Offloading of in-coverage network control on unlicensed sidelink

Abstract

A method performed by a first sidelink (SL) user equipment (UE) includes: receiving downlink control information (DCI) from multiple coupled DCIs. The DCI permits reception of multiple scheduled physical SL shared channels (PSSCHs) on an unlicensed SL carrier, and requests a hybrid automatic repeat request (HARQ) response for the scheduled PSSCHs. The method also includes: receiving at least one of the PSSCHs from a second SL UE. The method also includes: sending a HARQ response based on at least one received PSSCH.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. patent application No. 17 / 328,986, filed on May 24, 2021, and entitled “IN-COVERAGE NETWORK CONTROLLED OFF-LOADING OVER AN UNLICENSED SIDELINK,” which claims priority to U.S. Provisional Patent Application No. 63 / 041,066, filed on June 18, 2020, and entitled “IN-COVERAGENETWORK CONTROLLED OFF-LOADING OVER AN UNLICENSED SIDELINK,” the disclosures of which are expressly incorporated by reference in their entirety. Technical Field

[0003] Generally speaking, aspects of the present disclosure relate to wireless communications, and more specifically, aspects of the present disclosure relate to techniques and apparatus for New Radio (NR) Vehicle-to-Everything (V2X) communications on an unlicensed sidelink. Background Art

[0004] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcast. Typical wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0005] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at the city, country, region, and even global level. An example telecommunication standard is the fifth generation (5G) New Radio (NR). 5G NR is part of the continuous mobile broadband evolution released by the Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., together with the Internet of Things (IoT)) and other requirements. 5G NR includes services associated with the following: enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable low latency communication (URLLC). Some aspects of 5G NR may be based on the fourth generation (4G) long term evolution (LTE) standard. There is a need for further improvement of 5G NR technology. These improvements may also be applicable to other multiple access technologies and telecommunication standards that employ these technologies.

[0006] The wireless communication system may include or provide support for various types of communication systems, such as vehicle-related communication systems (e.g., vehicle-to-everything (V2X) communication systems). Vehicles may use vehicle-related communication systems to improve safety and help prevent vehicle collisions. Information about severe weather, nearby accidents, road conditions, and / or other information may be transmitted to the driver via the vehicle-related communication system. In some cases, sidelink user equipment (UE) (such as vehicles) may communicate directly with each other using D2D communications over a device-to-device (D2D) wireless link. These communications may be referred to as sidelink communications.

[0007] As the demand for sidelink communications increases, different V2X communication systems compete for the same wireless communication resources. In addition, some sidelink UEs may be power-limited. Therefore, there is a need to improve the efficiency of sidelink communications.

[0008] In order to meet the growing demand for extended mobile broadband connectivity, wireless communication technology is developing from long term evolution (LTE) technology to next generation new radio (NR) technology (which may be referred to as the 5th generation (5G)). For example, compared with LTE, NR is designed to provide lower latency, higher bandwidth or higher throughput, and higher reliability. NR is designed to operate on a variety of spectrum bands (e.g., from low frequency bands below about 1 gigahertz (GHz) and mid-frequency bands from about 1 GHz to about 6 GHz, to high frequency bands such as millimeter wave (mmWave) bands). NR is also designed to operate across different spectrum types, from licensed spectrum to unlicensed spectrum and shared spectrum. Spectrum sharing enables operators to opportunistically aggregate spectrum to dynamically support high bandwidth services. Spectrum sharing can extend the benefits of NR technology to operating entities that may not have access to licensed spectrum. Summary of the invention

[0009] According to one aspect of the present disclosure, a method performed by a first sidelink (SL) user equipment (UE) receives downlink control information (DCI) from multiple coupled DCIs. The DCI permits reception of multiple scheduled physical SL shared channels (PSSCHs) on an unlicensed SL carrier. The DCI also requests a hybrid automatic repeat request (HARQ) response for the multiple scheduled PSSCHs. The method also receives at least one of the multiple PSSCHs from a second SL UE. The method also sends the HARQ response based on at least one received PSSCH.

[0010] In another aspect of the present disclosure, a method performed by a first SL UE receives a DCI from a plurality of coupled DCIs. The DCI permits transmission of a plurality of physical SL shared channels (PSSCHs) on an unlicensed SL carrier. The DCI also configures a first listen-before-talk (LBT) for the plurality of PSSCHs and requests LBT feedback for the first LBT. The method also transmits at least one of the plurality of PSSCHs to a second SL UE. The method also transmits the LBT feedback for the at least one PSSCH.

[0011] In another aspect of the present disclosure, a method performed by a base station sends multiple coupled DCIs for sending multiple transport blocks (TBs) via an unlicensed SL carrier to at least a first SLUE and a second SLUE. The method also receives feedback from at least the first SL UE and the second SL UE based on the coupled DCIs.

[0012] In another aspect of the present disclosure, a device for wireless communication at a UE includes a processor and a memory coupled to the processor. The instructions stored in the memory are operable when executed by the processor to cause the device to receive DCI from multiple coupled DCIs. The DCI permits reception of multiple scheduled PSSCHs on an unlicensed SL carrier. The DCI also requests a HARQ response for the multiple scheduled PSSCHs. Execution of the instructions also causes the device to receive at least one of the multiple PSSCHs from a second SL UE. Execution of the instructions also causes the device to send the HARQ response based on at least one received PSSCH.

[0013] In another aspect of the present disclosure, a device for wireless communication at a UE includes a processor and a memory coupled to the processor. The instructions stored in the memory are operable when executed by the processor to cause the device to receive DCI from multiple coupled DCIs. The DCI permits the transmission of multiple PSSCHs on an unlicensed SL carrier. The DCI also configures a first LBT for the multiple PSSCHs and requests LBT feedback for the first LBT. Execution of the instructions also causes the device to send at least one PSSCH of the multiple PSSCHs to a second SL UE. Execution of the instructions also causes the device to send the LBT feedback for the at least one PSSCH.

[0014] In another aspect of the present disclosure, a device for wireless communication at a base station includes a processor and a memory coupled to the processor. The instructions stored in the memory are operable when executed by the processor to cause the device to send multiple coupled DCIs for sending multiple TBs via an unlicensed SL carrier to at least a first SL UE and a second SL UE. Execution of the instructions also causes the device to receive feedback from at least the first SL UE and the second SL UE based on the coupled DCI.

[0015] In another aspect of the present disclosure, a UE for wireless communication includes: a unit for receiving DCI from multiple coupled DCIs. The DCI includes a unit for allowing reception of multiple scheduled PSSCHs on an unlicensed SL carrier. The DCI also requests a HARQ response for the multiple scheduled PSSCHs. The UE includes a unit for receiving at least one PSSCH of the multiple PSSCHs from a second SLUE. The UE also includes a unit for sending the HARQ response based on at least one received PSSCH.

[0016] In another aspect of the present disclosure, a UE for wireless communication includes: a unit for receiving a first downlink control information (DCI) from a plurality of coupled DCIs. The DCI permits the transmission of a plurality of PSSCHs on an unlicensed SL carrier. The DCI also configures a first LBT for the plurality of PSSCHs and requests LBT feedback for the first LBT. The UE also includes a unit for transmitting at least one of the plurality of PSSCHs to a second SL UE. The UE also includes a unit for transmitting the LBT feedback for the at least one PSSCH.

[0017] In another aspect of the present disclosure, a base station for wireless communication includes: a unit for sending multiple coupled DCIs for sending multiple TBs via an unlicensed SL carrier to at least a first SLUE and a second SL UE. The base station also includes a unit for receiving feedback from at least the first SL UE and the second SL UE based on the coupled DCIs.

[0018] In another aspect of the present disclosure, a non-transitory computer-readable medium having a program code recorded thereon is disclosed. The program code is executed by a UE and includes program code for receiving a DCI from a plurality of coupled DCIs. The DCI permits reception of a plurality of scheduled PSSCHs on an unlicensed SL carrier. The DCI also requests a HARQ response for the plurality of scheduled PSSCHs. The UE also includes program code for receiving at least one of the plurality of PSSCHs from a second SL UE. The UE also includes program code for sending the HARQ response further based on at least one received PSSCH.

[0019] In another aspect of the present disclosure, a non-transitory computer-readable medium having a program code recorded thereon is disclosed. The program code is executed by a UE and includes a program code for receiving a first DCI from a plurality of coupled DCIs. The DCI permits the transmission of a plurality of PSSCHs on an unlicensed SL carrier. The DCI also configures a first LBT for the plurality of PSSCHs and requests LBT feedback for the first LBT. The UE also includes a program code for transmitting at least one of the plurality of PSSCHs to a second SL UE. The UE also includes a program code for transmitting the LBT feedback for the at least one PSSCH.

[0020] In another aspect of the present disclosure, a non-transitory computer-readable medium having a program code recorded thereon is disclosed. The program code is executed by a base station and includes program code for sending multiple coupled DCIs for sending multiple TBs via an unlicensed SL carrier to at least a first SL UE and a second SL UE. The base station also includes program code for receiving feedback from at least the first SL UE and the second SL UE based on the coupled DCI.

[0021] In summary, aspects include methods, apparatus, systems, computer program products, non-transitory computer readable media, user equipment, base stations, wireless communication devices, and processing systems as fully described with reference to and as illustrated by the drawings and description.

[0022] The foregoing has outlined the features and technical advantages of examples according to the present disclosure quite extensively so that the following detailed description may be better understood. Additional features and advantages will be described. The disclosed concepts and specific examples may be easily used as the basis for modifying or designing other structures for the same purpose of achieving the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. When considered in conjunction with the accompanying drawings, the characteristics of the disclosed concepts (both their organization and method of operation) and the associated advantages will be better understood from the description below. Each of the figures in the accompanying drawings is provided for the purpose of illustration and description and is not intended to be a definition of limitations to the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to be able to fully understand the above features of the present disclosure, a more specific description of the above brief summary can be obtained by referring to various aspects (some of which are shown in the accompanying drawings). However, it should be noted that the accompanying drawings only illustrate certain typical aspects of the present disclosure and are therefore not considered to limit the scope of the present disclosure, as the description may be suitable for other equally effective aspects. The same reference numerals in different drawings may identify the same or similar elements.

[0024] Figure 1 is a schematic diagram illustrating an example of a wireless communication system and an access network.

[0025] Figure 2A , 2B , 2C and 2D are schematic diagrams showing examples of a first fifth generation (5G) new radio (NR) frame, a downlink (DL) channel within a 5G NR subframe, a second 5G NR frame, and an uplink (UL) channel within a 5G NR subframe, respectively.

[0026] Figure 3 is a schematic diagram showing an example of a base station and a user equipment (UE) in an access network.

[0027] Figure 4 is a schematic diagram illustrating an example of a vehicle-to-everything (V2X) system according to various aspects of the present disclosure.

[0028] Figure 5 is a block diagram illustrating an example of a vehicle-to-everything (V2X) system with a roadside unit (RSU) according to various aspects of the present disclosure.

[0029] Figure 6 is a schematic diagram illustrating an example of a sidelink (SL) communication scheme according to various aspects of the present disclosure.

[0030] Figure 7is a diagram illustrating an example of a network implementing licensed carriers and unlicensed carriers in accordance with various aspects of the present disclosure.

[0031] Fig. 8A and 8B is a timing diagram illustrating an example for sending a pair of coupled downlink control information (DCI) to a SL transmitter and a SL receiver in accordance with aspects of the present disclosure.

[0032] Fig. 9 is a timing diagram illustrating an example of sending a second DCI to a SL receiver according to various aspects of the present disclosure.

[0033] Fig.10 is a timing diagram illustrating an example of sending a first DCI to a SL transmitter according to various aspects of the present disclosure.

[0034] Fig.11 is a timing diagram illustrating an example of sending a pair of coupled DCIs to a SL transmitter and a SL receiver in accordance with aspects of the present disclosure.

[0035] Fig. 12A and 12B is a timing diagram illustrating an example of sending coupled DCI to multiple SL receivers and one SL transmitter according to aspects of the present disclosure.

[0036] Fig.13A and 13B is a timing diagram illustrating an example of sending coupled DCI to multiple SL receivers and one SL transmitter according to aspects of the present disclosure.

[0037] Fig.14 is a timing diagram illustrating an example of granting bidirectional SL transmission on an unlicensed carrier via coupled DCI in accordance with aspects of the present disclosure.

[0038] Fig.15 is a timing diagram illustrating an example of sending uplink control information (UCI) of a shared channel occupancy time (COT) to a SL transmitter in accordance with various aspects of the present disclosure.

[0039] Fig.16 is a schematic diagram illustrating an example of a network with a SL receiver subject to hidden node interference in accordance with aspects of the present disclosure.

[0040] Fig.17 and 18 is a schematic diagram illustrating an example of a process performed, for example, by a UE according to various aspects of the present disclosure.

[0041] Fig.19is a diagram illustrating example processes performed, for example, by a base station according to various aspects of the present disclosure. DETAILED DESCRIPTION

[0042] The following is a more complete description of various aspects of the present disclosure with reference to the accompanying drawings. However, the present disclosure can be embodied in many different forms and should not be construed as being limited to any specific structure or function presented throughout the present disclosure. More specifically, these aspects are provided so that the present disclosure will be thorough and complete, and the scope of the present disclosure will be fully conveyed to those skilled in the art. Based on the teachings, it should be understood by those skilled in the art that the scope of the present disclosure is intended to cover any aspect of the disclosed disclosure, whether the aspect is implemented independently of any other aspect of the present disclosure or implemented in combination with any other aspect. For example, using any number of aspects set forth, a device can be implemented or a method can be implemented. In addition, the scope of the present disclosure is intended to cover such a device or method implemented using other structures, functions, or structures and functions other than the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the disclosed present disclosure can be embodied by one or more elements of the claims.

[0043] Several aspects of telecommunication systems will now be presented with reference to various devices and techniques. These devices and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using hardware, software, or a combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0044] It should be noted that while various aspects may be described using terminology commonly associated with 5G and later wireless technologies, various aspects of the present disclosure may be applied in communication systems based on other generations, such as and including 3G and / or 4G technologies.

[0045] In a cellular communication network, wireless devices can typically communicate with each other via one or more network entities (such as a base station or a scheduling entity). Some networks can support device-to-device (D2D) communication, which enables the use of direct links between devices (e.g., without passing through a base station, a relay, or another node) to discover and communicate with nearby devices. D2D communication can implement mesh networking and device-to-network relay functionality. Some examples of D2D technology include Bluetooth pairing, Wi-Fi Direct, Miracast, and LTE-D. D2D communication may also be referred to as point-to-point (P2P) or sidelink communication.

[0046] D2D communication can be implemented using licensed or unlicensed frequency bands. In addition, D2D communication can avoid the overhead involved in routing to and from the base station. Therefore, D2D communication can improve throughput, reduce latency and / or improve energy efficiency.

[0047] One type of D2D communication may include vehicle-to-everything (V2X) communication. V2X communication may help autonomous vehicles communicate with each other. For example, an autonomous vehicle may include multiple sensors (e.g., light detection and ranging (LiDAR), radar, cameras, etc.). In most cases, the sensors of an autonomous vehicle are line-of-sight sensors. In contrast, V2X communication may allow autonomous vehicles to communicate with each other for non-line-of-sight situations.

[0048] Sidelink (SL) communication refers to communication between user equipment (UE) without tunneling through a base station (BS) and / or a core network. Sidelink communication can be transmitted on a physical sidelink control channel (PSCCH) and a physical sidelink shared channel (PSSCH). PSCCH and PSSCH are similar to the physical downlink control channel (PDCCH) and the physical downlink shared channel (PDSCH) in downlink (DL) communication between a BS and a UE. For example, the PSCCH can carry sidelink control information (SCI), and the PSSCH can carry sidelink data (e.g., user data). Each PSCCH is associated with a corresponding PSSCH, wherein the SCI in the PSCCH can carry reservation and / or scheduling information for sidelink data transmission in the associated PSSCH. Use cases for sidelink communication may include, in particular, vehicle-to-everything (V2X), industrial Internet of Things (IIoT), and / or NR-lite (NR Lite).

[0049] Some wireless systems (such as NR) support two modes of radio resource allocation (RRA) for sidelinks on licensed spectrum, namely Mode-1 RRA and Mode-2 RRA. Mode-1 RRA supports network-controlled RRA for coverage inner sidelink communications. For example, the serving BS can determine radio resources on behalf of the sidelink UE and send an indication of the radio resources to the sidelink UE. Mode-2 RRA supports autonomous RRA for coverage outer sidelink UEs or partially covered sidelink UEs. For example, the coverage outer sidelink UE or partially covered UE may be pre-configured with a sidelink resource pool, and radio resources may be selected from the pre-configured sidelink resource pool for sidelink communications.

[0050] The deployment of NR on unlicensed spectrum is called NR unlicensed (NR-U). Some research has been conducted on the deployment of NR-U on the 5 GHz unlicensed band. The Federal Communications Commission (FCC) and the European Telecommunications Standards Institute (ETSI) are working to regulate 6 GHz as a new unlicensed band for wireless communications. The addition of the 6 GHz band allows hundreds of megahertz (MHz) of bandwidth (BW) to be used for unlicensed band communications. In addition, NR-U can also be deployed on the 2.4 GHz unlicensed band, which is currently shared by various radio access technologies (RATs) such as IEEE 802.11 wireless local area networks (WLANs) or Wi-Fi and / or licensed assisted access (LAA). The sidelink can benefit from using the additional bandwidth available in the unlicensed spectrum.

[0051] The present disclosure describes systems and methods for sidelink (SL) communications in an unlicensed band. In one implementation, a first SL user equipment (UE) receives downlink control information (DCI) from multiple coupled DCIs. The DCI may permit reception of multiple scheduled physical SL shared channels (PSSCHs) on an unlicensed SL carrier. In this implementation, the DCI also requests a hybrid automatic repeat request (HARQ) response for the multiple scheduled PSSCHs. In addition, in this implementation, the first SL UE also receives one or more of the multiple PSSCHs from a second SL UE. In addition, in this implementation, the first SL UE sends a HARQ response based on the received PSSCH.

[0052] In another implementation, a first SL UE receives DCI from multiple coupled DCIs. In this implementation, the DCI permits sending multiple PSSCHs on an unlicensed SL carrier. Furthermore, in this implementation, the DCI is configured for a first listen-before-talk (LBT) for multiple PSSCHs, and LBT feedback is requested for the first LBT. In this implementation, the first SL UE sends one or more of the multiple PSSCHs to a second SL UE. Furthermore, in this implementation, the first SL UE sends LBT feedback for one or more PSSCHs.

[0053] In another implementation, the base station sends a plurality of coupled DCIs for sending a plurality of transport blocks (TBs) via an unlicensed SL carrier to the first SL UE and the second SL UE. In this implementation, the base station receives feedback from the first SL UE and the second SL UE based on the coupled DCIs.

[0054] Various aspects of the present disclosure improve UE and network performance corresponding to sidelink communications. Specifically, for sidelink communications, various aspects of the present disclosure can increase data rates, increase capacity, increase spectrum efficiency, and improve communication reliability. The present disclosure can also improve various sidelink use cases, including but not limited to device-to-device (D2D) communications, vehicle-to-everything (V2X) communications, cellular vehicle-to-everything communications (C-V2X), IIoT, NR-lite, enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and / or massive machine type communications (mMTC).

[0055] Figure 1 1 is a schematic diagram showing an example of a wireless communication system and access network 100. The wireless communication system (also referred to as a wireless wide area network (WWAN)) includes a base station 102, a UE 104, an evolved packet core (EPC) 160, and another core network 190 (e.g., a 5G core (5GC)). The base station 102 may include a macro cell (a high-power cellular base station) and / or a small cell 102' (a low-power cellular base station). The macro cell includes a base station. The small cell 102' includes a femto cell, a pico cell, and a micro cell.

[0056] Base stations 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with EPC 160 via a backhaul link 132 (e.g., an S1 interface). Base stations 102 configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN)) can interface with core network 190 via a backhaul link 184. Among other functions, base stations 102 can also perform one or more of the following functions: transmission of user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), user and device tracking, RAN information management (RIM), paging, positioning, and delivery of warning messages. Base stations 102 may communicate with each other directly or indirectly (eg, through EPC 160 or core network 190) over backhaul links 134 (eg, X2 interfaces). Backhaul links 134 may be wired or wireless.

[0057] The base station 102 can communicate wirelessly with the UE 104. Each of the base stations 102 can provide communication coverage for a corresponding geographic coverage area 110. There can be overlapping geographic coverage areas 110. For example, a small cell 102' can have a coverage area 110' that overlaps with the coverage area 110 of one or more macro base stations 102. A network including both small cells and macro cells can be referred to as a heterogeneous network. A heterogeneous network can also include a home evolved Node B (eNB) (HeNB), which can provide services to a restricted group called a closed subscriber group (CSG). The communication link 120 between the base station 102 and the UE 104 can include an uplink (UL) (also referred to as a reverse link) transmission from the UE 104 to the base station 102 and / or a downlink (DL) (also referred to as a forward link) transmission from the base station 102 to the UE 104. The communication link 120 can use multiple-input multiple-output (MIMO) antenna technology, which includes spatial multiplexing, beamforming and / or transmit diversity. The communication link may be through one or more carriers. The base station 102 / UE 104 may use a spectrum of up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) for transmission in each direction. The carriers may be adjacent to each other or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL ​​than for UL). The component carrier may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PCell), and the secondary component carrier may be referred to as a secondary cell (SCell).

[0058] Some UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may use DL / UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). The D2D communication may be through a variety of wireless D2D communication systems, such as FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on IEEE 802.11 standards, LTE, or NR.

[0059] The wireless communication system may also include a Wi-Fi access point (AP) 150 that communicates with a Wi-Fi station (STA) 152 in the 5 GHz unlicensed spectrum via a communication link 154. When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a clear channel assessment (CCA) prior to communication to determine whether the channel is available.

[0060] The small cell 102' may operate in licensed and / or unlicensed spectrum. When operating in unlicensed spectrum, the small cell 102' may employ NR and use the same 5 GHz unlicensed spectrum used by the Wi-Fi AP 150. The small cell 102' employing NR in the unlicensed spectrum may improve coverage and / or increase capacity of the access network.

[0061] The base station 102 (whether a small cell 102' or a large cell (e.g., a macro base station)) may include an eNB, a gNodeB (gNB), or another type of base station. Some base stations (such as gNB 180) may operate in traditional sub-6 GHz spectrum, in millimeter wave (mmWave) frequencies, and / or near mmWave frequencies to communicate with the UE 104. When the gNB 180 operates in mmWave or near mmWave frequencies, the gNB 180 may be referred to as a mmWave base station. Extremely high frequency (EHF) is part of the radio frequency (RF) in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 mm and 10 mm. Radio waves in this band may be referred to as millimeter waves. Near mmWave may extend down to a frequency of 3 GHz, which has a wavelength of 100 mm. The super high frequency (SHF) band extends between 3 GHz and 30 GHz and is also referred to as centimeter waves. Communications using mmWave / near mmWave radio frequency bands (eg, 3 GHz-300 GHz) have extremely high path loss and short range. The mmWave base station 180 may utilize beamforming 182 with the UE 104 to compensate for the extremely high path loss and short range.

[0062] The base station 180 may transmit beamformed signals in one or more transmit directions 182' to the UE 104. The UE 104 may receive beamformed signals from the base station 180 in one or more receive directions 182". The UE 104 may also transmit beamformed signals to the base station 180 in one or more transmit directions. The base station 180 may receive beamformed signals from the UE 104 in one or more receive directions. The base station 180 / UE 104 may perform beam training to determine the best receive and transmit directions for each of the base station 180 / UE 104. The transmit direction and receive direction for the base station 180 may be the same or may be different. The transmit direction and receive direction for the UE 104 may be the same or may be different.

[0063] The EPC 160 may include a mobility management entity (MME) 162, other MMEs 164, a serving gateway 166, a multimedia broadcast multicast service (MBMS) gateway 168, a broadcast multicast service center (BM-SC) 170, and a packet data network (PDN) gateway 172. The MME 162 may communicate with a home subscriber server (HSS) 174. The MME 162 is a control node that handles signaling between the UE 104 and the EPC 160. Generally speaking, the MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through the serving gateway 166, which itself is connected to the PDN gateway 172. The PDN gateway 172 provides UE IP address allocation and other functions. The PDN gateway 172 and the BM-SC 170 are connected to IP services 176. The IP services 176 may include the Internet, an intranet, an IP multimedia subsystem (IMS), a PS streaming service, and / or other IP services. The BM-SC 170 may provide functionality for MBMS user service provision and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS gateway 168 may be used to distribute MBMS services to base stations 102 belonging to a multicast broadcast single frequency network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start / stop) and for collecting charging information related to evolved MBMS (eMBMS).

[0064] The core network 190 may include an access and mobility management function (AMF) 192, other AMFs 193, a session management function (SMF) 194, and a user plane function (UPF) 195. The AMF 192 may communicate with a unified data management (UDM) 196. The AMF 192 is a control node that handles signaling between the UE 104 and the core network 190. Typically, the AMF 192 provides QoS flow and session management. All user Internet Protocol (IP) packets are transmitted through the UPF 195. The UPF 195 provides UE IP address allocation and other functions. The UPF 195 is connected to an IP service 197. The IP service 197 may include the Internet, an intranet, an IP multimedia subsystem (IMS), a PS streaming service, and / or other IP services.

[0065] Base station 102 may also be referred to as a gNB, a Node B, an evolved Node B (eNB), an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit receive point (TRP), or some other appropriate term. Base station 102 provides an access point to EPC 160 or core network 190 for UE 104. Examples of UE 104 include a cellular phone, a smart phone, a Session Initiation Protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio unit, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., an MP3 player), a camera, a game console, a tablet computer, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor / actuator, a display, or any other similarly functional device. Some of UE 104 may be referred to as Internet of Things (IoT) devices (e.g., a parking meter, a gas pump, an oven, a vehicle, a heart monitor, etc.). UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

[0066] Reference again Figure 1, in certain aspects, a receiving device (such as UE 104) may receive sensing information from one or more other UEs 104. The UE 104 that receives the sensing information may also obtain the sensing information from its own measurements. The UE 104 may include a combining component 198, which is configured to determine whether to combine the received sensing information with the sensing information obtained from its own measurements. In addition or alternatively, the UE 104 may include a sidelink component 199, which is configured to receive a DCI from a plurality of coupled downlink control information (DCI). The DCI may permit reception of a plurality of scheduled PSSCHs on an unlicensed SL carrier. In this implementation, the DCI also requests a HARQ response for the plurality of scheduled PSSCHs. In addition, in this implementation, the sidelink component 199 also receives one or more of the plurality of PSSCHs from a second SL UE (e.g., one of the UEs 104). In addition, in this implementation, the sidelink component 199 sends a HARQ response based on one or more received PSSCHs.

[0067] In another implementation, the sidelink component 199 receives DCI from multiple coupled DCIs. In this implementation, the DCI permits multiple PSSCHs to be sent on an unlicensed SL carrier. Further, in this implementation, the DCI configures LBT for multiple PSSCHs and requests LBT feedback for the LBT. In this implementation, the sidelink component 199 sends one or more of the multiple PSSCHs to a second SL UE (e.g., one of UE 104). Further, in this implementation, the sidelink component 199 sends LBT feedback for one or more PSSCHs.

[0068] In some aspects, network 100 may operate on a shared channel, which may include a shared frequency band and / or an unlicensed frequency band. For example, network 100 may be an NR-U network operating on an unlicensed frequency band. In such aspects, BS 102 and UE 104 may be operated by multiple network operating entities. In order to avoid conflicts, BS 102 and UE 104 may use a listen-before-talk (LBT) process to monitor transmission opportunities (TXOPs) in a shared channel. TXOP may also be referred to as COT. For example, a transmitting node (e.g., BS 102 or UE 104) may perform LBT before transmitting in a channel. When LBT passes, the transmitting node may continue to transmit. When LBT fails, the transmitting node may avoid transmitting in the channel.

[0069] LBT can be based on energy detection (ED) or signal detection. For LBT based on energy detection, when the signal energy measured from the channel is lower than the threshold, LBT generates a pass. On the contrary, when the signal energy measured from the channel exceeds the threshold, LBT generates a failure. For LBT based on signal detection, when a channel reservation signal (e.g., a predetermined preamble signal) is not detected in the channel, LBT generates a pass. In addition, LBT can adopt multiple modes. The LBT mode can be, for example, Category 4 (CAT4) LBT, Category 2 (CAT2) LBT, or Category 1 (CAT1) LBT. CAT4 LBT can be referred to as Type 1 LBT, where LBT is performed independently on the carrier where the transmission is occurring or is about to occur. Under Type 2 LBT, one carrier can be selected to perform CAT4 LBT, and a single interval LBT (Type 2 LBT) can be performed on other carriers, which can be performed before the scheduled start time indicated by the UL grant. As an example, the transmitting node can determine the channel measurement in the time interval and determine whether the channel is available based on the comparison of the channel measurement with the ED threshold.

[0070] Although the following description may focus on 5G NR, it may be applicable to other similar areas such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

[0071] Figure 2A 200 is a diagram illustrating an example of a first subframe within a 5G / NR frame structure. Figure 2B 230 is a diagram illustrating an example of DL channels within a 5G NR subframe. Figure 2C 250 is a diagram illustrating an example of a second subframe within a 5G NR frame structure. Figure 2D 280 is a diagram illustrating an example of UL channels within a 5G NR subframe. The 5G NR frame structure may be frequency division duplex (FDD), where for a particular set of subcarriers (carrier system bandwidth), subframes within that subcarrier set are dedicated to either DL or UL, or the 5G / NR frame structure may be time division duplex (TDD), where for a particular set of subcarriers (carrier system bandwidth), subframes within that subcarrier set are dedicated to both DL and UL. Figure 2A , 2CIn the example provided, it is assumed that the 5G NR frame structure is TDD, where subframe 4 is configured with slot format 28 (mainly DL), where D is DL, U is UL, and X is flexibly used between DL / UL, and subframe 3 is configured with slot format 34 (mainly UL). Although subframes 3 and 4 are shown with slot formats 34 and 28, respectively, any particular subframe can be configured with any of the various available slot formats 0-61. Slot formats 0 and 1 are full DL and full UL, respectively. Other slot formats 2-61 include a mix of DL, UL and flexible symbols. The UE is configured with a slot format through a received slot format indicator (SFI) (dynamically through DL control information (DCI), or semi-statically / statically through radio resource control (RRC) signaling). It should be noted that the description below also applies to the 5G NR frame structure as TDD.

[0072] Other wireless communication technologies may have different frame structures and / or different channels. A frame (e.g., 10ms) may be divided into 10 subframes of equal size (1ms). Each subframe may include one or more time slots. A subframe may also include a microslot, which may include 7, 4, or 2 symbols. Each time slot may include 7 or 14 symbols, depending on the time slot configuration. For time slot configuration 0, each time slot may include 14 symbols, and for time slot configuration 1, each time slot may include 7 symbols. The symbol on the DL may be a cyclic prefix (CP) OFDM (CP-OFDM) symbol. The symbol on the UL may be a CP-OFDM symbol (for high throughput scenarios) or a discrete Fourier transform (DFT) spread OFDM (DFT-S-OFDM) symbol (also known as a single carrier frequency division multiple access (SC-FDMA) symbol) (for power-limited scenarios; limited to single-stream transmission). The number of time slots in a subframe is based on the time slot configuration and the digital scheme. For slot configuration 0, different digital schemes μ0 to 5 allow 1, 2, 4, 8, 16, and 32 slots per subframe, respectively. For slot configuration 1, different digital schemes 0 to 2 allow 2, 4, and 8 slots per subframe, respectively. Therefore, for slot configuration 0 and digital scheme μ, there are 14 symbols / slot and 2 μ The subcarrier spacing and symbol length / duration are functions of the digital scheme. The subcarrier spacing may be equal to 2^μ*15kHz, where μ is the digital scheme 0-5. As such, digital scheme μ=0 has a subcarrier spacing of 15kHz, and digital scheme μ=5 has a subcarrier spacing of 480kHz. The symbol length / duration is inversely proportional to the subcarrier spacing. Figures 2A-2DAn example is provided for slot configuration 0 with 14 symbols per slot and a digital scheme μ=0 with 1 slot per subframe. The subcarrier spacing is 15 kHz and the symbol duration is approximately 66.7 μs.

[0073] The resource grid may represent a frame structure. Each time slot includes a resource block (RB), also referred to as a physical RB (PRB), which extends over 12 consecutive subcarriers. The resource grid is divided into a plurality of resource elements (REs). The number of bits carried by each RE may depend on the modulation scheme.

[0074] like Figure 2A As shown in , some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include a demodulation RS (DM-RS) for channel estimation at the UE (for a specific configuration, which is indicated as Rx (where 100x is the port number), but other DM-RS configurations are possible) and a channel state information reference signal (CSI-RS). The RS may also include a beam measurement RS (BRS), a beam refinement RS (BRRS), and a phase tracking RS (PT-RS).

[0075] Figure 2B Examples of various DL channels within a subframe of a frame are shown. The physical downlink control channel (PDCCH) carries DCI in one or more control channel elements (CCEs), each CCE including nine RE groups (REGs), each REG including four consecutive REs in an OFDM symbol. The primary synchronization signal (PSS) may be within symbol 2 of a particular subframe of the frame. The PSS is used by UE 104 to determine subframe / symbol timing and physical layer identification. The secondary synchronization signal (SSS) may be within symbol 4 of a particular subframe of the frame. The SSS is used by the UE to determine the physical layer cell identification group number and radio frame timing. Based on the physical layer identification and the physical layer cell identification group number, the UE may determine the physical cell identifier (PCI). Based on the PCI, the UE may determine the location of the aforementioned DM-RS. The physical broadcast channel (PBCH) carrying the master information block (MIB) may be logically grouped together with the PSS and SSS to form a synchronization signal (SS) / PBCH block. The MIB provides the number of RBs in the system bandwidth and the system frame number (SFN). The Physical Downlink Shared Channel (PDSCH) carries user data, broadcast system information not sent through the PBCH (such as System Information Blocks (SIBs)), and paging messages.

[0076] like Figure 2CAs shown in , some of the REs carry DM-RS for channel estimation at the base station (for a specific configuration, which is indicated as R, but other DM-RS configurations are possible). The UE can send DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH). The PUSCH DM-RS can be sent in the first one or two symbols of the PUSCH. The PUCCH DM-RS can be sent in different configurations depending on whether a short PUCCH or a long PUCCH is sent and depending on the specific PUCCH format used. Although not shown, the UE can send a sounding reference signal (SRS). The SRS can be used by the base station for channel quality estimation in order to achieve frequency-dependent scheduling on the UL.

[0077] Figure 2D Examples of various UL channels within a subframe of a frame are shown. The PUCCH may be positioned as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), and HARQ acknowledgement / negative acknowledgement (ACK / NACK) feedback. The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0078] Figure 33 is a block diagram of a base station 310 communicating with a UE 350 in an access network. In the DL, IP packets from the EPC 160 may be provided to a controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functions. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller / processor 375 provides: RRC layer functions associated with broadcasting of system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functions associated with header compression / decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functions associated with transmission of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), and MAC Demultiplexing of SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling and logical channel prioritization.

[0079] The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functions associated with various signal processing functions. Layer 1 including the physical (PHY) layer may include error detection of the transmission channel, forward error correction (FEC) encoding / decoding of the transmission channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The TX processor 316 processes the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-order quadrature amplitude modulation (M-QAM)). The coded and modulated symbols can then be split into parallel streams. Each stream can then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time domain and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to generate a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to generate multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine coding and modulation schemes and for spatial processing. Channel estimates may be derived from reference signals and / or channel condition feedback sent by the UE 350. Each spatial stream is then provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX may modulate a radio frequency (RF) carrier with a corresponding spatial stream for transmission.

[0080] At the UE 350, each receiver 354RX receives a signal through its corresponding antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides the information to a receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functions associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial stream destined for the UE 350. If multiple spatial streams are destined for the UE 350, the RX processor 356 can combine them into a single OFDM symbol stream. The RX processor 356 then uses a fast Fourier transform (FFT) to convert the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier and the reference signal are recovered and demodulated by determining the most likely signal constellation point sent by the base station 310. These soft decisions can be based on the channel estimates calculated by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally sent on the physical channel by base station 310. The data and control signals are then provided to controller / processor 359, which implements layer 3 and layer 2 functions.

[0081] The controller / processor 359 may be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer readable medium. In the UL, the controller / processor 359 provides demultiplexing between transport channels and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets from the EPC 160. The controller / processor 359 is also responsible for error detection using an ACK and / or NACK protocol to support HARQ operations.

[0082] Similar to the functions described in conjunction with DL transmissions performed by the base station 310, the controller / processor 359 provides: RRC layer functions, which are associated with the following: system information (e.g., MIB, SIB) acquisition, RRC connection and measurement reporting; PDCP layer functions, which are associated with the following: header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions, which are associated with the following: transmission of upper layer PDUs, error correction through ARQ, concatenation, segmentation and reassembly of RLC SDUs, re-segmentation of RLC data PDUs and reordering of RLC data PDUs; and MAC layer functions, which are associated with the following: mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling and logical channel prioritization.

[0083] Channel estimates derived by the channel estimator 358 from a reference signal or feedback sent by the base station 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antennas 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a corresponding spatial stream for transmission.

[0084] At the base station 310, the UL transmission is processed in a manner similar to that described in conjunction with the receiver functionality at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370.

[0085] The controller / processor 375 may be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer readable medium. In the UL, the controller / processor 375 provides demultiplexing between transport channels and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover IP packets from the UE 350. The IP packets from the controller / processor 375 may be provided to the EPC 160. The controller / processor 375 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0086] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 may be configured to perform operations related to Figure 1 In addition, at least one of the TX processor 316, the RX processor 370, and the controller / processor 375 may be configured to perform operations related to the combined component 198 and / or the side link component 199. Figure 1 Various aspects related to the combined component 198 and / or the side link component 199.

[0087] Figure 4 4 is a schematic diagram of a device-to-device (D2D) communication system 400 (including V2X communication) according to various aspects of the present disclosure. For example, the D2D communication system 400 may include V2X communication (e.g., a first UE 450 communicates with a second UE 451). In some aspects, the first UE 450 and / or the second UE 451 may be configured to communicate in a licensed radio frequency spectrum and / or a shared radio frequency spectrum. The shared radio frequency spectrum may be unlicensed, and thus a variety of different technologies may communicate using the shared radio frequency spectrum, including New Radio (NR), LTE, Advanced LTE, Licensed Assisted Access (LAA), Dedicated Short Range Communication (DSRC), MuLTEFire, 4G, etc. The above list of technologies should be considered illustrative and is not meant to be exhaustive.

[0088] The D2D communication system 400 can use NR radio access technology. Of course, other radio access technologies, such as LTE radio access technology, can be used. In D2D communication (e.g., V2X communication or vehicle-to-vehicle (V2V) communication), UE450, 451 can be on the networks of different mobile network operators (MNOs). Each of these networks can operate in its own radio frequency spectrum. For example, the air interface (e.g., Uu interface) to the first UE 450 can be on one or more frequency bands different from the air interface of the second UE 451. The first UE 450 and the second UE 451 can communicate via a sidelink component carrier (e.g., via a PC5 interface). In some examples, the MNO can schedule sidelink communications between two or more UEs 450, 451 in a licensed radio frequency spectrum and / or a shared radio frequency spectrum (e.g., a 5GHz radio spectrum band).

[0089] The shared radio frequency spectrum may be unlicensed, and thus different technologies may communicate using the shared radio frequency spectrum. In some aspects, D2D communications (eg, sidelink communications) between two or more UEs 450, 451 are not scheduled by the MNO. The D2D communication system 400 may also include a third UE 452.

[0090] For example, the third UE 452 may operate on the first network 410 (e.g., of the first MNO) or another network. The third UE 452 may perform D2D communication with the first UE 450 and / or the second UE 451. The first base station 420 (e.g., gNB) may communicate with the third UE 452 via a downlink (DL) carrier 432 and / or an uplink (UL) carrier 442. DL communication may use various DL resources (e.g., DL subframes ( Figure 2A ) and / or DL ​​channel ( Figure 2B )). Various UL resources (eg, UL subframes ( Figure 2C ) and UL channels ( Figure 2D ))'s UL carrier 442 to perform UL communication.

[0091] For example, as in Figure 1-3 As described in the foregoing, the first network 410 operates in a first spectrum and includes at least a first base station 420 (e.g., gNB) that communicates with a first UE 450. The first base station 420 (e.g., gNB) may communicate with the first UE 450 via a DL carrier 430 and / or a UL carrier 440. DL communication may use various DL resources (e.g., DL subframes ( Figure 2A ) and / or DL ​​channel ( Figure 2B )). Various UL resources (eg, UL subframes ( Figure 2C ) and UL channels ( Figure 2D ))'s UL carrier 440 to perform UL communication.

[0092] In some aspects, the second UE 451 can be on a different network than the first UE 450. In some aspects, the second UE 451 can be on a second network 411 (e.g., of a second MNO). Figure 1-3 As described in, the second network 411 can operate in a second spectrum (e.g., a second spectrum different from the first spectrum) and can include a second base station 421 (e.g., a gNB) for communicating with the second UE 451.

[0093] The second base station 421 can communicate with the second UE 451 via the DL carrier 431 and the UL carrier 441. Figure 2A ) and / or DL ​​channel ( Figure 2B )) performs DL communication. Figure 2C ) and / or UL channel ( Figure 2D ))'s UL carrier 441 is used to perform UL communication.

[0094] In a conventional system, the first base station 420 and / or the second base station 421 assign resources for device-to-device (D2D) communication (e.g., V2X communication and / or V2V communication) to the UE. For example, the resources may be a UL resource pool that is both orthogonal (e.g., one or more frequency division multiplexing (FDM) channels) and non-orthogonal (e.g., code division multiplexing (CDM) / resource extension multiple access (RSMA) in each channel). The first base station 420 and / or the second base station 421 may configure the resources via PDCCH (e.g., a faster method) or RRC (e.g., a slower method).

[0095] In some systems, each UE 450, 451 autonomously selects resources for D2D communication. For example, each UE 450, 451 can sense and analyze channel occupancy during a sensing window. UE 450, 451 can use the sensing information to select resources from the sensing window. As discussed, one UE 451 can assist another UE 450 in performing resource selection. The UE 451 providing assistance can be referred to as a receiving UE or partner UE, which can potentially inform the sending UE 450. The sending UE 450 can send information to the receiving UE 451 via sidelink communication.

[0096] D2D communication (e.g., V2X communication and / or V2V communication) may be performed via one or more sidelink carriers 470, 480. For example, the one or more sidelink carriers 470, 480 may include one or more channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH).

[0097] In some examples, the sidelink carriers 470, 480 can operate using a PC5 interface. The first UE 450 can transmit to one or more (e.g., multiple) devices (including to the second UE 451) via the first sidelink carrier 470. The second UE 451 can transmit to one or more (e.g., multiple) devices (including to the first UE 450) via the second sidelink carrier 480.

[0098] In some aspects, the UL carrier 440 and the first sidelink carrier 470 can be aggregated to increase bandwidth. In some aspects, the first sidelink carrier 470 and / or the second sidelink carrier 480 can share a first spectrum (with the first network 410) and / or a second spectrum (with the second network 411). In some aspects, the sidelink carriers 470, 480 can operate in an unlicensed / shared radio frequency spectrum.

[0099] In some aspects, the sidelink communication on the sidelink carrier may occur between the first UE 450 and the second UE 451. In one aspect, the first UE 450 may perform sidelink communication with one or more (e.g., multiple) devices (including the second device 451) via the first sidelink carrier 470. For example, the first UE 450 may send a broadcast transmission to multiple devices (e.g., the second UE 451 and the third UE 452) via the first sidelink carrier 470. The second UE 451 (e.g., among other UEs) may receive such a broadcast transmission. Additionally or alternatively, the first UE 450 may send a multicast transmission to multiple devices (e.g., the second UE 451 and the third UE 452) via the first sidelink carrier 470. The second UE 451 and / or the third UE 452 (e.g., among other UEs) may receive such a multicast transmission. The multicast transmission may be connectionless or connection-oriented. The multicast transmission may also be referred to as a groupcast transmission.

[0100] In addition, the first UE 450 can send unicast transmissions to devices such as the second UE 451 via the first sidelink carrier 470. The second UE 451 (e.g., among the other UEs) can receive such unicast transmissions. Additionally or alternatively, the second UE 451 can perform sidelink communications with one or more (e.g., multiple) devices (including the first UE 450) via the second sidelink carrier 480. For example, the second UE 451 can send broadcast transmissions to multiple devices via the second sidelink carrier 480. The first UE 450 (e.g., among the other UEs) can receive such broadcast transmissions.

[0101] In another example, the second UE 451 may send a multicast transmission to multiple devices (e.g., the first UE 450 and the third UE 452) via the second sidelink carrier 480. The first UE 450 and / or the third UE 452 (e.g., among the other UEs) may receive such a multicast transmission. In addition, the second UE 451 may send a unicast transmission to a device such as the first UE 450 via the second sidelink carrier 480. The first UE 450 (e.g., among the other UEs) may receive such a unicast transmission. The third UE 452 may communicate in a similar manner.

[0102] In some aspects, for example, such sidelink communications on a sidelink carrier between a first UE 450 and a second UE 451 may occur without an MNO that allocates resources for such communications (e.g., one or more portions of resource blocks (RBs), time slots, frequency bands, and / or channels associated with sidelink carriers 470, 480) and / or without scheduling such communications. Sidelink communications may include traffic communications (e.g., data communications, control communications, paging communications, and / or system information communications). In addition, sidelink communications may include sidelink feedback communications associated with traffic communications (e.g., transmission of feedback information for previously received traffic communications). Sidelink communications may employ at least one sidelink communication structure having at least one feedback symbol. The feedback symbol of the sidelink communication structure may be allocated for any sidelink feedback information that may be transmitted in a device-to-device (D2D) communication system 400 between devices (e.g., a first UE 450, a second UE 451, and / or a third UE 452). As discussed, the UE may be a vehicle (eg, UE 450, 451), a mobile device (eg, 452), or another type of device. In some cases, the UE may be a special UE, such as a roadside unit (RSU).

[0103] Figure 5An example of a V2X system 500 with an RSU 510 according to aspects of the present disclosure is shown. Figure 5 As shown in FIG. 5 , a transmitting UE 504 transmits data to an RSU 510 and a receiving UE 502 via a sidelink transmission 512. Additionally or alternatively, the RSU 510 may transmit data to the transmitting UE 504 via a sidelink transmission 512. The RSU 510 may forward the data received from the transmitting UE 504 to a cellular network (e.g., a gNB) 508 via an UL transmission 514. The gNB 508 may transmit the data received from the RSU 510 to other UEs 506 via a DL transmission 516. The RSU 510 may be integrated with traffic infrastructure (e.g., traffic lights, light poles, etc.). For example, as Figure 5 As shown in FIG, RSU 510 is a traffic signal located on one side of road 520. Additionally or alternatively, RSU 510 may be a stand-alone unit.

[0104] Figure 6 6 is a block diagram illustrating an example of a sidelink communication scheme 600 according to aspects of the present disclosure. Scheme 600 may be employed by a UE (such as UE 104) in a network (such as network 100). Specifically, a sidelink UE may employ scheme 600 to transmit sidelink information on a shared radio frequency band (e.g., in a shared spectrum or an unlicensed spectrum). A shared radio frequency band may be shared by multiple radio access technologies. Figure 6 , the x-axis represents time, and the y-axis represents frequency.

[0105] In scheme 600, a shared radio frequency band 601 is divided in frequency into a plurality of sub-channels or frequency sub-bands 602 (shown as 602S0, 602S1, 602S2) and in time into a plurality of side link frames 604 (shown as 604a, 604b, 604c, 604d) for side link communications. Band 601 may be at any suitable frequency (e.g., at or near about 2.4 GHz, 5 GHz, or 6 GHz). Band 601 may have any suitable bandwidth (BW) and may be divided into any suitable number of frequency sub-bands 602. The number of frequency sub-bands 602 may depend on the side link communication BW requirements. Band 601 may be at any suitable frequency. In some aspects, band 601 is a 2.4 GHz unlicensed band and may have a bandwidth of approximately 80 megahertz (MHz) divided into approximately 15 5 MHz frequency sub-bands 602.

[0106] Each sidelink frame 604 includes sidelink resources 606 in each of these frequency subbands 602. The legend 605 indicates the type of sidelink channel within the sidelink resource 606. In some cases, frequency gaps or guard bands may be specified between adjacent frequency subbands 602, for example to mitigate adjacent band interference. The sidelink resources 606 may have a structure substantially similar to the NR sidelink resources. For example, the sidelink resources 606 may include multiple subcarriers or RBs in frequency and multiple symbols in time. In some cases, the sidelink resources 606 may have a duration between approximately 1 millisecond (ms) and approximately 20 ms. Each sidelink resource 606 may include a PSCCH 610 and a PSSCH 620. The PSCCH 610 and the PSSCH 620 may be multiplexed in time and / or frequency. Figure 6 In the example of FIG. 6 , for each sidelink resource 606, the PSCCH 610 is located during the start symbol of the sidelink resource 606 and occupies a portion of the corresponding frequency subband 602, while the PSSCH 620 occupies the remaining time-frequency resources in the sidelink resource 606. In some cases, the sidelink resource 606 may also include a physical sidelink feedback channel (PSFCH), which is located, for example, during the end symbol of the sidelink resource 606. In general, the PSCCH 610, the PSSCH 620, and / or the PSFCH may be multiplexed within the sidelink resource 606.

[0107] The PSCCH 610 may carry the SCI 660 and / or sidelink data. Depending on the sidelink application, the sidelink data may have various forms and types. For example, when the sidelink application is a V2X application, the sidelink data may carry V2X data (e.g., vehicle position information, driving speed and / or direction, vehicle sensing measurements, etc.). Alternatively, when the sidelink application is an IoT application, the sidelink data may carry IoT data (e.g., sensor measurements, device measurements, temperature readings, etc.). The PSFCH may carry feedback information, such as HARQ ACK / NACK for sidelink data received in an earlier sidelink resource 606.

[0108] In the NR sidelink frame structure, the sidelink frames 604 in the resource pool 608 may be continuous in time. A sidelink UE (e.g., UE 104) may include a reservation for a sidelink resource 606 in a later sidelink frame 604 in the SCI 660. Thus, another sidelink UE (e.g., a UE in the same NR-U sidelink system) may perform SCI sensing in the resource pool 608 to determine whether the sidelink resource 606 is available or occupied. For example, if the sidelink UE detects an SCI indicating a reservation for the sidelink resource 606, the sidelink UE may avoid transmitting in the reserved sidelink resource 606. If the sidelink UE determines that there is no reservation detected for the sidelink resource 606, the sidelink UE may transmit in the sidelink resource 606. Thus, SCI sensing may assist the UE in identifying a target frequency subband 602 to be reserved for sidelink communication and to avoid intra-system conflicts with another sidelink UE in the NR sidelink system. In some aspects, a UE may be configured with a sensing window for SCI sensing or monitoring to reduce intra-system conflicts.

[0109] In some aspects, the sidelink UE may be configured with a frequency hopping pattern. In this regard, the sidelink UE may hop from one frequency subband 602 in one sidelink frame 604 to another frequency subband 602 in another sidelink frame 604. Figure 6 In the example shown, during the sidelink frame 604a, the sidelink UE is located in the frequency subband 602. S2 SCI 660 is sent in the sidelink resource 606 in the next sidelink frame 604b to reserve the frequency subband 602 in the next sidelink frame 604b. S1 Similarly, during sidelink frame 604b, the sidelink UE is located at frequency subband 602. S1 606 in the sidelink frame 604c to reserve the sidelink resource 606 at the frequency subband 602S1 in the next sidelink frame 604c. During the sidelink frame 604c, the sidelink UE is located at the frequency subband 602S1. S1 SCI 664 is sent in the sidelink resource 606 in the next sidelink frame 604d to reserve the frequency subband 602 in the next sidelink frame 604d. S0 During the sidelink frame 604d, the sidelink UE is located at the frequency subband 602. S0 The SCI 668 is sent in the sidelink resources 606 in the sidelink frame 604. The SCI 668 can be reserved for the sidelink resources 606 in a later sidelink frame 604.

[0110] SCI can also indicate the destination identifier (ID) of the target receiving sidelink UE for the next sidelink resource 606 by indicating scheduling information and / or identifying.Therefore, the sidelink UE can monitor the SCI sent by other sidelink UEs.When detecting the SCI in the sidelink resource 606, the sidelink UE can determine whether the sidelink UE is the target recipient based on the destination ID.If the sidelink UE is the target recipient, the sidelink UE can continue to receive and decode the sidelink data indicated by the SCI.In some aspects, multiple sidelink UEs can transmit sidelink data simultaneously in the sidelink frame 604 in different frequency subbands (for example, via frequency division multiplexing (FDM)).For example, in the sidelink frame 604b, a pair of sidelink UEs can use the sidelink resource 606 in the frequency subband 602S2 to transmit sidelink data, and another pair of sidelink UEs can use the sidelink resource 606 in the frequency subband 602S1 to transmit sidelink data.

[0111] In some aspects, the scheme 600 is used to synchronize sidelink communications. That is, the sidelink UE can be synchronized in time and aligned in terms of symbol boundaries, sidelink resource boundaries (e.g., the start time of the sidelink frame 604). The sidelink UE can perform synchronization in various forms, for example, based on a sidelink synchronization signal block (SSB) received from the sidelink UE and / or an NR-USSB received from a BS (e.g., BS 105 and / or 205) when it is within the coverage of the BS. In some aspects, for example, when it is within the coverage of the serving BS, the sidelink UE can be pre-configured with a resource pool 608 in a frequency band 601. The resource pool 608 can include a plurality of sidelink resources 606. The BS can configure the sidelink UE with a resource pool configuration indicating resources in the frequency band 601 and / or subband 602 and / or timing information associated with the sidelink frame 604. In some aspects, the scheme 600 includes Mode-2 RRA (eg, supporting autonomous RRA for out-of-coverage sidelink UEs or partially-covered sidelink UEs).

[0112] NR sidelink has been specified in the 3rd Generation Partnership Project (3GPP) Release 16 for communications such as V2X on the Intelligent Vehicle Transport System (ITS) band or other licensed bands. As described above, NR supports different Radio Resource Allocation (RRA) modes. Mode-1 RRA can be specified for network-controlled deployments, where the base station issues a grant to the sidelink transmitter. Mode-2 RRA can be specified for autonomous deployments, where the sidelink transmitter UE selects the sidelink channel via a sensing operation. The sidelink (SL) transmitter (Tx) sends SL control information (SCI) along with the data, and the SL receiver (Rx) monitors the SCI to determine the time and location for receiving data from the SL transmitter.

[0113] For 3GPP Release 17 and beyond, the sidelink communication may be improved to extend potential use to enhanced mobile broadband / ultra-reliable low latency communications (eMBB / URLLC). In addition, as described, the sidelink communication may be deployed on an unlicensed band, such as a 5 GHz unlicensed band and / or a 6 GHz unlicensed band.

[0114] Figure 7 is a schematic diagram illustrating an example of a network 700 implementing licensed carriers (shown as dashed lines) and unlicensed carriers (shown as solid lines) according to aspects of the present disclosure. The network 700 may correspond to reference Figure 1 A portion of network 100 is described. Figure 7 As shown, SL UE 706, 708 may be within the network coverage 712 of base station 710. Each SL UE 706, 708 may be a base station 710, respectively. Figure 1 , 3 , 4 and 5. The base station 710 may be an example of a UE 104, 350, 450, 451, 452, 502, 504, 506 described in detail. Figure 1 , 3 , 4 and 5 describe examples of base stations 102, 310, 420, 421, 508.

[0115] exist Figure 7 In the example of , the first SL UE 706 can exchange communications 720 with the base station 710 via a licensed carrier and / or an unlicensed carrier. In the current example, the first SL UE 706 can also exchange sidelink communications 730 with the second SL UE 708 via an unlicensed carrier. The sidelink communication 730 can be a direct communication, such as a file transfer protocol (FTP) communication. The direct communication can be similar to the eMBB communication.

[0116] In one configuration, the base station 710 permits sidelink communications 730 on an unlicensed carrier. Figure 7 The base station 710 may also permit sidelink communications 730 in addition to other sidelink communications not shown in FIG. Figure 7 The example avoids triangular data delivery, thereby reducing radio resources and power usage.

[0117] In Release 16, SL communications are specified to have a low spectrum / power efficiency waveform / slot format for unlicensed carriers. Low spectrum / power efficiency is specified because each sidelink slot includes multiple symbols for transmitter-receiver switching gaps. In addition, non-continuous PSSCH is specified to avoid half-duplex deafness. The inefficiency may degrade the quality of UE SL communications on unlicensed carriers because the UE may perform a listen-before-talk (LBT) procedure to access the channel for a duration, which may be referred to as the channel occupancy time (COT).

[0118] In some cases, Release 16 SL Mode-1 assumes that only SL transmitters are within the coverage of the base station. This assumption may further degrade the quality of UE SL communications. For example, the SL receiver may blindly monitor a set of subchannels (e.g., all subchannels within a receiver resource pool) to identify the time and location for receiving data. The double-hop hybrid automatic repeat request (HARQ) response from the SL receiver to the base station may consume unnecessary resources and may be prone to errors. In addition, in Release 16, feedback from the SL transmitter to the base station may prevent the base station from knowing the reason for the rescheduling request. As a result, the base station may provide incorrect grants. For example, the base station may allocate a smaller modulation and coding scheme (MCS) to mitigate the presumed fading. However, in this example, the problem may be caused by LBT failure, which is caused by congestion. In most cases, an increase in the number of nodes leads to contention channels with reduced MCS, increased congestion, and increased LBT failures per node.

[0119] In some cases, an enhanced downlink control information (DCI) format 3_0 is defined to improve the efficiency of sidelink offloading on unlicensed carriers. In such cases, as in NR-U, the SL transmitter can use multiple PSSCHs facilitated by multiple LBT attempts. Multiple PSSCHs can be continuous and COT can also be satisfied. In such cases, it is assumed that appropriate cyclic prefix (CP) extensions can be used to cover unnecessary switching gaps. In addition, in order to be robust against LBT uncertainty, the base station can issue a two-stage grant.

[0120] In some cases, when the SL receiver is in coverage (such as reference Figure 7In the described network 700), the base station can communicate with both the SL transmitter and the SL receiver to configure efficient enhanced mobile broadband (eMBB) offloading via unlicensed carriers by using more robust control channel mechanisms on both unlicensed and licensed bands. Such a configuration can facilitate power savings at the SL receiver, which is freed from monitoring the SCI set. The SL receiver can also use more flexible COT features developed in NR-U (e.g., scheduling of continuous PUSCH with more advanced multiple-input multiple-output (MIMO) support and bidirectional COT sharing for robustness against LBT uncertainties).

[0121] According to aspects of the present disclosure, a base station sends a pair of coupled DCIs to a SL transmitter and a SL receiver. Fig. 8A An example of a timing diagram 800 for sending coupled DCI from a base station to a SL transmitter and a SL receiver is shown in accordance with aspects of the present disclosure. Fig. 8A In the example of Figure 1 , 3 , 4, 5, 7 described in the examples of base stations 102, 310, 420, 421, 508, 710, the SL transmitter can be respectively referred to Figure 1 , 3 , 4, 5 and 7 described in the examples of UE 104, 350, 450, 451, 452, 502, 504, 506, 706, and the SL receiver can be respectively referred to Figure 1 , 3 , 4, 5 and 7 describe examples of UE104, 350, 450, 451, 452, 502, 504, 506, 708. Fig. 8A As shown, at time t1, the base station sends a first DCI message (DCI1) to the SL transmitter and sends a second DCI message (DCI2) to the SL receiver. Fig. 8AIn an example, each DCI (such as a first DCI and a second DCI) may be sent on an unlicensed carrier. The first DCI message and the second DCI message sent at time t1 may be an example of a pair of coupled DCIs (DCI1 and DCI2). The DCI may include an LBT configuration and a request for responses from two SL UEs. In one configuration, the first DCI message permits the transmission of multiple consecutive PSSCHs. As described, consecutive PSSCHs may be sent without SCI. The first DCI message may also include an LBT configuration, and may further request uplink control information (UCI) for LBT feedback (e.g., LBT success or failure) for the corresponding PSSCH. The LBT configuration may configure the SL transmitter to perform type 1 LBT for the transmission of a series of PSSCHs (PSSCH1 and PSSCH2) toward the SL receiver at time t2. That is, the first DCI message permits the transmission of multiple transport blocks (TBs) on the sidelink unlicensed carrier.

[0122] In addition, at time t2, the SL transmitter may perform LBT by monitoring the PSSCH and determining whether the PSSCH is busy. In some examples, the SL transmitter may not transmit on the PSSCH when the PSSCH is busy. As an example, when another device (such as another SL transmitter) is performing a transmission on the PSSCH, the PSSCH may be busy. Such an example may be referred to as an LBT failure. In some other examples, when the PSSCH is not busy, the SL transmitter may perform one or more transmissions on the PSSCH. Such an example may be referred to as an LBT success. In some implementations, the SL transmitter may provide feedback to the base station via PUCCH (PUCCH1), which indicates an LBT success or LBT failure regarding the PSSCH. At time t2, the SL receiver receives one or more transmissions from the SL transmitter on the PSSCH. At time t3, the SL receiver sends a HARQ response to the base station via PUCCH (PUCCH2). The HARQ response indicates whether the PSSCH (PSSCH1 and PSSCH2) is successfully decoded. The NR sidelink standard in Release 16 specifies downlink control information to the SL transmitter for scheduling a single transport block on one HARQ process ID. In one configuration, the base station sends DCI via a licensed carrier and receives feedback (e.g., UCI) via a licensed carrier. For example, the SL receiver receives a second DCI message via a licensed carrier and sends it on the PUCCH via the licensed carrier. In another configuration, the base station sends DCI via a licensed carrier and receives feedback via an unlicensed carrier. That is, in this configuration, the SL receiver receives a second DCI message via a licensed carrier and sends it on the PUCCH via an unlicensed carrier.

[0123] exist Fig. 8A In the example of , the second DCI message permits reception of consecutive PSSCHs (PSSCH1 and PSSCH2). The consecutive PSSCHs may be sent without SCI. The second DCI message may request feedback (e.g., UCI) for HARQ ACK / NACK responses for transmissions on the corresponding PSSCHs. The HARQ ACK / NACK may be sent via the PUCCH (PUCCH2) at time t3.

[0124] Figure 8B An example of a timing diagram 850 for sending coupled DCI from a base station to a SL transmitter and a SL receiver is shown in accordance with aspects of the present disclosure. Figure 8B In the example of Figure 1 , 3 , 4, 5, 7 described in the examples of base stations 102, 310, 420, 421, 508, 710, the SL transmitter can be respectively referred to Figure 1 , 3 , 4, 5 and 7 described in the examples of UE104, 350, 450, 451, 452, 502, 504, 506, 706, and the SL receiver can be respectively referred to Figure 1 , 3 , 4, 5 and 7 describe examples of UE 104, 350, 450, 451, 452, 502, 504, 506, 708. Figure 8B As shown, at time t1, the base station sends a first DCI message (DCI1) to the SL transmitter and sends a second DCI message (DCI2) to the SL receiver. Figure 8BIn the example of , each DCI (such as a first DCI and a second DCI) can be sent on an unlicensed carrier or a licensed carrier. The second DCI message requests the SL receiver to perform type 1 LBT and share the COT with the SL transmitter. The COT can be shared via UCI. For example, the SL receiver can indicate that the COT is being shared via a COT sharing indicator included in the UCI. At time t2, the SL receiver performs LBT and can share its COT with the SL transmitter. In this configuration, a physical uplink control channel (PUCCH) transmission initiated from the SL receiver can notify the SL transmitter that the COT of the SL receiver is being shared. The first DCI message permits a series of PSSCHs (PSSCH1 and PSSCH2) to be sent toward the SL receiver at time t3 (within the COT). In addition, at time t3, the SL transmitter sends LBT feedback to the base station via PUCCH (PUCCH1). As described, the LBT feedback can indicate LBT success or LBT failure regarding the PSSCH. At time t3, the SL receiver receives one or more transmissions from the SL transmitter on the PSSCH. At time t4, the SL receiver sends a HARQ response to the base station via the PUCCH (PUCCH2). The HARQ response indicates whether the PSSCH was successfully decoded.

[0125] For ease of explanation, Fig. 8A and 8B In and other examples, coupled DCI is described as a pair of DCIs. Coupled DCI is not limited to a pair of DCIs. Coupled DCI may include two or more DCIs.

[0126] Various aspects of the present disclosure can improve the reliability of control signaling in carrier aggregation (CA) deployments, particularly for SL receivers. In addition, the feedback received at the base station can be improved by including information for the sidelink on an unlicensed carrier. As a result of the improved feedback, the scheduling decisions of the base station can be improved. In addition, since the SL receiver can no longer perform blind decoding on a set of subchannels or all subchannels in the receiver resource pool, power savings at the SL receiver can be improved. Finally, the reduced reliance on SCI and physical sidelink feedback channel (PSFCH) can provide the SL transmitter with novel waveform / slot format designs on unlicensed carriers.

[0127] Fig. 9 900 is a timing diagram illustrating an example of sending a second DCI from a base station to a SL receiver according to aspects of the present disclosure. Fig. 9 In the example of Figure 1 , 3, 4, 5, 7 described in the examples of base stations 102, 310, 420, 421, 508, 710, the SL transmitter can be respectively referred to Figure 1 , 3 , 4, 5 and 7 described in the examples of UE 104, 350, 450, 451, 452, 502, 504, 506, 706, and the SL receiver can be respectively referred to Figure 1 , 3 , 4, 5 and 7 described UE 104, 350, 450, 451, 452, 502, 504, 506, 708. The timing diagram 900 may correspond to the reference Fig. 8A A portion of timing diagram 800 is depicted. Fig. 9 In the example of , the second DCI message (DCI2) sent by the base station to the SL receiver at time t1 includes a time domain resource allocation (TDRA) for multiple consecutive PSSCHs and corresponding HARQ identifiers, new data indicators, redundancy versions, modulation and coding schemes, transmission configuration indicators, and common frequency domain resource allocations (FDRA). Fig. 9 In the example of , the second DCI may include timing information for transmissions by the SL transmitter and the SL receiver. Fig. 9 As shown, the second DCI may include a value k′0, the value k′0 indicating the number of time slots between the second DCI message sent at time t1 and the time slot (time t2) used for the transmission of the first PSSCH (PSSCH1) resource, wherein the value k′0 is greater than zero. In addition, the second DCI may include a value k′1, the value k′1 indicating the number of time slots between the second DCI message and the PUCCH resource for the HARQ response sent at time t3, wherein the value k′1 is greater than zero. The value k′1 may be large enough to absorb processing delays at the SL receiver. In some implementations, the SL receiver may not blindly decode one or more SCIs, instead, the SL receiver may decode the PSSCH received from the SL transmitter based on the grant in the second DCI message. In addition, as Fig. 9 As shown, at time t3, the SL receiver sends a HARQ response for the PSSCH scheduled by the second DCI message. The HARQ response may include a bitmap, where a bit value of 1 indicates that a cyclic redundancy check (CRC) passes for the corresponding PSSCH, and a bit value of 0 indicates that the CRC fails. Fig. 9 In the example of Fig. 9 ), while for the second PSSCH, the CRC passes (in Fig. 9 Therefore, at time t3, the SL receiver sends a bitmap of “01” to the base station via the PUCCH.

[0128] Fig.10 1000 is a timing diagram illustrating an example of sending a first DCI from a base station to a SL transmitter according to aspects of the present disclosure. Fig.10 In the example of Figure 1 , 3 , 4, 5, 7 described in the examples of base stations 102, 310, 420, 421, 508, 710, the SL transmitter can be respectively referred to Figure 1 , 3 , 4, 5 and 7 described in the examples of UE 104, 350, 450, 451, 452, 502, 504, 506, 706, and the SL receiver can be respectively referred to Figure 1 , 3 , 4, 5 and 7 described UE 104, 350, 450, 451, 452, 502, 504, 506, 708. The timing diagram 1000 may correspond to the reference Fig. 8A A portion of timing diagram 800 is depicted. Fig.10 In the example of , a first DCI message (DCI1) sent by the base station at time t1 may include content based on DCI format 1_0 for NR-U Release 16. The first DCI message may also include a grant for a PUCCH. The grant may specify the timing of the PUCCH. For example, the timing may be referenced to the first DCI message. As another example, the PUCCH is scheduled at the last PSSCH (e.g., PSSCH2, such as Fig.10 as shown).

[0129] The sounding reference signal (SRS) resource indicator (SRI) and / or precoding information of the PUCCH may be different from the SRI and / or precoding information of the scheduled PSSCH. As described, at time t2, the SL transmitter does not send the SCI corresponding to the PSSCH. Fig.10 As shown, at time t2, the SL transmitter performs multiple Type 1 LBT attempts for multiple PSSCHs. That is, each LBT attempt may correspond to a unique PSSCH attempt. After a successful LBT, the SL transmitter may send the corresponding PSSCH (e.g., without SCI). Fig.10 As shown, the first LBT fails, while the second LBT succeeds. The second LBT corresponds to the second PSSCH (PSSCH2). Therefore, at time t2, the SL transmitter performs a transmission to the SL receiver (SL Rx) on the second PSSCH.

[0130] Finally, at time t2, the SL transmitter sends LBT feedback via PUCCH. LBT feedback may include a bitmap for the corresponding PSSCH, where a bit value of 1 indicates that the corresponding PSSCH has been sent (e.g., LBT success), and a bit value of 0 indicates that the corresponding PSSCH has not been sent (e.g., LBT failure). As described, Fig.10 In the example of , the first LBT fails and the second LBT succeeds, and therefore, the bitmap transmitted via the PUCCH at time t2 is set to '01'. Alternatively, the UCI transmitted via the PUCCH may include an index of the PSSCH transmitted after the LBT succeeds.

[0131] In one implementation, the SL receiver may calculate log-likelihood ratios (LLRs) and combine the LLRs based on demodulation reference signal (DMRS) sequence detection. The SL receiver may apply two thresholds for the detection metric. The first threshold may be used from the initial PSSCH to the initial CRC, and the second threshold may be used after the initial CRC passes. The first threshold may be greater than the second threshold. In addition to the above reference Fig. 8A , 8B In addition to the HARQ ACK / NACK described in 9, the SL receiver may also report a second UCI indicating whether the SL receiver has stored and combined the LLRs for the corresponding HARQ process. The second UCI may be referred to as a combined LLR UCI.

[0132] In one implementation, based on the combined LLR UCI from the SL receiver and the LBT feedback from the SL transmitter, the base station can determine whether the SL receiver has incorrectly managed the HARQ soft information. Therefore, the base station can correct the HARQ soft information management in subsequent scheduling by requesting the SL receiver to refresh the HARQ buffer.

[0133] Fig.11 An example of a timing diagram 1100 for sending a pair of coupled DCIs from a base station to a SL transmitter and a SL receiver is shown in accordance with aspects of the present disclosure. Fig. 9 In the example of Figure 1 , 3 , 4, 5, 7 described in the examples of base stations 102, 310, 420, 421, 508, 710, the SL transmitter can be respectively referred to Figure 1 , 3 , 4, 5 and 7 described in the examples of UE104, 350, 450, 451, 452, 502, 504, 506, 706, and the SL receiver can be respectively referred to Figure 1 , 3, 4, 5 and 7 describe examples of UE 104, 350, 450, 451, 452, 502, 504, 506, 708. Fig.11 As shown, at time t1, the base station sends a first DCI (DCI1) to the SL transmitter and sends a second DCI (DCI2) to the SL receiver. Fig.11 In the example of , each DCI (such as the first DCI and the second DCI) can be sent on an unlicensed carrier or a licensed carrier.

[0134] In one configuration, in the absence of a licensed carrier, the base station configures LBT for the corresponding PUCCH. That is, LBT can be configured because the PUCCH is transmitted via an unlicensed carrier. In one example, the SL transmitter can be configured to transmit the PUCCH (PUCCH1) within the same COT as the scheduled PSSCH (PSSCH1 and PSSCH2). Fig.11 As shown, the SL transmitter can send PUCCH (PUCCH1) at time t2 without performing a separate LBT for PUCCH. Instead, the LBT performed for PSSCH can be used for PUCCH because both PSSCH and PUCCH are sent within the same COT. If all LBT attempts fail, the SL transmitter can send PUCCH based on a discontinuous transmission (DTX) configuration.

[0135] like Fig.11 As shown, at time t3, the SL receiver may perform LBT before sending PUCCH (PUCCH2). The type of LBT to be performed may be indicated in the second DCI. In one configuration, the SL receiver is configured for type 1 LBT to report all HARQ responses and soft buffers (thereby leaving enough time for UE processing). In another configuration, the SL receiver is configured to use type 2 LBT for early reporting if the CRC passes for the PSSCH transmission from the SL transmitter. When the CRC passes for the PSSCH transmission, the SL receiver may assume that the SL transmitter may share the COT. In this configuration, the second DCI message may provide an additional field for delayed UCI messages.

[0136] According to another aspect of the present disclosure, multiple SL receivers may be configured by sending DCI to each of the multiple SL receivers and sending the DCI to the SL transmitter. Fig. 12A and 12B 1200, 1250 are timing diagrams illustrating examples of sending coupled DCI from a base station to multiple SL receivers (eg, a first SL receiver and an SL receiver) and one SL transmitter according to aspects of the present disclosure. Fig. 12A and12B In the example of Figure 1 , 3 , 4, 5, 7 described in the examples of base stations 102, 310, 420, 421, 508, 710, the SL transmitter can be respectively referred to Figure 1 , 3 , 4, 5 and 7 describe examples of UE 104, 350, 450, 451, 452, 502, 504, 506, 706, and each SL receiver may be referenced respectively. Figure 1 , 3 , 4, 5 and 7 describe examples of UE 104, 350, 450, 451, 452, 502, 504, 506, 708. Fig. 12A and 12B As shown, at time t1, the base station sends a first DCI (DCI1) to the SL transmitter, sends a second DCI (DCI2) to the first SL receiver, and sends a third DCI (DCI13) to the second SL receiver. Fig. 12A and 12B In the example of , each DCI (such as the first DCI, the second DCI, and the third DCI) can be sent on an unlicensed carrier or a licensed carrier.

[0137] The first DCI message sent to the SL transmitter can configure different PSSCH sets, each PSSCH has a unique MCS, SRI and precoding. Fig. 12A As shown, at time t2, the SL transmitter may perform LBT by listening to the PSSCH and determining whether the PSSCH is busy. In some examples, the SL transmitter may not transmit on the PSSCH when the PSSCH is busy. As an example, the PSSCH may be busy when another device (such as another SL transmitter) is performing a transmission on the PSSCH. Such an example may be referred to as an LBT failure. In some other examples, the SL transmitter may perform one or more transmissions on the PSSCH when the PSSCH is not busy. Such an example may be referred to as an LBT success. In some implementations, the SL transmitter may provide feedback to the base station via the PUCCH, indicating an LBT success or LBT failure regarding the PSSCH. In addition, at time t2, the SL transmitter may send each PSSCH set (PSSCH1 and PSSCH2) to a different SL receiver. In one configuration, as Fig. 12A As shown, when transmitted at time t2, different PSSCH sets may be time division multiplexed. Fig. 12BAs shown, when transmitted at time t2, different PSSCH sets may be frequency division multiplexed. In other configurations, different PSSCH sets may be space division multiplexed or multicast.

[0138] exist Fig. 12A and 12B In the example of , at time t3, each SL receiver sends a HARQ response to the base station via the PUCCH. For example, SL Rx1 can send a HARQ response corresponding to PSSCH1, and SL Rx2 can send a HARQ response corresponding to PSSCH2. Fig. 12A and 12B The example avoids multiple CRC bits in the DCI, reduces the number of PUCCHs at the SL transmitter, and reduces the number of LBT attempts for PSSCH on unlicensed carriers. In addition, as described, the SL receiver can also use the more flexible COT features developed in NR-U. Therefore, according to various aspects of the present disclosure, bidirectional COT sharing between the SL transmitter and the SL receiver can alleviate the need for the SL receiver to perform LBT before performing uplink transmission.

[0139] According to another aspect of the present disclosure, multiple SL transmitters may be configured by sending DCI to each of the SL transmitters and sending the DCI to a SL receiver. Fig.13A and 13B 1300, 1350 are timing diagrams illustrating examples of sending coupled DCI from a base station to multiple SL transmitters (e.g., a first SL transmitter and a second SL transmitter) and one SL receiver according to aspects of the present disclosure. Fig.13A and 13B In the example of Figure 1 , 3 , 4, 5, 7 described in the examples of base stations 102, 310, 420, 421, 508, 710, each SL transmitter can be respectively referred to Figure 1 , 3 , 4, 5 and 7 described in the examples of UE 104, 350, 450, 451, 452, 502, 504, 506, 706, and the SL receiver can be respectively referred to Figure 1 , 3 , 4, 5 and 7 describe examples of UE 104, 350, 450, 451, 452, 502, 504, 506, 708. Fig.13A and 13BAs shown, at time t1, the base station sends a first DCI (DCI1) to the first SL transmitter, sends a second DCI (DCI2) to the second SL transmitter, and sends a third DCI (DCI3) to the SL receiver. Fig.13A and 13B In the example of , each DCI (such as the first DCI, the second DCI, and the third DCI) can be sent on an unlicensed carrier.

[0140] exist Fig.13A and 13B In the example of , the first DCI and the second DCI sent to the first SL transmitter and the second SL transmitter, respectively, can configure different PSSCHs (PSSCH1 and PSSCH2), and each PSSCH can have a unique MCS, SRI, and precoding. In addition, at time t2, each SL transmitter can perform PSSCH transmission to the SL receiver based on the received DCI. In one configuration, as Fig.13A As shown, based on the received DCI (e.g., the first and second DCI), the first SL transmitter and the second SL transmitter can perform time-division multiplexed transmissions such that the transmissions on the corresponding PSSCHs at time t2 do not overlap in time. In another configuration, as Fig. 13B As shown, based on the received DCI, the first SL transmitter and the second SL transmitter can perform frequency division multiplexing transmission, space division multiplexing transmission or multicast transmission on the corresponding PSSCH at time t2.

[0141] In addition, if Fig.13A and 13B As shown, at time t2, before performing a PSSCH transmission, each SL transmitter may perform LBT by listening to the PSSCH and determining whether the PSSCH is busy. In some examples, when the PSSCH is busy, the SL transmitter may not transmit on the PSSCH. As another example, when another device (such as another SL transmitter) is performing a PSSCH transmission, the PSSCH may be busy. Such an example may be referred to as an LBT failure. In some other examples, when the PSSCH is not busy, the SL transmitter may perform a PSSCH transmission. Such an example may be referred to as an LBT success. In some implementations, each SL transmitter may provide feedback to the base station via the PUCCH, which indicates an LBT success or LBT failure regarding the PSSCH.

[0142] exist Fig.13A and 13BIn the example of , the third DCI received at the SL receiver can be configured to receive different PSSCH (PSSCH1 and PSSCH2) transmissions at time t3, where the PSSCH transmissions are from different SL transmitters. As described, in one configuration, such as Fig.13A As shown, different PSSCHs can be time-division multiplexed. In another configuration, such as Fig. 13B As shown, different PSSCHs can be frequency-division multiplexed, space-division multiplexed, or multicast. Fig.13A and 13B In the example, at time t3, the SL receiver sends a HARQ response to the base station via the PUCCH. Fig.13A and 13B The example can reduce the number of CRC bits in the DCI and reduce the number of PUCCHs at the SL receiver. Fig. 12A , 12B As shown in , 13A and 13B, the coupled DCI may be sent to multiple SL transmitters or multiple SL receivers. In some implementations, the coupled DCI may be sent to multiple SL transmitters and multiple SL receivers.

[0143] According to another aspect of the disclosure, the coupled DCI may permit bidirectional sidelink transmissions on an unlicensed carrier. Fig.14 1400 is a timing diagram illustrating an example of a base station sending coupled DCI for granting bidirectional sidelink transmission on an unlicensed carrier according to aspects of the present disclosure. Each respective DCI in the coupled DCI may be sent from multiple SL UEs (such as a first SL UE and a second SL UE) to a single SL UE. Fig.14 In the example of Figure 1 , 3 , 4, 5, 7 described in the examples of base stations 102, 310, 420, 421, 508, 710, the first SL UE and the second SLUE can be respectively referred to Figure 1 , 3 , 4, 5 and 7 describe examples of UE 104, 350, 450, 451, 452, 502, 504, 506, 706, 708. Fig.14 As shown, at time t1, the base station sends a first DCI (DCI1) to the first SL UE (SL UE1), and sends a second DCI (DCI2) to the second SL UE. Fig.14 In the example of , each DCI (such as the first DCI and the second DCI) can be sent on an unlicensed carrier.

[0144] like Fig.14As shown, at time t2, the first SL UE performs LBT (LBT1) and sends PSSCH (PSSCH1) to the second SL UE. The second SL UE receives PSSCH at time t2. In addition, at time t3, the second SL UE performs LBT (LBT2), sends PSSCH (PSSCH2) to the first SL UE, and sends feedback via PUCCH (PUCCH1). The first SL UE receives PSSCH at time t3. The actions of the second SL UE at times t2 and t3 are based on the grant and request provided in the second DCI message. In addition, at time t4, the first SL UE sends feedback via PUCCH (PUCCH2). The actions of the first SL UE at times t2, t3, and t4 are based on the grant and request provided in the first DCI message.

[0145] exist Fig.14 In the example of , both the HARQ response and the LBT feedback may be sent via the same PUCCH. As an example, a PUCCH transmission (PUCCH1) from the second UE at time t3 may include both a HARQ response corresponding to a PSSCH transmission (PSSCH1) from the first UE and LBT feedback corresponding to an LBT (LBT2) performed by the second UE. As another example, a PUCCH transmission (PUCCH2) from the first UE at time t4 may include both a HARQ response corresponding to a PSSCH transmission (PSSCH2) from the second UE and LBT feedback corresponding to an LBT (LBT 1) performed by the first UE at time t2. The LBT (LBT1) performed by the first SL UE at time t2 may be a type 1 LBT. In addition, if the PSSCH received at the second SL UE passes the CRC, the LBT (LBT2) performed by the second SL UE at time t3 may be a type 2 LBT. If the CRC fails, the LBT at time t3 may fall back to type 1. In the absence of a licensed carrier, if CRC fails for the PSSCH received at the second SL UE at time t3, the LBT (LBT3) of the first SL UE at time t4 may be type 1, or if CRC passes for the PSSCH received at the second SLUE at time t3, the LBT (LBT3) of the first SL UE at time t4 may be type 2. In order to account for UE processing delays, the PUCCH (PUCCH1) of the second SL UE may be scheduled before the PUCCH (PUCCH2) of the first SL UE. Fig.14 Examples may reduce CRC bits in DCI, reduce the number of PUCCH transmitters, and reduce Type 1 LBT.

[0146] According to another aspect of the present disclosure, in order to be robust against LBT uncertainty, the DCI (e.g., Fig. 8A The second DCI message) configures the SL receiver to perform Type 1 LBT to measure the COT and share the measured COT with the SL transmitter. Fig.15 1500 is a timing diagram illustrating an example of sending a coupled pair of DCIs from a base station to a SL transmitter and a SL receiver in accordance with aspects of the present disclosure. Fig.15 In the example of Figure 1 , 3 , 4, 5, 7 described in the examples of base stations 102, 310, 420, 421, 508, 710, the SL transmitter can be respectively referred to Figure 1 , 3 , 4, 5 and 7 described in the examples of UE 104, 350, 450, 451, 452, 502, 504, 506, 706, and the SL receiver can be respectively referred to Figure 1 , 3 , 4, 5 and 7 describe examples of UE 104, 350, 450, 451, 452, 502, 504, 506, 708. In some implementations, such as Fig.15 As shown, according to various aspects of the present disclosure, the SL receiver can send the UCI of the shared COT to the SL transmitter. Fig.15 As shown, at time t1, the base station sends a first DCI (DCI1) to the SL transmitter and sends a second DCI (DCI2) to the SL receiver. Fig.15 In the example of , each DCI (such as the first DCI and the second DCI) can be sent on an unlicensed carrier or a licensed carrier.

[0147] As described, the second DCI message configures the SL receiver to perform Type 1 LBT and share the COT with the SL transmitter when Type 1 LBS is successful. Fig.15 As shown, at time t2, the SL receiver performs type 1 LBT. In addition, if type 1 LBT is successful, the COT is obtained, and an indication of COT sharing can be sent to the SL transmitter via a UCI message during the window. The second DCI message may include type 1 LBT configuration (such as channel access priority level (CAPC)), cyclic prefix extension, energy detection threshold, and a window for obtaining COT and sharing COT via UCI sent on PUCCH.

[0148] In addition, at time t1, the first DCI message received at the SL transmitter may configure the SL transmitter to receive the possibility of sharing the COT via UCI from the SL receiver. The SL transmitter may perform Type 1 LBT when searching for UCI indicating that the COT is being shared. After receiving UCI at time t2, the SL transmitter may perform Type 2 LBT at time t3 (at Fig.15 (not shown). The SL transmitter may perform Type 2 LBT after a specified Type 2 LBT gap. In another implementation, Fig.15 As shown, the SL transmitter performs type 2 LBT when searching for UCI indicating that the COT is being shared. The SL transmitter can perform type 2 LBT after receiving the UCI. At time t3, the SL transmitter sends one or more PSSCHs to the SL receiver and provides LBT feedback to the base station via PUCCH. At time t4, the SL receiver provides a HARQ response to the base station via PUCCH.

[0149] According to another aspect of the present disclosure, the above-mentioned coupled DCI can be configured to improve the reliability of sidelink transmission to SL receivers suffering from hidden node interference. Fig.16 1 is a diagram illustrating an example of a network 1600 having an SL receiver 1602 subject to hidden node interference according to aspects of the present disclosure. The network 1600 may correspond to reference Figure 1 SL receiver 1602 may be a portion of network 100 described herein. Figure 1 , 3 , 4, 5 and 7 described UE 104, 350, 450, 451, 452, 502, 504, 506, 708 examples, and SL transmitter 1608 can be referenced respectively Figure 1 , 3 , 4, 5 and 7. The base station 1606 may be an example of a UE 104, 350, 450, 451, 452, 502, 504, 506, 706 described in detail. Figure 1 , 3 , 4, 5, 7 describe examples of base stations 102, 310, 420, 421, 508, 710.

[0150] like Fig.16As shown, node 1604 (such as a Wi-Fi router) may be near SL receiver 1602. In the current example, node 1604 may be referred to as a hidden node. In one implementation, SL receiver 1602 determines the time for receiving data to improve the reliability of data reception. For example, base station 1606 may send DCI to SL transmitter 1608, indicating that sidelink transmission should be triggered by a message (e.g., UCI) sent from SL receiver 1602. The message may include an indication that the SL receiver is sharing a COT. In one example, SL transmitter 1608 performs only type 2 LBT when searching for UCI including a shared COT. In this example, SL transmitter 1608 does not perform type 1 LBT when searching for UCI. In some implementations, base station 1606 may send multiple DCIs to SL transmitter 1608. Each DCI may correspond to a different MCS. SL receiver 1602 may identify the appropriate COT to be shared via UCI.

[0151] As noted above, Figure 7-16 is provided as an example. Other examples may be related to Figure 7-16 The examples described are different.

[0152] Fig.17 1700 is a diagram illustrating an example process 1700 performed, for example, by a SL UE according to various aspects of the present disclosure. The SL UE implementing the process 1700 may be respectively referring to Figure 1 , 3 , 4, 5, and 7 describe examples of UEs 104, 350, 450, 451, 452, 502, 504, 506, 708, or components thereof. Example process 1700 is an example of in-coverage network controlled offloading on an unlicensed sidelink.

[0153] like Fig.17As shown, in some aspects, process 1700 may include receiving DCI from multiple coupled DCIs (box 1702). For example, a UE (e.g., using antenna 352, RX 354, RX processor 356, controller / processor 359, memory 360, etc.) may receive the DCI. In one implementation, the DCI permits reception of multiple PSSCHs on an unlicensed SL carrier. In addition, in this implementation, the DCI requests a HARQ response for multiple scheduled PSSCHs. In some examples, the DCI includes a time domain resource allocation (TDRA) for multiple PSSCHs and corresponding HARQ identifiers, new data indicators, redundancy versions, modulation and coding schemes, transmission configuration indicators, and common frequency domain resource allocations (FDRA). In such an example, the DCI also includes physical uplink control channel (PUCCH) resources for HARQ responses. In some implementations, the DCI permits SL transmission. The UE may send SL data to a second SL UE based on the SL transmission permission. Furthermore, in some examples, the DCI configures the first SL UE to perform Type 1 Listen Before Talk (LBT) to determine a Channel Occupancy Time (COT). In some such examples, the first SL UE shares the COT with the second SL UE.

[0154] like Fig.17 As shown, in some aspects, process 1700 may include receiving one or more of the plurality of PSSCHs from another SL UE (block 1704). For example, the UE (e.g., using antenna 352, RX 354, RX processor 356, controller / processor 359, memory 360, etc.) may receive at least one of the plurality of PSSCHs from the other SL UE. In some examples, the PSSCH is sent without SL control information (SCI).

[0155] In some implementations, the SL UE decodes each of the scheduled PSSCHs based on the DCI grant. Fig.17 As shown, in some aspects, process 1700 may include sending a HARQ response based on the received PSSCH (block 1706). For example, the UE (e.g., using antenna 352, TX 354, TX processor 368, controller / processor 359, memory 360, etc.) may send a HARQ response. In some examples, a bitmap may be sent via the HARQ response. The bitmap may indicate a cyclic redundancy check (CRC) pass or fail for multiple scheduled PSSCHs. In some implementations, the DCI may be received via a licensed anchor carrier, and the HARQ response may be sent via the licensed anchor carrier.

[0156] Fig.181 is a diagram illustrating an example process 1800 performed, for example, by a SL UE according to various aspects of the present disclosure. The SL UE implementing the process 1800 may be respectively referring to Figure 1 , 3 , 4, 5, and 7 describe examples of UEs 104, 350, 450, 451, 452, 502, 504, 506, 706, or components thereof. Example process 1800 is an example of in-coverage network controlled offloading on an unlicensed sidelink.

[0157] like Fig.18 As shown, in some aspects, process 1800 may include receiving DCI from multiple coupled DCIs (block 1802). For example, a UE (e.g., using antenna 352, RX 354, RX processor 356, controller / processor 359, memory 360, etc.) may receive the DCI. The DCI may grant transmission of multiple PSSCHs on an unlicensed SL carrier. In addition, the DCI may configure LBT for multiple PSSCHs and request LBT feedback for the LBT.

[0158] like Fig.18 As shown, in some aspects, process 1800 may include sending one or more of the plurality of PSSCHs to another SL UE (block 1804). For example, the UE (e.g., using antenna 352, TX 354, TX processor 368, controller / processor 359, memory 360, etc.) may send at least one of the plurality of PSSCHs.

[0159] like Fig.18 As shown, in some aspects, process 1800 may include sending LBT feedback for the transmitted PSSCH (block 1806). For example, the UE (e.g., using antenna 352, TX 354, TX processor 368, controller / processor 359, memory 360, etc.) may send LBT feedback.

[0160] Fig.19 1 is a diagram illustrating an example process 1900 performed, for example, by a base station according to various aspects of the present disclosure. The base station implementing the process 1900 may be respectively referred to as Figure 1 , 3 , 4, 5, 7, or components thereof. The example process 1900 is an example of in-coverage network-controlled offloading on an unlicensed sidelink.

[0161] like Fig.19As shown, in some aspects, process 1900 may include sending two or more coupled DCIs for sending multiple transport blocks (TBs) via an unlicensed SL carrier to at least a first SL UE and a second SL UE (box 1902). For example, a base station (e.g., using antenna 320, TX 318, TX processor 316, controller / processor 375, memory 376, etc.) may send multiple coupled DCIs. In some implementations, the first SL UE is a first SL transmitter and the second SL UE is a first SL receiver. In such an implementation, a first DCI in the coupled DCI is sent to the first SL transmitter, and a second DCI in the coupled DCI is sent to the first SL receiver. In some implementations, the coupled DCI permits a first SL transmission to the first SL UE and a second SL transmission to the second SL UE. In such an implementation, the first SL transmission and the second SL transmission may be permitted on the unlicensed SL carrier.

[0162] In some implementations, the DCI grants one or more physical SL shared channels (PSSCH) to be sent without SL control information (SCI), configures listen-before-talk (LBT) for the PSSCH, and requests uplink control information (UCI) indicating the success or failure of the LBT. In some such implementations, the first DCI grants a physical uplink control channel (PUCCH) and specifies the timing of the PUCCH. The precoding information for the PUCCH may be different from the precoding information for the PSSCH. In some examples, the PUCCH may be allocated after the last PSSCH in the PSSCH. In some implementations, the base station may receive a bitmap indicating the successful transmission of one or more PSSCHs. The bitmap may be received via the PUCCH.

[0163] In addition, in some such implementations, the second DCI requests UCI indicating the storage of log-likelihood ratios (LLRs) for the corresponding hybrid automatic repeat request (HARQ) process. The base station may receive a bitmap indicating whether the first SL receiver has stored the LLRs. In some other implementations, the second DCI permits the reception of one or more PSSCHs sent from at least the first SL transmitter without SL control information (SCI), and the second DCI may also request a HARQ response for the PSSCH. In such an implementation, the second DCI may include a time domain resource allocation (TDRA) for the PSSCH and a corresponding HARQ identifier, a new data indicator, a redundancy version, a modulation and coding scheme, a transmission configuration indicator, and a common frequency domain resource allocation (FDRA). The second DCI may also include a grant for a PUCCH for a HARQ response. In some other implementations, the second DCI may configure the first SL receiver to identify the COT by performing type 1 LBT and share the COT with the first SL transmitter.

[0164] like Fig.19 As shown, in some aspects, process 1900 may include receiving feedback from at least a first SL UE and a second SL UE based on multiple coupled DCIs (box 1904). For example, a base station (e.g., using antenna 320, RX 318, RX processor 370, controller / processor 375, memory 376, etc.) may receive feedback from at least a first SL UE and a second SL UE. In some examples, the first SL UE may provide LBT feedback. The LBT feedback may include a bitmap for the corresponding PSSCH, wherein a bit value of 1 indicates that the corresponding PSSCH has been sent (e.g., LBT success), and a bit value of 0 indicates that the corresponding PSSCH has not been sent (e.g., LBT failure). As described, reference Fig.10 In the example of , the first LBT fails and the second LBT succeeds, therefore, the bitmap (e.g., LBT feedback) sent via PUCCH at time t2 is set to "01". As another example, the feedback from the second SL UE may include a HARQ response via PUCCH. In one example, as shown in reference Fig. 8A As described, the HARQ response indicates the PSSCH (such as Fig. 8A Whether PSSCH1 and PSSCH2) are successfully decoded.

[0165] Implementation examples are described in the following numbered clauses:

[0166] 1. A method performed by a first sidelink (SL) user equipment (UE), comprising:

[0167] Receiving downlink control information (DCI) from a plurality of coupled DCIs, the DCI being used to:

[0168] Allowing reception of multiple scheduled physical SL shared channels (PSSCH) on an unlicensed SL carrier, and

[0169] requesting a hybrid automatic repeat request (HARQ) response for the plurality of scheduled PSSCHs;

[0170] receiving at least one PSSCH of the plurality of PSSCHs from a second SL UE; and

[0171] The HARQ response is sent based on at least one received PSSCH.

[0172] 2. A method as described in clause 1, wherein the plurality of PSSCHs are sent without SL control information (SCI).

[0173] 3. A method according to any of clauses 1-2, wherein the DCI comprises:

[0174] A time domain resource allocation (TDRA) and corresponding HARQ identifier, new data indicator, redundancy version, modulation and coding scheme, transmission configuration indicator, and common frequency domain resource allocation (FDRA) for the plurality of PSSCHs; and

[0175] A physical uplink control channel (PUCCH) resource is used for the HARQ response.

[0176] 4. A method according to any one of clauses 1 to 3, further comprising:

[0177] decoding each of the plurality of scheduled PSSCHs based on a grant of the DCI; and

[0178] A bitmap is transmitted via the HARQ response, the bitmap indicating a cyclic redundancy check (CRC) pass or fail for the plurality of scheduled PSSCHs.

[0179] 5. A method according to any of clauses 1-4, further comprising combining log-likelihood ratios (LLRs) based on a demodulation reference signal (DMRS) sequence.

[0180] 6. The method according to clause 5 further includes: applying a first detection threshold for a first PSSCH among the multiple scheduled PSSCHs, and applying a second detection threshold for a PSSCH scheduled after the first PSSCH, wherein the first detection threshold is greater than the second detection threshold.

[0181] 7. The method of clause 5, further comprising sending a message indicating storage of the combined LLRs.

[0182] 8. The method of clause 7, further comprising receiving a request to flush the HARQ buffer when the sent message indicates incorrect HARQ management.

[0183] 9. A method according to any one of clauses 1 to 8, further comprising:

[0184] receiving the DCI via a granted anchor carrier; and

[0185] The HARQ response is sent via the granted anchor carrier.

[0186] 10. The method according to any one of clauses 1-9 further includes: when a licensed carrier is not available, receiving a listen-before-talk (LBT) configuration for a physical uplink control channel (PUCCH) resource, wherein a type 1 LBT is configured for the HARQ response and soft buffer; when a cyclic redundancy check passes for a PSSCH received in a timeslot corresponding to the PUCCH resource for the HARQ response, a type 2 LBT is configured for delayed uplink control information (UCI), and when the first SL UE is configured for the type 2 LBT, the DCI includes a field for the delayed UCI.

[0187] 11. A method according to any of clauses 1-10, wherein the DCI grants SL transmission, and the method further comprises: sending SL data to the second SL UE based on the SL transmission grant.

[0188] 12. A method according to any one of clauses 1-11, wherein the DCI configures the first SL UE to perform Type 1 Listen Before Talk (LBT) to determine a channel occupation time (COT), and the method further comprises: sending an indication to the second SLUE that the COT is being shared.

[0189] 13. A method performed by a base station, comprising:

[0190] transmitting a plurality of coupled downlink control information (DCI) for transmitting a plurality of transport blocks (TBs) via an unlicensed SL carrier to at least a first sidelink (SL) user equipment (UE) and a second SL UE; and

[0191] Feedback is received from at least the first SL UE and the second SL UE based on the multiple coupled DCIs.

[0192] 14. A method according to clause 13, wherein:

[0193] The first SL UE is a first SL transmitter, and the second SL UE is a first SL receiver; and

[0194] A first DCI among the multiple coupled DCIs is sent to the first SL transmitter, and a second DCI among the multiple coupled DCIs is sent to the first SL receiver.

[0195] 15. A method as set out in clause 14, wherein the first DCI is used to:

[0196] Allows transmission of multiple physical SL shared channels (PSSCH) without SL control information (SCI);

[0197] configuring a listen-before-talk (LBT) for the plurality of PSSCHs; and

[0198] Request uplink control information (UCI) indicating the success or failure of LBT.

[0199] 16. A method as set out in any of clauses 14-15, wherein the first DCI grants a Physical Uplink Control Channel (PUCCH) and specifies the timing of the PUCCH.

[0200] 17. A method as described in clause 16, wherein the precoding information for the PUCCH is different from the precoding information for the plurality of PSSCHs.

[0201] 18. A method as described in any of clauses 16-17, wherein the PUCCH is allocated after a last PSSCH in the plurality of PSSCHs.

[0202] 19. A method as described in any of clauses 16-18, further comprising receiving via the PUCCH a bitmap indicating successful transmission of at least one PSSCH from the plurality of PSSCHs.

[0203] 20. A method according to clause 14, wherein the second DCI requests uplink control information (UCI), the UCI indicating the storage of log-likelihood ratios (LLRs) for a corresponding hybrid automatic repeat request (HARQ) process, and the method further comprises: receiving a bitmap indicating whether the first SL receiver has stored the LLRs.

[0204] 21. The method according to clause 20, further comprising:

[0205] Determining whether HARQ soft information management of the first SL receiver is correct based on the received bitmap and the PUCCH resources of the first SL transmitter; and

[0206] When the HARQ soft information management is incorrect, the HARQ buffer of the first SL receiver is refreshed during subsequent scheduling.

[0207] 22. A method as set out in clause 14, wherein the second DCI is used for:

[0208] permitting reception of a plurality of physical SL shared channels (PSSCHs) transmitted from at least the first SL transmitter without SL control information (SCI); and

[0209] A hybrid automatic repeat request (HARQ) response is requested for the plurality of PSSCHs.

[0210] 23. A method as set out in clause 22, wherein the second DCI comprises:

[0211] A time domain resource allocation (TDRA) and corresponding HARQ identifier, new data indicator, redundancy version, modulation and coding scheme, transmission configuration indicator, and common frequency domain resource allocation (FDRA) for the plurality of PSSCHs; and

[0212] A grant for a Physical Uplink Control Channel (PUCCH) for the HARQ response.

[0213] 24. A method according to any one of clauses 13 to 23, further comprising:

[0214] configuring listen-before-talk (LBT) for each physical uplink control channel (PUCCH) when a licensed carrier is not available; and

[0215] The first SL transmitter is configured to send the PUCCH without LBT when the PUCCH is scheduled within the same channel occupancy time (COT) as the physical SL shared channel (PSSCH).

[0216] 25. A method according to any of clauses 14-23, further comprising: configuring the first SL receiver to:

[0217] Type 1 Listen Before Talk (LBT) for Hybrid Automatic Repeat Request (HARQ) responses and soft buffers; or

[0218] Type 2LBT for delayed uplink control information (UCI) when a cyclic redundancy check passes for a physical SL shared channel (PSSCH) received in a time slot corresponding to a physical uplink control channel (PUCCH) resource, wherein when the first SL receiver is configured for the type 2LBT, the second DCI includes a field for the delayed UCI.

[0219] 26. A method according to any of clauses 14-23, wherein the second DCI configures the first SL receiver to: identify channel occupancy time (COT) by performing type 1 LBT, and share the COT with the first SL transmitter.

[0220] 27. A method according to any one of clauses 13 to 26, wherein:

[0221] The plurality of coupled DCIs permit a first SL transmission to the first SL UE and a second SL transmission to the second SL UE; and

[0222] The first SL transmission and the second SL transmission are permitted on an unlicensed SL carrier.

[0223] 28. A method according to any one of clauses 13 to 27, further comprising:

[0224] transmitting the plurality of coupled DCIs on a licensed anchor carrier; and

[0225] The feedback is received on the licensed anchor carrier.

[0226] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of the various aspects.

[0227] As used, the term "component" is intended to be broadly interpreted as hardware, firmware, and / or a combination of hardware and software. As used, a processor is implemented in hardware, firmware, and / or a combination of hardware and software.

[0228] Some aspects are described in conjunction with a threshold. As used, satisfying a threshold may refer to a value being greater than a threshold, greater than or equal to a threshold, less than a threshold, less than or equal to a threshold, equal to a threshold, not equal to a threshold, etc., depending on the context.

[0229] It will be apparent that the systems and / or methods described and in Appendix A may be implemented in various forms of hardware, firmware, and / or combinations of hardware and software. The actual specialized control hardware or software code used to implement these systems and / or methods does not limit the aspects. Thus, the operation and behavior of the systems and / or methods are described without reference to specific software code, with the understanding that software and hardware may be designed to implement the systems and / or methods based at least in part on the description.

[0230] Even if a specific combination of features is recorded in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, many of these features can be combined in a manner that is not specifically recorded in the claims and / or specifically disclosed in the specification. Although each dependent claim listed below may only be directly subordinate to one claim, the disclosure of various aspects includes the combination of each dependent claim with each other claim in the claim set. The phrase "at least one of" referring to the list of items refers to any combination of those items, including a single member. For example, "at least one of a, b or c" is intended to cover a, b, c, ab, ac, bc and abc, and any combination of identical elements in multiples (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc and ccc or any other ordering of a, b and c).

[0231] Any element, action or instruction used should not be interpreted as critical or necessary unless explicitly described as such. In addition, as used, the articles "a" and "an" are intended to include one or more items and can be used interchangeably with "one or more". In addition, as used, the terms "set" and "group" are intended to include one or more items (e.g., related items, unrelated items, combinations of related items and unrelated items, etc.), and can be used interchangeably with "one or more". In the case of only one item being expected, the phrase "only one" or similar language is used. In addition, as used, the terms "has", "have", "having" and / or similar terms are intended to be open terms. In addition, unless otherwise expressly stated, the phrase "based on" is intended to mean "based at least in part on".

Claims

1. A method performed by a first sidelink (SL) user equipment (UE), comprising: Receiving downlink control information (DCI) from a plurality of coupled DCIs, the DCI comprising: a grant of one or more resources for receiving one or more SL data transmissions via a plurality of scheduled physical SL shared channels (PSSCHs) on an unlicensed SL carrier, and a request for a hybrid automatic repeat request (HARQ) response for the one or more SL data transmissions; Receiving first SL data from a second SL UE via at least one PSSCH among the plurality of PSSCHs in response to receiving the DCI; decoding the first SL data based on the grant in the DCI; and The HARQ response is sent based on receiving the first SL data, the HARQ response including a bitmap indicating a pass or fail of a cyclic redundancy check (CRC) according to decoding the first SL data.

2. The method according to claim 1, wherein: The multiple PSSCHs are transmitted without SL control information (SCI).

3. The method according to claim 1, wherein: The DCI includes: a time domain resource allocation (TDRA) and a corresponding HARQ identifier, a new data indicator, a redundancy version, a modulation and coding scheme, a transmission configuration indicator, and a common frequency domain resource allocation (FDRA) for the one or more resources; and A grant for physical uplink control channel (PUCCH) resources for the HARQ response.

4. The method according to claim 1, further comprising: Log-likelihood ratios (LLRs) are combined based on a demodulation reference signal (DMRS) sequence.

5. The method according to claim 4, further comprising: A first detection threshold is applied to a first PSSCH among the multiple scheduled PSSCHs, and a second detection threshold is applied to a PSSCH scheduled after the first PSSCH, wherein the first detection threshold is greater than the second detection threshold.

6. The method according to claim 4, further comprising: A message is sent indicating storage of the combined LLRs.

7. The method according to claim 6, further comprising: When the message indicates incorrect HARQ management, a request for flushing the HARQ buffer is received.

8. The method according to claim 1, further comprising: receiving the DCI via a granted anchor carrier; as well as The HARQ response is sent via the granted anchor carrier.

9. The method according to claim 1, further comprising: When a licensed carrier is not available, a listen-before-talk (LBT) configuration for a physical uplink control channel (PUCCH) resource is received, wherein a type 1 LBT is configured for the HARQ response and soft buffer; when a cyclic redundancy check passes for a PSSCH received in a timeslot corresponding to the PUCCH resource for the HARQ response, a type 2 LBT is configured for delayed uplink control information (UCI), and when the first SL UE is configured for the type 2 LBT, the DCI includes a field for the delayed UCI.

10. The method according to claim 1, wherein: The DCI grants resources for SL transmission, and the method further includes sending second SL data to the second SL UE based on the resources for the SL transmission.

11. The method according to claim 1, wherein: The DCI configures the first SL UE to perform Type 1 Listen Before Talk (LBT) to determine a channel occupation time (COT), and the method further includes sending an indication to the second SL UE that the COT is being shared.

12. An apparatus for wireless communication at a first sidelink (SL) user equipment (UE), comprising: processor; a memory coupled to the processor; as well as Instructions, which are stored in the memory and are operable when executed by the processor to cause the apparatus to perform a method according to any one of claims 1 to 11.

13. A non-transitory computer-readable medium having a program code recorded thereon, the program code being executed to implement the method according to any one of claims 1 to 11.

14. An apparatus for wireless communication at a first sidelink (SL) user equipment (UE), comprising: Means for receiving downlink control information (DCI) from a plurality of coupled DCIs, the DCI comprising: a grant of one or more resources for receiving one or more SL data transmissions via a plurality of scheduled physical SL shared channels (PSSCHs) on an unlicensed SL carrier, and a request for a hybrid automatic repeat request (HARQ) response for the one or more SL data transmissions; a unit for receiving first SL data from a second SL UE via at least one PSSCH of the plurality of PSSCHs in response to receiving the DCI; means for decoding the first SL data based on the grant in the DCI; and A unit for sending the HARQ response based on receiving the first SL data, the HARQ response comprising a bitmap indicating a pass or fail of a cyclic redundancy check (CRC) according to decoding the first SL data.

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