CN114287115B

CN114287115B - HARQ feedback based on side link CBG and associated retransmissions on reserved resources

Info

Publication number: CN114287115B
Application number: CN201980099809.5A
Authority: CN
Inventors: 李栋; 刘勇; T·维尔德斯彻克; 谭钧
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: 2019-08-28
Filing date: 2019-08-28
Publication date: 2024-06-25
Anticipated expiration: 2039-08-28
Also published as: CN114287115A; WO2021035580A1

Abstract

According to example embodiments of the invention disclosed herein, there is at least one method and apparatus for performing, by a first communication device, side chain transmission towards a second communication device for a transport block associated with the side chain transmission using resource reservation; and in response to receiving hybrid automatic repeat request (HARQ) feedback for the side link transmission, performing at least one side link retransmission for the code block group of the negatively acknowledged transport block using some or all of the reserved resources of the resource reservation. In addition, at least one of the following methods and apparatus: monitoring, by the third communication device, a side link control channel for side link transmission from the first communication device; monitoring a side link feedback channel for feedback from the second communication device for the side link transmission; and performing resource selection for the sidelink transmission based on the monitored parameters associated with the sidelink retransmission from the sidelink control channel and the sidelink feedback channel.

Description

HARQ feedback based on side link CBG and associated retransmissions on reserved resources

Technical Field

The teachings according to the exemplary embodiments of this invention relate generally to side link transmission and retransmission and, more particularly, relate to side link transmission and retransmission using code block group based HARQ feedback associated with side link transmission.

Background

This section is intended to provide a background or context to the application that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Accordingly, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this section and is not admitted to be prior art by inclusion in this section.

Certain abbreviations that may be found in the specification and/or drawings are defined herein as follows:

CBG: code block group

CBGFI: code block group feedback information

CBGTI: code block group transmission information

D2D device-to-device

DCI: downlink control information

HARQ hybrid automatic repeat request

PRB: physical resource block

NR new radio

ProSe proximity-based services

PSFCH physical side link feedback channel

PSCCH: physical side link control channel

PSSCH: physical side link shared channel

PSFCH: physical side link feedback channel

PUCCH physical uplink control channel

RAN radio access network

ReTX: retransmission

SCI: side link control information

SFCI: side link feedback control information

SL: side link

TB: transmission block

TBS: transport block size

UE: user equipment

V2X vehicle to everything

Some communication systems are capable of performing V2X and D2D communications. V2X communication may be based on communication technologies, such as "side link" communication technologies. To this end, the side link resource pool and side link channel may be established for vehicles engaged in such communications. In addition, such a side-link communication technology for V2X communication may be referred to as a device-to-device (D2D) communication technology, and for example, proximity-based service (ProSe) communication is used.

Further, in V2X communication, when the side link/D2D communication technology is applied, a network device located in the vehicle may perform V2X communication using resources allocated by the base station or resources autonomously selected within a resource pool configured by the base station. The base station may also adjust V2X communication parameters in order to attempt to achieve maximum transmission power and/or range based on channel congestion.

Further, in V2X communication, a network device located in a vehicle may perform V2X communication with a base station using a radio interface (e.g., uu interface in LTE or 5G cellular network) to communicate with another V2X communication network device or V2X service application server through a wireless network.

Example embodiments of the present invention are directed to implementing improved operations associated with devices that perform at least these operations as described above.

Disclosure of Invention

This section contains examples of possible implementations and is not meant to be limiting.

In one example embodiment of the invention, a method includes: performing, by the first communication device, side chain transmission towards the second communication device for a transport block associated with the side chain transmission using the resource reservation; and in response to receiving hybrid automatic repeat request (HARQ) feedback for the side link transmission, performing at least one side link retransmission for the code block group of the negatively acknowledged transport block using some or all of the reserved resources of the resource reservation.

Another example embodiment of the present invention is a method, comprising the method of the preceding paragraph, wherein the side link transmission comprises: side link control channel transmission transmitting side link control information associated with the side link transmission; and side link shared channel transmission transmitting the code blocks associated with the transport blocks, wherein performing the side link transmission comprises: determining a code block segment of a transmission block; determining a number of code block groups associated with code blocks obtained by the code block segmentation; and determining reserved resources for retransmission for the code block group of the transport block, wherein performing side chain transmission further comprises: setting a code block group related information field in the side link control information based on the determined code block segment and the transport block code block group number associated with the transport block; and setting a resource reservation related information field in the sidelink control information based on the determined reserved resources for the potential retransmissions associated with the transport block; generating a side link control channel and a side link shared channel; and transmitting a side link control channel and a side link shared channel for the side link transmission toward the second communication device on the side link, wherein the hybrid automatic repeat request feedback comprises: receiving hybrid automatic repeat request feedback information based on code block groups from a second communication device on a side chain feedback channel from the second communication device, wherein determining the number of code block groups associated with code blocks obtained by code block segmentation comprises at least one of: determining the number of code block groups based on the total number of code blocks and the code block size; or determining the number of code block groups based on the transport block size, wherein the code block group related information field of the side link control information includes: code block group numbers corresponding to the determined number of code block groups of the associated transport block; and code block group transmission information including a bitmap identifying code block group numbers, the bitmap indicating the presence or absence of corresponding code block groups in the current side link transmission, wherein the resource reservation related information field of the side link control information includes at least one of: information about at least one resource reservation in a time domain, the time domain comprising one or more time slots; or information about at least one resource reservation in a frequency domain, the frequency domain comprising one or more sub-channels, and/or wherein performing at least one side link retransmission for a code block group of a negatively acknowledged transport block using a reserved part or all of the reserved resources comprises: using some or all of the reserved resources in the frequency domain, a side link retransmission is performed for the negatively acknowledged code block set on some or all of the reserved resources in the time domain.

In another example embodiment of the present invention, an apparatus includes: means for performing, by the first communication device, side chain transmission towards the second communication device for a transport block associated with the side chain transmission using the resource reservation; and means for performing at least one side link retransmission for the code block group of the negatively acknowledged transport block using some or all of the reserved resources in response to receiving hybrid automatic repeat request (HARQ) feedback for the side link transmission.

Another example embodiment of the present invention is an apparatus comprising means for a preceding paragraph, wherein the side link transmission comprises: side link control channel transmission transmitting side link control information associated with the side link transmission; and side link shared channel transmission transmitting the code blocks associated with the transport blocks, wherein performing the side link transmission comprises: determining a code block segment of a transmission block; determining a number of code block groups associated with code blocks obtained by the code block segmentation; and determining reserved resources for retransmission for the code block group of the transport block, wherein performing side chain transmission further comprises: setting a code block group related information field in the side link control information based on the determined code block segment and the transport block code block group number associated with the transport block; and setting a resource reservation related information field in the sidelink control information based on the determined reserved resources for the potential retransmissions associated with the transport block; generating a side link control channel and a side link shared channel; and transmitting a side link control channel and a side link shared channel for the side link transmission toward the second communication device on the side link, wherein the hybrid automatic repeat request feedback comprises: receiving hybrid automatic repeat request feedback information based on code block groups from a second communication device on a side chain feedback channel from the second communication device, wherein determining the number of code block groups associated with code blocks obtained by code block segmentation comprises at least one of: determining the number of code block groups based on the total number of code blocks and the code block size; or determining the number of code block groups based on the transport block size, wherein the code block group related information field of the side chain control information includes: code block group numbers corresponding to the determined number of code block groups of the associated transport block; and code block group transmission information including a bitmap identifying code block group numbers, the bitmap indicating the presence or absence of corresponding code block groups in the current side link transmission, wherein the resource reservation related information field of the side link control information includes at least one of: information about at least one resource reservation in a time domain, the time domain comprising one or more time slots; or information about at least one resource reservation in a frequency domain, the frequency domain comprising one or more sub-channels, and/or wherein performing at least one side link retransmission for a code block group of a negatively acknowledged transport block using a reserved part or all of the reserved resources comprises: using some or all of the reserved resources in the frequency domain, a side link retransmission is performed for the negatively acknowledged code block set on some or all of the reserved resources in the time domain.

In another example embodiment of the invention, an apparatus includes one or more processors and one or more memories including computer program code. The one or more memories and the computer program code are configured to, with the one or more processors, cause the apparatus at least to: performing, by the first communication device, side chain transmission towards the second communication device for a transport block associated with the side chain transmission using the resource reservation; and in response to receiving hybrid automatic repeat request (HARQ) feedback for the side link transmission, performing at least one side link retransmission for the code block group of the negatively acknowledged transport block using some or all of the reserved resources of the resource reservation.

Another example embodiment of the present invention includes a computer program comprising code for: performing, by the first communication device, side chain transmission towards the second communication device for a transport block associated with the side chain transmission using the resource reservation; and in response to receiving hybrid automatic repeat request (HARQ) feedback for the side link transmission, performing at least one side link retransmission for the code block group of the negatively acknowledged transport block using some or all of the reserved resources of the resource reservation.

In another example embodiment of the present invention, a method includes: monitoring, by the third communication device, a side link control channel for side link transmission from the first communication device; monitoring a side link feedback channel for feedback of the side link transmission from the second communication device; and performing resource selection for the side link transmission based on the monitored parameters and feedback for the side link transmission.

Other example embodiments of the invention include a method, including the method of the previous paragraph, wherein the parameters include: information of reserved resources for side link transmission and feedback, wherein the third communication device derives part or all of the resources to be used for side link retransmission and remaining resources to be implicitly released in the reserved resources from the parameters, wherein the monitoring comprises: decoding the side link control channel, and obtaining code block group related information and resource reservation information code blocks for side link retransmission from the side link control information, wherein the processing includes: detecting a side link feedback channel and obtaining information based on hybrid automatic repeat request feedback of a code block group from side link feedback control information, wherein performing resource selection for the side link transmission comprises: it is considered that in resource selection for side link transmission, at least one of the following is effectively reserved: the method comprises the steps of reserving resources by the first communication device, monitoring resources by the third communication device, and resources to be used by a plurality of negatively acknowledged code block sets indicating code blocks by hybrid automatic repeat request feedback based on the code block sets, and wherein any remaining reserved resources are implicitly released, wherein the resources are selected to use at least one of remaining reserved resources and unreserved resources that are implicitly released.

In another example embodiment of the present invention, an apparatus includes: means for monitoring, by the third communication device, a side link control channel for side link transmission from the first communication device; means for monitoring a side link feedback channel for feedback of the contralateral link transmission from the second communication device; and means for performing resource selection for the sidelink transmission based on the monitored parameters related to the sidelink retransmission from the sidelink control channel and the sidelink feedback channel.

An additional example embodiment of the present invention includes an apparatus comprising means of the preceding paragraph, wherein the parameter comprises information of reserved resources for side link transmission and feedback, wherein the third communication device derives from the parameter some or all of the resources to be used for side link retransmission and remaining resources to be implicitly released, wherein the means for monitoring comprises: decoding the side link control channel and obtaining code block group related information and resource reservation information code blocks for side link retransmission from the side link control information, wherein the means for processing comprises: means for detecting a side link feedback channel, and means for acquiring information of a hybrid automatic repeat request feedback based on a code block group from side link feedback control information, wherein the means for performing resource selection for side link transmission comprises: consider a component that is effectively reserved in resource selection for side link transmission, at least one of the following: the method comprises the steps of reserving resources by the first communication device, monitoring resources by the third communication device, and resources to be used by a plurality of negatively acknowledged code block sets indicating code blocks by hybrid automatic repeat request feedback based on the code block sets, and wherein any remaining reserved resources are implicitly released, wherein the resources are selected to use at least one of remaining reserved resources and unreserved resources that are implicitly released.

In another example embodiment of the invention, an apparatus includes one or more processors and one or more memories, the one or more memories including computer program code. The one or more memories and the computer program code are configured to, with the one or more processors, cause the apparatus at least to: monitoring, by the third communication device, a side link control channel for side link transmission from the first communication device; monitoring a side link feedback channel for feedback of the contralateral link transmission from the second communication device; and performing resource selection for the sidelink transmission based on the monitored parameters associated with the sidelink retransmission from the sidelink control channel and the sidelink feedback channel.

Another example embodiment of the present invention includes a computer program comprising code for monitoring, by a third communication device, a sidelink control channel for sidelink transmission from a first communication device; monitoring a side link feedback channel for feedback of the side link transmission from the second communication device; and performing resource selection for the sidelink transmission based on the monitored parameters associated with the sidelink retransmission from the sidelink control channel and the sidelink feedback channel.

Drawings

The above and other aspects, features and advantages of various embodiments of the present disclosure will become more apparent in the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters designate like or equivalent elements. The accompanying drawings, which are illustrated to facilitate a better understanding of the embodiments of the disclosure and are not necessarily drawn to scale, comprise:

FIG. 1A shows a flow chart of an example embodiment of the invention;

FIG. 1B shows a table of associated values having transport block sizes, code block group numbers, and control information bits for operation in accordance with an example embodiment of the invention;

FIG. 2 illustrates side chain transmission and retransmission operations on partially reserved resources and frequency shrinking the reserved resources according to an example embodiment of the invention;

FIG. 3 illustrates side chain transmission and retransmission operations on partially reserved resources and time-shrinking the reserved resources according to an example embodiment of the invention;

FIG. 4 illustrates side link operation between vehicles according to an example embodiment of the invention;

FIG. 5 illustrates a simplified block diagram of an exemplary electronic device suitable for use in practicing the various exemplary embodiments of the invention; and

Fig. 6A and 6B each illustrate a method that may be practiced by an apparatus according to an example embodiment of the invention.

Detailed Description

In the present invention, at least a method and apparatus for side link transmission and retransmission using code block group based HARQ feedback associated with side link transmission is presented.

LTE V2X side links are defined in LTE R14 to support direct communication of basic road safety services between vehicles and vehicles/pedestrians/infrastructure. In LTE release 15, the V2X side chain is further enhanced with features of carrier aggregation, higher order modulation and delay reduction to support more diverse services and more stringent service requirements.

In order to support advanced V2X services more effectively, 3GPP has created a study item of NR V2X in Rel-16 to investigate the feasibility and performance of potential solutions. The present study concludes that it is feasible to support advanced V2X services using the technical solutions identified during the study. On the RAN #83 en masse conference, an NR V2X workitem is created for standardizing the NR V2X specification in release 16 to support advanced V2X services. It is expected that NR V2X operation will continue in release 17 for performance/functional enhancement.

In advanced V2X services, the data packet size varies greatly over a large dynamic range, depending on the particular V2X service, e.g., from hundreds of bytes to tens of kilobytes. In the case of very large data packet Transport Blocks (TBs), the TBs may contain a relatively large number of code blocks, and in this case CBG-based HARQ feedback may effectively improve retransmission resource efficiency. On the other hand, in the Rel-16 NR v2x work item, agreed on RAN1-97, for the same packet transport block, the previous transmission may reserve resources for the next retransmission of the PSSCH for HARQ feedback. Inspired by the above aspects, some technical problems that the exemplary embodiments of the present invention aim to solve include:

how CBG-based HARQ feedback is supported in the side link; and

How to perform retransmissions triggered by CBG based HARQ feedback on reserved resources.

In an ongoing Rel-16 NR v2x work item, supporting HARQ feedback in the side link is an important topic. However, the discussion focuses mainly on simple TB-based HARQ feedback, not CBG-based HARQ feedback.

In the NR system (Rel-15), TB-based HARQ feedback and CBG-based HARQ feedback are supported based on NR PUCCH format 0 and format 2, respectively. For CBG-based HARQ feedback, UE-specific higher layer signaling is used to configure CBG numbers, and other HARQ related parameters are transmitted in dynamic DCI signaling. In principle, there is some significant difference between CBG-based HARQ feedback in cellular DL/UL and CBG-based HARQ feedback in the side link. The differences are mainly manifested in the following two aspects:

in the side link, the CBG based HARQ feedback channel PSFCH should be decodable and understandable not only by its target receiver (i.e. the transmitter of the data packet PSSCH), but also by other UEs that are sensing the side link channel; and

In the side link, as described above, for the same packet transport block, the previous transmission may reserve resources for the next retransmission of the PSSCH for HARQ feedback. In this case, how to retransmit based on CBG-based HARQ feedback on reserved resources remains a pending problem.

Inspired by these considerations, the present invention aims to address the technical challenges and needs described above.

Comments about some inventive aspects:

inventive aspects according to example embodiments of the present invention include at least the following:

dynamic configuration and indication of CBG-based HARQ feedback related parameters, step 1 as described below. This not only enables the CBG-based flexible HARQ feedback mechanism to accommodate dynamic packet sizes, but also facilitates other sensing UEs to monitor and learn HARQ feedback information; and

The side link retransmission may occupy only part of the reserved resources based on the specific CBG based HARQ feedback and release other reserved resources, step 3 as described below. In this way, the original reserved resources corresponding to the entire packet TB size are gradually released in multiple (re) transmissions of the TB. Therefore, the resource efficiency is greatly improved, and this is particularly significant for a large packet TB size.

Before describing example embodiments of the invention in more detail, however, reference is made to FIG. 5, which shows a block diagram of one possible and non-limiting example system in which example embodiments may be practiced.

Turning to FIG. 5, a block diagram of one possible and non-limiting exemplary system in which the exemplary embodiments may be practiced is shown. The network node NN 110 and the network node NN 90, either of which is, for example, a user equipment UE. Furthermore, there is one Radio Access Network (RAN) node 170 and network element(s) 190 shown in fig. 5. As shown in fig. 5, NNs 110 and 90 are in wireless communication with wireless network 100. NN 110 and NN 90 are generally wireless mobile devices, such as UEs that may access wireless network 100. The UE may comprise, for example, a mobile phone (or "cellular" phone) and/or a computer with mobile terminal functionality. For example, the UE or mobile terminal may also be a portable, pocket, hand-held, computer-embedded or vehicle-mounted mobile device and perform language signaling and/or data exchanges with the RAN.

The NN 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130, which are interconnected by one or more buses 127. Each of the one or more transceivers 130 includes a receiver Rx 132 and a transmitter Tx 133. The one or more buses 127 may be an address bus, a data bus, or a control bus, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optic or other optical communications device, or the like. One or more transceivers 130 are connected to one or more antennas 128. The one or more memories 125 include computer program code 123.NN 110 includes CBG module 140, which includes one or both of portions 140-1 and/or 140-2, which may be implemented in a variety of ways. The CBG module 140 may be configured to cause the NN 110 to perform operations in accordance with example embodiments of the invention disclosed herein. CBG module 140 may be implemented in hardware as CBG module 140-1, such as part of one or more processors 120. CBG module 140-1 may also be implemented as an integrated circuit or by other hardware, such as a programmable gate array. In another example, CBG module 140 may be implemented as CBG module 140-2, which is implemented as computer program code 123 and executed by one or more processors 120. For example, the one or more memories 125 and the computer program code 123 may be configured, with the one or more processors 120, to cause the NN 110 to perform one or more of the operations as described herein. NN 110 communicates with RAN node 170 and/or NN 90 via wireless link 111 and/or link 176 and/or link 81.

RAN node 170 is a network node, such as a base station, that provides access to wireless network 100 by wireless devices, such as NN 110. RAN node 170 may be, for example, a base station for 5G, also referred to as a New Radio (NR). In 5G, RAN node 170 may be a NG-RAN node, which is defined as a gNB or NG-eNB. RAN node 170 comprises one or more processors 152, one or more memories 155, one or more network interfaces (N/WI/F) 161, and one or more transceivers 160, which are interconnected by one or more buses 157. Each of the one or more transceivers 160 includes a receiver Rx 162 and a transmitter Tx 163. One or more transceivers 160 are connected to one or more antennas 158. The one or more memories 155 include computer program code 153.

RAN node 170 includes a CBG module 150, CBG module 150 including one or both of portions 150-1 and/or 150-2, which may be implemented as a side link relay for side link communication between communication devices of a network in accordance with an example embodiment of the present invention. CBG module 150 may be configured to cause RAN node 170 to perform operations in accordance with example embodiments of the present invention as disclosed herein. CBG module 150 may be implemented in hardware as CBG module 150-1, such as part of one or more processors 152. CBG module 150-1 may also be implemented as an integrated circuit or by other hardware, such as a programmable gate array. In another example, CBG module 150 may be implemented as CBG module 150-2, which is implemented as computer program code 153, and executed by one or more processors 152. For example, the one or more memories 155 and the computer program code 153 are configured, with the one or more processors 152, to cause the RAN node 170 to perform one or more of the operations as described herein.

Similarly, NN 90 is a network node such as, for example, another user equipment or access device (such as a base station). The NN 90 includes one or more processors 75, one or more memories 71, one or more network interfaces (N/W I/F) 80, although not shown, it should be noted that the (N/W I/F) 80 of the NN 90 includes one or more transceivers that are interconnected by one or more buses 85. Further, the NN 90 has one or more transceivers, each connected to an antenna, and includes a receiver Rx and a transmitter. One or more transceivers of the NN 90 are connected to one or more antennas. For example, one or more transceivers of the NN 90 may be implemented as Remote Radio Heads (RRHs). The one or more memories 71 include computer program code 73 and are executed by at least one or more processors 75.

NN 90 includes CBG module 50, which includes one or both of portions 50-1 and/or 50-2, which may be implemented in a variety of ways. The CBG module 50 may be configured to cause the NN 90 to perform operations in accordance with example embodiments of the invention disclosed herein. CBG module 50 may be implemented in hardware as CBG module 50-1, such as part of one or more processors 75. CBG module 50-1 may also be implemented as an integrated circuit or by other hardware, such as a programmable gate array. In another example, CBG module 50 may be implemented as CBG module 50-2, which is implemented as computer program code 73, and executed by one or more processors 75. For example, the one or more memories 71 and the computer program code 73 are configured to, with the one or more processors 75, cause the NN 90 to perform one or more of the operations as described herein.

One or more network interfaces N/W I/F161 and 80 may communicate over a network, such as via links 176 and/or 81. Two or more RAN nodes, such as RAN node 170, communicate and/or NN 90 may use, for example, links 176 or 81. Link 176 may be wired or wireless or both, and may implement, for example, an Xn interface for 5G, an X2 interface for LTE, or other suitable interfaces for other standards.

One or more buses (such as one or more buses 157 of RAN node 170 and/or one or more buses of NN 90) may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optic or other optical communication device, wireless channel, or the like. For example, one or more transceivers 160 may be implemented as Remote Radio Heads (RRHs), such as RRH 195 for LTE or a gNB implementation for 5G, where other elements of RAN node 170 may be physically located in a different location than the RRH, and one or more buses 157 may be implemented in part as, for example, fiber optic cables or other suitable network connections to connect other elements of RAN node 170 or NN 90 to the RRH, such as RRH 195.

Further, the RAN node 170 may comprise a gNB node to provide NR user plane and control plane protocol terminals to UEs and connect to 5GC (e.g., network element(s) 190) via an NG interface. Further, the RAN node 170 may comprise a NG-eNB node for providing E-UTRA user plane and control plane protocol terminals to UEs and is connected to the 5GC via an NG interface.

Note that the description herein indicates that a "cell" performs functions, but it should be clear that the base station forming the cell will perform these functions. The cell forms part of a base station. That is, there may be multiple cells per base station. For example, there may be three cells for a single carrier frequency and associated bandwidth, each covering one third of a 360 degree area, such that the coverage area of a single base station covers an approximately oval or circular shape. Further, each cell may correspond to a single carrier, and the base station may use multiple carriers. Thus, if there are three 120 degree cells per carrier and two carriers, then there is more than one cell for the base station. It is further noted that a single cell may have multiple transmission reception points (TRxP or TRPs) that are used to form the cell.

The wireless network 100 may include a network element 190 or may include elements of core network functionality and provides connectivity to another network, such as a telephone network and/or a data communication network (e.g., the internet), via at least one link 181 or link 176 or link 131. Such core network functions for 5G may include access and mobility management function(s) (AM) and/or user plane function(s) (UPF) and/or session management function(s) (SMF).

Such core network functions by network element 190 may include MME (mobility management entity)/SGW (serving gateway) functions for LTE and similar functions for 5G. These are merely exemplary functions that may be supported by network element(s) of network 100, and note that both 5G and LTE functions may be supported. RAN node 170 is coupled to network element 190 via link 131 and NN 90 is connected to network element 190 via link 181. Link 131 and/or link 181 may be implemented, for example, as an NG interface for 5G, or an S1 interface for LTE, or other suitable interfaces for other standards. The network element 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces (N/WI/F) 180, which are interconnected by one or more buses 185. The one or more memories 171 include computer program code 173. The one or more memories 171 and the computer program code 173 are configured, with the one or more processors 175, to cause the network element 190 to perform one or more operations, such as operations according to example embodiments of the present invention described herein.

Wireless network 100 may implement network virtualization, which is a process of combining hardware and software network resources and network functions into a single, software-based management entity, virtual network. Network virtualization involves platform virtualization, typically in combination with resource virtualization. Network virtualization is divided externally, grouping many networks or parts of networks into one virtual unit, or internally, providing network-like functionality to software containers on a single system. Note that the virtualized entities resulting from network virtualization still use hardware to some extent (such as processors 152 and/or 75 and/or 175 and memories 155 and/or 71 and/or 171), and that such virtualized entities create technical effects.

Computer readable memories 125, 155, 171, and 71 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. The computer readable memories 125, 155, 171, and 71 may be means for performing a storage function. Processors 120, 152, 175, and 75 may be of any type suitable to the local technical environment, and may include, as non-limiting examples, one or more of the following: general purpose computers, special purpose computers, microprocessors, digital Signal Processors (DSPs), and processors based on a multi-core processor architecture. Processors 120, 152, 175, and 75 may be components for performing functions, such as control NN 110, RAN node 170, NN 90, and other functions described herein.

In general, various embodiments of user device 110 may include, but are not limited to, cellular telephones such as smartphones, tablet computers, personal Digital Assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback appliances having wireless communication capabilities, internet appliances permitting wireless internet access and potential browsing, including internet appliance, tablet computers having wireless communication capabilities, as well as portable units or terminals that incorporate such functions.

Note that at least three UEs (UE-1, UE-2, and UE-3) may be assumed herein, wherein UE-1 performs HARQ-based side link transmission of the packet transport block to UE-2 while reserving resources for the potential next retransmission. The UE-2 then transmits the HARQ feedback channel PSFCH to the UE-1 based on the packet decoding result. Based on the CBG-based HARQ feedback, UE-1 may retransmit on part of the reserved resources and release other unused reserved resources. UE-3, which is sensing the sidelink channel, monitors transmissions between UE-1 and UE-2 and may utilize reserved resources released by UE-1/UE-2 for its own sidelink transmissions.

FIG. 1A shows a flow chart of an example embodiment of the invention. As shown in FIG. 1A, there are UE-1 110, UE-2 90, and UE-3 80.

As shown in fig. 1A, at step 115, UE-1 determines that a packet (e.g., transport block) is available for transmission to UE-2. As shown in step 120 of fig. 1A, UE-1 110 determines code block group(s) (CBG) number(s) based on packet size or code block number/size. As shown in step 125 of fig. 1A, UE-1 110 generates information including: side chain control information (SCI) indicating hybrid automatic repeat request (HARQ) feedback enabled, CBG related information, and resource reservation information for retransmission. At step 130 of FIG. 1A, UE-1 110 performs side link transmissions to UE-2 90 using the resource reservation indicated by the side link control channel for retransmission, including side link control channel transmissions and side link shared channel transmissions. UE-3 80 monitors at least the side link control channel. As shown in step 140, UE-3 decodes the PSCCH and Side Link (SL) measurements for SL channel sensing. As shown in step 135 of fig. 1A, the UE-2 decodes the sidelink control channel PSCCH and the sidelink shared channel pscsch, and in step 145 of fig. 1A, the UE-2 90 generates Sidelink Feedback Control Information (SFCI) and Physical Sidelink Feedback Channel (PSFCH) information from the decoding result of the pscsch and HARQ information acquired from the decoded sidelink control information. In step 150 of FIG. 1A, UE-2 90 transmits PSFCH including CBG-based HARQ feedback to UE-1 110. In this step 150, the UE-3 80 also monitors this information. As shown in step 155, UE-3 decodes PSFCH to monitor HARQ feedback from UE-2 90. As shown in step 165, UE-1 110 generates a PSCCH/PSSCH for retransmitting the negatively acknowledged CBG(s). UE-1 110 then transmits the retransmission on at least a portion of the reserved resources. Based on the monitored feedback, the UE-3 80 determines that at least a portion of the reserved resources are implicitly released and may be used by the UE-3 80 for Transmission (TX), as shown in step 160.

Furthermore, example embodiments of the present invention include:

Step 1: at the side link transmitter (e.g., UE-1), the following operations are performed to (re) transmit the packet Transport Block (TB) to the target receiver UE-2.

-If it is an initial transmission of a TB, UE-1 determines a Code Block Group (CBG) number for the TB, for example using one of the following methods:

Determining a CBG number according to the TB size;

The o determines the CBG number from the number and/or size of code blocks of the TB.

The threshold parameters (for TB size or number/size of code blocks) associated here may be predefined or (pre-) configured by the network.

Note that the CBG number determined in the initial transmission is reused in the retransmission. According to an example embodiment of the invention:

UE-1 indicates CBG number and CBG transmission information (CBGTI) in the side link control information (SCI) transmitted by the side link control channel PSCCH and associated with the side link shared channel PSCCH for the TB (e.g., a bitmap indicating the presence or absence of corresponding CBG(s) in this transmission, which is typically set to all 1's for initial transmission for the TB).

It is noted that inclusion of CBG numbers and CBGTI in SCI enables other sensing UEs (e.g., UE-3) to learn HARQ related parameters and to learn and monitor HARQ feedback from UE-2.

UE-1 also indicates a resource reservation for the possible next retransmission of the TB, the reserved resource size corresponding to the number of CBGs transmitted in this transmission (e.g., the initial transmission reserves resources corresponding to all CBGs).

The reserved resources for retransmission may be scheduled by the gNB (in resource allocation mode 1) or autonomously selected by the UE based on sensing of the contralateral link channel (in resource allocation mode 2).

UE-1 configures the other parameters of SCI and generates PSCCH and PSSCH, which are finally transmitted to the target receiver UE-2.

Step 2: at the side link receiver UE-2,

It decodes the PSCCH and associated PSSCH.

Based on the decoding result and HARQ parameters (e.g. CBG numbers and CBGTI), UE-2 transmits CBG based HARQ feedback to UE-1 on side link feedback channel PSFCH. Note that PSFCH may also be monitored by other sensing UEs, such as UE-3, so that UE-3 may derive information about resource release based on monitored PSFCH from UE-2 and resource reservation information from UE-1. Thus, UE-3 may use the released reserved resources for its side-chain transmission. Note that the rules regarding reserved resource release are shown in step 3.

Step 3, then, at the side link transmitter UE-1, there is:

Based on CBG based HARQ feedback from UE-2, if there are one or more CBGs that UE-2 did not decode correctly and the number of transmissions of TBs does not reach a maximum number, e.g. 4, UE-1 determines (part of) the resources on reserved resources and performs TB retransmission on these resources as step 1; otherwise the (re) transmission of the TB is completed. Other reserved resources will be implicitly released according to the assumption of step 2. Rules regarding selecting part of the resources for retransmission and releasing other resources are described as follows; and

If a partial CBG is to be retransmitted (i.e. 1< CBG number to be retransmitted < number of CBGs transmitted in last transmission), then the retransmission occupies part of the resources reserved for the last transmission and the other reserved resources are released. The use of partial resources and the release of other reserved resources may be achieved by using at least one of the following methods:

method of omicron-1: the resources are released only in the time domain, i.e. the retransmission occupies resources on only the first specific number of time slots and the reserved resources on the other time slots are released. Obviously, this method is only applicable to slot aggregation side link transmission;

Method of omicron-2: releasing resources only in the frequency domain, i.e. retransmission uses only the first specific number of reserved subchannels and releases other subchannels;

method of omicron-3: resource release in time and frequency domains (e.g., first in time, then in frequency); and/or

Method of omicron-4: without resource release, this means that the retransmission occupies all reserved resources, although the number of CBGs to be retransmitted is small. In this case, a more robust MCS scheme with better reliability is used at the cost of not releasing resources.

Note that although the steps described above are numbered, the numbering does not limit the operations to any particular order. Furthermore, any number or letter or indication of any step or operation disclosed herein is not limited to the order of such steps or operations, and any such step or operation may be performed in a different order than may be indicated by the number or letter or indication of steps disclosed in the present application.

The following operation assumes that UE-1 has a new packet TB to transmit to the target receiver UE-2.

First, assumptions for packet size, side link transport format, and allocated resources (in mode 1 or mode 2) are determined as follows:

[1] packet TB size: 2017 bytes (i.e., 16136 bits);

[2] SL transport format: single data layer, 16QAM, code rate 0.43, (imcs=12 of table 5.1.3.1-1 of 3gpp ts 38.214); and

[3] And (3) resource allocation: 40 PRBs on 2 slots (continuous in both time and frequency)

Based on the specification (TS 38.212) selected for the LDPC base map, the LDPC base map 1 is selected for the packet. For base fig. 1, the maximum code block size is 8448 according to TS 38.212.

According to the rule of code block segmentation specified in TS38.212, the number of code blocks is determined as follows

Fig. 1B shows a table of associated values with transport block size, code block group number and control information bits for operation in accordance with an example embodiment of the present invention. In this table of fig. 1B, it is assumed that the CBG number is determined as follows (as an example) based on the TB size.

As shown in fig. 1B, an association that may be established between a TB Size (TBs) and CBG number and control information bits in bytes is shown according to an example embodiment of the present invention.

In addition, as described above, the packet TB size is assumed to be 2017 bytes. Thus, from the above table, the CBG number is determined to be 2.

Two code blocks are distributed to two CBGs, each containing one code block, according to the rules for grouping code blocks into code block groups specified in TS38.214 (section 6.1.5).

As described above, it is assumed that the resources allocated for the initial transmission of a TB (mode 1 or mode 2) comprise 40 consecutive PRBs over 2 consecutive slots, while another resource of 40 PRBs over 2 future slots is selected for potential retransmission (the reservation of this resource is indicated by the SCI of the initial transmission).

The SCI of the initial transmission includes at least the following control information fields.

Aa CBG number: 01 (i.e., CBG number = 2 is indicated according to fig. 1B);

-CBG transfer information (CBGTI): 11 (a bitmap with length CBG number, indicating the presence or absence of CBG in the current (re) transmission, where "11" indicates that both CBG are present in the initial transmission); and

-Resource reservation for potential retransmissions: indicating reserved resources of 40 PRBs over 2 slots.

Note that other control information fields that are less relevant to the present invention are omitted in the specification.

After physical layer processing of SCI and packet TBs, UE-1 generates side link physical channels PSCCH and PSSCH and transmits them to target receiver UE-2 on allocated resources of 2 PRBs over 2 slots.

Assuming that the target receiver UE-2 successfully decodes the PSCCH and based on the control information, the receiver then attempts to decode the associated PSCCH, with the result that the first code block is decoded correctly and the second code block is decoded incorrectly. Based on this result, UE-2 transmits side link feedback control information (SFCI) "10" (indicating ACK for the 1 st CBG and NACK for the 2 nd CBG) to UE-1 on side link feedback channel PSFCH.

It may be assumed that PSFCH is correctly detected by UE-1 and another sensing UE (e.g., UE-3). Note that it is assumed that UE-3 also decodes the PSCCH from UE-1 during the sensing process so that UE-3 knows the resources reserved by UE-1 for its potential retransmissions. Thus, based on the detected PSFCH and resource reservation information, UE-3 may derive information of which portion of the reserved resource is to be used by UE-1 for retransmission and which portion of the reserved resource is to be implicitly released by UE-1. Based on this, the UE-3 may utilize the resources released by the UE-3 for its side link transmission.

At UE-1, it is assumed that it correctly detects PSFCH from UE-2 and knows that the second CBG is not decoded by the target receiver. In this case, UE-1 will select part of the resources over the resources reserved in the previous transmission and release other resources. The UE-1 may shrink the reserved resources for retransmission in the frequency and/or time domain.

Reserved resources in the shrink frequency:

in this case, among 40 PRBs reserved over 2 slots, UE-1 may reserve a portion of the first 20 PRBs over 2 slots for retransmission of the second CBG of the TB. In this case, other resources of 20 PRBs over 2 slots will be implicitly released.

In retransmission of the 2 nd CBG of TB, the relevant control information in SCI is configured as follows:

-CBG number: 01 (i.e., indicating CBG number = 2, same as initial transmission);

-CBG transfer information (CBGTI): 01 (a bitmap with length CBG number, indicating the presence or absence of CBG in the current (re) transmission, and here "01" indicates that only the second CBG is transmitted in this retransmission); and

Reserved resources for potential further retransmissions (if the maximum number of transmissions has not been reached): indicating reserved resources of 20 PRBs over 2 slots.

After physical layer processing of SCI and packet TB, UE-1 generates side link physical channels PSCCH and PSSCH for retransmission and transmits them to target receiver UE-2 on 20 PRB resources over 2 slots.

Fig. 2 illustrates transmission and retransmission operations of reserved resources that shrink in frequency or on partially reserved resources according to an example embodiment of the present invention.

As shown in step 205 of fig. 2, there is a 2-slot aggregation of the initial transmission of the resource allocation 225 for the initial transmission. Item 210 indicates transmission of a CBG (code block group) number equal to 2 and CBGTI (code block group transmission information) equal to 11. Item 230 of fig. 2 indicates that one subchannel of resource allocation is equal to 10 PRBs. At step 220 of fig. 2, there is a resource reservation for potential retransmissions. At step 215 of fig. 2, there is PSFCH associated with the side link initial transmission indicating that the first code block group was successfully decoded and the second code block group was not successfully decoded. This implicitly indicates the release of the second half of the reserved resources, as shown in step 250. After the retransmission in step 235, the CBG number is indicated to be equal to 2 and CBGTI is equal to 01. Including the resource reservation 245 for potential retransmissions. At step 240 of fig. 2, there is PSFCH associated with the side link retransmission indicating that the retransmitted code block set was successfully decoded, which implicitly implies a release of reserved resources, as shown at step 255. As shown in fig. 2, PSCCH, PSSCH, PSFCH and released resources are indicated by different fill patterns.

Reserved resources in shrink time:

in this case, among 40 PRBs reserved over 2 slots, UE-1 may reserve resources for retransmission of the second CBG of the TB for part of all 40 PRBs over the first slot of the reserved 2 slots. In this case, other resources of 40 PRBs on the 2 nd slot will be implicitly released.

In the 2 nd CBG retransmission of TB, the relevant control information in SCI is configured as follows:

-CBG transfer information (CBGTI): 01 (a bitmap with length CBG number, indicating the presence or absence of CBG in the current (re) transmission, and here "01" indicates that only the second CBG is transmitted in this retransmission); and/or

Resource reservation for potential further retransmissions (if the maximum number of transmissions has not been reached): indicating reserved resources of 40 PRBs on a single slot.

After physical layer processing of SCI and packet TBs, UE-1 generates side link physical channels PSCCH and PSSCH for retransmission and transmits them to target receiver UE-2 on resources of 40 PRBs on a single slot.

Fig. 3 illustrates side link transmission and retransmission operations on partially reserved resources and time-shrinking the reserved resources according to an example embodiment of the invention.

As shown in item 305 of fig. 3, there is a2 slot aggregation for the initial transmission, a resource allocation 325 for the initial transmission. Item 310 indicates transmission of a CBG (code block group) number having a value equal to 2 and CBGTI (code block group transmission information) having a value equal to 11. Item 330 of fig. 3 indicates that one subchannel of the resource allocation is equal to 10 PRBs. At step 320 of fig. 3, there is a reservation of resources for the potential retransmission. At step 315 of fig. 3, there is PSFCH associated with the side link initial transmission indicating that the first code block group was successfully decoded and the second code block group was not successfully decoded. This implicitly indicates that the second half of the resource is reserved, as shown in step 350. After the retransmission at step 335, the CBG number is indicated to be equal to 2 and CBGTI is equal to 01. Including the resource reservation 345 for potential retransmissions. In step 340 of fig. 3, there is a PSCCH associated with a side-link retransmission indicating that the retransmitted code block group was successfully decoded, which implicitly means a release of reserved resources, as shown in step 355. Similar to fig. 2, PSCCH, PSSCH, PSFCH and released resources are indicated by different fill patterns, as shown in fig. 3.

Additional rules for reserving resources for shrink retransmissions

In the current (re) transmission, it is assumed that the allocated resources span N _subch consecutive subchannels over N _slot consecutive slots. It is also assumed that the current (re) transmission has resources of the same dimension size for potential further retransmissions. Assume CBGTI (i), i=1, 2,..n _CBG represents a bitmap of CBG transmission information, where 1 represents the presence of CBG and 0 represents the absence in the current (re) transmission. Here N _CBG denotes the number of CBGs. Meanwhile, assume CBGFI (i), i=1, 2,..n _CBG, represents a bitmap of CBG-based HARQ feedback information associated with CBGTI (i), where 1 represents a NACK for a corresponding CBG and 0 represents an ACK for the corresponding CBG.

Based on CBG based HARQ feedback, the further retransmissions will occupy (part of) the reserved resources, wherein the resource size is determined by at least one of the following three methods:

method-1: resources shrink only in frequency

In this case, the resources for retransmission will potentially shrink only in the frequency domain, and the reserved resources in the time domain remain unchanged. The resource size for retransmission may be determined as follows:

Method-2: the resources being only shrunk in time

In this case, the resources for retransmission will potentially only shrink in the time domain and the reserved resources in the frequency domain remain unchanged. The resource size for retransmission may be determined as follows:

Here S _SA represents a set of allowable numbers of aggregated time slots. For example, S _SA = (1, 2,4, 8). In another example, S _SA = (1, 2,3,4,5,6,7, 8).

Method-3: resource contraction in time and frequency

In this case, the resources for retransmission would potentially shrink first in the time domain and then optionally in the frequency domain. The resource size for retransmission may be determined as follows:

note that the method used for reserved resource contraction for retransmissions may be predefined in the system specification or (pre) configured, e.g. in resource pool configuration signaling, so that the method used is not only known by the side link transmitter and receiver(s), but also by other UEs that are sensing the side link channel.

In the example shown in fig. 2 disclosed herein, method-1 is used, while in the example shown in fig. 3 disclosed herein, method-2 is used (note that in the particular case of the example, method-3 is equivalent to method-2).

Fig. 4 shows communication operations associated with three vehicles (or UEs) according to an example embodiment of the invention. Abbreviations and features associated with example embodiments of the invention are indicated as item 410 of fig. 4. These features of item 410 of FIG. 4 include SCI: side link control information, SFCI side link feedback control information, PSCCH: physical side link control channel, PSSCH: physical side link shared channel, PSFCH: physical side link feedback channel, reTX: retransmission, CBG: code block group and CBGTI: the CBG transmits information.

With respect to FIG. 4, item 420 shows an overview of the steps associated with the communication between UE-1 and UE-2 of FIG. 4. This overview of item 420 includes that the SCI represents control information typically conveyed by a physical side link control channel (PSCCH). The PSCCH is transmitted along with a data channel PSSCH. In addition, the summary of item 420 indicates that the SCI includes at least 1) CBG number; 2) CBGTI, 3) resource reservation information for reTX, and SCI may also include information indicating how to release unused reserved resources in the next reTX.

The communication between UE-1 and UE-2 as in FIG. 4 includes the presence of 1) an initial TX (PSCCH/PSSCH) from UE-1 to UE-2; then there is 2) CBG based HARQ feedback (PSFCH) from UE-2 to UE-1; and there is 3) retransmissions (PSCCH/PSCCH) from UE-1 to UE-2. As also shown in fig. 4, UE-3 monitors at least these PSCCH/PSFCH communications for channel sensing and resource selection for its own side chain transmissions.

Fig. 6A illustrates operations that may be performed by a network device, such as, but not limited to, a network device, such as NN 110 and/or NN 90 in fig. 5. As shown in step 610 of fig. 6A, a side chain transmission towards a second communication device is performed by the first communication device for a transport block associated with the side chain transmission using resource reservation. At least one side link retransmission is then performed for the code block group of the negatively acknowledged transport block using some or all of the reserved resources in response to receiving hybrid automatic repeat request (HARQ) feedback for the side link transmission, as shown in step 620 of fig. 6A.

According to an example embodiment described in the preceding paragraph, wherein the side link transmission comprises: side link control channel transmission transmitting side link control information associated with the side link transmission; and side chain shared channel transmission, transmitting the code blocks associated with the transport blocks.

According to an example embodiment described in the preceding paragraph, wherein performing the side link transmission comprises: determining a code block segment of a transmission block; determining a number of code block groups associated with code blocks obtained by the code block segmentation; and determining reserved resources for retransmission of the code block group of the transport block.

According to an example embodiment described in the preceding paragraph, wherein performing the side link transmission further comprises: setting a code block group related information field in the side link control information based on the determined code block segment and the transport block code block group number associated with the transport block; and setting a resource reservation related information field in the sidelink control information based on the determined reserved resources for the potential retransmissions associated with the transport block; generating a side link control channel and a side link shared channel; and transmitting the side link control channel and the side link shared channel for the side link transmission toward the second communication device on the side link.

According to an example embodiment described in the preceding paragraph, wherein the hybrid automatic repeat request feedback comprises: hybrid automatic repeat request feedback information based on the code block groups is received from the second communication device on a side chain feedback channel from the second communication device.

According to an example embodiment described in the preceding paragraph, wherein determining the number of code block groups associated with a code block obtained by a code block segmentation comprises at least one of: determining the number of code block groups based on the total number of code blocks and the code block size; or determining the number of code block groups based on the transport block size.

According to an example embodiment as described in the preceding paragraph, wherein the code block group related information field of the side link control information comprises: code block group numbers corresponding to the determined number of code block groups of the associated transport block; and the code blocks include code block group transmission information identifying a bitmap of code block group numbers, the bitmap indicating the presence or absence of corresponding code block groups in the current side link transmission.

According to an example embodiment as described in the preceding paragraph, wherein the resource reservation related information field of the side link control information comprises at least one of: information about at least one resource reservation in a time domain, the time domain comprising one or more time slots; or information about at least one resource reservation in the frequency domain, the frequency domain comprising one or more sub-channels.

According to an example embodiment as described in the preceding paragraph, wherein performing at least one side link retransmission for a code block group of a negatively acknowledged transport block using a reserved part or all of the reserved resources comprises: using some or all of the reserved resources in the frequency domain, a side link retransmission is performed for the set of code blocks of the negative acknowledgement on some or all of the reserved resources in the time domain.

A non-transitory computer readable medium storing program code that is executed by at least one processor to perform at least a method as described in the preceding paragraph.

In another example aspect of the invention, there is an apparatus comprising: means for performing, by the first communication device, side chain transmission towards the second communication device for a transport block associated with the side chain transmission using the resource reservation; means for performing (e.g., one or more transceivers 130 or one or more network interfaces (one or more transceivers 130 or N/WI/F) 80, memory(s) 125 or one or more memories 71, computer program code 123 or computer program code 73, and processor(s) 120 or processor(s) 75, CBG module 140-1 and/or CBG module 140-2 or CBG module 50-1 and/or CBG module 50-2) sidelink transmissions towards a second communication device (e.g., NN 110 or NN 90 in fig. 5) by a first communication device (e.g., NN 110 or NN 90 in fig. 5) using resource reservation for transport blocks associated with sidelink transmissions; and means for performing (e.g., one or more transceivers 130 or N/WI/F80, memory(s) 125 or memory(s) 71, computer program code 123 or computer program code 73 and processor(s) 120 or processor(s) 75, CBG module 140-1 and/or CBG module 140-2 or CBG module 50-1 and/or CBG module 50-2) at least one side link retransmission by the first communication device (e.g., NN 110 or NN 90 in fig. 5) for the code block group of negatively acknowledged transport blocks using some or all reserved resources for resource reservation in response to receiving hybrid automatic repeat request (HARQ) feedback for the side link transmission.

In an example aspect of the invention according to the preceding paragraph, wherein at least the means for performing and determining as described above comprises a non-transitory computer readable medium [ such as memory(s) 125 and/or memory(s) 71 in fig. 5 ], encoded with a computer program [ such as computer program code 123 and/or computer program code 73 in fig. 5 ], executable by at least one processor [ such as processor(s) 120 or processor(s) 75, CBG module 140-1, and/or CBG module 140-2 or CBG module 50-1, and/or CBG module 50-2] in fig. 5.

Fig. 6B illustrates operations that may be performed by a network device, such as, but not limited to, a network device such as RAN node 170 in fig. 5. As shown in step 650 of fig. 6B, a side link control channel for side link transmission from the first communication device is monitored by the third communication device. As shown in step 660 of fig. 6B, a side link feedback channel is monitored for feedback of the side link transmission from the second communication device. Resource selection is then performed for the sidelink transmission based on the monitored parameters associated with the sidelink retransmission from the sidelink control channel and the sidelink feedback channel, as indicated by step 670 of fig. 6B.

According to an example embodiment described in the preceding paragraph, the parameters include information of reserved resources used for side link transmission and feedback.

According to an example embodiment described in the preceding paragraph, the third communication device derives from the parameters some or all of the resources to be used for the side link retransmission, and the remaining resources to be implicitly released.

According to an example embodiment described in the preceding paragraph, the monitoring comprises decoding the side link control channel and obtaining the resource reservation information code blocks for the side link retransmission from the code block group related information in the side link control information.

According to an example embodiment as described previously, wherein the processing comprises: and detecting a side link feedback channel, and acquiring hybrid automatic repeat request feedback information based on the code block group from the side link feedback control information.

According to an example embodiment described in the preceding paragraph, wherein performing resource selection for a side link transmission comprises: it is considered that in resource selection for side link transmission, at least one of the following is effectively reserved: the resources reserved by the first communication device, the resources monitored by the third communication device, and the resources to be used by the plurality of negatively acknowledged code block sets indicating code blocks by the hybrid automatic repeat request feedback based on the code block sets, and wherein any remaining reserved resources are implicitly released.

According to an example embodiment described in the preceding paragraph, the resource selection uses at least one of remaining reserved resources and unreserved resources that are implicitly released.

A non-transitory computer readable medium storing program code for execution by at least one processor to perform at least a method as described in the preceding paragraph.

In another example aspect of the invention, there is an apparatus comprising: means for monitoring (e.g., RRH 195, memory(s) 155, computer program code 153, processor(s) 152 and/or CBG module 150-1 and/or CBG module 150-2) by a third communication device (e.g., NN 110 and/or NN 90) a side link control channel for side link transmissions from the first communication device; means for monitoring (e.g., as one or more transceivers 130 or N/WI/F80, memory(s) 125 or memory(s) 71, computer program code 123 or computer program code 73, and processor(s) 120 or processor(s) 75, CBG module 140-1 and/or CBG module 140-2 or CBG module 50-1 and/or CBG module 50-2) a side link feedback channel for feedback of the contralateral link transmission from the second communication device; and means for performing (e.g., as in fig. 5, one or more transceivers 130 or N/WI/F80, memory(s) 125 or one or more memories 71, computer program code 123 or computer program code 73, and processor(s) 120 or processor(s) 75, CBG module 140-1 and/or CBG module 140-2 or CBG module 50-1 and/or CBG module 50-2) resource selection for the side link transmission based on the monitored parameters associated with the side link retransmissions from the side link control channel and the side link feedback channel.

In an example aspect of the invention according to the preceding paragraph, wherein the means for at least monitoring and executing comprises a non-transitory computer readable medium [ such as memory(s) 125 or memory(s) 71 in fig. 5], encoded with a computer program [ such as computer program code 123 or computer program code 73 in fig. 5], executable by at least one processor [ such as processor(s) 120 or processor(s) 75, CBG module 140-1, and/or CBG module 140-2 or CBG module 50-1, and/or CBG module 50-2] in fig. 5.

In general, the various embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, 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, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, 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 some combination thereof.

Embodiments of the invention may be practiced in various components, such as integrated circuit modules. The design of integrated circuits is generally a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

The word "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. All of the examples described in this detailed description are provided as exemplary examples to enable persons skilled in the art to make or use the invention and are not intended to limit the scope of the invention which is defined by the claims.

The foregoing description has provided by way of exemplary and non-limiting examples a full and enabling description of the best method and apparatus presently contemplated by the inventors for carrying out the invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention.

It should be noted that the terms "connected," "coupled," or any variant thereof, mean any direct or indirect connection or coupling between two or more elements, and that two elements "connected" or "coupled" together may include the presence of one or more intervening elements. The coupling or connection between the elements may be physical, logical, or a combination thereof. As used herein, two elements may be considered to be "linked" or "coupled" together by: one or more wires, cables, and/or printed electrical connections are used, as well as by using electromagnetic energy (such as having wavelengths in the radio frequency region, the microwave region, and the optical (visible and invisible) regions), as a few non-limiting and non-exhaustive examples.

Furthermore, some of the features of the preferred embodiments of this invention could be used to advantage without the corresponding use of other features. Thus, the foregoing description should be considered as merely illustrative of the principles of the present invention, and not in limitation thereof.

Claims

1. A method of communication, comprising:

performing, by the first communication device, a side chain transmission towards the second communication device for a transport block associated with the side chain transmission using the resource reservation; and

In response to receiving hybrid automatic repeat request (HARQ) feedback for the side-link transmission, performing at least one side-link retransmission for the code block group of the negatively acknowledged transport block using some or all of the reserved resources of the resource reservation,

Wherein the hybrid automatic repeat request feedback comprises:

the method comprises the steps of receiving, on a side chain feedback channel from the second communication device, hybrid automatic repeat request feedback information based on a code block group from the second communication device, and monitoring the side chain feedback channel by a third communication device, wherein the third communication device derives information about resource release based on the monitored side chain feedback channel and the information of resource reservation;

wherein the side link transmission comprises:

side link control channel transmission for transmitting side link control information associated with the side link transmission; and transmitting a side link shared channel transmission of a code block associated with the transport block; and

Wherein performing the side link transmission comprises:

determining a code block segment of the transport block;

determining a number of code block groups associated with code blocks obtained by the code block segmentation; and

The reserved resources for the retransmission of the set of code blocks for the transport block are determined.

2. The method of claim 1, wherein performing the side link transmission further comprises:

Setting a code block group related information field in the side chain control information based on the determined code block segment and a transport block code block group number associated with the transport block; and

Setting a resource reservation related information field in the side link control information based on the determined reserved resources for potential retransmissions associated with the transport block;

Generating a side link control channel and a side link shared channel; and

And transmitting the side link control channel and the side link shared channel which are transmitted for the side link towards the second communication equipment on the side link.

3. The method of claim 1, wherein determining the number of code block groups associated with the code block obtained by the code block segmentation comprises at least one of:

Determining the number of the code block groups based on a total number of the code blocks and a code block size; or alternatively

The number of the code block groups is determined based on a transport block size.

4. The method of claim 2, wherein the code block set related information field of the side link control information comprises:

A code block group number corresponding to the determined number of code block groups of the associated transport block; and

Code block group transmission information including a bitmap identifying code block group numbers, the bitmap indicating the presence or absence of corresponding code block groups in a current side link transmission.

5. The method of claim 2, wherein the resource reservation related information field of the side link control information comprises at least one of:

information about at least one resource reservation in a time domain, the time domain comprising one or more time slots; or alternatively

Information regarding at least one resource reservation in a frequency domain, the frequency domain including one or more subchannels.

6. The method of claim 1, wherein performing the at least one secondary side link retransmission for the code block group of the negatively acknowledged transport block using the reserved portion or all of reserved resources comprises:

Using the partially or fully reserved resources in the frequency domain, performing a side link retransmission on the partially or fully reserved resources in the time domain for the negatively acknowledged code block set.

7. An apparatus for communication, comprising:

means for performing, by the first communication device, side chain transmission towards the second communication device for a transport block associated with the side chain transmission using the resource reservation; and

Means for performing at least one side link retransmission for a code block group of the transport block that was negatively acknowledged using some or all of the reserved resources of the resource reservation in response to receiving hybrid automatic repeat request (HARQ) feedback for the side link transmission,

Wherein the hybrid automatic repeat request feedback comprises:

wherein the side link transmission comprises:

Wherein the means for performing the side link transmission comprises:

means for determining a code block segment of the transport block;

means for determining a number of code block groups associated with code blocks obtained by the code block segmentation; and

Means for determining the reserved resources for the retransmission of the code block set for the transport block.

8. The apparatus of claim 7, wherein the means for performing the side chain transmission further comprises:

Means for setting a code block group related information field in the side chain control information based on the determined code block segment and code block group number associated with the transport block; and

Means for setting a resource reservation related information field in the side chain control information based on the determined reserved resources for potential retransmissions associated with the transport block;

means for generating a side chain control channel and a side chain shared channel; and

And means for transmitting the side link control channel and the side link shared channel for the side link transmission toward the second communication device on the side link.

9. The apparatus of claim 7, wherein means for determining the number of code block groups associated with the code block obtained by the code block segmentation comprises at least one of:

means for determining the number of the code block groups based on a total number of the code blocks and a code block size; or alternatively

Means for determining the number of the code block groups based on a transport block size.

10. The apparatus of claim 8, wherein the code block set related information field of the side link control information comprises:

11. The apparatus of claim 8, wherein the resource reservation related information comprises at least one of:

Information on at least one resource reservation in the frequency domain on the part or all reserved resources in the time domain.

12. The apparatus of claim 7, wherein performing the at least one primary side link retransmission for the code block group of the negatively acknowledged transport block using the partially or fully reserved resources of the resource reservation comprises:

and performing side link retransmission on the code block group which is negatively acknowledged on part or all of the reserved resources in the time domain by using part or all of the reserved resources in the frequency domain.

13. A method of communication, comprising:

Monitoring, by a third communication device, a side link control channel for side link transmission from a first communication device, wherein the first communication device performs the side link transmission towards a second communication device for a transport block associated with the side link transmission using a resource reservation; the first communication device performing at least one side link retransmission for a code block group of the negatively acknowledged transport block using some or all of the reserved resources in response to receiving hybrid automatic repeat request (HARQ) feedback for the side link transmission;

Monitoring, by a third communication device, a side link feedback channel for feedback from the second communication device for the side link transmission, wherein monitoring the side link feedback channel includes detecting the side link feedback channel and obtaining information based on a hybrid automatic repeat request feedback of a code block group from the side link feedback control information; and

Based on the monitored parameters from the side link control channel and the side link feedback channel related to the side link retransmission, resource selection is performed by a third communication device for side link transmission,

Wherein the third communication device derives information about resource release based on the monitored side link feedback channel and the information of the resource reservation.

14. The method of claim 13, wherein the parameters include information of reserved resources for the side link transmission and the feedback.

15. The method of claim 14, wherein the third communication device derives from the parameters the part or all of reserved resources to be used for side link retransmissions and remaining resources of the reserved resources to be implicitly released.

16. The method of claim 13, wherein the monitoring comprises:

And decoding the side link control channel, and acquiring code block group related information and resource reservation information code blocks for side link retransmission from the side link control information.

17. The method of claim 15, wherein performing resource selection for the side link transmission comprises:

it is contemplated that in the resource selection for the side link transmission, at least one of the following is effectively reserved:

the resources reserved by the first communication device,

A resource monitored by the third communication device, and

Resources to be used by a plurality of negative-acknowledged code block groups indicating code blocks by hybrid automatic repeat request feedback based on the code block groups, and wherein any remaining reserved resources are implicitly released.

18. The method of claim 17, wherein the resource selection uses at least one of the remaining reserved resources and unreserved resources that are implicitly released.

19. An apparatus for communication, comprising:

Means for monitoring, by a third communication device, a side link control channel for side link transmissions from a first communication device, wherein the first communication device performs the side link transmissions towards a second communication device for transport blocks associated with the side link transmissions using resource reservations; the first communication device performing at least one side link retransmission for a code block group of the negatively acknowledged transport block using some or all of the reserved resources in response to receiving hybrid automatic repeat request (HARQ) feedback for the side link transmission;

Means for monitoring a side link feedback channel for feedback of the side link transmission from the second communication device, wherein the means for monitoring the side link feedback channel comprises means for detecting the side link feedback channel, and means for obtaining information of hybrid automatic repeat request feedback based on a code block group from the side link feedback control information, the third communication device deriving information on resource release based on the monitored side link feedback channel and the information of resource reservation; and

Means for performing resource selection for the sidelink transmission based on the monitored parameters associated with the sidelink retransmission from the sidelink control channel and the sidelink feedback channel.

20. The apparatus of claim 19, wherein the parameters comprise information of reserved resources for the side chain transmission and the feedback.

21. The apparatus of claim 20, wherein the third communication device derives the portion or all of reserved resources to be used for side link retransmission and remaining resources to be implicitly released from the parameters.

22. The apparatus of claim 19, wherein the means for monitoring comprises:

23. The apparatus of claim 21, wherein means for performing resource selection for the side chain transmission comprises:

consider that in the resource selection for the side link transmission, at least one of the following is effectively reserved:

the resources reserved by the first communication device,

A resource monitored by the third communication device, and

24. The apparatus of claim 23, wherein the resource selection uses at least one of the remaining reserved resources and unreserved resources that are implicitly released.

25. A communication system comprising an apparatus according to any one of claims 7 to 12 and an apparatus according to any one of claims 19 to 24.

26. A computer program product comprising program code for performing the method according to any of claims 1 to 6 or 13 to 18.

27. A computer readable storage medium comprising program instructions which, when executed by an apparatus, cause the apparatus to perform the method of any one of claims 1 to 6 or 13 to 18.