines a reception status of the transport block based on at least a portion of the bit sequence.

In some example embodiments, determining the reception status of the transport block comprises: determining a subset of bits in at least a portion of the sequence corresponding to a transport block; determining whether the subset of bits includes bits of the first value; and in response to the absence of the bit of the first value, determining that a failure occurred in receiving the transport block by network device 110.

In some example embodiments, the method 1100 further comprises: in response to a determination that a failure occurred in receiving the transport block by network device 110, the transport block is retransmitted to network device 110.

In some example embodiments, determining a subset of bits in the sequence that correspond to a transport block comprises: obtaining a unique identification of a transmission block; and determining the position of the subset of bits in the sequence by hashing the unique identification.

In some example embodiments, obtaining the unique identification of the transport block comprises determining the unique identification of the transport block based on at least one of: an identity of terminal device 120; an identification of a hybrid automatic repeat request process during which transport blocks are sent; and an identification of the transport block used to distinguish the transport block from other transport blocks of terminal device 120.

In some example embodiments, the method 1100 further comprises: the length of the bit sequence and the number of hash functions used to hash the unique identification are received from network device 110.

In some example embodiments, the method 1100 further comprises: determining a duration of time since a transport block was transmitted; determining whether the duration exceeds a time threshold for receiving the indication of the status; and in response to a determination that the duration is below the time threshold, determining a reception status of the transport block based on the sequence of bits.

In some example embodiments, an apparatus capable of performing method 1000 may include means for performing the steps of method 1000. The method may be carried out in any suitable form. For example, the components may be implemented in a circuit or a software module.

In some example embodiments, the apparatus comprises: means for determining a reception status of a plurality of transport blocks received from at least one second device; means for generating a bit sequence based on reception states of a plurality of transport blocks such that each of the plurality of transport blocks corresponds to one or more bits in the sequence; and means for transmitting the bit sequence to the at least one second device as an indication of the reception status.

In some example embodiments, the means for generating the bit sequence comprises: means for assigning a first value to a bit in the sequence; and means for assigning a second value to a first subset of bits in the sequence corresponding to a first transport block in response to a failure in receiving the first transport block in the plurality of transport blocks, the second value being different from the first value.

In some example embodiments, the apparatus further comprises: means for assigning a second value to a second subset of bits in the sequence corresponding to a second transport block in response to a failure in receiving the second transport block in the plurality of transport blocks, the second subset of bits being at least partially different from the first subset of bits.

In some example embodiments, the means for assigning the second value to the first subset of bits corresponding to the first transport block comprises: means for obtaining a unique identification of a first transport block; and means for determining a position of the first subset of bits in the sequence by hashing the unique identification.

In some example embodiments, the means for obtaining the unique identification of the first transport block comprises means for determining the unique identification of the first transport block based on at least one of: an identification of a second device from which the first transport block was received; an identification of a hybrid automatic repeat request process during which the first transport block was received; and an identification of the first transport block for distinguishing the first transport block from other transport blocks of the second device.

In some example embodiments, the apparatus further comprises: means for determining a failure rate of transport blocks that have been received by a first device; means for determining an error rate tolerance for the indication of the reception status; means for determining a length of the bit sequence based on a failure rate, an error rate tolerance, and a number of the plurality of transport blocks; and means for determining a number of hash functions for hashing the unique identification based on the error rate tolerance.

In some example embodiments, the apparatus further comprises: means for transmitting the length of the bit sequence and the number of hash functions to the at least one second device.

In some example embodiments, an apparatus capable of performing the method 1100 may include means for performing the steps of the method 1100. The components may be embodied in any suitable form. For example, the components may be implemented in circuits or software modules.

In some example embodiments, the apparatus comprises: means for transmitting transport blocks to a first device, the first device receiving at least a plurality of transport blocks from a second device; means for receiving at least a portion of a sequence of bits from a first device, each transport block of a plurality of transport blocks corresponding to one or more bits in the sequence; and means for determining a reception status of the transport block based on at least a portion of the bit sequence.

In some example embodiments, the means for determining the reception status of the transport block comprises: means for determining a subset of bits in at least a portion of the sequence corresponding to a transport block; means for determining whether the subset of bits includes bits of the first value; and means for determining that a failure occurred in receiving the transport block by the first device in response to the absence of the bit of the first value.

In some example embodiments, the apparatus further comprises: means for retransmitting the transport block to the first device in response to a determination that a failure occurred while the transport block was received by the first device.

In some example embodiments, the means for determining a subset of bits in the sequence corresponding to a transport block comprises: means for obtaining a unique identification of a transport block; and means for determining the position of the subset of bits in the sequence by hashing the unique identification.

In some example embodiments, the means for obtaining the unique identification of the transport block comprises means for determining the unique identification of the transport block based on at least one of: an identity of the second device; an identification of a hybrid automatic repeat request process during which transport blocks are sent; and an identification of a transport block used to distinguish the transport block from other transport blocks of the second device.

In some example embodiments, the apparatus further comprises: means for receiving from the first device a length of the bit sequence and a number of hash functions for hashing the unique identification.

In some example embodiments, the apparatus further comprises: means for determining a duration of time since a transport block was transmitted; means for determining whether the duration exceeds a time threshold for receiving the indication of the status; and means for determining a reception status of the transport block based on the bit sequence in response to a determination that the duration is below a time threshold.

Fig. 12 is a simplified block diagram of a device 1200 suitable for implementing embodiments of the present disclosure. Device 1200 may be provided to implement a communication device, such as terminal device 120 or network device 110 as shown in FIG. 1. As shown, the device 1200 includes one or more processors 1210, one or more memories 1220 coupled to the processors 1210, and one or more communication modules 1240 coupled to the processors 1210.

The communication module 1240 is used for bidirectional communication. The communication module 1240 has at least one antenna to facilitate communication. A communication interface may represent any interface necessary to communicate with other network elements.

The processor 1210 may be of any type suitable for a local technology network, and may include one or more of the following, as non-limiting examples: general purpose computers, special purpose computers, microprocessors, Digital Signal Processors (DSPs) and processors based on a multi-core processor architecture. Device 1200 may have multiple processors, such as application specific integrated circuit chips that are subordinate in time to a clock synchronized to the host processor.

The memory 1220 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memory include, but are not limited to: read Only Memory (ROM)1224, Electrically Programmable Read Only Memory (EPROM), flash memory, a hard disk, a Compact Disc (CD), a Digital Video Disc (DVD), and other magnetic and/or optical storage. Examples of volatile memory include, but are not limited to: random Access Memory (RAM)1222 and other volatile memory that is not retained during power down.

Computer programs 1230 include computer-executable instructions that are executed by an associated processor 1210. The program 1230 may be stored in the ROM 1220. Processor 1210 may perform any suitable actions and processes by loading program 1230 into RAM 1220.

Embodiments of the present disclosure may be implemented by the program 1230 such that the device 1200 may perform any of the processes of the present disclosure discussed with reference to fig. 10-11. Embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some embodiments, program 1230 may be tangibly embodied in a computer-readable medium, which may be included in device 1200 (e.g., memory 1220) or other storage device accessible to device 1200. The device 1200 can load the program 1230 from the computer-readable medium to the RAM 1222 to be executed. The computer readable medium may include any type of tangible, non-volatile memory, such as ROM, EPROM, flash memory, a hard disk, a CD, a DVD, etc. Fig. 13 shows an example of a computer-readable medium 1300 in the form of a CD or DVD. The computer readable medium has stored thereon a program 1230.

In general, the various embodiments of the disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of the embodiments of the disclosure are illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that the block diagrams, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or combinations thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product comprises computer executable instructions, such as instructions comprised in program modules, executed in the device on the target real or virtual processor to perform the

method

1000 or 1100 as described above with reference to fig. 10 to 11. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In various embodiments, the functionality of the program modules may be combined or split between program modules as desired. Machine-executable instructions for program modules may be executed within local or distributed devices. In a distributed facility, program modules may be located in both local and remote memory storage media.

Program code for performing the disclosed methods may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowchart and/or block diagram to be performed. The program code may execute entirely on the machine, partly on the machine, as a stand-alone software package partly on the machine, partly on a remote machine or entirely on the remote machine or server.

In the context of this disclosure, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform various processes and operations as described above. Examples of a carrier include a signal, computer readable medium, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a computer-readable storage medium include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, while operations are described in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In some cases, multitasking and parallel processing may be advantageous. Similarly, while several specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

Although the disclosure has been described in language specific to structural features and/or methodological acts, it is to be understood that the disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A first device comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code configured to, with the at least one processor, cause the first apparatus at least to:

determining a reception status of a plurality of transport blocks received from at least one second device;

generating a sequence of bits based on the reception status of the plurality of transport blocks such that each transport block of the plurality of transport blocks corresponds to one or more bits in the sequence; and

transmitting the bit sequence to the at least one second device as an indication of the reception status.

2. The first device of claim 1, wherein the bit sequence is generated by:

assigning a first value to a bit in the sequence; and

in response to a failure in receiving a first transport block of the plurality of transport blocks, assigning a second value to a first subset of bits of the sequence corresponding to the first transport block, the second value being different from the first value.

3. The first device of claim 2, wherein the first device is further caused to:

in response to a failure in receiving a second transport block of the plurality of transport blocks, assigning the second value to a second subset of bits of the sequence corresponding to the second transport block, the second subset of bits being at least partially different from the first subset of bits.

4. The first device of claim 2, wherein the first subset of bits is determined by:

obtaining a unique identifier of the first transport block; and

determining a position of the first subset of bits in the sequence by hashing the unique identification.

5. The first device of claim 4, wherein the unique identification of the first transport block is determined based on at least one of:

an identification of a second device from which the first transport block was received;

an identification of a hybrid automatic repeat request process during which the first transport block was received; and

an identification of the first transport block to distinguish the first transport block from other transport blocks of the second device.

6. The first device of claim 4, wherein the first device is further caused to:

determining a failure rate of transport blocks that have been received by the first device;

determining an error rate tolerance for the indication of the reception status;

determining a length of the bit sequence based on the failure rate, the error rate tolerance, and the number of the plurality of transport blocks; and

determining a number of hash functions to hash the unique identification based on the error rate tolerance.

7. The first device of claim 6, wherein the first device is further caused to:

transmitting the length of the bit sequence and the number of hash functions to the at least one second device.

8. The first device of claim 1, wherein the first device comprises a network device and the at least one second device comprises a plurality of terminal devices.

9. A second device comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code configured to, with the at least one processor, cause the second apparatus at least to:

transmitting a transport block to a first device, the first device receiving at least a plurality of transport blocks from the second device;

receiving at least a portion of a sequence of bits from the first device, each transport block of the plurality of transport blocks corresponding to one or more bits in the sequence; and

determining a reception status of the transport block based on the at least a portion of the bit sequence.

10. The second device of claim 9, wherein the reception status of the transport block is determined by:

determining a subset of bits in the at least a portion of the sequence corresponding to the transport block;

determining whether the subset of bits includes bits of a first value; and

determining that a failure occurred in receiving the transport block by the first device in response to an absence of the bit of the first value.

11. The second device of claim 10, wherein the second device is further caused to:

in response to determining that the failure occurred in receiving the transport block by the first device, retransmitting the transport block to the first device.

12. The second device of claim 10, wherein the subset of bits in the sequence corresponding to the transport block is determined by:

obtaining a unique identifier of the transmission block; and

determining the position of the subset of bits in the sequence by hashing the unique identification.

13. The second device of claim 12, wherein the unique identification of the transport block is determined based on at least one of:

an identification of the second device;

an identification of a hybrid automatic repeat request process during which the transport block was sent; and

an identification of the transport block to distinguish the transport block from other transport blocks of the second device.

14. The second device of claim 12, wherein the second device is further caused to:

receiving, from the first device, a length of the bit sequence and a number of hash functions to hash the unique identification.

15. The second device of claim 9, wherein the second device is further caused to:

determining a duration of time since the transport block was transmitted;

determining whether the duration exceeds a time threshold for the indication of the reception status; and

in response to determining that the duration is below the time threshold, determining the reception status of the transport block based on the sequence of bits.

16. The second device of claim 9, wherein the first device comprises a network device and the second device comprises a terminal device.

17. A method, comprising:

18. The method of claim 17, wherein generating the bit sequence comprises:

assigning a first value to a bit in the sequence; and

19. The method of claim 18, wherein the method further comprises:

20. The method of claim 18, wherein assigning the second value to a first subset of the bits corresponding to the first transport block comprises:

obtaining a unique identifier of the first transport block; and

21. The method of claim 20, wherein obtaining the unique identification of the first transport block comprises determining the unique identification of the first transport block based on at least one of:

22. The method of claim 20, wherein the method further comprises:

determining an error rate tolerance for the indication of the reception status;

23. The method of claim 22, wherein the method further comprises:

24. The method of claim 17, wherein the first device comprises a network device and the at least one second device comprises a plurality of terminal devices.

25. A method, comprising:

26. The method of claim 25, wherein determining the reception status of the transport block comprises:

determining whether the subset of bits includes bits of a first value; and

27. The method of claim 26, wherein the method further comprises:

retransmitting the transport block to the first device in response to determining that a failure occurred in receiving the transport block by the first device.

28. The method of claim 26, wherein determining a subset of bits in the sequence corresponding to the transport block comprises:

obtaining a unique identifier of the transmission block; and

29. The method of claim 28, wherein obtaining the unique identification of the transport block comprises determining the unique identification of the transport block based on at least one of:

an identification of the second device;

30. The method of claim 28, wherein the method further comprises:

31. The method of claim 25, wherein the method further comprises:

determining a duration of time since the transport block was transmitted;

determining the reception status of the transport block based on the sequence of bits in response to a determination that the duration is below the time threshold.

32. The method of claim 25, wherein the first device comprises a network device and the second device comprises a terminal device.

33. An apparatus, comprising:

means for determining a reception status of a plurality of transport blocks received from at least one second device;

means for generating a sequence of bits based on the reception status of the plurality of transport blocks such that each transport block of the plurality of transport blocks corresponds to one or more bits in the sequence; and

means for transmitting the bit sequence to the at least one second device as an indication of the reception status.

34. An apparatus, comprising:

means for transmitting transport blocks to a first device, the first device receiving at least a plurality of transport blocks from the second device;

means for receiving a sequence of bits from the first device, each transport block of the plurality of transport blocks corresponding to one or more bits in the sequence; and

means for determining a reception status of the transport block based on the bit sequence.

35. A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least a method according to any one of claims 17-24.

36. A non-transitory computer readable medium comprising program instructions for causing a device to perform at least the method of any one of claims 25-32.