User equipment

Abstract

A user equipment (UE), in particular a transmitter user equipment (TX UE), is configured to transmit data packets, such as transport blocks (TBs), using data signals (1150), such as PSCCH and PSSCH, using one or more particular sub-channels or resource blocks (RBs) in one or more particular time slots, using sidelink communication, and desires to transmit the data packets, such as transport blocks (TBs), from feedback signals of a receiver user equipment (RX UE) of the data packets, such as in PSFCH (1100). A feedback signal is received within a PSFCH candidate resource (1100, 1200) at a plurality of time and / or frequency and / or cyclic shift positions. A user equipment (UE), in particular a receiver user equipment (RX UE), is configured to receive data packets, such as transport blocks (TBs), using data signals (1150), such as PSCCH and PSSCH, using one or more particular sub-channels or resource blocks (RBs) of sidelink communication in one or more particular time slots, and to transmit feedback messages to a transmitter user equipment (TX UE) in feedback signals, such as PSFCH (1100), wherein the feedback signal may be transmitted at a plurality of time and / or frequency and / or cyclic shift positions within the PSCCH candidate resources (1100, 1200).

Description

[0001] illustrate

[0002] Embodiments of the present invention relate to user equipment, in particular transmitter user equipment and receiver user equipment. Further embodiments relate to a method for performing sidelink communication in a computer program. In general, embodiments relate to sidelink communication and processing of feedback messages, such as in PSFCH.

[0003] FIG9 is a schematic diagram of an embodiment of a terrestrial wireless network 100. As shown in FIG9(a), the network includes a core network 102 and one or more radio access networks RAN1, RAN2, ...RAN N Figure 9(b) is a diagram of the radio access network RAN NSchematic diagram of an embodiment of the present invention, which may include one or more base stations gNB1 to gNB5, each serving a specific area around the base station, which is schematically represented by the corresponding cells 1061 to 1065. The base station is used to provide services to users within the cell. One or more base stations can provide services to users in licensed and / or unlicensed bands. The term base station BS refers to a gNB in ​​a 5G network, an eNB in ​​UMTS / LTE / LTE-A / LTE-A Pro, or a BS in other mobile communication standards. Users can be fixed devices or mobile devices. The wireless communication system can also be accessed by mobile or fixed IoT devices connected to the base station or users. Mobile or fixed devices can include physical devices, ground vehicles such as robots or cars, aerial vehicles such as manned or unmanned aerial vehicles, UAVs, the latter also known as drones, buildings and other objects or devices, in which electronic devices, software, sensors, actuators, or the like are embedded, connected by a network to enable these devices to collect and exchange data on the existing network infrastructure. Figure 9(b) shows two users UE1 and UE2, also known as user terminals or user equipment, which are located in the cell 1062 and are served by the base station gNB2. Another user UE3 is located in cell 1064 and is served by base station gNB4. Arrows 1081, 1082 and 1083 schematically represent uplink / downlink connections for transmitting data from users UE1, UE2 and UE3 to base stations gNB2, gNB4 or for transmitting data from base stations gNB2, gNB4 to users UE1, UE2, UE3. This can be implemented in a licensed band or an unlicensed band. In addition, Figure 9(b) shows two other devices 1101 and 1102 in cell 1064, such as IoT devices, which can be fixed or mobile devices. Device 1101 accesses the wireless communication system through base station gNB4 to receive and send data, as shown by arrow 1121. Device 1102 accesses the wireless communication system through user UE3, as shown by arrow 1122. The individual base stations gNB1 to gNB5 can be connected to the core network 102, for example, via an S1 interface, through individual backhaul links 1141 to 1145, schematically represented in FIG9(b) by arrows pointing to "core". The core network 102 can be connected to one or more external networks. The external network can be the Internet, or it can be a private network, such as an intranet or any other type of campus network, such as a private WiFi communication system or a 4G or 5G mobile communication system. In addition, some or all of the individual base stations gNB1 to gNB5 can be connected to each other, for example, via an S1 or X2 interface or an XN interface in NR, through individual backhaul links 1161 to 1165, in Figure 1 (b) points to “gNB s” is schematically represented by an arrow. The sidelink channel allows direct communication between UEs, also known as device-to-device D2D communication. The sidelink interface in 3GPP is called PC5.

[0004] For data transmission, a physical resource grid may be used. The physical resource grid may include a set of resource elements to which various physical channels and physical signals are mapped. For example, the physical channels may include physical downlink, uplink and sidelink shared channels PDSCH, PUSCH, PSSCH, carrying user-specific data, also known as downlink, uplink and sidelink payload data; physical broadcast channel PBCH, and physical sidelink broadcast channel, PSBCH, carrying, for example, a master information block MIB and one or more system information blocks SIB, one or more sidelink information blocks SLIB, if supported; physical downlink, uplink and sidelink control channels PDCCH, PUCCH, PSCCH, carrying, for example, downlink control information DCI, uplink control information UCI and sidelink control information SCI; and physical sidelink feedback channel PSFCH, carrying feedback responses. The sidelink interface may support two levels of SCI, which refers to a first control region containing some part of the SCI, also known as the first level SCI, and an optional second control region, which contains a second part of the control information, also known as the second level SCI.

[0005] For the uplink, the physical channels may also include a physical random access channel PRACH or RACH, which the UE uses to access the network after synchronization and obtaining the MIB and SIB. Physical signals may include reference signals or symbols, RS, synchronization signals, etc. The resource grid may include a frame or radio frame with a specific duration in the time domain and a given bandwidth in the frequency domain. The frame may have a certain number of subframes of a predefined length, such as 1ms. Each subframe may include one or more time slots of 12 or 14 OFDM symbols, depending on the length of the cyclic prefix CP. The frame may also have a smaller number of OFDM symbols, for example, when a shortened transmission time interval sTTI or a mini-slot / non-slot basic frame structure containing only a few OFDM symbols is used.

[0006] The wireless communication system may be any single carrier or multi-carrier system using frequency division multiplexing, such as an Orthogonal Frequency Division Multiplexing OFDM system, an Orthogonal Frequency Division Multiple Access OFDMA system or any other Inverse Fast Fourier Transform IFFT based signal with or without a cyclic prefix CP, such as Discrete Fourier Transform Spread OFDM, DFT-s-OFDM. Other waveforms may be used, such as non-orthogonal waveforms for multiple access, such as filter bank multi-carrier FBMC, generalized frequency division multiplexing GFDM or universal filter multi-carrier UFMC. The wireless communication system may operate in accordance with the LTE-Advanced pro standard, the 5G or NR new radio standard or the NR-U unlicensed new radio standard.

[0007] The wireless network or communication system shown in FIG9 may be a heterogeneous network with different coverage networks, for example, a macrocellular network, each macrocell including macro base stations, such as base stations gNB1 to gNB5, and a small cell base station network, not shown in FIG9 , such as a femto base station or a pico base station. In addition to the above-mentioned terrestrial wireless networks, there are non-terrestrial wireless communication networks NTN, including satellite-borne transceivers and / or airborne transceivers such as unmanned aerial vehicle systems. The non-terrestrial wireless communication network or system may operate in a similar manner to the terrestrial system in FIG9 above, for example, in accordance with the LTE-Advanced Pro standard or the 5G or NR new radio standard.

[0008] In a mobile communication network, for example, in a network as described above with reference to FIG. 9 , such as an LTE or 5G / NR network, there may be UEs that communicate directly with each other through one or more side link SL channels, for example, using a PC5 / PC3 interface or directly using WiFi. UEs that communicate directly with each other through side links may include vehicles that communicate directly with other vehicles, V2V communications, vehicles that communicate with other entities of a wireless communication network, V2X communications, such as roadside units RSUs, roadside entities such as traffic lights, traffic signs, or pedestrians. The RSU may have the functionality of a BS or a UE, depending on the specific network configuration. Other UEs may not be vehicle-related UEs and may include any of the above-mentioned devices. Such devices may also communicate directly with each other using SL channels, i.e., D2D communications.

[0009] When considering two UEs communicating directly with each other via a sidelink, the two UEs can be served by the same base station, so that the base station can provide sidelink resource allocation configuration or assistance to the UE. For example, both UEs may be within the coverage area of ​​a base station, such as one of the base stations shown in Figure 9. This is called the "in coverage" scenario. Another scenario is called the "out of coverage" scenario. It is worth noting that "out of coverage" does not mean that the two UEs are not within one of the cells shown in Figure 9, but rather that these UEs

[0010] - may not be connected to the base station, e.g., they are not in a Radio Resource Control (RRC) Connected state, so the UE does not receive any sidelink resource allocation configuration or assistance from the base station, and / or

[0011] - may be connected to a base station, but due to one or more reasons, the base station may not provide sidelink resource allocation configuration or assistance to the UE, and / or

[0012] -The base station you may be connected to may not support NR V2X services, such as GSM, UMTS, LTE base stations.

[0013] When considering two UEs communicating directly via a sidelink (e.g. using a PC5 / PC3 interface), one of the UEs can also be connected to the BS and can relay information from the BS to the other UE via the sidelink interface and vice versa. Relaying can be performed in the same frequency band, i.e. in-band relaying, or in another frequency band, i.e. out-of-band relaying. In the first case, different time slots can be used to decouple the communication on Uu and sidelink, just like in a time division duplex TDD system.

[0014] Fig.10 is a schematic diagram of a coverage scenario in which two UEs communicating directly with each other are both connected to one base station. The coverage area of ​​the base station gNB is schematically represented by a circle 200, which substantially corresponds to the cell schematically shown in FIG9 . The UEs communicating directly with each other include a first vehicle 202 and a second vehicle 204, both in the coverage area 200 of the base station gNB. Both vehicles 202, 204 are connected to the base station gNB and, in addition, are directly connected to each other via a PC5 interface. The gNB assists in the scheduling and / or interference management of V2V traffic via control signaling over the Uu interface, which is the wireless interface between the base station and the UE. In other words, the gNB provides the UE with SL resource allocation configuration or assistance, and the gNB allocates resources for V2V communication via a sidelink. This configuration is also referred to as a Mode 1 configuration in NR V2X and a Mode 3 configuration in LTE V2X.

[0015] Fig.11 is a schematic diagram of an out-of-coverage scenario, where UEs communicating directly with each other are either not connected to the base station, although they may be physically located within a cell of the wireless communication network, or some or all of the UEs communicating directly with each other are connected to the base station but the base station does not provide SL resource allocation configuration or assistance. The figure shows three vehicles 206, 208 and 210 communicating directly via a side link (e.g., using a PC5 interface). Scheduling and / or interference management of V2V traffic is based on algorithms implemented between vehicles. This configuration is also called Mode 2 configuration in NR V2X and Mode 4 configuration in LTE V2X. As described above, Fig.11The scenario in is an out-of-coverage scenario, which does not necessarily mean that each mode 2 UE in NR or mode 4 UE in LTE is outside the coverage range 200 of the base station, but means that each mode 2 UE in NR or mode 4 UE in LTE is not served by the base station, is not connected to the base station in the coverage area, or is connected to the base station but does not receive SL resource allocation configuration or assistance from the base station. Fig.10 In the illustrated coverage area 200, in addition to UEs 202 and 204 of NR mode 1 or LTE mode 3, there may also be UEs 206, 208, and 210 of NR mode 2 or LTE mode 4. Fig.11 An out-of-coverage UE communicating with the network using relays is schematically shown. For example, UE 210 may communicate with UE 212 via a sidelink, and UE 212 may in turn be connected to the gNB via a Uu interface. Thus, UE 212 may relay information between the gNB and UE 210.

[0016] although Fig.10 and Fig.11 A vehicle-mounted UE is shown, but it is worth noting that the described in-coverage and out-of-coverage scenarios also apply to non-vehicle UEs. In other words, any UE (such as a handheld device) can be in-coverage and out-of-coverage when communicating directly with another UE using a SL channel.

[0017] The initial vehicle-to-everything (V2X) specifications were included in 3GPP LTE Release 14. The scheduling and allocation of resources have been modified to meet V2X requirements, while the initial device-to-device (D2D) communications have been used as the basis for the design. 3GPP's LTE V2X (also known as enhanced V2X or eV2X) Release 15 was completed in June 2018, and the first release of 5G NR V2X, Release 16, was completed in March 2020. 3GPP Release 17 focuses on sidelink enhancements with an emphasis on energy saving, enhanced reliability and reduced latency to meet the needs of not only vehicular communications, but also public safety and commercial use cases.

[0018] The new 3GPP Release 18 will focus on enabling sidelinks on unlicensed spectrum.

[0019] Purpose

[0020] The object of the present invention is to provide a concept for transmitting feedback between UEs, in particular UEs communicating via a sidelink.

[0021] Below, the background of sidelink communication and feedback transmission will be given. The background is discussed according to the present invention, so it is obvious that the disclosure of the background, especially the explanation of the background, is part of the disclosure of the present invention and should not be interpreted as prior art.

[0022] Background on NR HARQ feedback: In Release 16 / 17, NR V2X introduced support for HARQ-based transmissions, transmitted by the RX UE to the TX UE, acknowledging receipt of a given transmission. The RX UE may transmit positive acknowledgement (ACK) / negative acknowledgement (NACK) for unicast and multicast (Type 1) transmissions, or only NACK for specific multicast (Type 2) transmissions. The RX UE transmits HARQ feedback depending on whether it was able to successfully decode the transport block.

[0023] For NACK-only operation of multicast type 2, the advantage of using this operation is that the number of feedback resources required to transmit feedback is reduced, which is useful when a large number of RX UEs need to send feedback to the same TX UE. Another feature introduced is the use of a minimum communication distance, where the RX UE will only send feedback to the TX UE when the RX UE and TX UE are within a predetermined distance of each other. This is because only when the RX UE is within this distance is the feedback relevant to the TX UE for retransmission attempts. When operating in Mode 1, the TX UE must in turn inform the gNB of the status of the feedback via PUCCH / PUSCH, as resources are allocated by the gNB in ​​the form of configuration or dynamic grant.

[0024] To transmit feedback, the RX UE uses 1 bit of the Physical Sidelink Feedback Channel (PSFCH). The RX UE uses the first PSFCH slot that meets the following 2 conditions.

[0025] Currently, the TX UE provides a "PSFCH Overhead Indication" in the SCI, i.e.

[0026] Parameter derived from the upper layer parameter sl-PSFCH-Period which is a resource pool configuration parameter. This parameter informs the RXUE of the period of the PSFCH resources defined within the resource pool.

[0027] Sl-MinTimeGapPSFCH is another upper layer parameter, which is a resource pool.

[0028] Configuration parameter that defines the minimum time interval between data transmission in PSSCH and feedback transmission in PSFCH.

[0029] Rel-16 NR-U Channel Access Background: The channel access procedure is a sensing-based procedure used to assess whether the channel is available for transmission. The basic unit of sensing is the sensing slot, which has a duration of T si =9us. If the eNB / gNB or UE senses the channel during the sensing time slot duration and determines that the detection power for at least 4us during the sensing time slot duration is less than the energy detection threshold XThresh , then the duration of the sensing time slot is considered to be T si is idle. Otherwise, the sensing time slot duration is T si Considered busy.

[0030] Channel occupancy refers to the transmission performed by the eNB / gNB / UE on the channel after executing the corresponding channel access procedures in this clause.

[0031] Channel Occupancy Time refers to the total time that the eNB / gNB / UE and any eNB / gNBA / UE occupying the shared channel perform transmissions on the channel after the eNB / gNB / UE performs the corresponding channel access procedures described above. For the purpose of determining the Channel Occupancy Time, if a transmission gap is less than or equal to 25us, the gap duration is counted towards the Channel Occupancy Time. The Channel Occupancy Time may be shared between the eNB / gNB and the corresponding UE.

[0032] Background on channel access procedure types:

[0033] Type 1: The idle duration sensed before transmission is random. The gNB or UE determines the interval between 0 and CW. p The initial counter N is randomly selected between min，p ≤CW p ≤CW max，p , C.W. min，p and CW max，p Limited by CAPC. When the channel is sensed to be idle for a period of time, N can be reduced. Transmission is possible only when N reaches 0.

[0034] Type-2A-The idle time before transmission is determined. The channel idle sensing interval is 25us.

[0035] Type-2B-The idle time before transmission is determined. The channel idle sensing interval is 16us.

[0036] Type-2C - Channel is not sensed before transmission. The duration of the corresponding transmission is at most 584us.

[0037] The above mentioned objects are solved by the subject-matter of the independent claims.

[0038] summary

[0039] The present embodiment provides a user equipment, in particular a transmitter user equipment, which is configured to use data signals, such as PSCCH and PSSCH, to use one or more specific sub-slots or resource blocks (RBS) in one or more specific (time) time slots to transmit data packets, such as transport blocks (TBs), through side link communication. The user equipment is also configured to expect a feedback message from a receiver user equipment of the data packet in a feedback signal (e.g., in a PSFCH). According to the present disclosure, the feedback signal can be received at multiple times and / or frequencies and / or cyclic shift positions within a PSFCH candidate resource.

[0040] Another embodiment provides a user equipment, in particular a receiver user equipment, configured to receive a data packet, such as a transport block (TB), using a data signal (e.g., PSCCH and PSSCH), using one or more specific subslots or resource blocks (RBS) in one or more specific time slots using side link communication. The receiver is configured to transmit a feedback message to the transmitter user equipment in a feedback signal (e.g., in a PSFCH), wherein the feedback signal can be transmitted in multiple time and / or frequency and / or cyclic shift positions in a PSFCH candidate resource.

[0041] Another embodiment provides a method for performing sidelink communication, comprising using a data signal (e.g., PSCCH and PSSCH), using sidelink communication to send a data packet, such as a transport block (TB), in one or more specific subchannels or resource blocks (RBs) in one or more specific time slots, and expecting a feedback message in a feedback signal (e.g., in a PSFCH) from a receiver user equipment of the data signal, wherein the feedback signal can be received at multiple time and / or frequency and / or cyclic shift positions within a PSCCH candidate resource.

[0042] Another embodiment provides a method for performing sidelink communication, including receiving a data packet (e.g., a transport block (TB)) using a data signal (e.g., a PSCCH and a PSSCH), using sidelink communication using one or more specific subchannels or resource blocks (RBs) in one or more specific time slots, and transmitting a transmission message to a transmitter user equipment in a feedback signal (e.g., in a PSFCH), wherein the feedback signal may be transmitted at multiple time and / or frequency and / or cyclic shift positions within a PSCCH candidate resource.

[0043] Another embodiment provides a user equipment configured to send and / or receive data signals, wherein the user equipment is configured to transmit a pseudo signal in a current time slot to maintain COT (continuous transmission) for the user equipment (itself) in the next time slot, or to maintain COT (continuous transmission) for another user equipment in the next time slot.

[0044] According to another method for performing sidelink communication, a data packet is transmitted in a current time slot so as to maintain the COT in a next time slot.

[0045] According to further embodiments, the methods may be computer implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of a conventional PSFCH is shown, whose period has four time slots, and according to an implementation scheme, additional non-licensed repetitions are introduced in case of LBT failure;

[0047] Figure 2 A schematic diagram showing the description and mapping of data to PSFCH and related repetitions according to an implementation scheme is shown;

[0048] Figure 3a and 3b The concept of avoiding "losing" COT by introducing a pseudo PSFCH according to a further embodiment is shown ( Figure 3a Including short LBT, Figure 3b LBT has less control);

[0049] Figure 4 shows a schematic diagram of a COT continuation signal sent by another UE (e.g., UE 2) according to a further embodiment;

[0050] Figure 5 1. A schematic diagram for illustrating over-configuring PSFCH feedback to map to multiple LBT subbands with respective PSFCHs according to a further embodiment;

[0051] Figure 6 A schematic diagram showing repetition of PSFCH (PSFCH multiple positions) in an LBT subband according to a further embodiment is shown;

[0052] Figure 7 shows a PSFCH formula which, according to a further embodiment, gives the PSFCH positions in a plurality of subbands;

[0053] Figure 8a , b, c show conceptual schematic diagrams of repeated feedback data, according to three different streams of the implementation scheme (8a exponential data stream, 8b Gaussian data stream, 8c exponential data stream until a maximum value with a long tail);

[0054] FIG9 shows a schematic diagram of a terrestrial network (9a core network, 9b wireless access network) to discuss the implementation of this embodiment;

[0055] Fig.10 A schematic diagram showing a scene within the coverage area;

[0056] Fig.11 A schematic diagram showing an out-of-coverage scenario; and

[0057] Fig.12 A schematic block diagram of a computer system according to an embodiment is shown.

[0058] Detailed description

[0059] Hereinafter, embodiments of the present invention will be discussed with reference to the accompanying drawings. Herein, objects with the same or similar functions have the same reference numerals, so that their descriptions are interchangeable and mutually applicable.

[0060] Before discussing the embodiments in detail, definitions of terms used in the context of describing the embodiments are provided:

[0061] - The feedback message may be the actual content of the HARQ feedback, such as ACK or NACK.

[0062] -The feedback signal is a coded feedback message, such as a PSFCH sequence.

[0063] -PSFCH is a physical channel for transmitting feedback signals. It is a set of time / frequency resources.

[0064] -PSFCH candidate resources may be a set of time / frequency / cyclic shift resources, where the TX UE expects to obtain a feedback signal in at least one of the candidate resources.

[0065] - A PSFCH opportunity is a set of PSFCHs, defined by the PSFCH period and the first instance of configuring a PSFCH (the starting point of the PSFCH period).

[0066] Embodiments of the present invention relate to user equipment, for example, user equipment belonging to a communication system and / or user equipment performing sidelink communication. According to some embodiments, unlicensed resources / unlicensed sidelink resources may be used, wherein LBT (Listen Before Talk) is typically used to access the channel.

[0067] In general, a transmitter UE, in particular, uses a data signal (such as PSCCH or PSSCH) to transmit a data packet (such as a transport block (TB)), and a receiver UE, in particular, uses a data signal (such as PSCCH and PSSCH) to receive a data packet (such as a transport block (TB)). The concept involved in the implementation scheme is how to exchange feedback messages (such as HARQ feedback) between the transmitter UE and the receiver UE. Transmission from the transmitter UE to the receiver UE is performed using one or more specific subchannels or resource blocks (RBS) in one or more specific time slots using sidelink communication. The receiver UE is configured to transmit the feedback message to the transmitter UE in a feedback signal (such as in a PSFCH). Vice versa, the transmitter UE is configured to expect or expect the feedback message transmitted by the receiver UE from the data packet in the feedback signal (such as in a PSFCH).

[0068] If feedback is enabled for sidelink transmission, since the TX UE cannot expect to receive HARQ feedback on the same slot as the data is transmitted, the RX UE will have to perform LBT to determine if feedback can be transmitted in a future slot in order to check if resources are available. If the TX and RX UEs share a COT and the COT is initiated by the TX UE, the RX UE does not need to perform LBT or only performs Type 2 LBT (shorter duration compared to Type 1 LBT) in order to access the channel and transmit in the PSFCH.

[0069] In the case of a so-called LBT failure, i.e., if a receiver UE attempts to access a channel (e.g., PSFCH) for transmitting a feedback message, but determines using LBT that the channel is not available or the time slot is not occupied by another UE providing a PSFCH, a method is required to enable the receiver UE to transmit the feedback message. According to an embodiment, the feedback signal is transmitted within multiple time and / or frequency and / or cyclic shift positions of at least one so-called PSFCH candidate resource. Thus, the transmitter UE receives the feedback signal within the PSFCH candidate resource at multiple locations, wherein the receiver UE can transmit the feedback signal within the PSCCH candidate resource at multiple locations. Therefore, an enhanced method is determined for how a UE determines resources for transmitting feedback, wherein feedback is enabled for transmission. This includes selecting resources on the feedback channel, optimal use of the channel, and procedures that the UE will perform in the event of a LBT failure.

[0070] According to an embodiment, the period of the PSFCH occasions is increased to determine additional PSFCH candidate resources. For example, the time interval between PSFCH occasions is shortened.

[0071] According to an embodiment, the increased PSFCH period may be based on a resource pool configuration.

[0072] Since the RX UE must comply with the minimum time interval after receiving the payload data on the PSSCH, it will determine the first PSFCH that meets the minimum time interval. This results in only one PSFCH to transmit feedback.

[0073] One way to improve the chances that the RX UE can find and use an available PSFCH instance is to ensure that for resource pools with PSFCH in unlicensed bands, the PSFCH periodicity is set to 1, which means that PSFCH is defined in every slot and also allows more PSFCH to be used for transmitting feedback. In one embodiment, the PSFCH periodicity is increased and multiple PSFCH transmission feedback is allowed to maximize the chances that the RX UE can find a PSFCH instance. The periodicity is higher compared to the current way feedback is transmitted in SL, for example, in every other slot, in every 3rd, 4th, etc. slots, reserving PSFCH resources.

[0074] Note that the PSFCH opportunity can be defined by a period and an offset, i.e., an existing PSFCH. As described above, one or more PSFCH opportunities can be determined as PSFCH candidate resources. Note that the PSFCH candidate element can be defined as a resource where feedback can be sent. According to an implementation scheme, PSFCH candidate resources in the PSFCH time position can be used, where the PSFCH candidate resources are all PSFCH opportunities between the minimum and maximum time gaps relative to a data packet or PSSCH. According to an implementation scheme, the maximum time interval is derived based on the period of the PDP and / or the transmitted TB. Therefore, the maximum time interval between PSSCH and PSFCH can be used.

[0075] Currently, the RX UE identifies the PSFCH resource to transmit feedback based on respecting sl-MinTimeGapPSFCH and the first time slot of the PSFCH cycle. In order to provide more PSFCH opportunities to the RX UE, we propose to introduce a maximum time interval between PSSCH and PSFCH. The RX UE is expected to transmit feedback between the minimum and maximum time intervals.

[0076] The maximum time interval can be determined based on the PDB of the TB being transmitted. Therefore, the TX UE can indicate this parameter in the SCI when transmitting a TB. It can also be a system-level parameter or resource pool configuration, where the UE can use the appropriate resource pool based on the PDB and the minimum / maximum time interval. In order to enable the transmitter to determine which data packet of a given PSFCH is acknowledged or not acknowledged, the PSFCH can include additional information.

[0077] Depending on the implementation scheme, additional PSFCH opportunities may be configured in the time domain and / or frequency domain. Furthermore, to avoid modifying the existing PSFCH structure, additional PSFCH opportunities or PSFCH resources may be configured by defining PSFCH repetitions that may be scheduled between current PSFCH opportunities. Thus, PSFCH repetitions may be configured in different ways so that a potential receiver can distinguish which data packet has been acknowledged or not acknowledged in a given PSFCH repetition. In other words, each PSFCH repetition is uniquely associated with a certain PSFCH opportunity and carries feedback only for that PSFCH opportunity.

[0078] Figure 1 Additional repetitions between scheduled PSFCH resources are shown. Figure 1 A PSFCH transmission scheme 1000 is shown, which includes a conventional PSCCH period of four time slots for conventional PSFCH 1100, wherein two additional unlicensed repetitions 1200 are introduced between the conventional PSFCCH 1100 and can be used, for example, in the case of LBT failure.

[0079] If UE1 has to transmit data to UE2 in the same time slot and UE1 has to receive PSFCH repetitions from another UE3, UE1 can prioritize transmitting data or receiving feedback based on the priority of the transmission. This happens when transmission and reception occur in different LBT subbands.

[0080] The UE will attempt to transmit PSFCH feedback on the scheduled PSFCH occasions and the associated PSFCH occasion repetitions. The UE may transmit feedback multiple times or stop after a successful transmission. For SL-U, the number of PSFCH repetitions may be fixedly increased because LBT failures may occur in SL-U, so the probability of transmission failure on PSFCH is greater than transmission on the licensed carrier. Figure 2 shown.

[0081] Figure 2 The mapping of the data portion 1150 transmitted on the PSSCH between the PSFCH 1100 and the PSFCH repetitions 1200 is shown. It can be seen that corresponding feedback is expected in some PSFCH repetitions 1200 after the data transmission 1150. The expected feedback is marked by reference number 1110.

[0082] From another perspective, this means that for each PSFCH opportunity, a PSFCH resource or a PSFCH repetition is defined so that they together constitute a PSFCH candidate resource. Additional PSFCH resources are configured in the time domain, such as Figure 1 and Figure 2 As shown, and / or configured in the frequency domain, such as Figure 5 and Figure 6 As shown, and / or configured in the cyclic shift domain. When looking at the entire resource space, additional PSFCH resources can be added between already available PSFCH opportunities. According to an embodiment, this can be applied in the frequency domain so that the PSFCH candidate resources are located on multiple (frequency) subbands. A subband can be a subchannel, an LBT subband or a (pre-)configured frequency resource. Therefore, according to an embodiment, the user equipment can be configured to use the same subband or different subbands, or multiple subbands or different multiple subbands to be processed as PSFCH candidate resources. Regarding the principle of using different subbands or multiple subbands, it will be combined with Figure 5 , 6 The enhanced embodiments formed by and 7 are discussed in more detail.

[0083] According to an embodiment, when transmitting a TB, the PSFCH candidate resources are defined by parameters indicated by the transmitter user equipment in the SCI. Additionally or alternatively, the PSFCH candidate resources are defined by the minimum and / or maximum time intervals derived from the parameters indicated in the SCI. In other words, this means that the minimum and / or maximum time intervals are derived from the parameters, so both the transmitter and the receiver UE can use this information to determine the PSFCH candidate resources.

[0084] In order to prevent another device from occupying the spectrum, according to an implementation scheme, one of the cyclic shifts is used as a channel busy pseudo signal by the UE that is transmitting data in the time slot so as to maintain the UE's COT in the next time slot. This is not necessary at the end of the COT. Another UE receiving the PSFCH only needs to perform a short LBT (Type 2 LBT) to regain channel access. In addition, the UE does not necessarily have to decode the PSFCH. In this way, any non-3GPP device cannot access the radio channel because it will feel that the channel is occupied. The feedback to be sent in the additional PSFCH can be HARQ feedback and / or channel state information (CSI). This additional feedback can also be called a COT continuation signal.

[0085] Figure 3a and 3b Timeslots in different sub-bands used for data transmission are shown. Figure 3a and 3bThe data packet transmission in is marked by reference number 3150 and is shown as arranged in one time slot, but with multiple time slots. After the data time slot 3150, a pseudo feedback / pseudo PSFCH or a general pseudo signal marked by reference number 330 is sent. In general, this means that the user equipment, in particular the transmitter user equipment, is configured to send a pseudo signal in the current time slot to maintain COT (continuous transmission) for the user equipment in the next time slot or for the receiving user equipment sending the feedback signal. According to an embodiment, the pseudo signal can be a signal shift or sequence orthogonal to the HARQ feedback to be transmitted in the time slot. This means that, according to an embodiment, the pseudo signal is a sequence similar to the HARQ feedback or cyclic shift, or a sequence orthogonal to the HARQ feedback, which will be transmitted in the same time slot.

[0086] According to an embodiment, this principle can also be used without providing additional PSFCH candidate resources. Therefore, in one embodiment, a user equipment is formed, wherein the transmitter of the user equipment is configured to send a dummy signal in a current time slot in order to maintain the COT or the user equipment in the next time slot, or to maintain the COT of another user equipment in the next time slot.

[0087] Furthermore, once multiple (one or more) PSFCH opportunities or repetitions occur in the COT, for example, future repetitions may be used for data. The number of PSFCH times / repetitions fed back may be configurable or preconfigured.

[0088] The continuation signal may also be sent by another UE or RSU to reserve the COT for future transmissions. In this case, UE2 transmits the continuation signal so that another UE (eg, UE1) can continue its data transmission.

[0089] Figure 4 A data transmission 3150a is shown, followed by a dummy signal 3300, followed by another data signal 3150b. Signal 3150b is a data packet sent by another UE (here UE2) in a subsequent time slot, where 3150a and 3300 are transmitted by the first UE UE1.

[0090] According to an embodiment, a dummy signal is transmitted in the PSFCH before and / or after the user equipment transmits the PSSCH.

[0091] When assuming that the second UE may be the receiver UE sending its feedback, the transmitter UE (UE1) sends the data portion 3150a and the enhanced dummy signal 3300 to the next PSFCH candidate resource, which is then used by the receiver UE. This means that, according to an implementation, the transmitter user equipment and the receiver user equipment are configured to use the same COT. According to an implementation, the receiver UE may perform type 1 or type 2 LBT, wherein the receiver user equipment may perform transmission of a feedback signal without LBT or type 2 LBT. In this case, the TX UE initiates a COT for data transmission, and the RX UE uses the same COT to transmit HARQ feedback for the data transmission.

[0092] The transmitter user equipment and the receiver user equipment use different COTs. For example, the transmitter user equipment may be configured to use Type 1 or Type 2 LBT, wherein the receiver user equipment is configured to use LBT before sending a feedback signal using a different COT or different resources.

[0093] According to an embodiment, a transmitter user equipment (TX UE) and a receiver user equipment (RX UE) use different COTs; wherein the transmitter user equipment (TX UE) uses a first COT to perform a first data transmission to the receiver user equipment (RX UE); wherein the receiver user equipment (RX UE) uses a second COT to perform a further data transmission to the transmitter user equipment (TXUE), and transmits a feedback signal corresponding to the first data transmission in the second COT. In this case, the TX UE initiates the first COT for TB1, the RX UE initiates a second COT for TB2 to the TX UE, and then uses the second COT to transmit HARQ feedback corresponding to TB1.

[0094] A method called over-allocation of PSFCH resources in the same time slot will be discussed below. This over-allocation of PSFCH resources can be combined with the previously mentioned implementation schemes (such as PSFCH repetition, maximum / minimum time) to achieve over-allocation of time and frequency. In addition, this over-allocation can be extended to the cyclic shift domain.

[0095] The RX UE may also be provided with multiple PSFCH opportunities in order to attempt to send feedback to the TX UE. One approach is for the RX UE to have more than 1 PSFCH resource per slot to exploit frequency diversity. As mentioned previously, this will still respect the time interval and PSFCH periodicity and / or PSFCH repetition, but will provide the RX UE with more resources within the PSFCH to send HARQ feedback to the TX UE. The receiver must know the exact mapping, either through configuration or implicit specification, so that a potential receiver knows which feedback information is associated with which data transmission or TB.

[0096] Figure 5 An over-configuration of multiple sub-band PSFCH feedback is shown.

[0097] Figure 5 Three subbands are shown, where PSFCH signals 5100a, 5100b, and 5100c are arranged in three different LBT subbands so that feedback messages assigned to two data packets 5150a and 5150b can be mapped. As shown in the figure, the three feedback messages generated by each data packet 5150a and 5150b are arranged in PSFCH 5100b, 5100a, and 5100c.

[0098] However, according to a further embodiment, the system may prioritize sending the PSFCH within the same LBT subband that is also used for related data, and limit further PSFCH transmission opportunities within the same subband, or within a maximum of x subbands, or only within adjacent subbands to reduce the signaling work to potential receivers, and reduce the decoding work or decoding bandwidth required by potential receivers.

[0099] like Figure 6 shown. Figure 6 The transmission of two data packets 5150a and 5150b and the transmission of feedback messages in three PSFCHs 5100a, 5100b and 5100c are shown. Here, repetition in different LBT subbands may be used.

[0100] In addition, mapping can also avoid frequency band limitation to obtain frequency diversity, so that PSFCH opportunities can span the entire frequency bandwidth or be part of a larger group of sub-channels, for example, as shown in the following figure, Figure 7 Transmissions 5150a and 5150b are shown along with PSFCH transmissions as 5100a, 5100b, and 5100c.

[0101] like Figure 6 As shown, Figure 6 An implementation scheme uses only one PSFCH opportunity for each feedback signal allocated to a data signal, wherein according to Figure 7An implementation scheme uses PSFCH opportunities in different frequency bands and allocates them to corresponding data signals 5150a and 5150b.

[0102] In order to be able to send feedback using one or more LBT subbands, PSFCH uses multiple subbands for each data transmission. According to the implementation, if more than one LBT is successful, the following principles can be used:

[0103] - Transmit on all PSFCHs;

[0104] -Transmit on one or more:

[0105] o Randomly,

[0106] o Prioritize subbands for data transmission,

[0107] oUse a configured or preconfigured priority order,

[0108] o On the same subband where the TX UE shares the COT,

[0109] oLimit how many subbands / additional subbands are used.

[0110] According to an embodiment, the feedback signal is transmitted on a subset of PSFCH candidates, i.e., not on every possible PSFCH candidate resource. According to an embodiment, the PSFCH candidate resources are prioritized by one or more of the following principles:

[0111] - Randomly prioritize sub-bands of packets;

[0112] - Use a configured or preconfigured priority order;

[0113] - using the subband containing the data signal;

[0114] - Position relative to the data packet;

[0115] - using the same sub-bands of the COT shared by the transmitter user equipment; and / or

[0116] - Limit how many subbands are used or how many other subbands are used.

[0117] According to the implementation, this principle can be described in a specific implementation in which the receiver user equipment transmits its feedback as follows:

[0118] If the LBT of a first PSFCH candidate resource among the PSFCH candidate resources fails, the receiver user equipment may use a second PSFCH candidate resource.

[0119] Note that, depending on the implementation, the receiver user equipment may be configured to transmit the feedback signal using SCI or MAC CE in case of feedback failure.

[0120] The principle of using the same or different COTs will be discussed below. For example, a receiver user equipment receives a transmission in one COT and sends HARQ feedback in resources belonging to the same COT or another COT.

[0121] According to another embodiment, the RX UE transmits feedback in the same COT that the TX UE uses for data transmission. Here, the RX UE may perform Type 2 LBT to reduce the time spent performing LBT and ensure that the PSFCH is available for transmission.

[0122] Another aspect is that the RX UE can transmit feedback to the TX UE in the same time slot in which it has scheduled a transmission, whether it is to the same TX UE or to another UE. In this case, the RX UE will use the COT performed for another transmission and use the PSCCH / PSSCH resources for another transmission, but use the PSFCH resources for the time slot in which the feedback is transmitted to the TX UE. In this case, the RX UE has performed LBT Type 1 or 2 to determine the availability of resources for other transmissions. In other words, the RX UE can transmit to a third UE using a COT that it initiated or shared (initiated by a third UE), transmit to the third UE using the time slot of PSCCH / PSSCH, but transmit feedback to the TX UE using PSFCH.

[0123] This means that, according to an embodiment, the transmitter user equipment and the receiver user equipment are configured to use the same COT. According to an embodiment, the transmitter user equipment performs (before data transmission) Type 1 or Type 2 LBT, wherein the receiver user equipment performs feedback transmission without LBT or Type 1 LBT.

[0124] Depending on the implementation, different COTs may be used. If the RX UE cannot transmit in the same COT as the TX UE, or does not transmit to another UE with a COT, the UE will have to perform LBT and determine another COT or another subband / subchannel or another resource pool.

[0125] Generally, this means that the transmitter user equipment and the receiver user equipment use different COTs. For example, the transmitter user equipment is configured to use Type 1 or Type 2 LBT, wherein the receiver user equipment is configured to use LBT before sending a feedback signal using different resources.

[0126] According to an embodiment, the RX UE attempts in x COTs, where x increases according to a function (e.g., exponentially). For example, the UE uses one COT for the first attempt and then increases the number of COTs for each subsequent attempt. Other functions may also be used, such as Gaussian feedback as shown in FIG8.

[0127] Figures 8a to 8b The usage of different feedback resources in different time frames is shown, where the resources are used in subsequent time frames, for example, if an LBT failure occurs in the worst time frame. Figure 8a , 8b and 8c, different COT schemes can be used. All three Figure 8a , 8b and 8c both plot different COT / feedback resource quantities over time, where Figure 8a shows that COT grows exponentially, Figure 8b It shows that COT grows in Gaussian fashion. Figure 8c It shows that the COT of Class 1LBT grows exponentially, with the maximum value of the exponential in the low-tail growth.

[0128] This means that, according to an embodiment, the transmitter user equipment may be configured to transmit the feedback signal within the PSFCH according to a function. Here, the function may be defined, for example, by a cyclic shift procedure for transmitting the feedback signal and / or by a cyclic shift procedure for transmitting the feedback signal multiplexed in a physical resource block.

[0129] Depending on the embodiment, the function may be a Gaussian function or an exponential function.

[0130] In addition, the UE can also multiplex multiple feedback signals in the PSFCH according to a function. This can be achieved by using cyclic shifts / cyclic shift pairs in the PSFCH transmission. For example, in the SL-PSFCH-Config, sl-NumMuxCS-Pair can be used to indicate the number of cyclic shift pairs used for PSFCH transmission that can be multiplexed in the PRB. The current setting supports values ​​​​n1, n2, n3 and n6. The more cyclic shift pairs there are, the more feedback data is multiplexed, but the stability of a given codeword is worse. Therefore, depending on the retransmission counter or the remaining time before the maximum retransmission counter is reached, sl-NumMuxCS-Pair can be configured (for example, reduced) to make the feedback more robust, or sl-NumMuxCS-Pair can be increased to multiplex more feedback data in a single feedback resource.

[0131] According to a further embodiment, the UE may perform an operation for HARQ feedback failure. The TX UE assumes that there are two reasons for HARQ feedback failure. One is that the RX UE is able to successfully decode the transmission from the TX UE, but cannot find the PSFCH resources for transmission feedback. The second case is that the RX UE cannot successfully decode the transmission and must send a NACK for retransmission from the TX UE, but cannot find the PSFCH resources for transmission feedback.

[0132] The reason why the RX UE cannot find PSFCH resources may be due to repeated LBT failures and the inability to find available resources on the scheduled PSFCH slot. To solve this problem, both the TX UE and the RX UE can take measures.

[0133] If PSFCH feedback fails a certain number of times and / or in addition, the feedback can be appended to the data transmission from Rx to Tx. In this case, the HARQ feedback can be indicated in the SCI field or as a MAC CE indication.

[0134] Depending on the implementation, actions taken by the transmitter user equipment, one of the actions that the TX UE can take is to provide redundancy - indicating multiple PSFCH opportunities to the RX UE for selection. These opportunities should be within the limits of the time interval and PSFCH period, but can include more than one time slot. The TX UE can explicitly indicate these PSFCH opportunities by using SCI format 2A / B / C, or it can implicitly indicate multiple PSFCH opportunities by indicating the maximum time interval between PSSCH and PSFCH. As mentioned earlier, this can also be a system-level parameter.

[0135] According to an embodiment, the TX UE may monitor these n indicated PSFCH opportunities where the RX UE may send HARQ feedback.At the same time, the RX UE will now have n PSFCH opportunities to check resource availability to send HARQ feedback.

[0136] In another embodiment, if the TX UE indicates n PSFCH opportunities to the RX UE, the RX UE may use these resources blindly without performing LBT. This may be provided when using the same COT initiated by the TX UE.

[0137] According to a further embodiment, in Mode 1, the TX UE shall report feedback to the gNB on the PUCCH resources determined by the sl-PSFCH-ToPUCCH-CG-Type1 parameter defined in the configured grant configuration, where the parameter indicates the timeslot offset between the PSFCH and PUCCH opportunities associated with the data transmission.

[0138] Since there are n different PSFCH opportunities, we recommend that the TX UE can report feedback to the gNB in ​​one of the following two ways:

[0139] - After receiving the actual PSFCH slot offset for feedback from the RX UE, feedback is reported on the PUCCH.

[0140] Feedback is reported on the PUCCH after an offset from the last of the n previously defined PSFCH candidate resources. In this case, the PUCCH can be after the maximum time interval or after the last PSFCH candidate resource defined by the TX UE.

[0141] Action taken by the receiver user equipment : According to the implementation scheme, if the RX UE cannot use the indicated PSFCH opportunity, but must send HARQ feedback to the TX UE, it may try to check other PSFCH opportunities that meet one or more of the following criteria:

[0142] Resources are available – LBT must be successful,

[0143] The resources come from the same COT initiated by the TX UE,

[0144] The time slot is within the PDB for a given transmission. Whenever the RX UE wants to send an ACK, the RX UE can pull it to the end of the PDB,

[0145] Transmission priority - If the priority is higher, the RX UE will want to inform the TX UE as soon as possible.

[0146] The RX UE can take the following actions:

[0147] Send feedback on the same or different channels / subchannels / resource pools,

[0148] Use non-SL-U carriers / resource pools to send feedback,

[0149] Request the gNB to inform the TX UE of the transmission status and, if NACK, attach a request to avoid transmission on the unlicensed carrier, e.g. retransmit on the licensed band or repeat the data on both licensed and unlicensed bands:

[0150] The gNB can use SFI (Sidelink Feedback Indicator) to notify the Tx UE.

[0151] According to an embodiment, this means that the receiver user equipment is configured to determine the enhanced PSFCH opportunities as follows:

[0152] - the resources available or available if the LBT is successfully performed; and / or

[0153] - Resources from the same COT initiated by a transmitter user equipment (TX UE); and / or

[0154] - PDB time slots for specific transmissions; and / or

[0155] -Transmission priority;

[0156] and / or

[0157] The receiver user equipment is configured to take one of the following actions:

[0158] - Send feedback on the same or different channel / sub-channel / resource pool;

[0159] - Use non-SL-U carriers / resource pools to send feedback;

[0160] - request the gNB to inform the transmitter UE of the transmission status; and / or

[0161] Request the gNB to inform the transmitter UE of the transmission status so that the gNB can use the sidelink feedback indicator to inform the transmitter UE.

[0162] Operation after LBT failure on PSFCH : According to the implementation, in case of n LBT failures (e.g., n failures occur consecutively for a given resource / subchannel), check the behavior of the RX UE in this case:

[0163] Stop using PSFCH resources and avoid sending HARQ feedback for data signals and possibly abandon the transmission;

[0164] Adjust HARQ behavior, such as transmission index feedback (see figure above);

[0165] Transmit the PSFCH in the licensed carrier;

[0166] Transmit feedback directly to the gNB (via Uu);

[0167] Switching / retransmitting on licensed bands.

[0168] Generally speaking, this means that the receiver UE is configured to do one of the following upon LBT failure:

[0169] - Stop using PSFCH resources and avoid sending HARQ feedback for data signals;

[0170] -Adjust HARQ behavior;

[0171] - Transmit PSFCH in the licensed carrier;

[0172] - Send feedback directly to the gNB; and / or

[0173] - Switching / retransmitting unlicensed frequency bands.

[0174] Regarding the transmitter user equipment, it should be noted that it may be configured to indicate enhanced PSFCH opportunities.According to an embodiment, the receiver user equipment may be configured to use enhanced PSFCH opportunities without performing listen-before-talk, or use type 1 listen-before-talk.

[0175] The following is an example configuration of NR-U:

[0176] Physical layer parameters Shared spectrum access

[0177] The IE Phy-ParametersSharedSpectrumChAccess is used to communicate physical layer capabilities specific to shared spectrum channel access.

[0178] Phy-ParametersSharedSpectrumChAccess Information Unit

[0179] --ASN1START

[0180] --TAG-PHY-PARAMETERSSHAREDSPECTRUMCHACCESS-START

[0181] Phy-ParametersSharedSpectrumChAccess-r16::=SEQUENCE{

[0182] --10-32(1-2):*SS block-based SINR measurement for unlicensed spectrum (SS-SINR)

[0183] ss-SINR-Meas-r16 ENUMERATED{supported}

[0184] OPTIONAL,

[0185] --10-33(2-32a): Semi-persistent CSI reporting for PUCCH in unlicensed spectrum

[0186] sp-CSI-ReportPUCCH-r16 ENUMERATED{supported}

[0187] OPTIONAL,

[0188] --10-33a(2-32b): Semi-persistent CSI reporting for PUSCH in unlicensed spectrum

[0189] sp-CSI-ReportPUSCH-r16 ENUMERATED{supported}

[0190] OPTIONAL,

[0191] --10-34(3-6): Dynamic SFI monitoring of unlicensed spectrum

[0192] dynamicSFI-r16 ENUMERATED{supported}

[0193] OPTIONAL,

[0194] --10-35c (4-19c): When SR / HARQ is multiplexed, use PUCCH (or HARQ-ACK / CSI on PUSCH) to multiplex SR / HARQ-ACK / CSI once in each time slot

[0195] --ACK / CSI should be sent with different starting symbols in time slots of unlicensed spectrum

[0196] --10-35(4-19): SR / HARQ - When SR / HARQ is multiplexed, use PUCCH (or HARQ-ACK / CSI on PUSCH) to multiplex SR / HARQ-ACK / CSI once in each time slot

[0197] --ACK / CSI should be sent on the PUCCH resources in the slots of unlicensed spectrum with the same starting symbol

[0198] mux-SR-HARQ-ACK-CSI-PUCCH-OncePerSlot-r16 SEQUENCE{

[0199] sameSymbol-r16 ENUMERATED{supported}

[0200] OPTIONAL,

[0201] diffSymbol-r16 ENUMERATED{supported}

[0202] OPTIONAL,

[0203] }

[0204] OPTIONAL,

[0205] --10-35a(4-19a): Overlapping PUCCH resources have different starting symbols in slots of unlicensed spectrum

[0206] mux-SR-HARQ-ACK-PUCCH-r16 ENUMERATED{supported}

[0207] OPTIONAL,

[0208] --10-35b(4-19b): Multiplex SR / HARQ-ACK / CSI multiple times per time slot using PUCCH (or HARQ-ACK / CSI on PUSCH) in the following cases

[0209] --SR / HHARQ ACK / CSI should be sent with the same or different starting symbols in the time slot of unlicensed spectrum

[0210] mux-SR-HARQ-ACK-CSI-PUCCH-MultiPerslot-r16 ENUMERATED{supported}

[0211] OPTIONAL,

[0212] ETSI

[0213] 3GPP TS 38.331version 17.0.0Release 17ETSI TS138 331V17.0.0(2022-05)

[0214] --10-36(4-28): HARQ-ACK multiplexing on unlicensed spectrum using different PUCCH / PUSCH start OFDM symbols on PUSCH

[0215] mux-HARQ-ACK-PUSCH-Diffsymb01-r16 ENUMERATED{supported}

[0216] OPTIONAL,

[0217] --10-37(4-23): Repetitions for PUCCH format 1,3,and 4 over multiple slots with K=2,4,8for unlicensed spectrum

[0218] pucch-Repetition-F1-3-4-r16 ENUMERATED{supported}

[0219] OPTIONAL,

[0220] --10-38(5-14): Type 1 configured PUSCH repeated over multiple slots for unlicensed spectrum

[0221] type1-PUSCH-RepetitionMuItiSlots-r16 ENUMERATED{supported}

[0222] OPTIONAL,

[0223] --10-39(5-16): Type 2 configured PUSCH repeated over multiple slots for unlicensed spectrum

[0224] type2-PUSCH-RepetitionMuItiSlots-r16 ENUMERATED{supported}

[0225] OPTIONAL,

[0226] --10-40(5-17): Unlicensed spectrum repeats PUSCH over multiple time slots

[0227] pusch-RepetitionMuItiSlots-r16 ENUMERATED{supported}

[0228] OPTIONAL,

[0229] --10-40a(5-17a): Unlicensed spectrum repeats PDSCH over multiple time slots

[0230] pdsch-RepetitionMuItislots-r16 ENUMERATED{supported}

[0231] OPTIONAL,

[0232] --10-41(5-19):DL SPS

[0233] downlinkSPS-r16 ENUMERATED{supported}

[0234] OPTIONAL,

[0235] 10-42(5-19): UL Authorization for Type 1 Configuration

[0236] configuredUL-GrantType1-r16 ENUMERATED{supported}

[0237] OPTIONAL,

[0238] 10-43(5-20): UL Authorization for Type 2 Configuration

[0239] configuredUL-GrantType2-r16 ENUMERATED{supported}

[0240] OPTIONAL,

[0241] 10-44(5-21):DL's preemptive instructions

[0242] pre-EmptIndication-DL-r16 ENUMERATED{supported}

[0243] OPTIONAL,

[0244] …

[0245] }

[0246] --TAG-PHY-PARAMETERSSHAREDSPECTRUMCHACCESS-STOP

[0247] --ASN1STOP

[0248] According to an embodiment, when COT / continuous transmission sharing is used, the side link communication as described above uses an unlicensed band and / or a band requiring LBT and / or a band requiring LBT type 1 and / or type 2.

[0249] According to an embodiment, the receiver unit is configured to perform LBT to determine available resources for feedback signals in future time slots.

[0250] As mentioned above, the application areas of the above teachings are sidelink communication systems, such as V2X, such as cellular (such as 3G, 4G, 5G or future systems), public safety communication systems, campus networks or ad hoc communication networks.

[0251] Another embodiment relates to a communication system comprising at least two user equipments, preferably user equipments performing sidelink. Here, a first user equipment of the at least three user equipments may be a transmitter user equipment, wherein a second user equipment of the at least two user equipments may be a receiver user equipment.

[0252] Overview

[0253] The embodiments of the present invention have been described above in detail, and each embodiment and aspect may be implemented independently, or two or more embodiments or aspects may be implemented in combination.

[0254] Depending on the embodiment, the wireless communication system may include a terrestrial network or a non-terrestrial network, or a network or network segment using an airborne vehicle or a spaceborne vehicle as a receiver, or a combination thereof.

[0255] According to the implementation scheme, the user equipment UE described herein may be one or more of a power-limited UE or a handheld UE, such as a UE used by pedestrians, referred to as a vulnerable road user VRU or a pedestrian UE P-UE, or a wearable or handheld UE used by public safety personnel and first responders, also referred to as a public safety UE, PS-UE or IoT UE, for example, a sensor, an actuator or a UE provided in a campus network for performing repetitive tasks and requiring regular input from a gateway node, or a mobile terminal, a fixed terminal, a cellular IoT UE, a vehicle UE or a vehicle master, GL, UE or IoT, or a narrowband IoT, NB-IoT device, or a WiFi non-access site, non-AP STA, such as 802.11ax or 802.11be, or a ground vehicle, or an aircraft, or a drone, or a mobile base station, or a roadside unit, or a building, or any other item or device equipped with a network connection, enabling the item / device to communicate using a wireless communication network, such as a sensor or actuator, or any other item or device with a network connection, enabling the item / device to communicate using a wireless communication network (such as a sensor or actuator) or any network entity with a sidelink function.

[0256] The base station BS described in this article can be implemented as a mobile or non-mobile base station, and can be a macrocell base station, a small cell base station, one or more of a central unit of a base station or a distributed unit of a base station, or an integrated access and backhaul (IAB) node, or a roadside unit, or a UE, or a central control (GL), or a relay, or a remote radio head, or an AMF, or an SMF, or a core network entity, or a mobile edge computing entity, or a network slice in the context of NR or 5G core, or a WiFi access site (such as 802.11ax or 802.11be) or any transmission / reception point (TRP) to enable an item or device to communicate using a wireless communication network, and the item or device is provided with a network connection to communicate using the wireless communication network.

[0257] Although some aspects of the described concepts are described in the context of an apparatus, it is clear that these aspects also represent a description of the corresponding method, where a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method step also represent a description of a corresponding block or item or feature of the corresponding apparatus.

[0258] The various elements and features of the present invention can be implemented in hardware using analog and / or digital circuits, in software by executing instructions through one or more general or special processors, or as a combination of hardware and software. For example, embodiments of the present invention can be implemented in the environment of a computer system or another processing system. Fig.12 An example of a computer system 600 is shown. The units or modules and the steps of the methods performed by the units can be executed on one or more computer systems 600. The computer system 600 includes one or more processors 602, such as a dedicated or general-purpose digital signal processor. The processor 602 is connected to a communication infrastructure 604, such as a bus or a network. The computer system 600 includes a main memory 606 (such as a random access memory RAM), and an auxiliary memory 608 (such as a hard drive and / or a removable storage drive). The auxiliary memory 608 can allow computer programs or other instructions to be loaded into the computer system 600. The computer system 600 can also include a communication interface 610 to allow software and data to be transmitted between the computer system 600 and external devices. The communication can be electronic, electromagnetic, optical or other signals that can be processed by the communication interface. The communication can use wires or cables, optical fibers, telephone lines, cellular phone links, radio frequency F links and other communication channels 612.

[0259] The terms "computer program medium" and "computer readable medium" generally refer to tangible storage media, such as a removable storage unit or a hard disk installed in a hard drive. These computer program products are a means for providing software to the computer system 600. Computer programs, also known as computer control logic, are stored in the main memory 606 and / or the secondary memory 608. The computer program may also be received via the communication interface 610. When the computer program is executed, the computer system 600 is able to implement the present invention. In particular, when executed, the computer program enables the processor 602 to implement the process of the present invention, such as any method described herein. Therefore, such a computer program may represent a controller of the computer system 600. In the case of implementing the present disclosure using software, the software may be stored in a computer program product and loaded into the computer system 600 using a removable storage drive, an interface (such as the communication interface 610).

[0260] Regarding the implementation in hardware or software, it can be performed using a digital storage medium, such as cloud storage, floppy disk, DVD, Blu-ray disc, CD, ROM, PROM, EPROM, EEPROM or flash memory, on which electronically readable control signals are stored, which cooperate with a programmable computer system to perform the corresponding method. Therefore, the digital storage medium can be computer readable.

[0261] Some embodiments according to the invention comprise a data carrier having electronically readable control signals, which are capable of cooperating with a programmable computer system, such that one of the methods described herein is performed.

[0262] Generally, the embodiments of the present invention can be realized as a computer program product with a program code, wherein the program code is used to perform one of the methods when the computer program product runs on a computer. The program code can be stored on a machine-readable carrier, for example.

[0263] Other embodiments comprise the computer program for performing one of the methods described herein, stored on a machine readable carrier. In other words, therefore, one embodiment of the inventive method is a computer program having a program code for performing one of the methods described herein when it runs on a computer.

[0264] Therefore, another embodiment of the method of the present invention is a data carrier or a digital storage medium or a computer-readable medium, which contains a computer program for performing one of the methods described herein. Therefore, another embodiment of the method of the present invention is a data stream or a signal sequence representing a computer program for performing one of the methods described herein. The data stream or signal sequence can, for example, be configured to be transmitted via a data communication connection (for example, via the Internet). Another embodiment includes a processing device, such as a computer or a programmable logic device, which is configured or adapted to perform one of the methods described herein. Another embodiment includes a computer having a computer program for performing one of the methods described herein installed thereon.

[0265] In certain embodiments, a programmable logic device, such as a field programmable gate array, can be used to perform some or all of the functions of the methods described herein. In certain embodiments, a field programmable gate array can be used in conjunction with a microprocessor to perform one of the methods described herein. Generally, these methods are preferably performed by any hardware device.

[0266] The above embodiments are only used to illustrate the principles of the present invention. It should be understood that modifications and variations of the arrangements and details described herein will be apparent to other persons skilled in the art. Therefore, the present invention is intended to be limited only by the scope of the patent claims to be proposed, and not by the specific details proposed herein by describing and explaining the embodiments.

[0267]

[0268]

Claims

1. A user equipment (UE), in particular a transmitter user equipment (TX UE), configured to transmit a data packet, such as a transport block (TB), using a data signal (1150), such as a physical sidelink control channel PSCCH and a physical sidelink shared channel PSSCH, using one or more specific subchannels or resource blocks (RBs) in one or more specific time slots, using sidelink communication, and expecting to receive a feedback message in a feedback signal from a receiver user equipment (RX UE) of the data packet, in, The feedback signal may be received at multiple time and / or frequency and / or cyclic shift positions within the PSFCH candidate resources (1100, 1200).

2. A user equipment (UE), in particular a receiver user equipment (RX UE), is configured to receive data packets, such as transport blocks (TBs), using data signals (1150), such as PSCCH and PSSCH, in one or more specific time slots using one or more specific subchannels or resource blocks (RBs) of sidelink communication, and transmit a feedback message to a transmitter user equipment (TX UE) in a feedback signal, such as in a PSFCH (1100), wherein the feedback signal can be transmitted in multiple time and / or frequency and / or cyclic shift positions within the PSCCH candidate resources (1100, 1200).

3. The user equipment (UE) according to one of the preceding claims, wherein The periodicity of the PSFCH (1100) opportunities is increased (the time between PSFCH (1100) opportunities is reduced) to define additional PSFCH candidate resources (1100, 1200).

4. The user equipment (UE) according to one of the preceding claims, wherein More than one PSFCH (1100) opportunities are determined as PSFCH candidate resources (1100, 1200).

5. The user equipment (UE) according to claim 4, wherein: The PSFCH candidate resources (1100, 1200) are all PSFCH (1100) opportunities between the minimum and maximum time intervals relative to the data packet.

6. The user equipment (UE) according to claim 5, wherein: The maximum time interval is determined based on the priority of the PDB and / or TB being transmitted.

7. User Equipment (UE) according to one of the preceding claims, wherein When transmitting a TB, the PSFCH candidate resources (1100, 1200) are defined by parameters indicated by the transmitter user equipment (TX UE) in the sidelink control information SCI.

8. User Equipment (UE) according to one of the preceding claims, wherein The PSFCH candidate resources (1100, 1200) are defined by minimum and / or maximum time intervals derived from parameters indicated in the SCI.

9. The user equipment (UE) according to one of the preceding claims, wherein For each PSFCH (1100) opportunity, an additional PSFCH resource or PSFCH (1100) repetition is defined, so that the PSFCH opportunity and the additional PSFCH (1100) resource or PSFCH (1100) repetition constitute PSFCH candidate resources (1100, 1200).

10. The user equipment (UE) according to claim 9, wherein: The additional PSFCH (1100) resources are configured in the time domain and / or the frequency domain and / or the cyclic shift domain.

11. The user equipment (UE) according to claim 9 or 10, wherein: The additional PSFCH (1100) resources are added between the already available PSFCH opportunities.

12. The user equipment (UE) according to one of the preceding claims, wherein The PSFCH candidate resources (1100, 1200) are located on more than one (frequency) sub-band.

13. The user equipment (UE) according to claim 12, wherein: The same subband or different subbands or multiple subbands or different multiple subbands may be used.

14. User Equipment (UE) according to one of the preceding claims, wherein transmitting the feedback signal on a subset of the PSFCH candidate resources (1100, 1200), and / or The PSFCH candidate resources (1100, 1200) are prioritized according to one or more of the following principles: - Randomly prioritize sub-bands of packets; - Use a configured or preconfigured priority order; - using a subband containing a data signal (1150); - a temporal order relative to the location of the data packet or the PSFCH candidate resources (1100, 1200); - using the same sub-band of the channel occupation time COT shared by the transmitter user equipment (TX UE); and / or - Limit how many subbands are used or how many other subbands are used.

15. User Equipment (UE) according to one of the preceding claims, wherein The receiver user equipment (UI) uses a second PSFCH candidate resource (1100, 1200) when the first PSFCH candidate resource among the PSFCH candidate resources fails to perform a listen-before-talk mechanism LBT.

16. User Equipment (UE) according to one of the preceding claims, wherein The receiver user equipment (RXUE) is configured to transmit the feedback signal using SCI or medium access control layer control element MAC CE in case of feedback failure.

17. User Equipment (UE) according to one of the preceding claims, wherein When COT (Continuous Transmission) sharing is used, the side link communication uses an unlicensed band and / or a type 1 and / or type 2 band requiring LBT.

18. User Equipment (UE) according to one of the preceding claims, wherein The receiver unit is configured to perform LBT to determine available resources for the feedback signal in a future time slot.

19. User Equipment (UE) according to one of the preceding claims, wherein The user equipment (UE), in particular the transmitter user equipment (TX UE) is configured to transmit a dummy signal (3300) in a current time slot to maintain COT (continuous transmission) in a next time slot for the user equipment (UE) or for a receiving user equipment (UE) sending the feedback signal.

20. The user equipment (UE) according to claim 19, wherein: The dummy signal (3300) is a sequence similar to a hybrid automatic repeat request HARQ feedback or a cyclic shift, or is an orthogonal sequence to the HARQ feedback to be transmitted in the time slot.

21. The user equipment (UE) according to claim 19 or 20, wherein: The dummy signal (3300) is transmitted in the PFSCH before and / or after the PSSCH transmitted by the user equipment (UE).

22. The user equipment (UE) according to one of the preceding claims, wherein A transmitter user equipment (UE) and the receiver user equipment (RX UE) are configured to use the same COT (continuous transmission); wherein the transmitter user equipment (TX UE) performs type 1 or type 2 LBT before data transmission, and wherein the receiver user equipment (RX UE) performs transmission of a feedback signal without LBT or type 2 LBT.

23. The user equipment (UE) according to one of the preceding claims, wherein The transmitter user equipment (TXUE) and the receiver user equipment (RX UE) use different COTs; The transmitter user equipment (TX UE) is configured to use Type 1 or Type 2 LBT, and the receiver user equipment (RX UE) is arranged to perform LBT before transmitting the feedback signal using different COTs.

24. The user equipment (UE) according to one of the preceding claims, wherein The transmitter user equipment (TXUE) and the receiver user equipment (RX UE) use different COTs; The transmitter user equipment (TX UE) uses the first COT to perform first data transmission to the receiver user equipment (RX UE); The receiver user equipment (RX UE) further transmits data to the transmitter user equipment (TX UE) using a second COT, and transmits a feedback signal corresponding to the first data transmission in the second COT.

25. User Equipment (UE) according to one of the preceding claims, wherein The transmitter user equipment (TXUE) is configured to transmit one or more feedback signals within the PSFCH (1100) by multiplexing these signals according to a function.

26. The user equipment (UE) according to claim 25, wherein: The function is defined by a cyclic shift pair used to transmit the feedback signal and / or by a cyclic shift pair used to transmit the feedback signal multiplexed in a physical resource block.

27. The User Equipment (UE) according to claims 25 and 26, wherein the function is defined by a Gaussian function or an exponential function.

28. User Equipment (UE) according to one of the preceding claims, wherein The transmitter user equipment (TXUE) is configured to indicate one or more PSFCH (1100) candidate resources for corresponding data transmission, wherein the transmitter user equipment (TX UE) uses physical layer signaling, for example, using SCI in PSCCH / PSSCH or using MAC layer signaling, for example, using MAC CE to indicate the one or more PSFCH candidate resources.

29. The user equipment (UE) according to one of the preceding claims, wherein The receiver user equipment (RXUE) is configured to use the PSFCH (1100) without performing a listen-before-talk mechanism or using a listen-before-talk mechanism of type 2 with a shorter duration.

30. The user equipment (UE) according to one of the preceding claims, wherein The receiver user equipment (RXUE) is configured to determine the availability of enhanced PSFCH (1100) opportunities in the following manner: - the resources available or available if the LBT is successfully performed; and / or - Resources from the same COT initiated by a transmitter user equipment (TX UE); and / or - PDB time slots for specific transmissions; and / or -Transmission priority; and / or The receiver user equipment (RX UE) is configured to take one of the following actions: - Send feedback on the same or different channel / sub-channel / resource pool; - Use non-sidelink unicast SL-U carrier / resource pool to send feedback; - request the next generation base station gNB to inform the transmitter user equipment (TX UE) of the transmission status; and / or - Request the gNB to inform the transmitter user equipment (TX UE) of the transmission status so that the gNB can use the sidelink feedback indicator to inform the transmitter user equipment (TX UE).

31. The user equipment (UE) according to one of the preceding claims, wherein The receiver user equipment (RXUE) is configured to perform one or more of the following operations in case of one or more LBT failures: - Stop using PSFCH (1100) resources and avoid transmitting HARQ feedback for data signals (1150); -Adjust HARQ behavior; - Transmitting PSFCH in a licensed carrier (1100); - Transmit feedback directly to the gNB; - Switching / retransmitting unlicensed frequency bands.

32. A communication system comprising at least two user equipments (UEs), wherein: A first one of the at least two UEs is a transmitter user equipment (TX UE), and a second one of the at least two UEs is a receiver user equipment (RX UE).

33. A user equipment (UE) configured to transmit and / or receive a data signal (1150), wherein: The user equipment (UI) is configured to transmit a dummy signal (3300) in a current time slot so as to maintain the COT (continuous transmission) of the user equipment (UE) in a next time slot, or to maintain the COT (continuous transmission) of another user equipment (UE) in a next time slot.

34. The user equipment according to claim 33, wherein: The user equipment (UE) is configured to perform a handover in order to transfer resources to another user equipment (UE).

35. A user equipment (UE) according to one of claims 1 to 34, wherein the user equipment (UE) is selected from one of the following groups: a power-limited UE, a handheld UE, a UE used by pedestrians, a vulnerable road user VRU or pedestrian UE P-UE, a wearable or handheld UE used by public safety personnel and first responders, an Internet of Things IoT UE, a sensor, an actuator or a UE deployed in a campus network for performing repetitive tasks and requiring regular input from a gateway node, or a mobile terminal, a fixed terminal, a cellular Internet of Things UE or a vehicle-mounted UE, or a vehicle-mounted master UE, or an Internet of Things or Narrowband Internet of Things NB-IoT, an Internet of Things, a device or a WiFi non-access station, a non-AP STA, such as 802.11ax or 802.11be, or a ground vehicle, an aircraft, a drone, a mobile base station, a roadside unit, a building, or any other item or device with a network connection that enables the item / device to communicate using a wireless communication network, a sensor or an actuator, or any other item or device equipped with a network connection that enables the item / device to communicate using a wireless communication network, such as a sensor or an actuator, or any network entity with sidelink functionality.

36. A method for performing sidelink communication, comprising: Using data signals (1150), such as PSCCH and PSSCH, using one or more specific subchannels or resource blocks (RBs) in one or more specific time slots, using side link communication to transmit data packets, such as transport blocks (TBs), and expecting to obtain a feedback message from a feedback signal of a receiver user equipment (RX UE) of the data signal (1150), such as a feedback signal in PSFCH (1100), wherein the feedback signal can be received at multiple time and / or frequency and / or cyclic shift positions within the PSFCH candidate resources (1100, 1200).

37. A method for performing sidelink communication, comprising: Using data signals (1150), such as PSCCH and PSSCH, using one or more specific subchannels or resource blocks (RBs) in one or more specific time slots, using sidelink communication to receive data packets, such as transport blocks (TBs), and transmitting feedback messages to a transmitter user equipment (TX UE) in a feedback signal, such as in a PSFCH (1100), wherein the feedback signal can be transmitted within a plurality of PSFCH candidate resources (1100, 1200) at multiple time and / or frequency and / or cyclic shift positions.

38. A method for performing sidelink communications, comprising transmitting a data packet in a current time slot to maintain a COT in a next time slot.

39. A computer program for performing one of the methods according to claims 36, 37 and 38 when run on a computer.

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