Radio resource mapping for feedback channels

Abstract

A wireless device receives a sidelink transmission. The sidelink transmission includes a transport block. A feedback resource is determined from: a first feedback resource, in response to the sidelink transmission indicating one of unicast and multicast with a first feedback operation; and a second feedback resource, in response to the sidelink transmission indicating multicast with a second feedback operation. Feedback for the transport block is transmitted via the feedback resource.

Description

[0001] Divisional application

[0002] This application is a divisional application of the invention application with the application date of October 5, 2020, application number 202080069486.8, and title “Radio Resource Mapping for Feedback Channel”.

[0003] CROSS-REFERENCE TO RELATED APPLICATIONS

[0004] This application claims the benefit of U.S. Provisional Application No. 62 / 910,195, filed October 3, 2019, which is hereby incorporated by reference in its entirety. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Examples of several of the various embodiments of the present disclosure are described herein with reference to the accompanying drawings.

[0006] Figure 1A and Figure 1B An exemplary mobile communications network is shown in which embodiments of the present disclosure may be implemented.

[0007] Figure 2A and Figure 2B The New Radio (NR) user plane and control plane protocol stacks are shown separately.

[0008] Figure 3 Shown in Figure 2A Examples of services provided between the protocol layers of the NR user plane protocol stack.

[0009] Figure 4A Shows the flow Figure 2A Example downlink data flow of the NR user plane protocol stack.

[0010] Figure 4B An exemplary format of a MAC subheader in a MAC PDU is shown.

[0011] Figure 5A and Figure 5B The mapping between logical channels, transport channels and physical channels is shown for downlink and uplink respectively.

[0012] Figure 6 is an example diagram showing RRC state transition of a UE.

[0013] Figure 7 An exemplary configuration of an NR frame into which OFDM symbols are grouped is shown.

[0014] Figure 8 An exemplary configuration of time slots in the time and frequency domains of an NR carrier is shown.

[0015] Figure 9 An example of bandwidth adaptation using three configured BWPs for an NR carrier is shown.

[0016] Figure 10A Three carrier aggregation configurations with two component carriers are shown.

[0017] Figure 10B An example is shown of how aggregated cells may be configured into one or more PUCCH groups.

[0018] Figure 11A An example of the structure and location of SS / PBCH blocks is shown.

[0019] Figure 11B An example of CSI-RS mapped in the time and frequency domains is shown.

[0020] Figure 12A and Figure 12B Three examples of downlink and uplink beam management procedures are shown respectively.

[0021] Figure 13A 、 Figure 13B and Figure 13C A four-step contention-based random access procedure, a two-step contention-free random access procedure, and another two-step random access procedure are shown respectively.

[0022] Figure 14A An example of a CORESET configuration for the bandwidth portion is shown.

[0023] Figure 14B An example of CCE to REG mapping for DCI transmission on CORESET and PDCCH processing is shown.

[0024] Figure 15 An example of a wireless device communicating with a base station is shown.

[0025] Figure 16A 、 Figure 16B 、 Figure 16C and Figure 16D Exemplary structures for uplink and downlink transmissions are shown.

[0026] Figure 17 is an example of device-to-device (D2D) communication according to aspects of embodiments of the present disclosure.

[0027] Figure 18 is an example of a resource pool for sidelink operation according to aspects of an embodiment of the present disclosure.

[0028] Figure 19 is an example of PSFCH resource configuration.

[0029] Figure 20 is an example of mapping between radio resources for sidelink transmission and candidate PSFCH resources.

[0030] Figure 21 is an example of grouping candidate PSFCH resources by sub-channel according to aspects of the embodiments of the present disclosure.

[0031] Figure 22 This is an example of determining PSFCH resources based on grouping of candidate PSFCH resources according to aspects of the embodiments of the present disclosure.

[0032] Figure 23 This is an example of determining PSFCH resources based on method 2 of grouping candidate PSFCH resources according to aspects of the embodiments of the present disclosure.

[0033] Figure 24 is an example of determining PSFCH resources by one or more wireless devices according to aspects of an embodiment of the present disclosure.

[0034] Figure 25 is an example of grouping candidate PSFCH resources by sidelink resource pool according to aspects of embodiments of the present disclosure.

[0035] Figure 26 This is an example of determining PSFCH resources based on the grouping method 1 of candidate PSFCH resources according to aspects of the embodiments of the present disclosure and counting the indexes of the PSFCH resources in the same order.

[0036] Figure 27 It is an example of determining PSFCH resources based on the grouping method 1 of candidate PSFCH resources according to aspects of the embodiments of the present disclosure and counting the indexes of the PSFCH resources in different orders.

[0037] Figure 28 This is an example of determining PSFCH resources based on the grouping method 2 of candidate PSFCH resources according to aspects of the embodiments of the present disclosure and counting the indexes of the PSFCH resources in the same order.

[0038] Figure 29 It is an example of determining PSFCH resources based on grouping method 2 of candidate PSFCH resources according to aspects of an embodiment of the present disclosure and counting indexes of the PSFCH resources in different orders.

[0039] Figure 30 is an example of determining PSFCH resources by one or more wireless devices when counting indices of PSFCH resources in the same order according to aspects of an embodiment of the present disclosure.

[0040] Figure 31is an example of determining PSFCH resources by one or more wireless devices when indexes of PSFCH resources are counted in different orders according to aspects of embodiments of the present disclosure.

[0041] Figure 32 is an example of determining PSFCH resources by one or more wireless devices when counting indices of PSFCH resources in both ascending and descending orders according to aspects of embodiments of the present disclosure.

[0042] Figure 33 is an example of a procedure for feedback resource selection and HARQ message transmission in Mode 1 according to aspects of an embodiment of the present disclosure.

[0043] Figure 34A and Figure 34B is an example of one or more control messages according to aspects of an embodiment of the present disclosure.

[0044] Figure 35 is an example of a procedure for feedback resource selection and HARQ message transmission in Mode 2 according to aspects of an embodiment of the present disclosure.

[0045] Figure 36A 、 Figure 36B 、 Figure 36C 、 Figure 36D and Figure 36E is an example of an SCI according to aspects of an embodiment of the present disclosure.

[0046] Figure 37 is a flowchart illustrating aspects of an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0047] In the present disclosure, various embodiments are presented in the form of examples of how the disclosed technology can be implemented and / or how the disclosed technology can be practiced in various environments and scenarios. It will be obvious to those skilled in the relevant art that various changes in form and detail can be made therein without departing from the scope of the present invention. In fact, after reading this specification, it will be obvious to those skilled in the relevant art how to implement alternative embodiments. The embodiments of the present invention should not be limited to any described exemplary embodiments. The embodiments of the present disclosure will be described with reference to the accompanying drawings. The limitations, features and / or elements from the disclosed exemplary embodiments can be combined to form additional embodiments within the scope of the present disclosure. Any drawings that highlight functions and advantages are presented for illustrative purposes only. The disclosed architecture is flexible and configurable enough that it can be utilized in a manner different from that shown. For example, the actions listed in any flow chart can be reordered or used only optionally in some embodiments.

[0048] Implementations can be configured to operate as needed. When certain criteria are met, such as in a wireless device, base station, radio environment, network, or combinations thereof, the disclosed mechanisms can be executed. Example criteria can be based, at least in part, on, for example, wireless device or network node configuration, traffic load, initial system setup, packet size, traffic characteristics, or combinations thereof. When one or more criteria are met, various exemplary implementations can be applied. Thus, exemplary implementations that selectively implement the disclosed protocol can be implemented.

[0049] A base station may communicate with a mixture of wireless devices. A wireless device and / or base station may support multiple technologies and / or multiple versions of the same technology. A wireless device may have certain capabilities depending on the wireless device class and / or capabilities. When the present disclosure refers to a base station communicating with multiple wireless devices, the present disclosure may refer to a subset of the total wireless devices in the coverage area. For example, the present disclosure may refer to multiple wireless devices of a given LTE or 5G version with given capabilities and in a given sector of a base station. The multiple wireless devices in the present disclosure may refer to a selected plurality of wireless devices and / or a subset of the total wireless devices in the coverage area that perform according to the disclosed methods, etc. There may be multiple base stations or multiple wireless devices in the coverage area that may not comply with the disclosed methods, for example, these wireless devices or base stations may perform based on older versions of LTE or 5G technology.

[0050] In this disclosure, “a” and “an” and similar expressions should be interpreted as “at least one” and “one or more”. Similarly, any term ending in the suffix “(s)” will be interpreted as “at least one” and “one or more”. In this disclosure, the term “may” should be interpreted as “may, for example”. In other words, the term “may” indicates that the expression following the term “may” is an example of one suitable possibility among many suitable possibilities that one or more of the various embodiments may or may not adopt. As used herein, the terms “comprises” and “consists of” list one or more components of the element being described. The term “comprises” is interchangeable with “includes” and does not exclude unlisted components from being included in the element being described. In contrast, “consists of” provides a complete listing of the one or more components of the element being described. As used herein, the term “based on” should be interpreted as “based at least in part on,” rather than, for example, “based only on.” As used herein, the term "and / or" means any possible combination of the listed elements. For example, "A, B and / or C" can mean: A; B; C; A and B; A and C; B and C; or A, B and C.

[0051] If A and B are sets, and every element of A is also an element of B, then A is called a subset of B. In this specification, only non-empty sets and subsets are considered. For example, the possible subsets of B = {cell1, cell2} are: {cell1}, {cell2}, and {cell1, cell2}. The phrase "based on" (or equivalently, "based at least on") indicates that the phrase following the term "based on" is an example of one of multiple suitable possibilities that may or may not be used in one or more different embodiments. The phrase "in response to" (or equivalently, "in response to at least") indicates that the phrase following the phrase "in response to" is an example of one of multiple suitable possibilities that may or may not be used in one or more different embodiments. The phrase "depending on" (or equivalently, "at least depending on") indicates that the phrase following the phrase "depending on" is an example of one of multiple suitable possibilities that may or may not be used in one or more different embodiments. The phrase "using / employing" (or equivalently, "at least employing / employing") indicates that the phrase following the phrase "employing / employing" is an example of one of multiple suitable possibilities that may or may not be used in one or more different embodiments.

[0052] The term "configured" may refer to the capabilities of a device, whether the device is in an operational or non-operational state. "Configured" may refer to specific settings in a device that affect the operational characteristics of the device, whether the device is in an operational or non-operational state. In other words, hardware, software, firmware, registers, memory values, etc. may be "configured" within a device to provide specific characteristics to the device, whether the device is in an operational or non-operational state. Terms such as "control messages caused in a device" may mean that the control message has parameters that can be used to configure specific characteristics in the device or parameters that can be used to implement certain actions in the device, whether the device is in an operational or non-operational state.

[0053] In the present disclosure, a parameter (or equivalently referred to as a field or information element: IE) may include one or more information objects, and an information object may include one or more other objects. For example, if parameter (IE) N includes parameter (IE) M, and parameter (IE) M includes parameter (IE) K, and parameter (IE) K includes parameter (information element) J, then, for example, N includes K and N includes J. In an exemplary embodiment, when one or more messages include multiple parameters, it means that the parameters of the multiple parameters are in at least one message in the one or more messages, but not necessarily in every message in the one or more messages.

[0054] Many of the features presented are described as optional, either by the use of "may" or by the use of parentheses. For the sake of brevity and readability, this disclosure does not explicitly recite every permutation that can be obtained by selecting from the set of optional features. This disclosure should be interpreted as explicitly disclosing all such permutations. For example, a system described as having three optional features can be embodied in seven ways, namely, with only one of the three possible features, with any two of the three possible features, or with three of the three possible features.

[0055] Many elements in the elements described in the disclosed embodiments can be implemented as modules. Module is defined here as an element that performs a defined function and has a defined interface to other elements. The module described in this disclosure can be implemented in the form of hardware, software, firmware, wetware (i.e., hardware with biological elements) or a combination thereof in combination with hardware (the above items can be equivalent in behavior). For example, a module can be implemented as a software routine written in a computer language that is configured to be executed by a hardware machine (such as C, C++, Fortran, Java, Basic, Matlab, etc.) or a modeling / simulation program (such as Simulink, Stateflow, GNU Octave, or LabVIEW MathScript). Modules can be implemented using physical hardware that is incorporated with discrete or programmable analog, digital, and / or quantum hardware. Examples of programmable hardware include: computers, microcontrollers, microprocessors, application specific integrated circuits (ASICs); field programmable gate arrays (FPGAs); and complex programmable logic devices (CPLDs). Computers, microcontrollers, and microprocessors are programmed using languages ​​such as assembly, C, and C++. FPGAs, ASICs, and CPLDs are often programmed using a hardware description language (HDL), such as VHSIC Hardware Description Language (VHDL) or Verilog, that configures the connections between the less functional internal hardware modules on the programmable device. The mentioned techniques are often used in combination to achieve the results of the functional modules.

[0056] Figure 1A 1 shows an example of a mobile communication network 100 in which embodiments of the present disclosure may be implemented. The mobile communication network 100 may be, for example, a public land mobile network (PLMN) operated by a network operator. Figure 1A As shown in , the mobile communication network 100 includes a core network (CN) 102 , a radio access network (RAN) 104 , and wireless devices 106 .

[0057] The CN 102 may provide an interface to one or more data networks (DNs), such as a public DN (e.g., the Internet), a private DN, and / or an intra-carrier DN, for the wireless device 106. As part of the interface functionality, the CN 102 may establish an end-to-end connection between the wireless device 106 and the one or more DNs, authenticate the wireless device 106, and provide billing functionality.

[0058] The RAN 104 can connect the CN 102 to the wireless device 106 via radio communication over an air interface. As part of the radio communication, the RAN 104 can provide scheduling, radio resource management, and retransmission protocols. The direction of communication from the RAN 104 to the wireless device 106 over the air interface is referred to as downlink, while the direction of communication from the wireless device 106 to the RAN 104 over the air interface is referred to as uplink. Downlink transmissions can be separated from uplink transmissions using frequency division duplexing (FDD), time division duplexing (TDD), and / or some combination of these two duplexing techniques.

[0059] The term "wireless device" may be used throughout this disclosure to refer to and encompass any mobile or fixed (non-mobile) device for which wireless communication is desired or available. For example, a wireless device may be a phone, a smartphone, a tablet, a computer, a laptop, a sensor, a meter, a wearable device, an Internet of Things (IoT) device, a vehicle roadside unit (RSU), a relay node, a car, and / or any combination thereof. The term "wireless device" encompasses other terms including user equipment (UE), user terminal (UT), access terminal (AT), mobile station, handset, wireless transceiver unit (WTRU), and / or wireless communication device.

[0060] The RAN 104 may include one or more base stations (not shown). The term "base station" may be used throughout this disclosure to refer to and encompass: a Node B (associated with UMTS and / or 3G standards); an evolved Node B (eNB, associated with E-UTRA and / or 4G standards); a remote radio head (RRH); a baseband processing unit coupled to one or more RRHs; a repeater node or relay node for extending the coverage area of ​​a donor node; a next-generation evolved Node B (ng-eNB); a generation Node B (gNB, associated with NR and / or 5G standards); an access point (AP, associated with, for example, WiFi or any other suitable wireless communication standard); and / or any combination thereof. A base station may include at least one gNB central unit (gNB-CU) and at least one gNB distributed unit (gNB-DU).

[0061] The base stations included in the RAN 104 may include one or more antennas for communicating with the wireless devices 106 over the air interface. For example, one or more base stations may include three antennas to control three cells (or sectors). The size of a cell can be determined based on the range at which a receiver (e.g., a base station receiver) can successfully receive transmissions from a transmitter (e.g., a wireless device transmitter) operating in the cell. Together, the cells of the base stations can provide radio coverage to the wireless devices 106 over a wide geographic area to support wireless device mobility.

[0062] In addition to three sector sites, other implementations of base stations are possible. For example, one or more base stations in the RAN 104 can be implemented as a sectorized site with more or less than three sectors. One or more base stations in the RAN 104 can be implemented as an access point, as a baseband processing unit coupled to several remote radio heads (RRHs), and / or as a repeater or relay node for extending the coverage area of ​​a donor node. The baseband processing units coupled to the RRHs can be part of a centralized RAN architecture or a cloud RAN architecture, where the baseband processing units can be centralized in a pool of baseband processing units or virtualized. The repeater node can amplify and rebroadcast the radio signal received from the donor node. The relay node can perform the same / similar functions as the repeater node, but can decode the radio signal received from the donor node to remove noise before amplifying and rebroadcasting the radio signal.

[0063] The RAN 104 may be implemented in a homogeneous network of macrocell base stations having similar antenna patterns and similar high levels of transmit power. The RAN 104 may be implemented in a heterogeneous network. In a heterogeneous network, small cell base stations may be used to provide small coverage areas, for example, overlapping with the relatively larger coverage area provided by macrocell base stations. Small coverage areas may be provided in areas with high data traffic (or so-called "hotspots") or in areas where macrocell coverage is weak. Examples of small cell base stations include, in descending order of coverage area: microcell base stations, picocell base stations, and femtocell base stations or home base stations.

[0064] The Third Generation Partnership Project (3GPP) was established in 1998 to Figure 1A 100 in the mobile communication network 100. To date, 3GPP has developed specifications for three generations of mobile networks: the third generation (3G) network known as the Universal Mobile Telecommunications System (UMTS), the fourth generation (4G) network known as the Long Term Evolution (LTE), and the fifth generation (5G) network known as the 5G System (5GS). The embodiments of the present disclosure are described with reference to the RAN of the 3GPP 5G network known as the Next Generation RAN (NG-RAN). These embodiments may be applicable to the RAN of other mobile communication networks, such as Figure 1A The RAN 104 in 5G networks, the RANs of earlier 3G and 4G networks, and those of yet-to-be-specified future networks (e.g., 3GPP 6G networks). The NG-RAN implements the 5G radio access technology known as New Radio (NR) and may be configured to implement 4G radio access technology or other radio access technologies, including non-3GPP radio access technologies.

[0065] Figure 1B1 shows another exemplary mobile communication network 150 in which embodiments of the present disclosure may be implemented. The mobile communication network 150 may be, for example, a PLMN operated by a network operator. Figure 1B As shown in FIG, a mobile communication network 150 includes a 5G core network (5G-CN) 152, an NG-RAN 154, and UEs 156A and 156B (collectively referred to as UE 156). Figure 1A The corresponding components described herein are implemented and operated in the same or similar manner.

[0066] 5G-CN 152 provides an interface to one or more DNs, such as a public DN (e.g., the Internet), a private DN, and / or an operator's internal DN, to the UE 156. As part of the interface functionality, the 5G-CN 152 can establish an end-to-end connection between the UE 156 and the one or more DNs, authenticate the UE 156, and provide charging functionality. Compared to the CN of the 3GPP 4G network, the basis of the 5G-CN 152 can be a service-based architecture. This means that the architecture of the nodes that make up the 5G-CN 152 can be defined as network functions that provide services to other network functions via interfaces. The network functions of the 5G-CN 152 can be implemented in several ways, including as network elements on dedicated or shared hardware, as software instances running on dedicated or shared hardware, or as virtualized functions instantiated on a platform (e.g., a cloud-based platform).

[0067] like Figure 1B As shown in FIG, 5G-CN 152 includes an access and mobility management function (AMF) 158A and a user plane function (UPF) 158B, which are not shown in FIG. Figure 1B They are shown as one component AMF / UPF 158 in FIG. The UPF 158B may act as a gateway between the NG-RAN 154 and the one or more DNs. The UPF 158B may perform functions such as packet routing and forwarding, packet inspection and user plane policy rule enforcement, service usage reporting, uplink classification to support routing of service flows to the one or more DNs, user plane Quality of Service (QoS) processing (e.g., packet filtering, gating, uplink / downlink rate enforcement and uplink service verification), downlink packet buffering and downlink data notification triggering. The UPF 158B may act as an anchor point for intra / inter-radio access technology (RAT) mobility, an external protocol (or packet) data unit (PDU) session point interconnected with the one or more DNs and / or a fulcrum to support multi-homed PDU sessions. The UE 156 may be configured to receive services through a PDU session, which is a logical connection between the UE and the DN.

[0068] The AMF 158A may perform functions such as: non-access stratum (NAS) signaling termination, NAS signaling security, access stratum (AS) security control, inter-CN node signaling for mobility between 3GPP access networks, idle mode UE reachability (e.g., control and execution of paging retransmissions), registration area management, intra-system and inter-system mobility support, access authentication, access authorization including roaming rights verification, mobility management control (subscription and policy), network slicing support and / or session management function (SMF) selection. NAS may refer to a function operating between the CN and the UE, and AS may refer to a function operating between the UE and the RAN.

[0069] 5G-CN 152 may include Figure 1B . For example, the 5G-CN 152 may include one or more of the following: a session management function (SMF), an NR repository function (NRF), a policy control function (PCF), a network exposure function (NEF), a unified data management (UDM), an application function (AF), and / or an authentication server function (AUSF).

[0070] NG-RAN 154 can connect 5G-CN 152 to UE 156 via radio communications over the air interface. NG-RAN 154 may include one or more gNBs, such as gNB 160A and gNB 160B (collectively, gNB 160), and / or one or more ng-eNBs, such as ng-eNB 162A and ng-eNB 162B (collectively, ng-eNB 162). gNB 160 and ng-eNB 162 may be more generally referred to as base stations. gNB 160 and ng-eNB 162 may include one or more antennas for communicating with UE 156 over the air interface. For example, one or more of gNB 160 and / or one or more of ng-eNB 162 may include three antennas to control three cells (or sectors), respectively. The cells of gNB 160 and ng-eNB 162 may together provide radio coverage to UE 156 over a wide geographic area to support UE mobility.

[0071] like Figure 1BAs shown in FIG, gNB 160 and / or ng-eNB 162 may be connected to 5G-CN 152 via an NG interface and to other base stations via an Xn interface. The NG and Xn interfaces may be established using direct physical connections and / or indirect connections through underlying transport networks, such as Internet Protocol (IP) transport networks. gNB 160 and / or ng-eNB 162 may be connected to UE 156 via a Uu interface. For example, Figure 1B As shown in FIG, gNB 160A can be connected to UE 156A via a Uu interface. The NG, Xn, and Uu interfaces are associated with a protocol stack. The protocol stack associated with the interface can be composed of Figure 1B Network elements in a network exchange data and signaling messages and may include two planes: the user plane and the control plane. The user plane processes data of interest to users, while the control plane processes signaling messages of interest to network elements.

[0072] The gNB 160 and / or ng-eNB 162 may be connected to one or more AMF / UPF functions of the 5G-CN 152, such as the AMF / UPF 158, via one or more NG interfaces. For example, the gNB 160A may be connected to the UPF 158B of the AMF / UPF 158 via an NG user plane (NG-U) interface. The NG-U interface may provide for delivery of user plane PDUs (e.g., non-guaranteed delivery) between the gNB 160A and the UPF 158B. The gNB 160A may be connected to the AMF 158A via an NG control plane (NG-C) interface. The NG-C interface may provide, for example, NG interface management, UE context management, UE mobility management, delivery of NAS messages, paging, PDU session management, and configuration delivery and / or warning message transmission.

[0073] The gNB 160 can provide NR user plane and control plane protocol termination to the UE 156 via a Uu interface. For example, the gNB 160A can provide NR user plane and control plane protocol termination to the UE 156A via a Uu interface associated with the first protocol stack. The ng-eNB 162 can provide Evolved UMTS Terrestrial Radio Access (E-UTRA) user plane and control plane protocol termination to the UE 156 via a Uu interface, where E-UTRA refers to a 3GPP 4G radio access technology. For example, the ng-eNB 162B can provide E-UTRA user plane and control plane protocol termination to the UE 156B via a Uu interface associated with the second protocol stack.

[0074] The 5G-CN 152 is described as being configured to handle both NR and 4G radio access. One of ordinary skill in the art will appreciate that it is possible for NR to be connected to a 4G core network in a mode known as "non-standalone operation." In non-standalone operation, the 4G core network is used to provide (or at least support) control plane functions (e.g., initial access, mobility, and paging). Although Figure 1B Only one AMF / UPF 158 is shown in the figure, but one gNB or ng-eNB can be connected to multiple AMF / UPF nodes to provide redundancy and / or load sharing across the multiple AMF / UPF nodes.

[0075] As discussed, Figure 1B The interfaces between network elements in a network (e.g., Uu, Xn, and NG interfaces) can be associated with a protocol stack used by the network elements to exchange data and signaling messages. The protocol stack can include two planes: the user plane and the control plane. The user plane can handle data of interest to users, while the control plane can handle signaling messages of interest to network elements.

[0076] Figure 2A and Figure 2B Examples of NR user plane and NR control plane protocol stacks for the Uu interface between UE 210 and gNB 220 are shown, respectively. Figure 2A and Figure 2B The protocol stack shown in can be used with e.g. Figure 1B The protocol stacks of the Uu interface between UE 156A and gNB 160A shown in FIG are the same or similar.

[0077] Figure 2A The NR user plane protocol stack is shown, including five layers implemented in the UE 210 and gNB 220. At the bottom of the protocol stack, the physical layers (PHY) 211 and 221 can provide transport services to higher layers of the protocol stack and can correspond to Layer 1 of the Open Systems Interconnection (OSI) model. The next four protocols above PHY 211 and 221 include the medium access control layer (MAC) 212 and 222, the radio link control layer (RLC) 213 and 223, the packet data convergence protocol layer (PDCP) 214 and 224, and the service data application protocol layer (SDAP) 215 and 225. Together, these four protocols can constitute Layer 2, or the data link layer, of the OSI model.

[0078] Figure 3 An example of services provided between protocol layers of the NR user plane protocol stack is shown. Figure 2A and Figure 3Starting from the top, SDAPs 215 and 225 can perform QoS flow processing. UE 210 can receive services via a PDU session, which can be a logical connection between UE 210 and a DN. A PDU session can have one or more QoS flows. The UPF of the CN (e.g., UPF 158B) can map IP packets to the one or more QoS flows of the PDU session based on QoS requirements (e.g., in terms of latency, data rate, and / or error rate). SDAPs 215 and 225 can perform mapping / demapping between the one or more QoS flows and one or more data radio bearers. The mapping / demapping between QoS flows and data radio bearers can be determined by SDAP 225 at gNB 220. SDAP 215 at UE 210 can learn the mapping between QoS flows and data radio bearers through reflective mapping or control signaling received from gNB 220. For reflective mapping, the SDAP 225 at the gNB 220 may mark downlink packets with a QoS flow indicator (QFI), which may be observed by the SDAP 215 at the UE 210 to determine the mapping / de-mapping between QoS flows and data radio bearers.

[0079] PDCPs 214 and 224 can perform header compression / decompression to reduce the amount of data transmitted over the air interface, encryption / decryption to prevent unauthorized decoding of data transmitted over the air interface, and integrity protection to ensure that control messages originate from the intended source. PDCPs 214 and 224 can also perform retransmission of undelivered packets, in-sequence delivery and reordering of packets, and removal of duplicate packets received due to, for example, intra-gNB handovers. PDCPs 214 and 224 can also perform packet duplication to increase the likelihood of packet reception and remove any duplicate packets at the receiver. Packet duplication can be suitable for services requiring high reliability.

[0080] although Figure 3 Not shown, but PDCP 214 and 224 can perform mapping / demapping between split radio bearers and RLC channels in dual connectivity scenarios. Dual connectivity is a technology that allows a UE to connect to two cells or more generally to two cell groups: a primary cell group (MCG) and a secondary cell group (SCG). Split bearers are split bearers when a single radio bearer (such as one of the radio bearers provided by PDCP 214 and 224 as a service to SDAP 215 and 225) is handled by a cell group in dual connectivity. PDCP 214 and 224 can map / demapped split radio bearers between RLC channels belonging to a cell group.

[0081] RLC 213 and 223 can perform segmentation, retransmission via automatic repeat request (ARQ), and removal of duplicate data units received from MAC 212 and 222, respectively. RLC 213 and 223 can support three transmission modes: transparent mode (TM); unacknowledged mode (UM); and acknowledged mode (AM). Based on the transmission mode in which the RLC is operating, the RLC can perform one or more of the functions described. RLC configuration can be on a per-logical channel basis, independent of parameter sets and / or transmission time interval (TTI) durations. Figure 3 As shown in FIG, RLC 213 and 223 may provide RLC channels as services to PDCP 214 and 224, respectively.

[0082] MACs 212 and 222 may perform multiplexing / demultiplexing of logical channels and / or mapping between logical channels and transport channels. Multiplexing / demultiplexing may include multiplexing / demultiplexing data units belonging to one or more logical channels into / from transport blocks (TBs) delivered to / from PHYs 211 and 221. MAC 222 may be configured to perform scheduling, scheduling information reporting, and priority handling between UEs using dynamic scheduling. Scheduling may be performed in gNB 220 (at MAC 222) for both downlink and uplink. MACs 212 and 222 may be configured to perform error correction using hybrid automatic repeat request (HARQ) (e.g., one HARQ entity per carrier in the case of carrier aggregation (CA)), priority handling between logical channels of UE 210 using logical channel prioritization, and / or padding. MACs 212 and 222 may support one or more parameter sets and / or transmission timing. In an example, mapping restrictions in logical channel prioritization can control which parameter sets and / or transmission timings a logical channel can use. Figure 3 As shown in FIG, MAC 212 and 222 may provide logical channels as a service to RLC 213 and 223.

[0083] PHY 211 and 221 can perform mapping of transport channels to physical channels and digital and analog signal processing functions for sending and receiving information over the air interface. These digital and analog signal processing functions may include, for example, encoding / decoding and modulation / demodulation. PHY 211 and 221 can perform multi-antenna mapping. Figure 3 As shown in , PHYs 211 and 221 may provide one or more transport channels as a service to MACs 212 and 222 .

[0084] Figure 4A An exemplary downlink data flow through the NR user plane protocol stack is shown. Figure 4AThe figure shows the downlink data flow of three IP packets (n, n+1, and m) flowing through the NR user plane protocol stack to generate two TBs at the gNB 220. The uplink data flow flowing through the NR user plane protocol stack can be the same as Figure 4A The downlink data flow is similar to that depicted in .

[0085] Figure 4A The downlink data flow of starts when the SDAP 225 receives three IP packets from one or more QoS flows and maps the three packets to radio bearers. Figure 4A In the SDAP header (in Figure 4A The data unit from / to the higher protocol layer is called the service data unit (SDU) of the lower protocol layer, and the data unit to / from the lower protocol layer is called the protocol data unit (PDU) of the higher protocol layer. Figure 4A As shown in , the data units from SDAP 225 are SDUs of the lower protocol layer PDCP 224 and are PDUs of SDAP 225 .

[0086] Figure 4A The remaining protocol layers in the Figure 3 ), add the corresponding headers and forward their corresponding output to the next lower layer. For example, PDCP 224 may perform IP header compression and encryption and forward its output to RLC 223. RLC 223 may optionally perform segmentation (e.g., Figure 4A 2) and forwards its output to the MAC 222. The MAC 222 may multiplex many RLC PDUs and may append MAC subheaders to the RLC PDUs to form a transport block. In NR, MAC subheaders may be distributed throughout the MAC PDUs, as shown in FIG. Figure 4A In LTE, the MAC subheader can be located entirely at the beginning of the MAC PDU. The NR MAC PDU structure can reduce processing time and associated latency because the MAC PDU subheader can be calculated before assembling the complete MAC PDU.

[0087] Figure 4BAn exemplary format of a MAC subheader in a MAC PDU is shown. The MAC subheader includes: an SDU length field for indicating the length (e.g., in bytes) of the MAC SDU to which the MAC subheader corresponds; a logical channel identifier (LCID) field for identifying the logical channel from which the MAC SDU originates to assist in the demultiplexing process; a flag (F) for indicating the size of the SDU length field; and a reserved bit (R) field for future use.

[0088] Figure 4B Further shown is a MAC Control Element (CE) inserted into the MAC PDU by a MAC, such as MAC 223 or MAC 222. For example, Figure 4B Two MAC CEs are shown inserted into the MAC PDU. Figure 4B ) and inserting a MAC CE at the end of a MAC PDU for uplink transmission. MAC CE may be used for in-band control signaling. Exemplary MAC CEs include: scheduling-related MAC CEs, such as buffer status reports and power headroom reports; activation / deactivation MAC CEs, such as those used for PDCP duplicate detection, channel state information (CSI) reporting, sounding reference signal (SRS) transmission, and activation / deactivation of previously configured components; discontinuous reception (DRX)-related MAC CEs; timing advance MAC CEs; and random access-related MAC CEs. A MAC subheader having a format similar to that described with respect to a MAC SDU may precede the MAC CE, and the MAC CE may be identified with a reserved value in the LCID field that indicates the type of control information included in the MAC CE.

[0089] Before describing the NR control plane protocol stack, we first describe the mapping between logical channels, transport channels, and physical channels, as well as channel types. One or more of these channels can be used to perform functions associated with the NR control plane protocol stack described later below.

[0090] Figure 5A and Figure 5BThe mapping between logical channels, transport channels and physical channels is shown for downlink and uplink respectively. Information is passed through channels between RLC, MAC and PHY of the NR protocol stack. Logical channels can be used between RLC and MAC and can be classified as control channels that carry control and configuration information in the NR control plane, or as traffic channels that carry data in the NR user plane. Logical channels can be classified as dedicated logical channels dedicated to a specific UE, or as common logical channels that can be used by more than one UE. Logical channels can also be defined by the type of information they carry. The set of logical channels defined by NR includes, for example:

[0091] - Paging Control Channel (PCCH), which is used to carry paging messages for UEs whose locations are unknown to the network at the cell level;

[0092] - Broadcast Control Channel (BCCH), which is used to carry system information messages in the form of a Master Information Block (MIB) and several System Information Blocks (SIBs), which can be used by UEs to obtain information about how a cell is configured and how it operates within the cell;

[0093] - Common Control Channel (CCCH), which is used to carry control messages and random access;

[0094] - a dedicated control channel (DCCH), which is used to carry control messages to / from a specific UE to configure that UE; and

[0095] - Dedicated Traffic Channel (DTCH), which is used to carry user data to / from a specific UE.

[0096] Transport channels are used between the MAC layer and the PHY layer and can be defined by how the information they carry is transmitted over the air interface. The set of transport channels defined by NR includes, for example:

[0097] - Paging Channel (PCH), which is used to carry paging messages originating from PCCH;

[0098] - Broadcast Channel (BCH), which is used to carry the MIB from the BCCH;

[0099] - Downlink Shared Channel (DL-SCH), which is used to carry downlink data and signaling messages, including SIBs from BCCH;

[0100] - Uplink Shared Channel (UL-SCH), which is used to carry uplink data and signaling messages; and

[0101] - Random Access Channel (RACH), which is used to allow a UE to contact the network without any previous scheduling.

[0102] The PHY may use physical channels to pass information between processing levels of the PHY. A physical channel may have a set of associated time-frequency resources for carrying information for one or more transport channels. The PHY may generate control information to support the low-level operation of the PHY and provide control information to the lower levels of the PHY via physical control channels (referred to as L1 / L2 control channels). The set of physical channels and physical control channels defined by NR includes, for example:

[0103] - Physical Broadcast Channel (PBCH), which is used to carry the MIB from the BCH;

[0104] - Physical Downlink Shared Channel (PDSCH), which is used to carry downlink data and signaling messages from DL-SCH and paging messages from PCH;

[0105] - Physical Downlink Control Channel (PDCCH), which is used to carry downlink control information (DCI), which may include downlink scheduling commands, uplink scheduling grants, and uplink power control commands;

[0106] - Physical Uplink Shared Channel (PUSCH), which is used to carry uplink data and signaling messages from the UL-SCH, and in some cases uplink control information (UCI) as described below;

[0107] - Physical Uplink Control Channel (PUCCH), which is used to carry UCI, which may include HARQ acknowledgment, channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), and scheduling request (SR); and

[0108] - Physical Random Access Channel (PRACH), which is used for random access.

[0109] Similar to the physical control channel, the physical layer generates physical signals to support the low-level operations of the physical layer. Figure 5A and Figure 5B As shown in [1], the physical layer signals defined by NR include: Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), Channel State Information Reference Signal (CSI-RS), Demodulation Reference Signal (DMRS), Sounding Reference Signal (SRS), and Phase Tracking Reference Signal (PT-RS). These physical layer signals will be described in more detail below.

[0110] Figure 2B An exemplary NR control plane protocol stack is shown. Figure 2BAs shown in FIG, the NR control plane protocol stack may use the same / similar first four protocol layers as the exemplary NR user plane protocol stack. These four protocol layers include PHY 211 and 221, MAC 212 and 222, RLC 213 and 223, and PDCP 214 and 224. Instead of having SDAP 215 and 225 at the top of the stack as in the NR user plane protocol stack, the NR control plane protocol stack instead has radio resource control (RRC) 216 and 226 and NAS protocols 217 and 237 at the top of the NR control plane protocol stack.

[0111] The NAS protocols 217 and 237 may provide control plane functionality between the UE 210 and the AMF 230 (e.g., AMF 158A), or more generally between the UE 210 and the CN. The NAS protocols 217 and 237 may provide control plane functionality between the UE 210 and the AMF 230 via signaling messages known as NAS messages. There is no direct path between the UE 210 and the AMF 230 through which NAS messages may be transmitted. NAS messages may be transmitted using the AS of the Uu and NG interfaces. The NAS protocols 217 and 237 may provide control plane functionality such as authentication, security, connection setup, mobility management, and session management.

[0112] RRCs 216 and 226 may provide control plane functionality between UE 210 and gNB 220, or more generally, between UE 210 and the RAN. RRCs 216 and 226 may provide control plane functionality between UE 210 and gNB 220 via signaling messages, referred to as RRC messages. RRC messages may be transported between UE 210 and the RAN using signaling radio bearers and the same / similar PDCP, RLC, MAC, and PHY protocol layers. MAC may multiplex control plane and user plane data into the same transport block (TB). The RRC 216 and 226 may provide control plane functions such as: broadcast of system information related to the AS and NAS; paging initiated by the CN or RAN; establishment, maintenance, and release of an RRC connection between the UE 210 and the RAN; security functions including key management; establishment, configuration, maintenance, and release of signaling radio bearers and data radio bearers; mobility functions; QoS management functions; UE measurement reporting and control of the reporting; detection of radio link failure (RLF) and recovery from radio link failure; and / or NAS messaging. As part of establishing an RRC connection, the RRC 216 and 226 may establish an RRC context, which may involve configuring parameters for communication between the UE 210 and the RAN.

[0113] Figure 6 is an example diagram showing the RRC state transition of the UE. Figure 1A The wireless device 106 depicted in Figure 2A and Figure 2B The UE 210 depicted in FIG or any other wireless device described in this disclosure is the same or similar. Figure 6 As shown in FIG, a UE may be in at least one of three RRC states: RRC connected 602 (eg, RRC_CONNECTED), RRC idle 604 (eg, RRC_IDLE), and RRC inactive 606 (eg, RRC_INACTIVE).

[0114] In RRC connection 602, the UE has an established RRC context and may have at least one RRC connection with a base station. The base station may be similar to one of the following: Figure 1A The one or more base stations included in the RAN 104 depicted in FIG; Figure 1B One of the gNB 160 or ng-eNB 162 depicted in FIG; Figure 2A and Figure 2B or any other base station described in the present disclosure. A base station connected to a UE may have an RRC context for the UE. The RRC context, referred to as the UE context, may include parameters used for communication between the UE and the base station. These parameters may include, for example: one or more AS contexts; one or more radio link configuration parameters; bearer configuration information (e.g., relating to data radio bearers, signaling radio bearers, logical channels, QoS flows, and / or PDU sessions); security information; and / or PHY, MAC, RLC, PDCP, and / or SDAP layer configuration information. While in RRC connection 602, the UE's mobility may be managed by the RAN (e.g., RAN 104 or NG-RAN 154). The UE may measure signal levels (e.g., reference signal levels) from a serving cell and neighboring cells and report these measurements to the base station currently serving the UE. The UE's serving base station may request handover to a cell of one of the neighboring base stations based on the reported measurements. The RRC state may transition from RRC connected 602 to RRC idle 604 via a connection release procedure 608 , or to RRC inactive 606 via a connection deactivation procedure 610 .

[0115] In RRC Idle 604, an RRC context may not be established for the UE. In RRC Idle 604, the UE may not have an RRC connection with a base station. While in RRC Idle 604, the UE may be in a dormant state for most of the time (e.g., to conserve battery power). The UE may periodically wake up (e.g., once per discontinuous reception cycle) to monitor for paging messages from the RAN. The UE's mobility may be managed by the UE through a procedure known as cell reselection. The RRC state may transition from RRC Idle 604 to RRC Connected 602 through a connection establishment procedure 612, which may involve a random access procedure, as discussed in more detail below.

[0116] In RRC Inactive 606, the previously established RRC context is maintained in the UE and the base station. This allows for a quick transition to RRC Connected 602 with reduced signaling overhead compared to the transition from RRC Idle 604 to RRC Connected 602. While in RRC Inactive 606, the UE may be in a sleep state, and the UE's mobility may be managed by the UE through cell reselection. The RRC state may transition from RRC Inactive 606 to RRC Connected 602 via a Connection Resumption Procedure 614, or to RRC Idle 604 via a Connection Release Procedure 616, which may be the same as or similar to the Connection Release Procedure 608.

[0117] The RRC state can be associated with mobility management mechanisms. In RRC Idle 604 and RRC Inactive 606, mobility is managed by the UE through cell reselection. The purpose of mobility management in RRC Idle 604 and RRC Inactive 606 is to allow the network to notify the UE of events via paging messages without having to broadcast paging messages across the entire mobile communications network. The mobility management mechanisms used in RRC Idle 604 and RRC Inactive 606 can allow the network to track the UE at a cell group level, so that paging messages can be broadcast to cells in the cell group in which the UE is currently residing, rather than across the entire mobile communications network. The mobility management mechanisms used in RRC Idle 604 and RRC Inactive 606 track the UE at a cell group level. These mobility management mechanisms can do so using groupings of different granularities. For example, there can be three levels of cell grouping granularity: individual cells; cells within a RAN area identified by a RAN Area Identifier (RAI); and cells within a group of RAN areas, known as tracking areas and identified by a Tracking Area Identifier (TAI).

[0118] Tracking areas can be used to track UEs at the CN level. The CN (e.g., CN 102 or 5G-CN 152) can provide the UE with a list of TAIs associated with the UE's registration area. If the UE moves to a cell associated with a TAI that is not included in the list of TAIs associated with the UE's registration area through cell reselection, the UE can perform a registration update on the CN to allow the CN to update the UE's location and provide the UE with a new UE registration area.

[0119] RAN areas can be used to track UEs at the RAN level. For a UE in the RRC Inactive 606 state, a RAN notification area can be assigned to the UE. The RAN notification area can include one or more cell identities, a list of RAIs, or a list of TAIs. In an example, a base station can belong to one or more RAN notification areas. In an example, a cell can belong to one or more RAN notification areas. If a UE moves to a cell not included in the RAN notification area assigned to the UE through cell reselection, the UE can perform a notification area update on the RAN to update the UE's RAN notification area.

[0120] The base station that stores the RRC context for the UE or the last serving base station of the UE may be referred to as the anchor base station. The anchor base station may maintain the RRC context for the UE at least for the period of time that the UE remains in the RAN notification area of ​​the anchor base station and / or for the period of time that the UE remains in RRC inactivity 606.

[0121] gNBs, such as Figure 1B The gNB 160 in the LTE network can be divided into two parts: a central unit (gNB-CU) and one or more distributed units (gNB-DUs). The gNB-CU can be coupled to one or more gNB-DUs using the F1 interface. The gNB-CU can include RRC, PDCP, and SDAP. The gNB-DU can include RLC, MAC, and PHY.

[0122] In NR, physical signals and physical channels (about Figure 5A and Figure 5BDiscussed) can be mapped onto orthogonal frequency division multiplexing (OFDM) symbols. OFDM is a multi-carrier communication scheme that transmits data over F orthogonal subcarriers (or tones). Before transmission, the data can be mapped to a series of complex symbols called source symbols (e.g., M-quadrature amplitude modulation (M-QAM) symbols or M-phase shift keying (M-PSK) symbols) and divided into F parallel symbol streams. The F parallel symbol streams can be treated as if they were in the frequency domain and used as input to an inverse fast Fourier transform (IFFT) block that transforms them into the time domain. The IFFT block can take F source symbols at a time (one source symbol from each of the F parallel symbol streams) and use each source symbol to modulate the amplitude and phase of one of the F sinusoidal basis functions corresponding to the F orthogonal subcarriers. The output of the IFFT block can be F time domain samples representing the sum of the F orthogonal subcarriers. The F time domain samples can form a single OFDM symbol. After some processing (e.g., addition of a cyclic prefix) and up-conversion, the OFDM symbols provided by the IFFT block can be transmitted over the air interface at the carrier frequency. The F parallel symbol streams can be mixed using the FFT block before being processed by the IFFT block. This operation produces discrete Fourier transform (DFT) precoded OFDM symbols and can be used by the UE in the uplink to reduce the peak-to-average power ratio (PAPR). The FFT block can be used to perform inverse processing on the OFDM symbols at the receiver to restore the data mapped to the source symbols.

[0123] Figure 7 An exemplary configuration of an NR frame into which OFDM symbols are grouped is shown. An NR frame may be identified by a system frame number (SFN). The SFN may repeat for a period of 1024 frames. As shown, an NR frame may have a duration of 10 milliseconds (ms) and may include 10 subframes of 1 ms duration. A subframe may be divided into time slots, which may include, for example, 14 OFDM symbols per time slot.

[0124] The duration of a timeslot may depend on the parameter set used for the OFDM symbol for that timeslot. In NR, flexible parameter sets are supported to accommodate different cell deployments (e.g., cells with carrier frequencies below 1 GHz, up to cells with carrier frequencies in the mmWave range). Parameter sets may be defined in terms of subcarrier spacing and cyclic prefix duration. For parameter sets in NR, the subcarrier spacing may be scaled up by two powers from a baseline subcarrier spacing of 15 kHz, and the cyclic prefix duration may be scaled down by two powers from a baseline cyclic prefix duration of 4.7 μs. For example, NR defines parameter sets with the following subcarrier spacing / cyclic prefix duration combinations: 15 kHz / 4.7 μs; 30 kHz / 2.3 μs; 60 kHz / 1.2 μs; 120 kHz / 0.59 μs; and 240 kHz / 0.29 μs.

[0125] A slot may have a fixed number of OFDM symbols (eg, 14 OFDM symbols). Parameter sets with higher subcarrier spacing have shorter slot durations and correspondingly more slots per subframe. Figure 7 The transmission structure of the time slot duration and time slot per subframe associated with the parameter set is shown (for ease of illustration, Figure 7 (The numerology with 240kHz subcarrier spacing is not shown in the figure). The subframe in NR can be used as a time reference independent of the numerology, while the slot can be used as the unit for scheduling uplink and downlink transmissions. To support low latency, scheduling in NR can be decoupled from the slot duration and start at any OFDM symbol and continue for as many symbols as needed. These partial slot transmissions can be called mini-slots or sub-slot transmissions.

[0126] Figure 8 An exemplary configuration of a time slot in the time and frequency domains of an NR carrier is shown. The time slot includes a resource element (RE) and a resource block (RB). RE is the smallest physical resource in NR. RE spans one OFDM symbol in the time domain through one subcarrier in the frequency domain, as shown in FIG. Figure 8 As shown in . RB spans twelve consecutive REs in the frequency domain, as Figure 8 As shown. The NR carrier can be limited to a width of 275RB or 275×12=3300 subcarriers. If this restriction is used, the NR carrier can be limited to 50, 100, 200 and 400 MHz for subcarrier spacing of 15, 30, 60 and 120 kHz, respectively, where the 400 MHz bandwidth can be set based on the 400 MHz bandwidth limit per carrier.

[0127] Figure 8A single parameter set is shown used across the entire bandwidth of the NR carrier. In other example configurations, multiple parameter sets may be supported on the same carrier.

[0128] NR can support wide carrier bandwidths (e.g., up to 400 MHz for a 120 kHz subcarrier spacing). Not all UEs may be able to receive the full carrier bandwidth (e.g., due to hardware limitations). Moreover, receiving the full carrier bandwidth may be prohibitive in terms of UE power consumption. In an example, to reduce power consumption and / or for other purposes, the UE can adapt the size of the UE's receive bandwidth based on the amount of traffic the UE plans to receive. This is called bandwidth adaptation.

[0129] NR defines bandwidth parts (BWPs) to support UEs that cannot receive the full carrier bandwidth and to support bandwidth adaptation. In an example, a BWP can be defined by a subset of contiguous RBs on a carrier. The UE can be configured (e.g., via the RRC layer) with one or more downlink BWPs and one or more uplink BWPs per serving cell (e.g., up to four downlink BWPs and up to four uplink BWPs per serving cell). At a given time, one or more of the configured BWPs for a serving cell can be active. The one or more BWPs can be referred to as the active BWPs of the serving cell. When a serving cell is configured with a secondary uplink carrier, the serving cell can have one or more first active BWPs in the uplink carrier and one or more second active BWPs in the secondary uplink carrier.

[0130] For unpaired spectrum, a downlink BWP from the set of configured downlink BWPs may be linked with an uplink BWP from the set of configured uplink BWPs if the downlink BWP index of the downlink BWP is the same as the uplink BWP index of the uplink BWP. For unpaired spectrum, the UE may expect the center frequency of the downlink BWP to be the same as the center frequency of the uplink BWP.

[0131] For a downlink BWP in the set of configured downlink BWPs on a primary cell (PCell), the base station can configure the UE with one or more control resource sets (CORESETs) for at least one search space. A search space is a set of locations in the time and frequency domain where a UE can search for control information. A search space can be a UE-specific search space or a common search space (potentially usable by multiple UEs). For example, the base station can configure a common search space for a UE on a PCell or a primary / secondary cell (PSCell) in an active downlink BWP.

[0132] For an uplink BWP in a set of configured uplink BWPs, the BS may configure one or more resource sets for the UE for one or more PUCCH transmissions. The UE may receive downlink transmissions (e.g., PDCCH or PDSCH) in the downlink BWP based on the configured parameter set for the downlink BWP (e.g., subcarrier spacing and cyclic prefix duration). The UE may transmit uplink transmissions (e.g., PUCCH or PUSCH) in the uplink BWP based on the configured parameter set (e.g., subcarrier spacing and cyclic prefix length of the uplink BWP).

[0133] One or more BWP indicator fields may be provided in downlink control information (DCI). The value of the BWP indicator field may indicate which BWP in a set of configured BWPs is the active downlink BWP for one or more downlink receptions. The value of the one or more BWP indicator fields may indicate the active uplink BWP for one or more uplink transmissions.

[0134] The base station may semi-statically configure a default downlink BWP for the UE within the set of configured downlink BWPs associated with the PCell. If the base station does not provide a default downlink BWP to the UE, the default downlink BWP may be the initial active downlink BWP. The UE may determine which BWP is the initial active downlink BWP based on the CORESET configuration obtained using the PBCH.

[0135] The base station may configure the BWP inactivity timer value for the PCell for the UE. The UE may start or restart the BWP inactivity timer at any appropriate time. For example, the UE may start or restart the BWP inactivity timer in the following circumstances: (a) when the UE detects a DCI indicating an active downlink BWP other than the default downlink BWP for paired spectrum operation; or (b) when the UE detects a DCI indicating an active downlink BWP or an active uplink BWP other than the default downlink BWP or uplink BWP for unpaired spectrum operation. If the UE does not detect the DCI within a time interval (e.g., 1 ms or 0.5 ms), the UE may run the BWP inactivity timer towards expiration (e.g., incrementing the BWP inactivity timer value from zero to, or decrementing the BWP inactivity timer value from zero). When the BWP inactivity timer expires, the UE may switch from the active downlink BWP to the default downlink BWP.

[0136] In an example, the base station may semi-statically configure the UE with one or more BWPs. The UE may switch the active BWP from the first BWP to the second BWP in response to receiving a DCI indicating that the second BWP is the active BWP and / or in response to expiration of a BWP inactivity timer (e.g., when the second BWP is the default BWP).

[0137] Downlink and uplink BWP switching can be performed independently in paired spectrum (where BWP switching refers to switching from the currently active BWP to the non-currently active BWP). In unpaired spectrum, downlink and uplink BWP switching can be performed simultaneously. Switching between configured BWPs can occur based on RRC signaling, DCI, expiration of the BWP inactivity timer, and / or initiation of random access.

[0138] Figure 9 An example of bandwidth adaptation using three configured BWPs of an NR carrier is shown. A UE configured with these three BWPs can switch from one BWP to another at a switching point. Figure 9 In the example shown in , the BWPs include: BWP 902, with a bandwidth of 40 MHz and a subcarrier spacing of 15 kHz; BWP 904, with a bandwidth of 10 MHz and a subcarrier spacing of 15 kHz; and BWP 906, with a bandwidth of 20 MHz and a subcarrier spacing of 60 kHz. BWP 902 may be the initial active BWP, and BWP 904 may be the default BWP. The UE may switch between BWPs at a switching point. Figure 9 In the example shown in FIG. 1 , the UE may switch from BWP 902 to BWP 904 at switch point 908. The switch at switch point 908 may occur for any suitable reason, such as in response to expiration of a BWP inactivity timer (indicating a switch to a default BWP) and / or in response to receiving a DCI indicating that BWP 904 is the active BWP. The UE may switch from active BWP 904 to BWP 906 at switch point 910 in response to receiving a DCI indicating that BWP 906 is the active BWP. The UE may switch from active BWP 906 to BWP 904 at switch point 912 in response to expiration of a BWP inactivity timer and / or in response to receiving a DCI indicating that BWP 904 is the active BWP. The UE may switch from active BWP 904 to BWP 902 at switch point 914 in response to receiving a DCI indicating that BWP 902 is the active BWP.

[0139] If the UE is configured for a secondary cell with a default downlink BWP and timer values ​​from the set of configured downlink BWPs, the UE procedures for switching the BWP on the secondary cell may be the same / similar to those on the primary cell. For example, the UE may use the timer values ​​and default downlink BWP for the secondary cell in the same / similar manner as the UE would use these values ​​for the primary cell.

[0140] To provide higher data rates, carrier aggregation (CA) can be used to aggregate two or more carriers and transmit them simultaneously to / from the same UE. The aggregated carriers in CA may be referred to as component carriers (CCs). When CA is used, there are many serving cells for the UE, one for each CC. CCs can have three configurations in the frequency domain.

[0141] Figure 10A Three CA configurations with two CCs are shown. In the intra-band contiguous configuration 1002, the two CCs are aggregated in the same frequency band (Band A) and located directly adjacent to each other within the band. In the intra-band non-contiguous configuration 1004, the two CCs are aggregated in the frequency band (Band A) and separated by a gap within the band. In the inter-band configuration 1006, the two CCs are located in frequency bands (Band A and Band B).

[0142] In an example, up to 32 CCs can be aggregated. Aggregated CCs can have the same or different bandwidths, subcarrier spacing, and / or duplexing schemes (TDD or FDD). A serving cell for a UE using CA can have downlink CCs. For FDD, one or more uplink CCs can optionally be configured for the serving cell. For example, the ability to aggregate more downlink carriers than uplink carriers can be useful when the UE has more data traffic in the downlink than in the uplink.

[0143] When CA is used, one of the aggregated cells for a UE may be referred to as a primary cell (PCell). The PCell may be the serving cell to which the UE initially connects at RRC connection establishment, re-establishment, and / or handover. The PCell may provide NAS mobility information and security input to the UE. The UE may have different PCells. In the downlink, the carrier corresponding to the PCell may be referred to as a downlink primary CC (DL PCC). In the uplink, the carrier corresponding to the PCell may be referred to as an uplink primary CC (UL PCC). Other aggregated cells for the UE may be referred to as secondary cells (SCells). In an example, the SCell may be configured after the PCell is configured for the UE. For example, the SCell may be configured through an RRC connection reconfiguration procedure. In the downlink, the carrier corresponding to the SCell may be referred to as a downlink secondary CC (DL SCC). In the uplink, the carrier corresponding to the SCell may be referred to as an uplink secondary CC (UL SCC).

[0144] The configured SCell for a UE can be activated and deactivated based on, for example, traffic and channel conditions. Deactivation of an SCell can mean stopping PDCCH and PDSCH reception on the SCell, and stopping PUSCH, SRS, and CQI transmission on the SCell. Figure 4B The configured SCells may be activated and deactivated using a MAC CE. For example, the MAC CE may use a bitmap (e.g., one bit per SCell) to indicate which SCells (e.g., a subset of configured SCells) are activated or deactivated for the UE. The configured SCells may be deactivated in response to the expiration of an SCell deactivation timer (e.g., one SCell deactivation timer per SCell).

[0145] The downlink control information of a cell (such as scheduling assignments and scheduling grants) can be transmitted on the cell corresponding to the assignment and grant, which is called self-scheduling. The DCI of a cell can be transmitted on another cell, which is called cross-carrier scheduling. The uplink control information for the aggregated cell (e.g., HARQ confirmation and channel state feedback, such as CQI, PMI and / or RI) can be transmitted on the PUCCH of the PCell. For a large number of aggregated downlink CCs, the PUCCH of the PCell may become overloaded. The cell can be divided into multiple PUCCH groups.

[0146] Figure 10B An example of how aggregated cells can be configured into one or more PUCCH groups is shown. PUCCH group 1010 and PUCCH group 1050 may each include one or more downlink CCs. Figure 10B In the example of FIG, PUCCH group 1010 includes three downlink CCs: PCell 1011, SCell 1012, and SCell 1013. PUCCH group 1050 in this example includes three downlink CCs: PCell 1051, SCell 1052, and SCell 1053. One or more uplink CCs may be configured as PCell 1021, SCell 1022, and SCell 1023. One or more other uplink CCs may be configured as primary Scell ​​(PSCell) 1061, SCell 1062, and SCell 1063. Uplink control information (UCI) related to the downlink CCs of PUCCH group 1010 (shown as UCI 1031, UCI 1032, and UCI 1033) may be transmitted in the uplink of PCell 1021. Uplink control information (UCI) related to the downlink CCs of PUCCH group 1050 (shown as UCI 1071, UCI 1072, and UCI 1073) may be transmitted in the uplink of PSCell 1061. In this example, if Figure 10B If the aggregated cell depicted in FIG is not divided into PUCCH group 1010 and PUCCH group 1050, a single uplink PCell transmits UCI associated with the downlink CC and the PCell may become overloaded. Overload can be prevented by dividing the transmission of UCI between PCell 1021 and PSCell 1061.

[0147] A physical cell ID and a cell index may be assigned to a cell comprising a downlink carrier and an optional uplink carrier. The physical cell ID or cell index may identify the downlink carrier and / or uplink carrier of the cell, for example, depending on the context in which the physical cell ID is used. The physical cell ID may be determined using a synchronization signal transmitted on a downlink component carrier. The cell index may be determined using an RRC message. In the present disclosure, the physical cell ID may be referred to as a carrier ID, and the cell index may be referred to as a carrier index. For example, when the present disclosure refers to a first physical cell ID of a first downlink carrier, the present disclosure may mean that the first physical cell ID is for a cell comprising the first downlink carrier. The same / similar concepts may apply, for example, to carrier activation. When the present disclosure indicates that a first carrier is activated, the present specification may mean that a cell comprising the first carrier is activated.

[0148] In carrier aggregation, the multi-carrier nature of the PHY can be exposed to the MAC. In an example, the HARQ entity can operate on the serving cell. A transport block can be generated based on the assignment / grant of each serving cell. A transport block and potential HARQ retransmissions of the transport block can be mapped to the serving cell.

[0149] In the downlink, the base station may transmit (e.g., unicast, multicast, and / or broadcast) one or more reference signals (RS) to the UE (e.g., PSS, SSS, CSI-RS, DMRS, and / or PT-RS, such as Figure 5A In the uplink, the UE may transmit one or more RSs to the base station (e.g., DMRS, PT-RS, and / or SRS, as shown in FIG. Figure 5B (as shown). The PSS and SSS may be transmitted by a base station and used by a UE to synchronize the UE with the base station. The PSS and SSS may be provided in a synchronization signal (SS) / physical broadcast channel (PBCH) block that includes the PSS, SSS, and PBCH. The base station may periodically transmit bursts of SS / PBCH blocks.

[0150] Figure 11A An example of the structure and location of SS / PBCH blocks is shown. A burst of SS / PBCH blocks may include one or more SS / PBCH blocks (e.g., 4 SS / PBCH blocks, such as Figure 11A ). The burst may be transmitted periodically (e.g., every 2 frames or 20 ms). The burst may be limited to half a frame (e.g., the first half frame having a duration of 5 ms). It will be understood that Figure 11A are examples, and these parameters (number of SS / PBCH blocks per burst, periodicity of bursts, burst position within a frame) may be configured based on, for example: the carrier frequency of the cell in which the SS / PBCH blocks are transmitted; the parameter set or subcarrier spacing of the cell; configuration by the network (e.g., using RRC signaling); or any other suitable factor. In an example, the UE may assume the subcarrier spacing of the SS / PBCH blocks based on the carrier frequency being monitored unless the radio network configures the UE to assume a different subcarrier spacing.

[0151] SS / PBCH blocks may span one or more OFDM symbols in the time domain (e.g., 4 OFDM symbols, e.g., Figure 11A) and may span one or more subcarriers in the frequency domain (e.g., 240 consecutive subcarriers). The PSS, SSS, and PBCH may have a common center frequency. The PSS may be transmitted first and may span, for example, 1 OFDM symbol and 127 subcarriers. The SSS may be transmitted after the PSS (e.g., two symbols later) and may span 1 OFDM symbol and 127 subcarriers. The PBCH may be transmitted after the PSS (e.g., spanning the next 3 OFDM symbols) and may span 240 subcarriers.

[0152] The UE may not know the location of the SS / PBCH blocks in the time and frequency domain (for example, when the UE is searching for a cell). In order to find and select a cell, the UE may monitor the carrier of the PSS. For example, the UE may monitor the frequency position within the carrier. If no PSS is found after a certain duration (for example, 20ms), the UE may search for the PSS at different frequency positions within the carrier, as indicated by the synchronization raster. If the PSS is found at a certain position in the time and frequency domain, the UE may determine the location of the SSS and PBCH based on the known structure of the SS / PBCH block, respectively. The SS / PBCH block may be a cell definition SS block (CD-SSB). In an example, the primary cell may be associated with the CD-SSB. The CD-SSB may be located on the synchronization raster. In an example, cell selection / search and / or reselection may be based on the CD-SSB.

[0153] The SS / PBCH block can be used by the UE to determine one or more parameters of the cell. For example, the UE can determine the physical cell identifier (PCI) of the cell based on the sequence of the PSS and SSS, respectively. The UE can determine the location of the cell's frame boundary based on the location of the SS / PBCH block. For example, the SS / PBCH block can indicate that it has been transmitted according to a transmission mode in which the SS / PBCH block is a known distance from the frame boundary.

[0154] The PBCH may use QPSK modulation and forward error correction (FEC). FEC may use polarity coding. One or more symbols spanned by the PBCH may carry one or more DMRS for demodulating the PBCH. The PBCH may include an indication of the current system frame number (SFN) of the cell and / or an SS / PBCH block timing index. These parameters may facilitate time synchronization between the UE and the base station. The PBCH may include a master information block (MIB) for providing one or more parameters to the UE. The MIB may be used by the UE to locate the remaining minimum system information (RMSI) associated with the cell. The RMSI may include a system information block type 1 (SIB1). SIB1 may contain information required for the UE to access the cell. The UE may use one or more parameters of the MIB to monitor the PDCCH that may be used to schedule the PDSCH. The PDSCH may include SIB1. SIB1 may be decoded using the parameters provided in the MIB. The PBCH may indicate that SIB1 does not exist. Based on the PBCH indicating that SIB1 does not exist, the UE may point to a frequency. The UE may search for SS / PBCH blocks at the frequency to which the UE is pointed.

[0155] The UE may assume that one or more SS / PBCH blocks transmitted with the same SS / PBCH block index are quasi-co-located (QCLed) (e.g., having the same / similar Doppler spread, Doppler shift, average gain, average delay, and / or spatial Rx parameters). The UE may not assume QCL for SS / PBCH blocks transmitted with different SS / PBCH block indices.

[0156] SS / PBCH blocks (e.g., those within a half-frame) may be transmitted in spatial directions (e.g., using different beams across the coverage area of ​​the cell). In an example, a first SS / PBCH block may be transmitted in a first spatial direction using a first beam, and a second SS / PBCH block may be transmitted in a second spatial direction using a second beam.

[0157] In an example, a base station may transmit multiple SS / PBCH blocks within a frequency range of a carrier. In an example, a first PCI of a first SS / PBCH block of the multiple SS / PBCH blocks may be different from a second PCI of a second SS / PBCH block of the multiple SS / PBCH blocks. The PCIs of SS / PBCH blocks transmitted in different frequency locations may be different or the same.

[0158] The CSI-RS may be transmitted by a base station and used by a UE to obtain channel state information (CSI). The base station may configure the UE with one or more CSI-RS for channel estimation or any other suitable purpose. The base station may configure the UE with one or more of the same / similar CSI-RS. The UE may measure the one or more CSI-RS. The UE may estimate the downlink channel state and / or generate a CSI report based on the measurement of the one or more downlink CSI-RS. The UE may provide the CSI report to the base station. The base station may use the feedback provided by the UE (e.g., the estimated downlink channel state) to perform link adaptation.

[0159] The base station can semi-statically configure the UE with one or more CSI-RS resource sets. CSI-RS resources can be associated with a location in the time and frequency domains and a periodicity. The base station can selectively activate and / or deactivate CSI-RS resources. The base station can indicate to the UE that CSI-RS resources in a CSI-RS resource set are activated and / or deactivated.

[0160] The base station can configure the UE to report CSI measurement values. The base station can configure the UE to provide CSI reports periodically, aperiodically, or semi-persistently. For periodic CSI reporting, the UE can be configured with the timing and / or periodicity of multiple CSI reports. For aperiodic CSI reporting, the base station can request a CSI report. For example, the base station can command the UE to measure the configured CSI-RS resources and provide a CSI report related to the measurement values. For semi-persistent CSI reporting, the base station can configure the UE to transmit periodically and selectively activate or deactivate periodic reporting. The base station can configure the UE with a CSI-RS resource set and CSI reporting using RRC signaling.

[0161] The CSI-RS configuration may include one or more parameters indicating, for example, up to 32 antenna ports. The UE may be configured to use the same OFDM symbol for the downlink CSI-RS and control resource set (CORESET) when the downlink CSI-RS and CORESET are spatially QCLed and the resource elements associated with the downlink CSI-RS are outside the physical resource blocks (PRBs) configured for the CORESET. The UE may be configured to use the same OFDM symbol for the downlink CSI-RS and SS / PBCH blocks when the downlink CSI-RS and SS / PBCH blocks are spatially QCLed and the resource elements associated with the downlink CSI-RS are outside the PRBs configured for the SS / PBCH blocks.

[0162] Downlink DMRS can be transmitted by the base station and used by the UE for channel estimation. For example, downlink DMRS can be used for consistent demodulation of one or more downlink physical channels (e.g., PDSCH). The NR network can support one or more variable and / or configurable DMRS patterns for data demodulation. At least one downlink DMRS configuration can support a frontload DMRS pattern. The frontload DMRS can be mapped on one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). The base station can semi-statically configure the UE with the number (e.g., maximum number) of frontload DMRS symbols used for PDSCH. The DMRS configuration can support one or more DMRS ports. For example, for single-user MIMO, the DMRS configuration can support up to eight orthogonal downlink DMRS ports per UE. For multi-user MIMO, the DMRS configuration can support up to four orthogonal downlink DMRS ports per UE. The radio network can (e.g., at least for CP-OFDM) support a common DMRS structure for downlink and uplink, where the DMRS positions, DMRS patterns, and / or scrambling sequences can be the same or different. The base station may use the same precoding matrix to transmit the downlink DMRS and the corresponding PDSCH. The UE may use the one or more downlink DMRSs to perform consistent demodulation / channel estimation on the PDSCH.

[0163] In an example, a transmitter (e.g., a base station) may use a precoder matrix for a portion of the transmission bandwidth. For example, the transmitter may use a first precoder matrix for a first bandwidth and a second precoder matrix for a second bandwidth. The first precoder matrix and the second precoder matrix may be different based on the first bandwidth being different from the second bandwidth. The UE may assume that the same precoding matrix is ​​used across a set of PRBs. The set of PRBs may be denoted as a precoding resource block group (PRG).

[0164] The PDSCH may include one or more layers. The UE may assume that at least one symbol with DMRS is present on a layer in the one or more layers of the PDSCH. Higher layers may configure up to three DMRS for the PDSCH.

[0165] The downlink PT-RS may be transmitted by the base station and used by the UE for phase noise compensation. The presence or absence of the downlink PT-RS may depend on the RRC configuration. The presence and / or pattern of the downlink PT-RS may be configured on a UE-specific basis through a combination of RRC signaling and / or association with one or more parameters that may be indicated by the DCI for other purposes (e.g., modulation and coding scheme (MCS)). When configured, the dynamic presence of the downlink PT-RS may be associated with one or more DCI parameters including at least the MCS. NR networks may support multiple PT-RS densities defined in the time / frequency domain. When present, the frequency domain density may be associated with at least one configuration of the scheduled bandwidth. The UE may use the same precoding for both DMRS ports and PT-RS ports. The number of PT-RS ports may be less than the number of DMRS ports in the scheduled resources. The downlink PT-RS may be restricted to the scheduled time / frequency duration of the UE. The downlink PT-RS may be transmitted on a symbol to facilitate phase tracking at the receiver.

[0166] The UE may transmit an uplink DMRS to the base station for channel estimation. For example, the base station may use the uplink DMRS to uniformly demodulate one or more uplink physical channels. For example, the UE may transmit an uplink DMRS with a PUSCH and / or a PUCCH. The uplink DM-RS may span a frequency range similar to the frequency range associated with the corresponding physical channel. The base station may configure the UE with one or more uplink DMRS configurations. At least one DMRS configuration may support a frontload DMRS pattern. The frontload DMRS may be mapped on one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). One or more uplink DMRS may be configured to be transmitted at one or more symbols of the PUSCH and / or PUCCH. The base station may semi-statically configure the UE with the number (e.g., maximum number) of frontload DMRS symbols for the PUSCH and / or PUCCH, and the UE may use the frontload DMRS symbols to schedule single-symbol DMRS and / or double-symbol DMRS. NR networks may support a common DMRS structure for downlink and uplink (e.g., for cyclic prefix orthogonal frequency division multiplexing (CP-OFDM)), where the DMRS positions, DMRS patterns, and / or scrambling sequences of the DMRS may be the same or different.

[0167] The PUSCH may include one or more layers, and the UE may transmit at least one symbol having a DMRS present on a layer in the one or more layers of the PUSCH. In an example, a higher layer may configure up to three DMRSs for the PUSCH.

[0168] Depending on the RRC configuration of the UE, the uplink PT-RS (which can be used by the base station for phase tracking and / or phase noise compensation) may or may not be present. The presence and / or pattern of the uplink PT-RS can be configured based on the UE specific configuration through a combination of RRC signaling and / or one or more parameters indicated by the DCI for other purposes (e.g., modulation and coding scheme (MCS)). When configured, the dynamic presence of the uplink PT-RS can be associated with one or more DCI parameters including at least the MCS. The radio network can support multiple uplink PT-RS densities defined in the time / frequency domain. When present, the frequency domain density can be associated with at least one configuration of the scheduled bandwidth. The UE can use the same precoding for DMRS ports and PT-RS ports. The number of PT-RS ports can be less than the number of DMRS ports in the scheduled resources. For example, the uplink PT-RS can be restricted to the scheduled time / frequency duration of the UE.

[0169] The UE may transmit an SRS to the base station for channel state estimation to support uplink channel-dependent scheduling and / or link adaptation. The SRS transmitted by the UE may allow the base station to estimate the uplink channel state at one or more frequencies. The scheduler at the base station may use the estimated uplink channel state to assign one or more resource blocks for uplink PUSCH transmission from the UE. The base station may semi-statically configure the UE with one or more SRS resource sets. For an SRS resource set, the base station may configure the UE with one or more SRS resources. The applicability of the SRS resource set may be configured by a higher layer (e.g., RRC) parameter. For example, when the higher layer parameter indicates beam management, the SRS resources in the SRS resource set in the one or more SRS resource sets (e.g., having the same / similar time domain behavior, periodic, aperiodic, etc.) may be transmitted at a certain time (e.g., at the same time). The UE may transmit one or more SRS resources in the SRS resource set. The NR network may support aperiodic, periodic, and / or semi-persistent SRS transmission. The UE may transmit SRS resources based on one or more trigger types, wherein the one or more trigger types may include higher layer signaling (e.g., RRC) and / or one or more DCI formats. In an example, at least one DCI format may be used for the UE to select at least one configured SRS resource set from one or more configured SRS resource sets. SRS trigger type 0 may refer to SRS triggered based on higher layer signaling. SRS trigger type 1 may refer to SRS triggered based on one or more DCI formats. In an example, when PUSCH and SRS are transmitted in the same time slot, the UE may be configured to transmit SRS after the transmission of PUSCH and the corresponding uplink DMRS.

[0170] The base station can semi-statically configure the UE using one or more SRS configuration parameters indicating at least one of the following: an SRS resource configuration identifier; the number of SRS ports; the time domain behavior of the SRS resource configuration (e.g., an indication of periodic, semi-persistent, or aperiodic SRS); time slot, mini-slot, and / or subframe level periodicity; time slot of periodic and / or aperiodic SRS resources; the number of OFDM symbols in the SRS resources; the starting OFDM symbol of the SRS resources; the SRS bandwidth; the frequency hopping bandwidth; the cyclic shift; and / or the SRS sequence ID.

[0171] Antenna ports are defined such that the channel over which a symbol on the antenna port is communicated can be inferred from the channel over which another symbol on the same antenna port is communicated. If a first symbol and a second symbol are transmitted on the same antenna port, the receiver can infer the channel (e.g., fading gain, multipath delay, etc.) used to communicate the second symbol on the antenna port from the channel used to communicate the first symbol on the antenna port. If one or more large-scale properties of the channel over which the first symbol on the first antenna port is communicated can be inferred from the channel over which the second symbol on the second antenna port is communicated, the first antenna port and the second antenna port can be referred to as quasi-co-located (QCLed). The one or more large-scale properties may include at least one of the following: delay spread; Doppler spread; Doppler shift; average gain; average delay; and / or spatial receive (Rx) parameters.

[0172] Channels using beamforming require beam management. Beam management can include beam measurement, beam selection, and beam indication. A beam can be associated with one or more reference signals. For example, a beam can be identified by one or more beamforming reference signals. The UE can perform downlink beam measurements and generate beam measurement reports based on downlink reference signals (e.g., channel state information reference signals (CSI-RS)). After setting up an RRC connection with a base station, the UE can perform a downlink beam measurement procedure.

[0173] Figure 11B An example of a channel state information reference signal (CSI-RS) mapped in the time and frequency domain is shown. Figure 11BThe squares shown in the figure may represent resource blocks (RBs) within the bandwidth of the cell. The base station may transmit one or more RRC messages including CSI-RS resource configuration parameters indicating one or more CSI-RSs. One or more of the following parameters may be configured for the CSI-RS resource configuration via higher layer signaling (e.g., RRC and / or MAC signaling): CSI-RS resource configuration identity, number of CSI-RS ports, CSI-RS configuration (e.g., symbol and resource element (RE) positions in a subframe), CSI-RS subframe configuration (e.g., subframe position, offset, and periodicity in a radio frame), CSI-RS power parameters, CSI-RS sequence parameters, code division multiplexing (CDM) type parameters, frequency density, transmission comb, quasi co-location (QCL) parameters (e.g., QCL-scramblingidentity, crs-portscount, mbsfn-subframeconfiglist, csi-rs-configZPid, qcl-csi-rs-configNZPid), and / or other radio resource parameters.

[0174] Figure 11B The three beams shown may be configured for a UE in a UE-specific configuration. Figure 11B Three beams (beam #1, beam #2, and beam #3) are shown in the figure, and more or fewer beams can be configured. CSI-RS 1101 can be allocated to beam #1, which can be transmitted in one or more subcarriers in the RB of the first symbol. CSI-RS 1102 can be allocated to beam #2, which can be transmitted in one or more subcarriers in the RB of the second symbol. CSI-RS 1103 can be allocated to beam #3, which can be transmitted in one or more subcarriers in the RB of the third symbol. By using frequency division multiplexing (FDM), the base station can use other subcarriers in the same RB (for example, those subcarriers not used to transmit CSI-RS 1101) to transmit another CSI-RS associated with the beam of another UE. By using time domain multiplexing (TDM), the beam for the UE can be configured so that the beam for the UE uses symbols from the beam of the other UE.

[0175] CSI-RS, such as Figure 11BThose shown in (e.g., CSI-RS 1101, 1102, 1103) can be transmitted by a base station and used by a UE for one or more measurement values. For example, the UE can measure the reference signal received power (RSRP) of the configured CSI-RS resource. The base station can configure the UE with a reporting configuration, and the UE can report the RSRP measurement value to the network (e.g., via one or more base stations) based on the reporting configuration. In the example, the base station can determine one or more transmission configuration indication (TCI) states including multiple reference signals based on the reported measurement results. In the example, the base station can indicate one or more TCI states to the UE (e.g., via RRC signaling, MAC CE and / or DCI). The UE can receive a downlink transmission with a receive (Rx) beam determined based on the one or more TCI states. In the example, the UE may or may not have beam correspondence capability. If the UE has beam correspondence capability, the UE can determine the spatial domain filter of the transmit (Tx) beam based on the spatial domain filter of the corresponding Rx beam. If the UE does not have beam-matching capability, the UE may perform an uplink beam selection procedure to determine the spatial domain filter for the Tx beam. The UE may perform the uplink beam selection procedure based on one or more sounding reference signal (SRS) resources configured for the UE by the base station. The base station may select and instruct the UE on an uplink beam based on measurements of one or more SRS resources transmitted by the UE.

[0176] In the beam management procedure, the UE may assess (e.g., measure) the channel quality of one or more beam pair links, including the beam pair links of the transmit beam transmitted by the base station and the receive beam received by the UE. Based on the assessment, the UE may transmit a beam measurement report indicating one or more beam pair quality parameters, including, for example, one or more beam identifiers (e.g., beam index, reference signal index, etc.), RSRP, precoding matrix indicator (PMI), channel quality indicator (CQI), and / or rank indicator (RI).

[0177] Figure 12AExamples of three downlink beam management procedures are shown: P1, P2, and P3. Procedure P1 can enable UE measurements of transmit (Tx) beams of a transmit reception point (TRP) (or multiple TRPs), for example to support selection of one or more base station Tx beams and / or UE Rx beams (shown as ovals in the top and bottom rows of P1, respectively). Beamforming at the TRP can include Tx beam sweeping for a set of beams (shown as ovals rotating in a counterclockwise direction indicated by dashed arrows in the top rows of P1 and P2). Beamforming at the UE can include Rx beam sweeping for a set of beams (shown as ovals rotating in a clockwise direction indicated by dashed arrows in the bottom rows of P1 and P3). Procedure P2 can be used to enable UE measurements of Tx beams of the TRPs (shown as ovals rotating in a counterclockwise direction indicated by dashed arrows in the top row of P2). The UE and / or base station may perform procedure P2 using a smaller beam set than the beam set used in procedure P1, or using a narrower beam than the beam used in procedure P1. This may be referred to as beam refinement. The UE may perform procedure P3 for Rx beam determination by using the same Tx beam at the base station and sweeping the Rx beam at the UE.

[0178] Figure 12B Examples of three uplink beam management procedures are shown: U1, U2, and U3. Procedure U1 can be used to enable a base station to perform measurements on a UE's Tx beam, for example, to support selection of one or more UE Tx beams and / or base station Rx beams (shown as ovals in the top and bottom rows of U1, respectively). Beamforming at the UE can include, for example, Rx beam sweeping from a set of beams (shown as ovals rotating in a clockwise direction indicated by dashed arrows in the bottom rows of U1 and U3). Beamforming at the base station can include, for example, Rx beam sweeping from a set of beams (shown as ovals rotating in a counterclockwise direction indicated by dashed arrows in the top rows of U1 and U2). When the UE uses a fixed Tx beam, procedure U2 can be used to enable the base station to adjust its Rx beam. The UE and / or base station can perform procedure U2 using a smaller beam set than the beam set used in procedure P1, or using a narrower beam than the beam used in procedure P1. This may be referred to as beam refinement. The UE may perform procedure U3 to adjust its Tx beam when the base station uses a fixed Rx beam.

[0179] The UE may initiate a beam failure recovery (BFR) procedure based on the detection of a beam failure. The UE may transmit a BFR request (e.g., preamble, UCI, SR, MAC CE, etc.) based on the initiation of the BFR procedure. The UE may detect a beam failure based on a determination that the quality of the beam-pair link of the associated control channel is unsatisfactory (e.g., having an error rate above an error rate threshold, a received signal power below a received signal power threshold, expiration of a timer, etc.).

[0180] The UE may measure the quality of a beam-pair link using one or more reference signals (RS), the one or more reference signals including one or more SS / PBCH blocks, one or more CSI-RS resources and / or one or more demodulation reference signals (DMRS). The quality of a beam-pair link may be based on one or more of the following: a block error rate (BLER), an RSRP value, a signal-to-interference-plus-noise ratio (SINR) value, a reference signal received quality (RSRQ) value and / or a CSI value measured on an RS resource. The base station may indicate that the RS resource is quasi-co-located (QCLed) with one or more DM-RSs of a channel (e.g., a control channel, a shared data channel, etc.). When the channel characteristics (e.g., Doppler shift, Doppler spread, average delay, delay spread, spatial Rx parameters, fading, etc.) from the transmission to the UE via the RS resource are similar or identical to the channel characteristics from the transmission to the UE via the channel, the RS resource and the one or more DMRSs of the channel may be QCLed.

[0181] The network (e.g., gNB and / or ng-eNB of the network) and / or the UE may initiate a random access procedure. A UE in RRC_IDLE state and / or RRC_INACTIVE state may initiate a random access procedure to request connection setup to the network. The UE may initiate a random access procedure from the RRC_CONNECTED state. The UE may initiate a random access procedure to request uplink resources (e.g., uplink transmission for SR when there are no available PUCCH resources) and / or to obtain uplink timing (e.g., when the uplink synchronization state is not synchronized). The UE may initiate a random access procedure to request one or more system information blocks (SIBs) (e.g., other system information, such as SIB2, SIB3, etc.). The UE may initiate a random access procedure for a beam failure recovery request. The network may initiate a random access procedure for handover and / or for establishing timing alignment for SCell addition.

[0182] Figure 13A A four-step contention-based random access procedure is shown. Before initiating the procedure, the base station may transmit a configuration message 1310 to the UE. Figure 13AThe procedure shown includes the transmission of four messages: Msg 1 1311, Msg 2 1312, Msg 3 1313, and Msg 4 1314. Msg 1 1311 may include and / or be referred to as a preamble (or random access preamble). Msg 2 1312 may include and / or be referred to as a random access response (RAR).

[0183] The configuration message 1310 may be transmitted, for example, using one or more RRC messages. The one or more RRC messages may indicate one or more random access channel (RACH) parameters to the UE. The one or more RACH parameters may include at least one of the following: general parameters for one or more random access procedures (e.g., RACH-configGeneral); cell-specific parameters (e.g., RACH-ConfigCommon); and / or dedicated parameters (e.g., RACH-configDedicated). The base station may broadcast or multicast the one or more RRC messages to one or more UEs. The one or more RRC messages may be UE-specific (e.g., dedicated RRC messages transmitted to the UE in the RRC_CONNECTED state and / or the RRC_INACTIVE state). The UE may determine the time-frequency resources and / or uplink transmission power for transmitting Msg 1 1311 and / or Msg 3 1313 based on the one or more RACH parameters. Based on the one or more RACH parameters, the UE may determine the reception timing and downlink channel for receiving Msg 2 1312 and Msg 4 1314.

[0184] The one or more RACH parameters provided in the configuration message 1310 may indicate one or more physical RACH (PRACH) opportunities that may be used to transmit Msg 11311. The one or more PRACH opportunities may be predefined. The one or more RACH parameters may indicate one or more available sets of one or more PRACH opportunities (e.g., prach-ConfigIndex). The one or more RACH parameters may indicate an association between: (a) one or more PRACH opportunities, and (b) one or more reference signals. The one or more RACH parameters may indicate an association between: (a) one or more preambles, and (b) one or more reference signals. The one or more reference signals may be SS / PBCH blocks and / or CSI-RS. For example, the one or more RACH parameters may indicate the number of SS / PBCH blocks mapped to the PRACH opportunity and / or the number of preambles mapped to the SS / PBCH block.

[0185] The one or more RACH parameters provided in the configuration message 1310 may be used to determine the uplink transmission power of Msg 1 1311 and / or Msg 3 1313. For example, the one or more RACH parameters may indicate a reference power for preamble transmission (e.g., a received target power and / or an initial power for preamble transmission). There may be one or more power offsets indicated by the one or more RACH parameters. For example, the one or more RACH parameters may indicate: a power ramp step size; a power offset between an SSB and a CSI-RS; a power offset between transmissions of Msg 1 1311 and Msg 3 1313; and / or a power offset value between preamble groups. The one or more RACH parameters may indicate one or more thresholds based on which the UE may determine at least one reference signal (e.g., an SSB and / or a CSI-RS) and / or an uplink carrier (e.g., a normal uplink (NUL) carrier and / or a supplementary uplink (SUL) carrier).

[0186] Msg 1 1311 may include one or more preamble transmissions (e.g., a preamble transmission and one or more preamble retransmissions). The RRC message may be used to configure one or more preamble groups (e.g., group A and / or group B). A preamble group may include one or more preambles. The UE may determine the preamble group based on the path loss measurement value and / or the size of Msg 3 1313. The UE may measure the RSRP of one or more reference signals (e.g., SSB and / or CSI-RS) and determine at least one reference signal having an RSRP greater than an RSRP threshold (e.g., rsrp-ThresholdSSB and / or rsrp-ThresholdCSI-RS). For example, if the association between the one or more preambles and the at least one reference signal is configured by the RRC message, the UE may select at least one preamble associated with the one or more reference signals and / or the selected preamble group.

[0187] The UE may determine the preamble based on the one or more RACH parameters provided in the configuration message 1310. For example, the UE may determine the preamble based on a path loss measurement, an RSRP measurement, and / or the size of Msg 3 1313. As another example, the one or more RACH parameters may indicate: a preamble format; a maximum number of preamble transmissions; and / or one or more thresholds for determining one or more preamble groups (e.g., Group A and Group B). The base station may use the one or more RACH parameters to configure an association between one or more preambles and one or more reference signals (e.g., SSB and / or CSI-RS) for the UE. If the association is configured, the UE may determine the preamble included in Msg 1 1311 based on the association. Msg 1 1311 may be transmitted to the base station via one or more PRACH opportunities. The UE may use one or more reference signals (e.g., SSB and / or CSI-RS) to select a preamble and to determine a PRACH opportunity. One or more RACH parameters (eg, ra-ssb-OccasionMskIndex and / or ra-OccasionList) may indicate an association between a PRACH opportunity and the one or more reference signals.

[0188] If no response is received after the preamble transmission, the UE may perform a preamble retransmission. The UE may increase the uplink transmission power for the preamble retransmission. The UE may select the initial preamble transmission power based on the path loss measurement and / or the target received preamble power configured by the network. The UE may determine to retransmit the preamble and may ramp up the uplink transmission power. The UE may receive one or more RACH parameters (e.g., PREAMBLE_POWER_RAMPING_STEP) indicating the ramp-up step size for preamble retransmission. The ramp-up step size may be the amount of incremental increase in the uplink transmission power for retransmission. If the UE determines the same reference signal (e.g., SSB and / or CSI-RS) as the previous preamble transmission, the UE may ramp up the uplink transmission power. The UE may count the number of preamble transmissions and / or retransmissions (e.g., PREAMBLE_TRANSMISSION_COUNTER). For example, if the number of preamble transmissions exceeds a threshold (eg, preambleTransMax) configured by the one or more RACH parameters, the UE may determine that the random access procedure is not successfully completed.

[0189] Msg 2 1312 received by the UE may include a RAR. In some scenarios, Msg 2 1312 may include multiple RARs corresponding to multiple UEs. Msg 2 1312 may be received after or in response to the transmission of Msg 1 1311. Msg 2 1312 may be scheduled on the DL-SCH and indicated on the PDCCH using a random access RNTI (RA-RNTI). Msg 2 1312 may indicate that Msg 1 1311 was received by the base station. Msg 2 1312 may include a time alignment command, which may be used by the UE to adjust the UE's transmission timing, a scheduling grant for transmitting Msg 3 1313, and / or a temporary cell RNTI (TC-RNTI). After transmitting the preamble, the UE may initiate a time window (e.g., a RA-ResponseWindow) to monitor the PDCCH for Msg 2 1312. The UE may determine when to initiate the time window based on the PRACH opportunity used by the UE to transmit the preamble. For example, the UE may start a time window of one or more symbols after the last symbol of the preamble (e.g., at the first PDCCH opportunity starting from the end of the preamble transmission). The one or more symbols may be determined based on a parameter set. The PDCCH may be in a common search space (e.g., Type1-PDCCH common search space) configured by an RRC message. The UE may identify the RAR based on a radio network temporary identifier (RNTI). The RNTI may be used depending on one or more events for initiating a random access procedure. The UE may use a random access RNTI (RA-RNTI). The RA-RNTI may be associated with the PRACH opportunity in which the UE transmits the preamble. For example, the UE may determine the RA-RNTI based on: an OFDM symbol index; a time slot index; a frequency domain index; and / or a UL carrier indicator of a PRACH opportunity. Examples of RA-RNTI may be as follows:

[0190] RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id, where s_id may be the index of the first OFDM symbol of the PRACH opportunity (e.g., 0≤s_id<14), t_id may be the index of the first time slot of the PRACH opportunity in the system frame (e.g., 0≤t_id<80), f_id may be the index of the PRACH opportunity in the frequency domain (e.g., 0≤f_id<8), and ul_carrier_id may be the UL carrier used for preamble transmission (e.g., 0 for the NUL carrier and 1 for the SUL carrier).

[0191] The UE may transmit Msg 3 1313 in response to successfully receiving Msg 2 1312 (e.g., using the resources identified in Msg 2 1312). Msg 3 1313 may be used, for example, Figure 13A 1314 ). Contention resolution in the contention-based random access procedure shown in . In some scenarios, multiple UEs may transmit the same preamble to the base station, and the base station may provide RARs corresponding to the UEs. If the multiple UEs interpret the RARs as corresponding to themselves, a collision may occur. Contention resolution (e.g., using Msg 3 1313 and Msg 4 1314) may be used to increase the likelihood that a UE does not mistakenly use the identity of another UE. To perform contention resolution, the UE may include a device identifier in Msg 3 1313 (e.g., if a C-RNTI is assigned, the TC-RNTI included in Msg 2 1312 and / or any other suitable identifier).

[0192] Msg 4 1314 may be received after or in response to the transmission of Msg 3 1313. If a C-RNTI is included in Msg 3 1313, the base station will use the C-RNTI to address the UE on the PDCCH. If the UE's unique C-RNTI is detected on the PDCCH, the random access procedure is determined to have been successfully completed. If a TC-RNTI is included in Msg 3 1313 (e.g., if the UE is in the RRC_IDLE state or is not otherwise connected to the base station), Msg 4 1314 will be received using the DL-SCH associated with the TC-RNTI. If the MAC PDU is successfully decoded and the MAC PDU includes a UE contention resolution identity MAC CE that matches or otherwise corresponds to the CCCH SDU sent (e.g., transmitted) in Msg 3 1313, the UE may determine that contention resolution was successful and the UE may determine that the random access procedure was successfully completed.

[0193] The UE may be configured with a supplementary uplink (SUL) carrier and a normal uplink (NUL) carrier. Initial access (e.g., a random access procedure) may be supported in the uplink carrier. For example, the base station may configure two separate RACH configurations for the UE: one for the SUL carrier and the other for the NUL carrier. For random access in a cell configured with a SUL carrier, the network may indicate which carrier (NUL or SUL) to use. For example, if the measured quality of one or more reference signals is below a broadcast threshold, the UE may determine the SUL carrier. The uplink transmissions for the random access procedure (e.g., Msg1 1311 and / or Msg 3 1313) may remain on the selected carrier. In one or more cases, the UE may switch uplink carriers during the random access procedure (e.g., between Msg 1 1311 and Msg 3 1313). For example, the UE may determine and / or switch an uplink carrier for Msg 1 1311 and / or Msg 3 1313 based on channel clarity assessment (eg, listen before talk).

[0194] Figure 13B The two-step contention-free random access procedure is shown. Figure 13A Similar to the four-step contention-based random access procedure shown, the base station may transmit a configuration message 1320 to the UE before the procedure is initiated. The configuration message 1320 may be similar to the configuration message 1310 in some aspects. Figure 13B The procedure shown includes the transmission of two messages: Msg 1 1321 and Msg 2 1322. Msg 1 1321 and Msg 2 1322 may be similar in some respects to Figure 13A As shown in Msg 1 1311 and Msg 2 1312. Figure 13A and Figure 13B It will be appreciated that the contention-free random access procedure may not include messages similar to Msg 3 1313 and / or Msg 4 1314 .

[0195] Can be initiated for beam failure recovery, other SI requests, SCell addition and / or handover Figure 13B For example, the base station may indicate or assign a preamble to be used for Msg 1 1321 to the UE. The UE may receive an indication of the preamble (eg, ra-PreambleIndex) from the base station via PDCCH and / or RRC.

[0196] After transmitting the preamble, the UE may start a time window (e.g., ra-ResponseWindow) to monitor the PDCCH for the RAR. In the case of a beam failure recovery request, the base station may configure the UE with a separate time window and / or a separate PDCCH in the search space indicated by the RRC message (e.g., recoverySearchSpaceId). The UE may monitor PDCCH transmissions addressed to the Cell RNTI (C-RNTI) on the search space. Figure 13B In the illustrated contention-free random access procedure, the UE may determine that the random access procedure has been successfully completed after or in response to the transmission of Msg 1 1321 and the reception of the corresponding Msg 2 1322. For example, if the PDCCH transmission is addressed to the C-RNTI, the UE may determine that the random access procedure has been successfully completed. For example, if the UE receives a RAR including a preamble identifier corresponding to a preamble transmitted by the UE and / or the RAR includes a MAC sub-PDU with the preamble identifier, the UE may determine that the random access procedure has been successfully completed. The UE may determine that the response is an indication of confirmation of the SI request.

[0197] Figure 13C Another two-step random access procedure is shown. Figure 13A and Figure 13B Similar to the random access procedure shown, the base station may transmit a configuration message 1330 to the UE before the procedure is initiated. Configuration message 1330 may be similar to configuration message 1310 and / or configuration message 1320 in some aspects. Figure 13C The procedure shown includes the transmission of two messages: Msg A 1331 and Msg B 1332.

[0198] Msg A 1331 may be transmitted by the UE in an uplink transmission. Msg A 1331 may include one or more transmissions of a preamble 1341 and / or one or more transmissions of a transport block 1342. Transport block 1342 may include Figure 13A The content of Msg 3 1313 shown in FIG. 1342 may include UCI (e.g., SR, HARQ ACK / NACK, etc.). The UE may receive Msg B 1332 after or in response to the transmission of Msg A 1331. Msg B 1332 may include the content of Msg 3 1313 shown in FIG. Figure 13A and Figure 13B Msg 2 1312 (eg, RAR) and / or Figure 13A 1314 shown in .

[0199] The UE can initiate a call for licensed spectrum and / or unlicensed spectrum. Figure 13C The UE may determine whether to initiate a two-step random access procedure based on one or more factors. The one or more factors may include: the radio access technology being used (e.g., LTE, NR, etc.); whether the UE has a valid TA; the cell size; the RRC state of the UE; the type of spectrum (e.g., licensed vs. unlicensed); and / or any other suitable factors.

[0200] The UE may determine the radio resources and / or uplink transmission power of the preamble 1341 and / or transport block 1342 included in Msg A 1331 based on the two-step RACH parameters included in the configuration message 1330. The RACH parameters may indicate the modulation and coding scheme (MCS), time-frequency resources, and / or power control of the preamble 1341 and / or transport block 1342. The time-frequency resources (e.g., PRACH) used for transmission of the preamble 1341 and the time-frequency resources (e.g., PUSCH) used for transmission of the transport block 1342 may be multiplexed using FDM, TDM, and / or CDM. The RACH parameters may enable the UE to determine the reception timing and downlink channel used for monitoring and / or receiving Msg B 1332.

[0201] Transport block 1342 may include data (e.g., delay-sensitive data), an identifier of the UE, security information, and / or device information (e.g., an International Mobile Subscriber Identity (IMSI)). The base station may transmit Msg B 1332 in response to Msg A 1331. Msg B 1332 may include at least one of the following: a preamble identifier; a timing high-level command; a power control command; an uplink grant (e.g., a radio resource assignment and / or MCS); a UE identifier for contention resolution; and / or an RNTI (e.g., a C-RNTI or TC-RNTI). The UE may determine that the two-step random access procedure is successfully completed if: the preamble identifier in Msg B 1332 matches the preamble transmitted by the UE; and / or the UE identifier in Msg B 1332 matches the UE identifier in Msg A 1331 (e.g., transport block 1342).

[0202] The UE and the base station may exchange control signaling. The control signaling may be referred to as L1 / L2 control signaling and may originate from the PHY layer (e.g., Layer 1) and / or the MAC layer (e.g., Layer 2). The control signaling may include downlink control signaling transmitted from the base station to the UE and / or uplink control signaling transmitted from the UE to the base station.

[0203] Downlink control signaling may include: downlink scheduling assignments; uplink scheduling grants indicating uplink radio resources and / or transport formats; time slot format information; preemption indications; power control commands; and / or any other suitable signaling. The UE may receive downlink control signaling in a payload transmitted by the base station on a physical downlink control channel (PDCCH). The payload transmitted on the PDCCH may be referred to as downlink control information (DCI). In some scenarios, the PDCCH may be a group common PDCCH (GC-PDCCH) common to a group of UEs.

[0204] The base station may attach one or more cyclic redundancy check (CRC) parity bits to the DCI to facilitate detection of transmission errors. When the DCI is intended for a UE (or a group of UEs), the base station may scramble the CRC parity bits with an identifier for the UE (or an identifier for the group of UEs). Scrambling the CRC parity bits with the identifier may include a Modulo-2 addition (or an exclusive OR operation) of the identifier value and the CRC parity bits. The identifier may include a 16-bit value of a Radio Network Temporary Identifier (RNTI).

[0205] DCI can be used for different purposes. The purpose can be indicated by the type of RNTI used to scramble the CRC parity bits. For example, a DCI with CRC parity bits scrambled with a paging RNTI (P-RNTI) can indicate paging information and / or system information change notification. The P-RNTI can be predefined as "FFFE" in hexadecimal. A DCI with CRC parity bits scrambled with a system information RNTI (SI-RNTI) can indicate a broadcast transmission of system information. The SI-RNTI can be predefined as "FFFF" in hexadecimal. A DCI with CRC parity bits scrambled with a random access RNTI (RA-RNTI) can indicate a random access response (RAR). A DCI with CRC parity bits scrambled with a cell RNTI (C-RNTI) can indicate a dynamically scheduled unicast transmission and / or a triggering of a PDCCH ordered random access. A DCI with CRC parity bits scrambled with a temporary cell RNTI (TC-RNTI) can indicate contention resolution (e.g., with a unicast transmission). Figure 13A313 is similar to Msg 3 shown in ). Other RNTIs configured by the base station to the UE may include: configured scheduling RNTI (CS-RNTI), transmit power control PUCCH RNTI (TPC-PUCCH-RNTI), transmit power control PUSCH RNTI (TPC-PUSCH-RNTI), transmit power control SRS RNTI (TPC-SRS-RNTI), interruption RNTI (INT-RNTI), slot format indication RNTI (SFI-RNTI), semi-persistent CSI RNTI (SP-CSI-RNTI), modulation and coding scheme cell RNTI (MCS-C-RNTI), etc.

[0206] Depending on the purpose and / or content of the DCI, the base station may transmit DCI with one or more DCI formats. For example, DCI format 0_0 may be used for scheduling PDSCH in a cell. DCI format 0_0 may be a fallback DCI format (e.g., having a compact DCI payload). DCI format 0_1 ​​may be used for scheduling PUSCH in a cell (e.g., having a larger DCI payload than DCI format 0_0). DCI format 1_0 may be used for scheduling PDSCH in a cell. DCI format 1_0 may be a fallback DCI format (e.g., having a compact DCI payload). DCI format 1_1 may be used for scheduling PDSCH in a cell (e.g., having a larger DCI payload than DCI format 1_0). DCI format 2_0 may be used to provide a slot format indication to a UE group. DCI format 2_1 may be used to notify a UE group of physical resource blocks and / or OFDM symbols, where the UE may assume that no transmission to the UE is expected. DCI format 2_2 may be used to transmit a transmit power control (TPC) command for PUCCH or PUSCH. DCI formats 2_3 can be used to transmit a set of TPC commands for SRS transmission by one or more UEs. DCI formats for new functions may be defined in future releases. DCI formats can have different DCI sizes or can share the same DCI size.

[0207] After scrambling the DCI with the RNTI, the base station can process the DCI with channel coding (e.g., polarity coding), rate matching, scrambling and / or QPSK modulation. The base station can map the coded and modulated DCI on resource elements used for and / or configured for PDCCH. Based on the payload size of the DCI and / or the coverage of the base station, the base station can transmit the DCI via a PDCCH occupying multiple consecutive control channel elements (CCEs). The number of consecutive CCEs (referred to as the aggregation level) can be 1, 2, 4, 8, 16 and / or any other suitable number. CCE may include the number of resource element groups (REGs) (e.g., 6). REG may include resource blocks in an OFDM symbol. The mapping of the coded and modulated DCI on the resource elements can be based on the mapping of CCEs and REGs (e.g., CCE to REG mapping).

[0208] Figure 14A An example of a CORESET configuration for a bandwidth portion is shown. The base station may transmit DCI via PDCCH on one or more control resource sets (CORESETs). A CORESET may include time-frequency resources in which the UE attempts to decode the DCI using one or more search spaces. The base station may configure the CORESET in the time-frequency domain. Figure 14A In the example shown in FIG1 , first CORESET 1401 and second CORESET 1402 appear at the first symbol in a time slot. First CORESET 1401 overlaps with second CORESET 1402 in the frequency domain. Third CORESET 1403 appears at the third symbol in a time slot. Fourth CORESET 1404 appears at the seventh symbol in a time slot. CORESETs can have different numbers of resource blocks in the frequency domain.

[0209] Figure 14B An example of CCE to REG mapping for DCI transmission on a CORESET and PDCCH processing is shown. The CCE to REG mapping can be an interleaved mapping (e.g., for the purpose of providing frequency diversity) or a non-interleaved mapping (e.g., for the purpose of facilitating interference coordination and / or frequency selective transmission of control channels). The base station can perform different or the same CCE to REG mapping for different CORESETs. A CORESET can be associated with the CCE to REG mapping through RRC configuration. A CORESET can be configured with an antenna port quasi-co-location (QCL) parameter. The antenna port QCL parameter can indicate the QCL information of the demodulation reference signal (DMRS) for PDCCH reception in the CORESET.

[0210] The base station may transmit an RRC message including configuration parameters of one or more CORESETs and one or more search space sets to the UE. The configuration parameters may indicate the association between the search space set and the CORESET. The search space set may include a set of PDCCH candidates formed by CCEs at a given aggregation level. The configuration parameters may indicate: the number of PDCCH candidates to be monitored per aggregation level; the PDCCH monitoring period and the PDCCH monitoring mode; one or more DCI formats to be monitored by the UE; and / or whether the search space set is a common search space set or a UE-specific search space set. The set of CCEs in the common search space set may be predefined and known to the UE. The set of CCEs in the UE-specific search space set may be configured based on the identity of the UE (e.g., C-RNTI).

[0211] like Figure 14B As shown, the UE may determine the time-frequency resources of the CORESET based on the RRC message. The UE may determine the CCE to REG mapping of the CORESET based on the configuration parameters of the CORESET (e.g., interleaving or non-interleaving and / or mapping parameters). The UE may determine the number of search space sets configured on the CORESET based on the RRC message (e.g., up to 10). The UE may monitor a set of PDCCH candidates based on the configuration parameters of the search space set. The UE may monitor a set of PDCCH candidates in one or more CORESETs for detecting one or more DCIs. Monitoring may include decoding one or more PDCCH candidates in the set of PDCCH candidates based on the monitored DCI format. Monitoring may include decoding DCI content of one or more PDCCH candidates, which has possible (or configured) PDCCH positions, possible (or configured) PDCCH formats (e.g., the number of CCEs, the number of PDCCH candidates in the common search space, and / or the number of PDCCH candidates in the UE-specific search space), and possible (or configured) DCI formats. Decoding may be referred to as blind decoding. The UE may determine that the DCI is valid for the UE in response to a CRC check (e.g., scrambled bits of the CRC parity bits of the DCI matching the RNTI value). The UE may process the information contained in the DCI (e.g., scheduling assignments, uplink grants, power control, slot format indication, downlink preemption, etc.).

[0212] The UE may transmit uplink control signaling (e.g., uplink control information (UCI)) to the base station. The uplink control signaling transmission may include a hybrid automatic repeat request (HARQ) acknowledgment for the received DL-SCH transport block. The UE may transmit the HARQ acknowledgment after receiving the DL-SCH transport block. The uplink control signaling may include channel state information (CSI) indicating the channel quality of the physical downlink channel. The UE may transmit the CSI to the base station. Based on the received CSI, the base station may determine the transport format parameters for downlink transmission (e.g., including multiple antennas and beamforming schemes). The uplink control signaling may include a scheduling request (SR). The UE may transmit the SR indicating that uplink data is available for transmission to the base station. The UE may transmit UCI (e.g., HARQ acknowledgment (HARQ-ACK), CSI report, SR, etc.) via a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH). The UE may transmit uplink control signaling via the PUCCH using one of several PUCCH formats.

[0213] There may be five PUCCH formats, and the UE may determine the PUCCH format based on the size of the UCI (e.g., the number of uplink symbols for the UCI transmission and the number of UCI bits). PUCCH format 0 may have a length of one or two OFDM symbols and may include two or fewer bits. If the transmission exceeds one or two symbols and the number of HARQ-ACK information bits (HARQ-ACK / SR bits) with positive or negative SR is one or two, the wireless device may use PUCCH format 0 to transmit UCI in the PUCCH resource. PUCCH format 1 may occupy between four and fourteen OFDM symbols and may include two or fewer bits. If four or more symbols are transmitted and the number of HARQ-ACK / SR bits is one or two, the UE may use PUCCH format 1. PUCCH format 2 may occupy one or two OFDM symbols and may include more than two bits. If the transmission exceeds one or two symbols and the number of UCI bits is two or more, the UE may use PUCCH format 2. PUCCH format 3 may occupy between four and fourteen OFDM symbols and may include more than two bits. If four or more symbols are transmitted, the number of UCI bits is two or more, and the PUCCH resources do not include orthogonal cover codes, the UE may use PUCCH format 3. PUCCH format 4 may occupy between four and fourteen OFDM symbols and may include more than two bits. If four or more symbols are transmitted, the number of UCI bits is two or more, and the PUCCH resources include orthogonal cover codes, the UE may use PUCCH format 4.

[0214] The base station may transmit configuration parameters of multiple PUCCH resource sets to the UE using, for example, an RRC message. The multiple PUCCH resource sets (e.g., up to four sets) may be configured on the uplink BWP of the cell. The PUCCH resource set may be configured with: a PUCCH resource set index; multiple PUCCH resources having PUCCH resources identified by a PUCCH resource identifier (e.g., pucch-Resourceid); and / or multiple (e.g., maximum number) UCI ​​information bits that the UE may transmit using one of the multiple PUCCH resources in the PUCCH resource set. When multiple PUCCH resource sets are configured, the UE may select one of the multiple PUCCH resource sets (e.g., HARQ-ACK, SR, and / or CSI) based on the total bit length of the UCI information bits. If the total bit length of the UCI information bits is two or less, the UE may select the first PUCCH resource set with a PUCCH resource set index equal to "0". If the total bit length of the UCI information bits is greater than two and less than or equal to the first configured value, the UE may select a second PUCCH resource set having a PUCCH resource set index equal to "1". If the total bit length of the UCI information bits is greater than the first configured value and less than or equal to the second configured value, the UE may select a third PUCCH resource set having a PUCCH resource set index equal to "2". If the total bit length of the UCI information bits is greater than the second configured value and less than or equal to a third value (e.g., 1406), the UE may select a fourth PUCCH resource set having a PUCCH resource set index equal to "3".

[0215] After determining a PUCCH resource set from a plurality of PUCCH resource sets, the UE may determine the PUCCH resources for UCI (HARQ-ACK, CSI, and / or SR) transmission from the PUCCH resource set. The UE may determine the PUCCH resources based on a PUCCH resource indicator in a DCI received on a PDCCH (e.g., a DCI format 1_0 or a DCI for 1_1). The three-bit PUCCH resource indicator in the DCI may indicate one of eight PUCCH resources in the PUCCH resource set. Based on the PUCCH resource indicator, the UE may use the PUCCH resource indicated by the PUCCH resource indicator in the DCI to transmit UCI (HARQ-ACK, CSI, and / or SR).

[0216] Figure 15 An example of a wireless device 1502 in communication with a base station 1504 according to an embodiment of the present disclosure is shown. The wireless device 1502 and the base station 1504 may be part of a mobile communication network, such as Figure 1A The mobile communication network 100 shown, Figure 1B The mobile communication network 150 shown or any other communication network. Figure 15 Only one wireless device 1502 and one base station 1504 are shown in FIG. 1 , but it should be understood that a mobile communication network may include more than one UE and / or more than one base station having the same Figure 15 The same or similar configurations as those shown.

[0217] Base station 1504 can connect wireless device 1502 to a core network (not shown) via radio communication over an air interface (or radio interface) 1506. The direction of communication from base station 1504 to wireless device 1502 over air interface 1506 is referred to as downlink, while the direction of communication from wireless device 1502 to base station 1504 over the air interface is referred to as uplink. Downlink transmissions can be separated from uplink transmissions using FDD, TDD, and / or some combination of the two duplexing techniques.

[0218] In the downlink, data to be transmitted from base station 1504 to wireless device 1502 may be provided to processing system 1508 of base station 1504. The data may be provided to processing system 1508 via, for example, a core network. In the uplink, data to be transmitted from wireless device 1502 to base station 1504 may be provided to processing system 1518 of wireless device 1502. Processing system 1508 and processing system 1518 may implement layer 3 and layer 2 OSI functions to process data for transmission. Layer 2 may include, for example, information about Figure 2A 、 Figure 2B 、 Figure 3 and Figure 4A The 3 layers include the SDAP layer, PDCP layer, RLC layer and MAC layer. Figure 2B RRC layer.

[0219] After processing by processing system 1508, data to be transmitted to wireless device 1502 may be provided to transmission processing system 1510 of base station 1504. Similarly, after processing by processing system 1518, data to be transmitted to base station 1504 may be provided to transmission processing system 1520 of wireless device 1502. Transmission processing system 1510 and transmission processing system 1520 may implement layer 1 OSI functions. Layer 1 may include information about Figure 2A 、 Figure 2B 、 Figure 3 and Figure 4A For transmission processing, the PHY layer may perform, for example, forward error correction coding of transport channels, interleaving, rate matching, mapping of transport channels to physical channels, modulation of physical channels, multiple-input multiple-output (MIMO) or multi-antenna processing, and the like.

[0220] At base station 1504, receive processing system 1512 may receive uplink transmissions from wireless device 1502. At wireless device 1502, receive processing system 1522 may receive downlink transmissions from base station 1504. Receive processing system 1512 and receive processing system 1522 may implement layer 1 OSI functionality. Layer 1 may include information about Figure 2A 、 Figure 2B 、 Figure 3 and Figure 4A For receive processing, the PHY layer may perform, for example, error detection, forward error correction decoding, deinterleaving, demapping of transport channels to physical channels, demodulation of physical channels, MIMO or multi-antenna processing, and the like.

[0221] like Figure 15 As shown, wireless device 1502 and base station 1504 may include multiple antennas. These multiple antennas may be used to implement one or more MIMO or multi-antenna techniques, such as spatial multiplexing (e.g., single-user MIMO or multi-user MIMO), transmit / receive diversity, and / or beamforming. In other examples, wireless device 1502 and / or base station 1504 may have a single antenna.

[0222] Processing system 1508 and processing system 1518 may be associated with memory 1514 and memory 1524, respectively. Memory 1514 and memory 1524 (e.g., one or more non-transitory computer-readable media) may store computer program instructions or code that may be executed by processing system 1508 and / or processing system 1518 to perform one or more of the functions discussed herein. Figure 15 Not shown, transmit processing system 1510, transmit processing system 1520, receive processing system 1512, and / or receive processing system 1522 may be coupled to a memory (e.g., one or more non-transitory computer-readable media) storing computer program instructions or code that may be executed to perform one or more of their respective functions.

[0223] The processing system 1508 and / or the processing system 1518 may include one or more controllers and / or one or more processors. The one or more controllers and / or one or more processors may include, for example, a general purpose processor, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) and / or other programmable logic device, discrete gate and / or transistor logic, discrete hardware components, onboard units, or any combination thereof. The processing system 1508 and / or the processing system 1518 may perform at least one of signal encoding / processing, data processing, power control, input / output processing, and / or any other functionality that enables the wireless device 1502 and the base station 1504 to operate in a wireless environment.

[0224] The processing system 1508 and / or the processing system 1518 can be connected to one or more peripheral devices 1516 and one or more peripheral devices 1526, respectively. The one or more peripheral devices 1516 and the one or more peripheral devices 1526 can include software and / or hardware that provides features and / or functionality, such as a speaker, a microphone, a keyboard, a display, a touchpad, a power supply, a satellite transceiver, a universal serial bus (USB) port, a hands-free headset, a frequency modulation (FM) radio unit, a media player, an Internet browser, an electronic control unit (e.g., for a motor vehicle), and / or one or more sensors (e.g., an accelerometer, a gyroscope, a temperature sensor, a radar sensor, a lidar sensor, an ultrasonic sensor, a light sensor, a camera, etc.). The processing system 1508 and / or the processing system 1518 can receive user input data from the one or more peripheral devices 1516 and / or the one or more peripheral devices 1526 and / or provide user output data to the one or more peripheral devices. The processing system 1518 in the wireless device 1502 can receive power from a power source and / or can be configured to distribute power to other components in the wireless device 1502. The power source can include one or more power sources, such as batteries, solar cells, fuel cells, or any combination thereof. The processing system 1508 and / or the processing system 1518 can be connected to a GPS chipset 1517 and a GPS chipset 1527, respectively. The GPS chipset 1517 and the GPS chipset 1527 can be configured to provide geographic location information of the wireless device 1502 and the base station 1504, respectively.

[0225] Figure 16AAn exemplary structure for uplink transmission is shown. The baseband signal representing the physical uplink shared channel can perform one or more functions. The one or more functions may include at least one of the following: scrambling; modulating scrambled bits to generate complex-valued symbols; mapping complex-valued modulated symbols to one or several transmission layers; transform precoding to generate complex-valued symbols; precoding of complex-valued symbols; mapping of precoded complex-valued symbols to resource elements; generating complex-valued time-domain single-carrier frequency division multiple access (SC-FDMA) or CP-OFDM signals for antenna ports; and the like. In the example, when transform precoding is enabled, an SC-FDMA signal for uplink transmission can be generated. In the example, when transform precoding is not enabled, the uplink transmission can be performed by Figure 16A Generates a CP-OFDM signal for uplink transmission. These functions are shown as examples, and it is contemplated that other mechanisms may be implemented in various embodiments.

[0226] Figure 16B An exemplary structure for modulation and up-conversion of a baseband signal to a carrier frequency is shown. The baseband signal can be a complex-valued SC-FDMA or CP-OFDM baseband signal for an antenna port and / or a complex-valued physical random access channel (PRACH) baseband signal. Filtering can be employed prior to transmission.

[0227] Figure 16C An exemplary structure for downlink transmission is shown. The baseband signal representing the physical downlink channel can perform one or more functions. These one or more functions may include: scrambling the coded bits in the codeword to be transmitted on the physical channel; modulating the scrambled bits to generate complex-valued modulation symbols; mapping the complex-valued modulation symbols onto one or more transmission layers; precoding the complex-valued modulation symbols on the layers for transmission on the antenna ports; mapping the complex-valued modulation symbols for the antenna ports to resource elements; generating a complex-valued time-domain OFDM signal for the antenna ports; and so on. These functions are shown as examples, and it is contemplated that other mechanisms may be implemented in various embodiments.

[0228] Figure 16D Another exemplary structure for modulation and up-conversion of a baseband signal to a carrier frequency is shown. The baseband signal can be a complex-valued OFDM baseband signal at the antenna port. Filtering can be applied before transmission.

[0229] A wireless device may receive one or more messages (e.g., RRC messages) from a base station including configuration parameters for multiple cells (e.g., a primary cell, a secondary cell). The wireless device may communicate with at least one base station (e.g., two or more base stations in dual connectivity) via the multiple cells. The one or more messages (e.g., as part of the configuration parameters) may include parameters for configuring the wireless device at the physical layer, MAC layer, RLC layer, PCDP layer, SDAP layer, and RRC layer. For example, the configuration parameters may include parameters for configuring physical layer and MAC layer channels, bearers, etc. For example, the configuration parameters may include parameters indicating values ​​of timers for the physical layer, MAC layer, RLC layer, PCDP layer, SDAP layer, RRC layer, and / or communication channels.

[0230] Once started, a timer can begin running and continue running until it is stopped or expires. If the timer is not running, it can be started, or if it is running, it can be restarted. A timer can be associated with a value (e.g., a timer can start or restart at a certain value, or can start at zero and expire once it reaches that value). The duration of a timer may not be updated until the timer is stopped or expires (e.g., due to a BWP switch). A timer can be used to measure a time period / window of a procedure. When the description refers to implementations and procedures related to one or more timers, it should be understood that there are various ways to implement the one or more timers. For example, it should be understood that one or more of these various ways of implementing a timer can be used to measure a time period / window of a procedure. For example, a random access response window timer can be used to measure the time window for receiving a random access response. In an example, instead of the start and expiration of the random access response window timer, the time difference between two timestamps can be used. When the timer is restarted, the time window measurement process can be restarted. Other exemplary implementations for restarting the time window measurement can be provided.

[0231] Figure 17 An example of device-to-device (D2D) communication is shown, in which direct communication occurs between wireless devices. In this example, D2D communication can be performed via a sidelink (SL). The wireless devices can exchange sidelink communications via a sidelink interface (e.g., a PC5 interface). Sidelinks are distinguished between uplinks (in which the wireless device communicates with a base station) and downlinks (in which the base station communicates with the wireless device). The wireless device and the base station can exchange uplink and / or downlink communications via a user plane interface (e.g., a Uu interface).

[0232] As shown in the figure, wireless device #1 and wireless device #2 may be within the coverage area of ​​base station #1. For example, both wireless device #1 and wireless device #2 may communicate with base station #1 via the Uu interface. Wireless device #3 may be within the coverage area of ​​base station #2. Base stations #1 and #2 may share a network and may jointly provide network coverage. Wireless device #4 and wireless device #5 may be outside the network coverage area.

[0233] In-coverage D2D communication can be performed when two wireless devices share a network coverage area. Wireless device #1 and wireless device #2 are both within the coverage area of ​​base station #1. Therefore, they can perform in-coverage intra-cell D2D communication, labeled as sidelink A. Wireless device #2 and wireless device #3 are within the coverage areas of different base stations, but share the same network coverage area. Therefore, they can perform in-coverage inter-cell D2D communication, labeled as sidelink B. When one wireless device is within the network coverage area and the other wireless device is outside the network coverage area, partial coverage D2D communication can be performed. Wireless device #3 and wireless device #4 can perform partial coverage D2D communication, labeled as sidelink C. When both wireless devices are outside the network coverage area, out-of-coverage D2D communication can be performed. Wireless device #4 and wireless device #5 can perform out-of-coverage D2D communication, labeled as sidelink D.

[0234] Sidelink communications may be configured using physical channels, such as the physical sidelink broadcast channel (PSBCH), the physical sidelink feedback channel (PSFCH), the physical sidelink discovery channel (PSDCH), the physical sidelink control channel (PSCCH), and / or the physical sidelink shared channel (PSSCH). A first wireless device may use the PSBCH to send broadcast information to a second wireless device. The PSBCH may be similar in some respects to the PBCH. The broadcast information may include, for example, a slot format indication, resource pool information, a sidelink system frame number, or any other suitable broadcast information. The first wireless device may use the PSFCH to send feedback information to the second wireless device. The feedback information may include, for example, HARQ feedback information. The first wireless device may use the PSDCH to send discovery information to the second wireless device. A wireless device may use the discovery information to signal its presence and / or service availability to other wireless devices in the area. The first wireless device may use the PSCCH to send sidelink control information (SCI) to the second wireless device. The PSCCH may be similar in some respects to the PDCCH and / or PUCCH. The control information may include, for example, time / frequency resource allocation information (RB size, number of retransmissions, etc.), demodulation-related information (DMRS, MCS, RV, etc.), identification information for the transmitting wireless device and / or the receiving wireless device, process identifiers (HARQ, etc.), or any other suitable control information. The PSCCH may be used to allocate, prioritize, and / or reserve sidelink resources for sidelink transmissions. A first wireless device may use the PSSCH to send and / or relay data and / or network information to a second wireless device. The PSSCH may be similar to the PDSCH and / or PUSCH in some aspects. Each sidelink channel may be associated with one or more demodulation reference signals. Sidelink operations may utilize a sidelink synchronization signal to establish timing for sidelink operations. A wireless device configured for sidelink operation may, for example, use the PSBCH to transmit a sidelink synchronization signal. The sidelink synchronization signal may include a primary sidelink synchronization signal (PSSS) and a secondary sidelink synchronization signal (SSSS).

[0235] Sidelink resources may be configured to a wireless device in any suitable manner. The wireless device may be pre-configured for the sidelink, for example, by being pre-configured with sidelink resource information. Additionally or alternatively, the network may broadcast system information related to a resource pool for the sidelink. Additionally or alternatively, the network may configure a specific wireless device with a dedicated sidelink configuration. This configuration may identify the sidelink resources to be used for sidelink operation (e.g., configuring a sidelink band combination).

[0236] The wireless device can operate in different modes, for example, an assisted mode (which may be referred to as mode 1) or an autonomous mode (which may be referred to as mode 2). Mode selection may be based on the coverage status of the wireless device, the radio resource control status of the wireless device, information and / or instructions from the network, and / or any other suitable factors. For example, if the wireless device is idle or inactive, or the wireless device is out of network coverage, the wireless device may choose to operate in autonomous mode. For example, if the wireless device is in connected mode (e.g., connected to a base station), the wireless device may choose to operate in assisted mode (or be instructed to operate by the base station). For example, the network (e.g., a base station) may instruct a connected wireless device to operate in a particular mode.

[0237] In assisted mode, the wireless device may request scheduling from the network. For example, the wireless device may send a scheduling request to the network, and the network may allocate sidelink resources to the wireless device. Assisted mode may be referred to as network-assisted mode, gNB-assisted mode, or base station-assisted mode. In autonomous mode, the wireless device may select sidelink resources based on measurements within one or more resource pools (e.g., pre-configured or network-assigned resource pools), sidelink resource selections made by other wireless devices, and / or sidelink resource usage by other wireless devices.

[0238] To select a sidelink resource, the wireless device may observe a sensing window and a selection window. During the sensing window, the wireless device may use the sidelink resource pool to observe the SCI transmitted by other wireless devices. The SCI may identify resources available and / or reserved for sidelink transmission. Based on the resources identified by the SCI, the wireless device may select a resource within the selection window (e.g., a resource different from the resource identified in the SCI). The wireless device may transmit using the selected sidelink resource.

[0239] Figure 18 An example of a resource pool for sidelink operation is illustrated. A wireless device can operate using one or more sidelink cells. A sidelink cell can include one or more resource pools. Each resource pool can be configured to operate according to a specific mode (e.g., assisted or autonomous). The resource pool can be divided into resource units. In the frequency domain, each resource unit can include, for example, one or more resource blocks, which can be referred to as subchannels. In the time domain, each resource unit can include, for example, one or more time slots, one or more subframes, and / or one or more OFDM symbols. The resource pool can be continuous or non-continuous in the frequency domain and / or time domain (e.g., including continuous resource units or non-continuous resource units). The resource pool can be divided into overlapping resource pool portions. The resource pool can be shared between one or more wireless devices. For example, each wireless device can attempt to use different resource units for transmission to avoid conflicts.

[0240] The sidelink resource pools can be arranged in any suitable manner. In the figure, the exemplary resource pool is non-contiguous in the time domain and limited to a single sidelink BWP. In the exemplary resource pool, frequency resources are divided into Nf resource units per time unit, numbered from zero to Nf-1. The exemplary resource pool can include multiple sections (non-contiguous in this example) that repeat every k time units. In the figure, time resources are numbered n, n+1...n+k, n+k+1...etc.

[0241] The wireless device may select one or more resource units from the resource pool for transmission. In an exemplary resource pool, the wireless device selects resource unit (n, 0) for sidelink transmission. The wireless device may also select periodic resource units in later portions of the resource pool, such as resource unit (n+k, 0), resource unit (n+2k, 0), resource unit (n+3k, 0), and so on. This selection may be based on, for example, a determination that a transmission using resource unit (n, 0) will not (or is unlikely to) collide with a sidelink transmission from a wireless device sharing the sidelink resource pool. This determination may be based on, for example, the behavior of other wireless devices sharing the resource pool. For example, if no sidelink transmission is detected in resource unit (nk, 0), the wireless device may select resource unit (n, 0), resource (n+k, 0), and so on. For example, if a sidelink transmission from another wireless device is detected in resource unit (nk, 1), the wireless device may avoid selecting resource unit (n, 1), resource (n+k, 1), and so on.

[0242] Different sidelink physical channels may use different resource pools. For example, PSCCH may use a first resource pool, and PSSCH may use a second resource pool. Different resource priorities may be associated with different resource pools. For example, data associated with a first QoS, service, priority, and / or other characteristic may use a first resource pool, and data associated with a second QoS, service, priority, and / or other characteristic may use a second resource pool. For example, the network (e.g., a base station) may configure a priority level for each resource pool, supported services for each resource pool, and the like. For example, the network (e.g., a base station) may configure a first resource pool for use by unicast UEs, a second resource pool for use by multicast UEs, and the like. For example, the network (e.g., a base station) may configure a first resource pool for transmitting sidelink data, a second resource pool for transmitting discovery messages, and the like.

[0243] Figure 19An example of a PSFCH resource configuration is shown. The sidelink resource pool may include one or more frequency resources in the frequency domain and one or more time slots in the time domain. In the frequency domain, the sidelink resource pool may be divided into subchannels. Each subchannel may include one or more physical resource blocks (PRBs), and each PRB may include multiple subcarriers. In the time domain, the sidelink resource pool may be divided into resource pool portions including one or more time slots. Each resource pool portion may include a PSFCH resource for transmitting HARQ feedback messages. The PSFCH resource may be provided in the last symbol of the last time slot of the resource pool portion, such as Figure 19 As shown in .

[0244] All or part of the frequency resources corresponding to the last symbol may be used as candidate PSFCH resources. Other resources within the resource pool portion may be used for transmissions via PSCCH and / or PSSCH. When the wireless device receives a sidelink transmission via PSSCH in a particular resource pool portion, the wireless device may select a PSFCH resource from the candidate PSFCH resources in the resource pool portion and may use the selected PSFCH resource to transmit a HARQ message corresponding to the sidelink transmission.

[0245] Figure 20 An example of a mapping between radio resources for a sidelink transmission and candidate PSFCH resources is shown. As shown in the figure, a first sidelink transmission can be transmitted across two time slots via subchannel 1. A second sidelink transmission can be transmitted across one time slot via subchannel 3 and subchannel 4. In response to receiving the first sidelink transmission, the first wireless device can select PSFCH resources restricted to subchannel 1 (e.g., candidate PSFCH resources 1-4 in the figure) and use the selected PSFCH resources to transmit a first HARQ message corresponding to the first sidelink transmission. In response to receiving the second sidelink transmission, the second wireless device can select PSFCH resources restricted to subchannels 3 and 4 (e.g., candidate PSFCH resources 9-16 in the figure) and use the selected PSFCH resources to transmit a second HARQ message corresponding to the second sidelink transmission.

[0246] In the prior art, wireless devices can use PSFCH resources to transmit feedback. The wireless device can select a PSFCH resource based on a resource mapping between PSSCH resources and PSFCH resources. In an example, when a PSSCH transmission corresponds to one or more specific subchannels, the wireless device can select candidate PSFCH resources corresponding to those one or more specific subchannels for HARQ transmission. In an example, the wireless device can be configured to select PSFCH resources for one or more sidelink transport blocks based on configuration parameters and / or predefined mapping rules. For example, a multicast sidelink transmission can be associated with multiple feedback operations. The multiple feedback operations can include HARQ feedback option 1 and HARQ feedback option 2. If HARQ feedback option 1 is indicated for the multicast sidelink transmission, wireless devices that are intended receivers of the multicast sidelink transmission can share a single feedback resource. A wireless device receiving a multicast sidelink transmission with HARQ feedback option 1 can only provide HARQ feedback (e.g., transmit only a NACK) when decoding fails. If HARQ feedback option 2 feedback is indicated for the multicast sidelink transmission, wireless devices that are intended receivers of the multicast sidelink transmission can select a dedicated feedback resource. A wireless device receiving a multicast sidelink transmission with HARQ feedback option 2 may provide an acknowledgement (ACK) if decoding was successful or a negative ACK (NACK) if decoding failed.

[0247] Existing PSFCH resource selection for unicast and multicast with different feedback operations may result in inefficient results and / or require increased PSFCH resources to reduce conflicts. Implementation of existing techniques for determining PSFCH resources may not effectively address different scenarios / situations considering different broadcast types (e.g., unicast, multicast, and broadcast) of sidelink transmissions and / or different feedback operations of sidelink transmissions. In the case of HARQ feedback option 2, implementation of existing techniques for determining PSFCH resources may not provide sufficient PSFCH resources. For example, multiplexing multiple HARQ messages on the same time / frequency PSFCH resource may increase the interference level to the PSFCH resource and degrade the decoding performance of the HARQ messages multiplexed on the PSFCH resource. When implementing existing techniques, enhanced PSFCH resource mapping for sidelink unicast and multicast with different feedback operations is needed to address the problem.

[0248] An exemplary embodiment implements an enhanced PSFCH resource mapping and determination method. In an exemplary embodiment, candidate PSFCH resources may include multiple resources, including a first feedback resource and a second feedback resource. A wireless device may receive a sidelink transmission including a transport block. The transport block may be used for unicast or multicast communication. Multicast communication may use a first feedback operation or a second feedback operation. The wireless device may determine a feedback resource from the first feedback resource in response to the sidelink transmission indicating one of unicast and multicast with the first feedback operation, and may determine a feedback resource from the second feedback resource in response to the sidelink transmission indicating multicast with the second feedback operation. The first feedback resource may be shared by unicast and multicast with the first feedback operation. The second feedback resource may be shared by multicast with the second feedback operation. The wireless device may transmit feedback for the transport block via the feedback resource. In an example, when the feedback information includes only a negative acknowledgement (NACK), the first feedback operation may be used for HARQ operation. In an example, when the feedback information includes an ACK or a negative acknowledgement (NACK), the second feedback operation may be used for HARQ operation.

[0249] Implementation of the exemplary embodiment can improve the resource efficiency of PSFCH resources by allocating an appropriate amount of feedback resources in response to different broadcast types and / or different feedback operations. In the exemplary embodiment, the feedback resource efficiency can be improved for unicast and multicast with the first feedback operation, as unicast and multicast with the first feedback option require fewer feedback resources (e.g., one feedback resource). The feedback resource efficiency can be improved for multicast with the second feedback operation, as multicast with the second feedback operation may require more resources, for example, each wireless device may require dedicated resources. The exemplary embodiment can increase congestion for unicast and multicast with the first feedback operation. The increase may be minimal because these communications require fewer feedback resources. Implementation of the exemplary embodiment can reduce the overall feedback resources required for sidelink communications and reduce the level of interference with PSFCH resources, and / or can improve the decoding performance of HARQ messages.

[0250] In an exemplary embodiment, feedback resources, including a first feedback resource and a second feedback resource, are grouped into a first feedback resource group and a second feedback resource group. The first feedback resource group includes the first feedback resource. The second feedback resource group includes the second feedback resource. The first feedback resource group and the second feedback resource group may have different sizes. In an exemplary embodiment, the first feedback resource group may fully and / or partially overlap with the second feedback resource group. Implementing the grouping method can increase flexibility in allocating PSFCH resources by achieving overlap between the first feedback resource group and the second feedback resource group.

[0251] In an exemplary embodiment, a wireless device may receive a sidelink transmission. The sidelink transmission may include a transport block and at least one field. For a transport block, the at least one field may indicate one of the following: unicast; multicast with a first feedback operation; and / or multicast with a second feedback operation. In an example, the at least one field may include a first field indicating whether the broadcast type is unicast or multicast. The broadcast type may include unicast, multicast, or broadcast. In an example, the second field may indicate a feedback operation. The feedback operation may be one of the first feedback operation or the second feedback operation. In the first feedback operation, the feedback information may include only a negative acknowledgement (NACK). In the second feedback operation, the feedback information may include an acknowledgement (ACK) or a negative acknowledgement (NACK). In an exemplary embodiment, the implementation of the first and second fields enables the transmitting and receiving wireless devices to dynamically determine the broadcast type and feedback operation based on an SCI. The exemplary embodiment may increase SCI signaling overhead by introducing new fields. The exemplary embodiment enhances sidelink transport block transmission and feedback resource determination because the SCI indicates the broadcast type and feedback operation of the transport block included in the SCI. The exemplary embodiments increase communication flexibility and reduce required feedback resources while reducing congestion and interference in the feedback resources.

[0252] In an exemplary embodiment, candidate PSFCH resources may be grouped into multiple groups in a subchannel. In an exemplary embodiment, candidate PSFCH resources may be grouped into multiple groups in a resource pool. Grouping candidate PSFCH resources may reduce the level of interference to the PSFCH resources and improve radio resource efficiency for different broadcast types. In an exemplary embodiment, a wireless device may determine a PSFCH group and then determine one or more PSFCH resources within the PSFCH group. In an example, the one or more PSFCH resources may be determined in ascending order of PRB index. In an example, the one or more PSFCH resources may be determined in descending order of PRB index. In an example for determining PSFCH resources for two or more sidelink transmissions, a first wireless device may determine a first PSFCH group and then determine one or more first PSFCH resources within the first group in ascending (descending) order of PRB index, while a second wireless device determines a second PSFCH group and then determines one or more second PSFCH resources within the second group in descending (ascending) order of PRB index. For example, a first receiver wireless device for a unicast sidelink transmission may select the kth PSFCH resource starting from the PSFCH resource index with the lowest PRB index of the candidate PSFCH resources. For example, a second receiver wireless device for a groupcast sidelink transmission may select the m×gth PSFCH resource starting from the PSFCH resource index with the highest PRB index of the candidate PSFCH resources. In an example, k or m may represent the first subchannel index of the sidelink transmission. In an example, g may represent the number of wireless devices in the group for the sidelink transmission. Selecting PSFCH resources based on different commands can reduce the level of interference with the PSFCH resources by reducing the probability of multiple wireless devices selecting the same PSFCH resource.

[0253] The candidate PSFCH resources limited to a set of frequency resources can be grouped into multiple groups. The wireless device can select a group from the multiple groups based on certain conditions. For example, the group of frequency resources can be a subchannel. For example, the group of frequency resources can be a sidelink resource pool. For example, the group of frequency resources can be a sidelink bandwidth part (BWP). In an example, the condition can be the broadcast type of the sidelink transmission. The grouping method of candidate PSFCH resources based on the broadcast type is referred to as grouping method 1 of candidate PSFCH resources. In an example, the condition can be the broadcast type and / or HARQ feedback option for the groupcast corresponding to the sidelink transmission. The grouping method of candidate PSFCH resources based on the broadcast type and HARQ feedback option is referred to as grouping method 2 of candidate PSFCH resources.

[0254] In the case of grouping method 1, one or more first PRBs within the group of frequency resources may be grouped for transmitting one or more first HARQ messages corresponding to one or more unicast sidelink transmissions. One or more second PRBs within the group of frequency resources may be grouped for transmitting one or more second HARQ messages corresponding to one or more multicast sidelink transmissions. The one or more first PRBs may be separated from the one or more second PRBs. The one or more first PRBs may partially or completely overlap with the one or more second PRBs.

[0255] In the case of grouping method 2, when one or more first HARQ messages correspond to one or more unicast sidelink transmissions or one or more multicast transmissions with HARQ feedback option 1, one or more first PRBs in the group of frequency resources may be grouped for transmitting the one or more first HARQ messages. When one or more second HARQ messages correspond to one or more multicast transmissions with HARQ feedback option 2, one or more second PRBs within the group of frequency resources may be grouped for transmitting the one or more second HARQ messages. The one or more first PRBs may partially overlap with the one or more second PRBs.

[0256] Figure 21 An example of grouping candidate PSFCH resources by subchannel is shown. As shown in the figure, the resource pool may include five subchannels. A subchannel in the five subchannels may include four PSFCH resources in the frequency domain. The four PSFCH resources of the five subchannels (e.g., Figure 21 The first PSFCH resources among the candidate PSFCH resources 1, 5, 9, 13 and 17 in the candidate PSFCH resource group 1 can be grouped into candidate PSFCH resource group 1. The four PSFCH resources of the five subchannels (e.g., Figure 21The remaining PSFCH resources in the candidate PSFCH resources 2, 3, 4, 6, 7, 8, 10, 11, 12, 14, 15, 16, 18, 19, and 20 in the subchannel may be grouped into candidate PSFCH resource group 2. In an example, grouping method 1 may be used to generate candidate PSFCH resource group 1 and candidate PSFCH resource group 2. In an example, grouping method 2 may be used to generate candidate PSFCH resource group 1 and candidate PSFCH resource group 2. In the case of grouping method 2, when one or more first HARQ messages correspond to one or more unicast sidelink transmissions or one or more multicast transmissions with HARQ feedback option 1, one or more first PRBs within the subchannel may be grouped for transmitting the one or more first HARQ messages. When one or more second HARQ messages correspond to one or more multicast transmissions with HARQ feedback option 2, one or more second PRBs within the subchannel may be grouped for transmitting the one or more second HARQ messages. The one or more first PRBs may partially overlap with the one or more second PRBs.

[0257] There may be a mapping rule between sidelink transmissions and candidate PSFCH resources. The mapping between sidelink transmissions and candidate PSFCH resources may be based on the subchannel index used to transmit the sidelink transmission and the index of the candidate PSFCH resource. For example, the subchannel index may be the starting subchannel index of the PSCCH used to transmit the sidelink transmission. For example, the subchannel index may be the starting subchannel index of the PSSCH used to transmit the sidelink transmission. For example, the index of the candidate PSFCH resource may be the starting PRB index of the candidate PSFCH resource.

[0258] Implementing a grouping approach can improve PSFCH resource efficiency by allocating an appropriate amount of feedback resources in response to different broadcast types and / or different feedback operations. Implementing a grouping approach can reduce interference levels on PSFCH resources and improve HARQ message decoding performance by allocating more feedback resources to multicasts with HARQ feedback option 2. Implementing a grouping approach can increase flexibility in allocating PSFCH resources by enabling overlap between the first feedback resource group and the second feedback resource group.

[0259] like Figure 36A As shown in , SCI can indicate the broadcast type indication of the side link transmission. Figure 36B As shown in , the SCI may also indicate HARQ feedback options corresponding to the sidelink transmission. In an example, in response to receiving Figure 36B, the wireless device may determine a first candidate PSFCH resource group from the multiple candidate PSFCH resource groups based on the SCI indicating that the broadcast type of the sidelink transmission is unicast. In an example, the wireless device may determine the first candidate PSFCH resource group from the multiple candidate PSFCH resource groups based on the SCI indicating that the broadcast type of the sidelink transmission is multicast and the HARQ feedback option is 1. In an example, the wireless device may determine a second candidate PSFCH resource group from the multiple candidate PSFCH resource groups based on the SCI indicating that the broadcast type of the sidelink transmission is multicast and the HARQ feedback option is 2.

[0260] In an exemplary embodiment, a wireless device may determine the grouping of candidate PSFCH resources for a sidelink transmission based on an implicit indication in the SCI of the sidelink transmission. The SCI may include at least one field indicating the broadcast type of the sidelink transmission. The at least one field may indicate a HARQ feedback option. The wireless device may determine the grouping of candidate PSFCH resources based on the implicit indication in the SCI. Compared to explicitly indicating the grouping of candidate PSFCH resources by adding additional bits in the SCI, the implicit indication may save additional bits and reduce SCI overhead.

[0261] Figure 22 An example of determining PSFCH resources based on grouping method 1 of candidate PSFCH resources is shown. The first sidelink transmission may be a multicast transmission. The second sidelink transmission may be a unicast transmission. Twenty candidate PSFCH resources may be grouped based on grouping method 1. Candidate PSFCH resource group 1 may include candidate PSFCH resources 1, 5, 9, 13, and 17. Candidate PSFCH resource group 2 may include candidate PSFCH resources 2, 3, 4, 6, 7, 8, 10, 11, 12, 14, 15, 16, 18, 19, and 20. Candidate PSFCH resource group 1 may be used to transmit HARQ messages corresponding to unicast sidelink transmissions. Candidate PSFCH resource group 2 may be used to transmit HARQ messages corresponding to multicast sidelink transmissions.

[0262] In an exemplary mapping rule, the index of the starting subchannel of the unicast sidelink transmission can be mapped to the index of the candidate PSFCH resource in candidate PSFCH resource group 1, which is limited to the starting subchannel of the unicast sidelink transmission. The index of the starting subchannel of the group sidelink transmission can be mapped to the index of the candidate PSFCH resource in candidate PSFCH resource group 2, which is limited to the starting subchannel of the multicast sidelink transmission.

[0263] In response to receiving a first sidelink transmission, the first wireless device may determine candidate PSFCH resource group 2 for a first PSFCH resource selection because the first sidelink transmission is a multicast transmission. The first wireless device may also determine candidate PSFCH resource 2 for HARQ message transmission based on the exemplary mapping rule because candidate PSFCH resource 2 is restricted to the starting subchannel of the first sidelink transmission (e.g., subchannel 1). In response to receiving a second sidelink transmission, the second wireless device may determine candidate PSFCH resource group 1 for PSFCH resource selection because the second sidelink transmission is a unicast transmission. The second wireless device may also determine candidate PSFCH resource 9 for HARQ message transmission based on the exemplary mapping rule because candidate PSFCH resource 9 is restricted to the starting subchannel of the second sidelink transmission (e.g., subchannel 3).

[0264] Figure 23 An example of determining PSFCH resources based on grouping method 2 of candidate PSFCH resources is shown. In this example, the first sidelink transmission may be a multicast transmission with HARQ feedback option 1. In this example, the second sidelink transmission may be a unicast transmission. Twenty candidate PSFCH resources may be grouped based on grouping method 2. Candidate PSFCH resource group 1 may include candidate PSFCH resources 1, 5, 9, 13, and 17. Candidate PSFCH resource group 2 may include candidate PSFCH resources 2, 3, 4, 6, 7, 8, 10, 11, 12, 14, 15, 16, 18, 19, and 20. In response to the sidelink transmission being a unicast transmission or a multicast transmission with HARQ feedback option 1, candidate PSFCH resource group 1 may be used to transmit a HARQ message corresponding to the sidelink transmission. In response to the sidelink transmission being a multicast transmission with HARQ feedback option 2, candidate PSFCH resource group 2 may be used to transmit a HARQ message corresponding to the sidelink transmission.

[0265] In an exemplary mapping rule, the index of the starting subchannel of the unicast sidelink transmission can be mapped to the index of the candidate PSFCH resource in candidate PSFCH resource group 1, which is limited to the starting subchannel of the unicast sidelink transmission. The index of the starting subchannel of the group sidelink transmission can be mapped to the index of the candidate PSFCH resource in candidate PSFCH resource group 2, which is limited to the starting subchannel of the multicast sidelink transmission.

[0266] In response to receiving a first sidelink transmission, the first wireless device may determine candidate PSFCH resource group 1 for a first PSFCH resource selection because the first sidelink transmission is a multicast transmission with HARQ feedback option 1. The first wireless device may also determine candidate PSFCH resource 1 for HARQ message transmission based on the exemplary mapping rule because candidate PSFCH resource 1 is restricted to a starting subchannel (e.g., subchannel 1) of the first sidelink transmission. In response to receiving a second sidelink transmission, the second wireless device may determine candidate PSFCH resource group 1 for PSFCH resource selection because the second sidelink transmission is a unicast transmission. The second wireless device may also determine candidate PSFCH resource 9 for HARQ message transmission based on the exemplary mapping rule because candidate PSFCH resource 9 is restricted to a starting subchannel (e.g., subchannel 3) of the second sidelink transmission.

[0267] Figure 24 An example of determining PSFCH resources by one or more wireless devices is shown. The first sidelink transmission may be a multicast transmission with HARQ feedback option 2. The second sidelink transmission may be a unicast transmission. In the example, twenty candidate PSFCH resources may be grouped based on grouping method 1. Candidate PSFCH resource group 1 may include candidate PSFCH resources 1, 5, 9, 13, and 17. Candidate PSFCH resource group 2 may include candidate PSFCH resources 2, 3, 4, 6, 7, 8, 10, 11, 12, 14, 15, 16, 18, 19, and 20. Candidate PSFCH resource group 1 may be used to transmit HARQ messages corresponding to unicast sidelink transmissions. Candidate PSFCH resource group 2 may be used to transmit HARQ messages corresponding to multicast sidelink transmissions.

[0268] In an exemplary mapping rule, the index of the starting subchannel of a unicast sidelink transmission may be mapped to the index of a candidate PSFCH resource in candidate PSFCH resource group 1, which is confined within the starting subchannel of the unicast sidelink transmission. The index of the starting subchannel of a group sidelink transmission may be mapped to the index of a candidate PSFCH resource in candidate PSFCH resource group 2, which is confined within the starting subchannel of a multicast sidelink transmission. When multiple candidate PSFCH resources are required for a multicast sidelink transmission with HARQ feedback option 2, the mapping between the index of the starting subchannel of the group sidelink transmission and the index of the candidate PSFCH resources in candidate PSFCH resource group 2 may be used to determine a starting candidate PSFCH resource of the multiple candidate PSFCH resources.

[0269] In response to receiving the first sidelink transmission, one or more first wireless devices may request nine first PSFCH resources (eg, Figure 24The one or more first wireless devices may further determine, based on the exemplary mapping rule, candidate PSFCH resource 2 as the starting candidate PSFCH resource of the nine first PSFCH resources for one or more HARQ message transmissions, because candidate PSFCH resource 2 is restricted to the starting subchannel (e.g., subchannel 1) of the first sidelink transmission. In response to receiving the second sidelink transmission, the second wireless device may determine candidate PSFCH resource group 1 for PSFCH resource selection, because the second sidelink transmission is a unicast transmission. The second wireless device may further determine, based on the exemplary mapping rule, candidate PSFCH resource 9 for HARQ message transmission, because candidate PSFCH resource 9 is restricted to the starting subchannel (e.g., subchannel 3) of the second sidelink transmission.

[0270] In the case of determining the PSFCH resources based on the grouping method 2 of the candidate PSFCH resources, in response to receiving the first sidelink transmission, the one or more first wireless devices may select the nine first PSFCH resources (eg, Figure 24 The one or more first wireless devices may determine candidate PSFCH resource group 2 for selection based on the exemplary mapping rule, based on candidate PSFCH resources 2, 3, 4, 6, 7, 8, 10, 11, and 12 in the first sidelink transmission, because the first sidelink transmission is a multicast transmission with HARQ feedback option 2. The one or more first wireless devices may also determine candidate PSFCH resource 2 as the starting candidate PSFCH resource of the nine first PSFCH resources for the one or more HARQ message transmissions based on the exemplary mapping rule, because candidate PSFCH resource 2 is restricted to the starting subchannel (e.g., subchannel 1) of the first sidelink transmission. In response to receiving the second sidelink transmission, the second wireless device may determine candidate PSFCH resource group 1 for PSFCH resource selection because the second sidelink transmission is a unicast transmission. The second wireless device may also determine candidate PSFCH resource 9 for HARQ message transmission based on the exemplary mapping rule, because candidate PSFCH resource 9 is restricted to the starting subchannel (e.g., subchannel 3) of the multicast sidelink transmission.

[0271] Figure 25 An example of grouping candidate PSFCH resources by side link resource pool is shown. As shown in the figure, the resource pool may include five subchannels. A subchannel in the five subchannels may include four PSFCH resources in the frequency domain. The first five candidate PSFCH resources (e.g., Figure 25 The candidate PSFCH resources 1, 2, 3, 4, and 5 in the CANDIDATE PSFCH RESOURCE GROUP 1 can be grouped into candidate PSFCH resource group 1. The remaining PSFCH resources (e.g., Figure 25Candidate PSFCH resources 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20 in the sidelink resource pool may be grouped into candidate PSFCH resource group 2. In an example, grouping method 1 may be used to generate candidate PSFCH resource group 1 and candidate PSFCH resource group 2. In an example, grouping method 2 may be used to generate candidate PSFCH resource group 1 and candidate PSFCH resource group 2. In the case of grouping method 2, when one or more first HARQ messages correspond to one or more unicast sidelink transmissions or one or more multicast transmissions with HARQ feedback option 1, one or more first PRBs within the sidelink resource pool may be grouped for transmitting the one or more first HARQ messages. When one or more second HARQ messages correspond to one or more multicast transmissions with HARQ feedback option 2, one or more second PRBs within the sidelink resource pool may be grouped for transmitting the one or more second HARQ messages. The one or more first PRBs may partially overlap with the one or more second PRBs.

[0272] There may be a mapping rule between sidelink transmissions and candidate PSFCH resources. The mapping between sidelink transmissions and candidate PSFCH resources may be based on the subchannel index used to transmit the sidelink transmission and the index of the candidate PSFCH resource. For example, the subchannel index may be the starting subchannel index of the PSCCH used to transmit the sidelink transmission. For example, the subchannel index may be the starting subchannel index of the PSSCH used to transmit the sidelink transmission. For example, the index of the candidate PSFCH resource may be the starting PRB index of the candidate PSFCH resource.

[0273] Implementing a grouping approach can improve PSFCH resource efficiency by allocating an appropriate amount of feedback resources in response to different broadcast types and / or different feedback operations. Implementing a grouping approach can reduce interference levels on PSFCH resources and improve HARQ message decoding performance by allocating more feedback resources to multicasts with HARQ feedback option 2. Implementing a grouping approach can increase flexibility in allocating PSFCH resources by enabling overlap between the first feedback resource group and the second feedback resource group.

[0274] like Figure 36A As shown in , SCI can indicate the broadcast type indication of the side link transmission. Figure 36B As shown in , the SCI may also indicate HARQ feedback options corresponding to the sidelink transmission. In an example, in response to receiving Figure 36B, the wireless device may determine a first candidate PSFCH resource group from the multiple candidate PSFCH resource groups based on the SCI indicating that the broadcast type of the sidelink transmission is unicast. In an example, the wireless device may determine the first candidate PSFCH resource group from the multiple candidate PSFCH resource groups based on the SCI indicating that the broadcast type of the sidelink transmission is multicast and the HARQ feedback option is 1. In an example, the wireless device may determine a second candidate PSFCH resource group from the multiple candidate PSFCH resource groups based on the SCI indicating that the broadcast type of the sidelink transmission is multicast and the HARQ feedback option is 2.

[0275] In an exemplary embodiment, a wireless device may determine the grouping of candidate PSFCH resources for a sidelink transmission based on an implicit indication in the SCI of the sidelink transmission. The SCI may include at least one field indicating the broadcast type of the sidelink transmission. The at least one field may indicate a HARQ feedback option. The wireless device may determine the grouping of candidate PSFCH resources based on the implicit indication in the SCI. Compared to explicitly indicating the grouping of candidate PSFCH resources by adding additional bits in the SCI, the implicit indication may save additional bits and reduce SCI overhead.

[0276] Figure 26 An example is shown of determining PSFCH resources based on grouping method 1 of candidate PSFCH resources and counting the indexes of the PSFCH resources in the same order. The first sidelink transmission may be a multicast transmission. The second sidelink transmission may be a unicast transmission. Twenty candidate PSFCH resources may be grouped based on grouping method 1. Candidate PSFCH resource group 1 may include candidate PSFCH resources 1, 2, 3, 4, and 5. Candidate PSFCH resource group 2 may include candidate PSFCH resources 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20. Candidate PSFCH resource group 1 may be used to transmit HARQ messages corresponding to unicast sidelink transmissions. Candidate PSFCH resource group 2 may be used to transmit HARQ messages corresponding to multicast sidelink transmissions.

[0277] There may be a mapping rule between sidelink transmissions and candidate PSFCH resources. In an exemplary mapping rule, the index of the starting subchannel of a unicast sidelink transmission may be mapped to the index of a candidate PSFCH resource in candidate PSFCH resource group 1. The index of the starting subchannel of a group sidelink transmission may be mapped to the index of a candidate PSFCH resource in candidate PSFCH resource group 2.

[0278] In response to receiving a first sidelink transmission, the first wireless device may determine candidate PSFCH resource group 2 for a first PSFCH resource selection because the first sidelink transmission is a multicast transmission. The first wireless device may also determine candidate PSFCH resource 6 for HARQ message transmission based on the exemplary mapping rule because, when the indices of the PSFCH resources are counted in ascending order, candidate PSFCH resource 6 is the first PSFCH resource in candidate PSFCH resource group 2, which can be mapped to the starting subchannel of the first sidelink transmission (e.g., subchannel 1). In response to receiving a second sidelink transmission, the second wireless device may determine candidate PSFCH resource group 1 for PSFCH resource selection because the second sidelink transmission is a unicast transmission. The second wireless device may also determine candidate PSFCH resource 3 for HARQ message transmission based on the exemplary mapping rule because, when the indices of the PSFCH resources are counted in ascending order, candidate PSFCH resource 3 is the third PSFCH resource in candidate PSFCH resource group 1, which can be mapped to the starting subchannel of the second sidelink transmission (e.g., subchannel 3). Note that the selection of candidate PSFCH resources may follow a descending order.

[0279] Figure 27 An example of determining PSFCH resources based on method 1 for grouping candidate PSFCH resources and counting the indices of the PSFCH resources in different orders is shown. In response to receiving a first sidelink transmission, the first wireless device can determine candidate PSFCH resource group 2 for first PSFCH resource selection because the first sidelink transmission is a multicast transmission. The first wireless device can also determine candidate PSFCH resource 20 for HARQ message transmission based on the exemplary mapping rule because, when the indices of the PSFCH resources are counted in descending order, candidate PSFCH resource 20 is the first PSFCH resource in candidate PSFCH resource group 2, which can be mapped to the starting subchannel (e.g., subchannel 1) of the first sidelink transmission. In response to receiving a second sidelink transmission, the second wireless device can determine candidate PSFCH resource group 1 for PSFCH resource selection because the second sidelink transmission is a unicast transmission. The second wireless device can also determine candidate PSFCH resource 3 for HARQ message transmission based on the exemplary mapping rule, because when the indexes of the PSFCH resources are counted in ascending order, candidate PSFCH resource 3 is the third PSFCH resource in candidate PSCFH resource group 1, which can be mapped to the starting subchannel of the second side link transmission (e.g., subchannel 3).

[0280] Figure 28This example illustrates determining PSFCH resources based on method 2 for grouping candidate PSFCH resources and counting PSFCH resource indices in the same order. The first sidelink transmission may be a multicast transmission with HARQ feedback option 1. The second sidelink transmission may be a unicast transmission. Twenty candidate PSFCH resources may be grouped based on method 2. Candidate PSFCH resource group 1 may include candidate PSFCH resources 1, 2, 3, 4, and 5. Candidate PSFCH resource group 2 may include candidate PSFCH resources 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20. In response to the sidelink transmission being a unicast transmission or a multicast transmission with HARQ feedback option 1, candidate PSFCH resource group 1 may be used to transmit a HARQ message corresponding to the sidelink transmission. In response to the sidelink transmission being a multicast transmission with HARQ feedback option 2, candidate PSFCH resource group 2 may be used to transmit a HARQ message corresponding to the sidelink transmission.

[0281] In an exemplary mapping rule, the index of the starting subchannel of a unicast sidelink transmission may be mapped to the index of a candidate PSFCH resource in candidate PSFCH resource group 1. The index of the starting subchannel of a group sidelink transmission may be mapped to the index of a candidate PSFCH resource in candidate PSFCH resource group 2.

[0282] In response to receiving a first sidelink transmission, the first wireless device may determine candidate PSFCH resource group 1 for a first PSFCH resource selection because the first sidelink transmission is a multicast transmission with HARQ feedback option 1. The first wireless device may also determine candidate PSFCH resource 1 for HARQ message transmission based on an exemplary mapping rule because, when the indices of the PSFCH resources are counted in ascending order, candidate PSFCH resource 1 is the first PSFCH resource in candidate PSFCH resource group 1, which can be mapped to the starting subchannel (e.g., subchannel 1) of the first sidelink transmission. In response to receiving a second sidelink transmission, the second wireless device may determine candidate PSFCH resource group 1 for PSFCH resource selection because the second sidelink transmission is a unicast transmission. The second wireless device may also determine candidate PSFCH resource 3 for HARQ message transmission based on the exemplary mapping rule, because when the indices of the PSFCH resources are counted in ascending order, candidate PSFCH resource 3 is the third PSFCH resource in candidate PSFCH resource group 1, which can be mapped to the starting subchannel (e.g., subchannel 3) of the second sidelink transmission. Note that the selection of candidate PSFCH resources may follow a descending order.

[0283] Figure 29An example of determining PSFCH resources based on method 2 for grouping candidate PSFCH resources and counting PSFCH resource indices in different orders is shown. In response to receiving a first sidelink transmission, a first wireless device may determine candidate PSFCH resource group 1 for first PSFCH resource selection because the first sidelink transmission is a multicast transmission with HARQ feedback option 1. The first wireless device may also determine candidate PSFCH resource 5 for HARQ message transmission based on an exemplary mapping rule because, when counting the PSFCH resource indices in descending order, candidate PSFCH resource 5 is the first PSFCH resource in candidate PSFCH resource group 1 and can be mapped to the starting subchannel (e.g., subchannel 1) of the first sidelink transmission. In response to receiving a second sidelink transmission, a second wireless device may determine candidate PSFCH resource group 1 for PSFCH resource selection because the second sidelink transmission is a unicast transmission. The second wireless device can also determine candidate PSFCH resource 3 for HARQ message transmission based on the exemplary mapping rule, because when the indexes of the PSFCH resources are counted in ascending order, candidate PSFCH resource 3 is the third PSFCH resource in candidate PSCFH resource group 1, which can be mapped to the starting subchannel of the second side link transmission (e.g., subchannel 3).

[0284] Figure 30 An example of determining PSFCH resources by one or more wireless devices when counting the indices of the PSFCH resources in the same order is shown. The first sidelink transmission may be a multicast transmission with HARQ feedback option 2. The second sidelink transmission may be a unicast transmission. In the example, twenty candidate PSFCH resources may be grouped based on grouping method 1. Candidate PSFCH resource group 1 may include candidate PSFCH resources 1, 2, 3, 4, and 5. Candidate PSFCH resource group 2 may include candidate PSFCH resources 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20. Candidate PSFCH resource group 1 may be used to transmit HARQ messages corresponding to unicast sidelink transmissions. Candidate PSFCH resource group 2 may be used to transmit HARQ messages corresponding to multicast sidelink transmissions.

[0285] In an exemplary mapping rule, the index of the starting subchannel of a unicast sidelink transmission may be mapped to the index of a candidate PSFCH resource in candidate PSFCH resource group 1. The index of the starting subchannel of a group sidelink transmission may be mapped to the index of a candidate PSFCH resource in candidate PSFCH resource group 2. When a multicast sidelink transmission with HARQ feedback option 2 requires multiple candidate PSFCH resources, the mapping between the index of the starting subchannel of the group sidelink transmission and the index of the candidate PSFCH resources in candidate PSFCH resource group 2 may be used to determine a starting candidate PSFCH resource of the multiple candidate PSFCH resources.

[0286] In response to receiving the first sidelink transmission, one or more first wireless devices may request K (eg, K=9) first PSFCH resources (eg, Figure 30Candidate PSFCH resources 6, 7, 8, 9, 10, 11, 12, 13, and 14) in the sidelink transmission group are selected to determine candidate PSFCH resource group 2 because the first sidelink transmission is a multicast transmission. For example, K can be determined based on the number of receiver wireless devices in the sidelink transmission group. For example, K can be configured by the transmitter wireless device of the sidelink transmission group. For example, K can be configured as a resource pool for multicast sidelink transmission. For example, K can be a fixed value for multicast HARQ feedback option 2. For example, K can be indicated by the SCI for scheduling the multicast sidelink transmission or by the reserved SCI for the sidelink resources. Each of the one or more first wireless devices can also select a PSFCH resource from the selected PSFCH resources. In an example, the transmitter wireless device of the sidelink transmission can be configured to determine an index of a PSFCH resource within the selected PSFCH resources. For example, an index i from 0 to K-1 (e.g., K=9) can be assigned to each receiver wireless device of the one or more first wireless devices. Each receiver wireless device can select the i-th PSFCH resource from the selected PSFCH resources. In an example, each receiver wireless device from the one or more first wireless devices may randomly select a PSFCH resource from the selected PSFCH resources. In an example, each receiver wireless device from the one or more first wireless devices may select a PSFCH resource from the selected PSFCH resources based on a UE ID (e.g., UE ID %K). In an example, each receiver wireless device from the one or more first wireless devices may select a PSFCH resource from the selected PSFCH resources based on a distance between each receiver wireless device and a transmitter wireless device sending a first sidelink transmission. In an example, each receiver wireless device from the one or more first wireless devices may select a PSFCH resource from the selected PSFCH resources based on a reference signal received power (RSRP) level of one or more reference signals in the first sidelink transmission. The one or more first wireless devices may also determine, based on the exemplary mapping rule, candidate PSFCH resource 6 as a starting candidate PSFCH resource of the nine first PSFCH resources for one or more HARQ message transmissions, because when the indices of the PSFCH resources are counted in ascending order, candidate PSFCH resource 6 is the first PSFCH resource in candidate PSFCH resource group 2, which can be mapped to the starting subchannel (e.g., subchannel 1) of the first sidelink transmission. In response to receiving the second sidelink transmission, the second wireless device may determine candidate PSFCH resource group 1 for PSFCH resource selection because the second sidelink transmission is a unicast transmission.The second wireless device may also determine candidate PSFCH resource 3 for HARQ message transmission based on the exemplary mapping rule, because when the indices of the PSFCH resources are counted in ascending order, candidate PSFCH resource 3 is the third PSFCH resource in candidate PSFCH resource group 1, which can be mapped to the starting subchannel (e.g., subchannel 3) of the second sidelink transmission. Note that the selection of candidate PSFCH resources may follow a descending order.

[0287] In the case of determining the PSFCH resources based on the grouping method 2 of the candidate PSFCH resources, in response to receiving the first sidelink transmission, the one or more first wireless devices may select the nine first PSFCH resources (eg, Figure 30 The one or more first wireless devices may further determine, based on the exemplary mapping rule, candidate PSFCH resource 6 as the starting candidate PSFCH resource of the nine first PSFCH resources for the one or more HARQ message transmissions, because when the indices of the PSFCH resources are counted in ascending order, candidate PSFCH resource 6 is the first PSFCH resource in candidate PSFCH resource group 2, which can be mapped to the starting subchannel (e.g., subchannel 1) of the first sidelink transmission. In response to receiving the second sidelink transmission, the second wireless device may determine candidate PSFCH resource group 1 for PSFCH resource selection because the second sidelink transmission is a unicast transmission. The second wireless device may also determine candidate PSFCH resource 3 for HARQ message transmission based on the exemplary mapping rule, because when the indices of the PSFCH resources are counted in ascending order, candidate PSFCH resource 3 is the third PSFCH resource in candidate PSFCH resource group 1, which can be mapped to the starting subchannel (e.g., subchannel 3) of the second sidelink transmission. Note that the selection of candidate PSFCH resources may follow a descending order.

[0288] Figure 31 An example of determining a PSFCH resource by one or more wireless devices when the indexes of the PSFCH resources are counted in different orders is shown. In the case of determining the PSFCH resource based on the grouping method 1 of the candidate PSFCH resources, in response to receiving the first sidelink transmission, one or more first wireless devices may select nine first PSFCH resources (e.g., Figure 31The one or more first wireless devices may further determine, based on the exemplary mapping rule, candidate PSFCH resource 20 as the starting candidate PSFCH resource of the nine first PSFCH resources for the one or more HARQ message transmissions, because when the indices of the PSFCH resources are counted in descending order, candidate PSFCH resource 20 is the first PSFCH resource in candidate PSFCH resource group 2, which can be mapped to the starting subchannel (e.g., subchannel 1) of the first sidelink transmission. In response to receiving the second sidelink transmission, the second wireless device may determine candidate PSFCH resource group 1 for PSFCH resource selection because the second sidelink transmission is a unicast transmission. The second wireless device can also determine candidate PSFCH resource 3 for HARQ message transmission based on the exemplary mapping rule, because when the indexes of the PSFCH resources are counted in ascending order, candidate PSFCH resource 3 is the third PSFCH resource in candidate PSCFH resource group 1, which can be mapped to the starting subchannel of the second side link transmission (e.g., subchannel 3).

[0289] In the case of determining the PSFCH resources based on the grouping method 2 of the candidate PSFCH resources, in response to receiving the first sidelink transmission, the one or more first wireless devices may select the nine first PSFCH resources (eg, Figure 31The one or more first wireless devices may further determine candidate PSFCH resource group 2 for selection from candidate PSFCH resources 12, 13, 14, 15, 16, 17, 18, 19, and 20 in the first sidelink transmission because the first sidelink transmission is a multicast transmission with HARQ feedback option 2. The one or more first wireless devices may further determine candidate PSFCH resource 20 as a starting candidate PSFCH resource of the nine first PSFCH resources for the one or more HARQ message transmissions based on the exemplary mapping rule because, when the indices of the PSFCH resources are counted in descending order, candidate PSFCH resource 20 is the first PSFCH resource in candidate PSFCH resource group 2 that can be mapped to a starting subchannel (e.g., subchannel 1) of the first sidelink transmission. In response to receiving the second sidelink transmission, the second wireless device may determine candidate PSFCH resource group 1 for PSFCH resource selection because the second sidelink transmission is a unicast transmission. The second wireless device can also determine candidate PSFCH resource 3 for HARQ message transmission based on the exemplary mapping rule, because when the indexes of the PSFCH resources are counted in ascending order, candidate PSFCH resource 3 is the third PSFCH resource in candidate PSCFH resource group 1, which can be mapped to the starting subchannel of the second side link transmission (e.g., subchannel 3).

[0290] Figure 32 An example of determining a PSFCH resource by one or more wireless devices when counting the indexes of the PSFCH resource in both ascending and descending order is shown. The first sidelink transmission may be a multicast transmission with HARQ feedback option 2. The second sidelink transmission may be a unicast transmission. The third sidelink transmission may be a multicast transmission with HARQ feedback option 2. In the example, twenty candidate PSFCH resources may be grouped based on grouping method 1. Candidate PSFCH resource group 1 may include candidate PSFCH resources 1, 2, 3, 4, and 5. Candidate PSFCH resource group 2 may include candidate PSFCH resources 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20. Candidate PSFCH resource group 1 may be used to transmit a HARQ message corresponding to a unicast sidelink transmission. Candidate PSFCH resource group 2 may be used to transmit a HARQ message corresponding to a multicast sidelink transmission.

[0291] In an exemplary mapping rule, the index of the starting subchannel of a unicast sidelink transmission may be mapped to the index of a candidate PSFCH resource in candidate PSFCH resource group 1. The index of the starting subchannel of a group sidelink transmission may be mapped to the index of a candidate PSFCH resource in candidate PSFCH resource group 2. When a multicast sidelink transmission with HARQ feedback option 2 requires multiple candidate PSFCH resources, the mapping between the index of the starting subchannel of the group sidelink transmission and the index of the candidate PSFCH resources in candidate PSFCH resource group 2 may be used to determine a starting candidate PSFCH resource of the multiple candidate PSFCH resources.

[0292] In response to receiving the first sidelink transmission, one or more first wireless devices may request nine first PSFCH resources (eg, Figure 32 The one or more first wireless devices may further determine, based on the exemplary mapping rule, candidate PSFCH resource 20 as the starting candidate PSFCH resource of the nine first PSFCH resources for the one or more HARQ message transmissions, because when the indices of the PSFCH resources are counted in descending order, candidate PSFCH resource 20 is the first PSFCH resource in candidate PSFCH resource group 2, which can be mapped to the starting subchannel (e.g., subchannel 1) of the first sidelink transmission. In response to receiving the second sidelink transmission, the second wireless device may determine candidate PSFCH resource group 1 for PSFCH resource selection because the second sidelink transmission is a unicast transmission. The second wireless device may also determine candidate PSFCH resource 3 for HARQ message transmission based on the exemplary mapping rule, because when the indices of the PSFCH resources are counted in ascending or descending order, candidate PSFCH resource 3 is the third PSFCH resource in candidate PSFCH resource group 1, which can be mapped to the starting subchannel (e.g., subchannel 3) of the second sidelink transmission. In response to receiving the third sidelink transmission, one or more third wireless devices may select four third PSFCH resources (e.g., Figure 32The one or more third wireless devices may also determine candidate PSFCH resource 6 as the starting candidate PSFCH resource of the four third PSFCH resources for the one or more HARQ message transmissions based on the exemplary mapping rule, because when the indices of the PSFCH resources are counted in ascending order, candidate PSFCH resource 6 is the first PSFCH resource in candidate PSFCH resource group 2, and the PSFCH resource may be mapped to the starting subchannel (e.g., subchannel 5) of the third sidelink transmission.

[0293] In the case of determining PSFCH resources based on method 2 of grouping candidate PSFCH resources, in response to receiving a first sidelink transmission, one or more first wireless devices may select nine first PSFCH resources (e.g., Figure 32 The one or more first wireless devices may further determine, based on the exemplary mapping rule, candidate PSFCH resource 20 as the starting candidate PSFCH resource of the nine first PSFCH resources for the one or more HARQ message transmissions, because when the indices of the PSFCH resources are counted in descending order, candidate PSFCH resource 20 is the first PSFCH resource in candidate PSFCH resource group 2, which can be mapped to the starting subchannel (e.g., subchannel 1) of the first sidelink transmission. In response to receiving the second sidelink transmission, the second wireless device may determine candidate PSFCH resource group 1 for PSFCH resource selection because the second sidelink transmission is a unicast transmission. The second wireless device may also determine candidate PSFCH resource 3 for HARQ message transmission based on the exemplary mapping rule, because when the indices of the PSFCH resources are counted in ascending or descending order, candidate PSFCH resource 3 is the third PSFCH resource in candidate PSFCH resource group 1, which can be mapped to the starting subchannel (e.g., subchannel 3) of the second sidelink transmission. In response to receiving the third sidelink transmission, one or more third wireless devices may select four third PSFCH resources (e.g., Figure 32The one or more third wireless devices may further determine candidate PSFCH resource 6 as a starting candidate PSFCH resource of the four third PSFCH resources for the one or more HARQ message transmissions based on the exemplary mapping rule, because when the indices of the PSFCH resources are counted in ascending order, candidate PSFCH resource 6 is the first PSFCH resource in candidate PSFCH resource group 2, and the PSFCH resource may be mapped to the starting subchannel (e.g., subchannel 5) of the third sidelink transmission.

[0294] Figure 33 An example of a procedure for feedback resource selection and HARQ message transmission in Mode 1 is shown. In this example, base station 3310 may transmit one or more control messages to wireless device 3320. A control message in the one or more control messages may be a radio resource control (RRC) message. A control message in the one or more control messages may be a medium access control element (MAC CE). A control message in the one or more control messages may be downlink control information (DCI). In response to receiving the one or more control messages, wireless device 3320 may transmit a sidelink transmission to wireless device 3330. The sidelink transmission may include sidelink control information (SCI). The sidelink transmission may also include a transport block (TB). When the SCI indicates control information for a TB, the SCI may be associated with the TB. In response to receiving the sidelink transmission, wireless device 3330 may determine one or more radio resources for feedback transmission based on the SCI of the sidelink transmission. The one or more radio resources for feedback transmission may be one or more PSFCH resources. The feedback transmission may be a HARQ message transmission from wireless device 3330 to wireless device 3320 corresponding to decoding of the TB of the sidelink transmission. Wireless device 3330 may transmit feedback via the determined one or more radio resources.

[0295] Figure 34A and Figure 34B An example of the one or more control messages is shown. Figure 34AAs shown in , the one or more control messages may indicate a grouping of candidate PSFCH resources. In an example, the grouping of candidate PSFCH resources may indicate a plurality of candidate PSFCH resource groups and a portion of candidate PSFCH resources in a candidate PSFCH resource group in the plurality of candidate PSFCH resource groups. For example, an X percentage of candidate PSFCH resources are located in a first candidate PSFCH resource group, and a Y percentage of candidate PSFCH resources are located in a second candidate PSFCH resource group, and so on. In an example, the grouping of candidate PSFCH resources may indicate a plurality of candidate PSFCH resource groups and the number of candidate PSFCH resources in a candidate PSFCH resource group in the plurality of candidate PSFCH resource groups. For example, the number of x candidate PSFCH resources are located in a first candidate PSFCH resource group, and the number of y candidate PSFCH resources are located in a second candidate PSFCH resource group, and so on. For example, the plurality of candidate PSFCH resource groups may be generated based on grouping method 1. For example, the plurality of candidate PSFCH resource groups may be generated based on grouping method 2. As Figure 34B As shown in , the one or more control messages may also indicate the PSFCH format.

[0296] Figure 35 An example of a procedure for feedback resource selection and HARQ message transmission in Mode 2 is shown. In this example, wireless device 3510 may determine a grouping of feedback resources. The feedback resources may be candidate PSFCH resources. Wireless device 3510 may also determine a PSFCH format. Wireless device 3510 may transmit a sidelink transmission to wireless device 3520. The sidelink transmission may include an SCI. The sidelink transmission may also include a TB. When the SCI indicates control information for a TB, the SCI may be associated with the TB. In response to receiving the sidelink transmission, wireless device 3520 may determine one or more radio resources for feedback transmission based on the SCI of the sidelink transmission. The one or more radio resources for feedback transmission may be one or more PSFCH resources. The feedback transmission may be a HARQ message transmission from wireless device 3520 to wireless device 3510 corresponding to decoding of the TB of the sidelink transmission. Wireless device 3520 may transmit feedback via the determined one or more radio resources.

[0297] Figure 36A 、 Figure 36B 、 Figure 36C 、 Figure 36D and Figure 36E An example of SCI is shown.

[0298] like Figure 36AAs shown in , the SCI may indicate a broadcast type indication of the sidelink transmission. The SCI may also indicate a grouping of candidate PSFCH resources. In an example, the grouping of candidate PSFCH resources may indicate a plurality of candidate PSFCH resource groups and a portion of candidate PSFCH resources in a candidate PSFCH resource group in the plurality of candidate PSFCH resource groups. In an example, the grouping of candidate PSFCH resources may indicate a plurality of candidate PSFCH resource groups and the number of candidate PSFCH resources in a candidate PSFCH resource group in the plurality of candidate PSFCH resource groups. For example, the plurality of candidate PSFCH resource groups may be generated based on grouping method 1. For example, the plurality of candidate PSFCH resource groups may be generated based on grouping method 2.

[0299] In the example of using grouping method 1, in response to receiving Figure 36A , the wireless device may determine a first candidate PSFCH resource group from the plurality of candidate PSFCH resource groups based on the SCI indicating that the broadcast type of the sidelink transmission is unicast. The wireless device may determine one or more PSFCH resources in the first candidate PSFCH resource group based on a mapping between a subchannel index of the sidelink transmission and an index of a PSFCH resource from the one or more PSFCH resources within the first candidate PSFCH resource group. The wireless device may transmit a HARQ message via the one or more PSFCH resources in response to decoding a TB of the sidelink transmission.

[0300] In the example of using grouping method 1, in response to receiving Figure 36A , the wireless device may determine a second candidate PSFCH resource group from the plurality of candidate PSFCH resource groups based on the SCI indicating that the broadcast type of the sidelink transmission is multicast. The wireless device may determine one or more PSFCH resources in the second candidate PSFCH resource group based on a mapping between a subchannel index of the sidelink transmission and an index of a PSFCH resource from the one or more PSFCH resources within the second candidate PSFCH resource group. The wireless device may transmit a HARQ message via the one or more PSFCH resources in response to decoding a TB of the sidelink transmission.

[0301] like Figure 36B As shown in , the SCI may also indicate the HARQ feedback options corresponding to the sidelink transmission.

[0302] In an example, in response to receiving Figure 36B, the wireless device may determine a first candidate PSFCH resource group from the multiple candidate PSFCH resource groups based on the SCI indicating that the broadcast type of the sidelink transmission is unicast. In an example, the wireless device may determine the first candidate PSFCH resource group from the multiple candidate PSFCH resource groups based on the SCI indicating that the broadcast type of the sidelink transmission is multicast and the HARQ feedback option is 1. In an example, the wireless device may determine a second candidate PSFCH resource group from the multiple candidate PSFCH resource groups based on the SCI indicating that the broadcast type of the sidelink transmission is multicast and the HARQ feedback option is 2.

[0303] like Figure 36C As shown in , the SCI may also indicate the number of required feedback resources corresponding to the sidelink transmission.

[0304] In an example, in response to receiving Figure 36C Based on the SCI shown, the wireless device may determine a first candidate PSFCH resource group from the multiple candidate PSFCH resource groups based on the SCI indicating that the broadcast type of the sidelink transmission is unicast. In an example, the wireless device may determine the first candidate PSFCH resource group from the multiple candidate PSFCH resource groups based on the SCI indicating that the broadcast type of the sidelink transmission is multicast and the HARQ feedback option is 1. In an example, the wireless device may implicitly determine the HARQ feedback option based on the broadcast type and the number of required feedback resources corresponding to the sidelink transmission. That is, if the broadcast type of the sidelink transmission is multicast and the number of required feedback resources is less than or equal to a threshold, the wireless device may determine that the sidelink transmission is a multicast transmission and the HARQ feedback option is 1. If the broadcast type of the sidelink transmission is multicast and the number of required feedback resources is greater than the threshold, the wireless device may determine that the sidelink transmission is a multicast transmission and the HARQ feedback option is 2.

[0305] like Figure 36D As shown in , the SCI can also indicate the mapping order of PSFCH resources corresponding to the sidelink transmission.

[0306] In an example, in response to receiving Figure 36D , one or more first wireless devices may determine one or more first PSFCH resources corresponding to the first sidelink transmission. The one or more first wireless devices may also determine a first mapping order of the one or more first PSFCH resources based on the first SCI. In an example, in response to receiving Figure 36D, one or more second wireless devices may determine one or more second PSFCH resources corresponding to the second sidelink transmission based on the second SCI shown in . The one or more second wireless devices may also determine a second mapping order of the one or more second PSFCH resources based on the second SCI. The first mapping order may be the same as the second mapping order. The first mapping order may be different from the second mapping order. The one or more first PSFCH resources may be in the same time slot as the one or more second PSFCH resources. The one or more first PSFCH resources may be in a different time slot from the one or more second PSFCH resources. The one or more first PSFCH resources may be in the same candidate PSCFH resource group as the one or more second PSFCH resources. The one or more first PSFCH resources may be in a different candidate PSCFH resource group from the one or more second PSFCH resources.

[0307] like Figure 36E As shown in , SCI can also indicate the PSFCH format.

[0308] In an example, in response to receiving Figure 36E The wireless device may determine the PSFCH format based on the first SCI shown in FIG.

[0309] In an example, a wireless device may receive a sidelink transmission including a TB and an SCI, where the SCI may indicate a broadcast type. The wireless device may select a first feedback resource group from a plurality of feedback resource groups based on the SCI indicating that the broadcast type of the sidelink transmission is unicast. The wireless device may transmit a HARQ message via one or more feedback resources in the selected feedback resource group in response to decoding the TB. In an example, the wireless device may select a second feedback resource group from the plurality of feedback resource groups based on the SCI indicating that the broadcast type of the sidelink transmission is multicast.

[0310] In an example, the SCI may indicate a HARQ feedback option. The wireless device may select a second feedback resource group from the plurality of feedback resource groups based on the SCI indicating that the broadcast type of the sidelink transmission is multicast and the HARQ feedback option is HARQ feedback option 2. In an example, the wireless device may select a first feedback resource group from the plurality of feedback resource groups based on the SCI indicating that the broadcast type of the sidelink transmission is multicast and the HARQ feedback option is HARQ feedback option 1. In an example, the SCI may indicate a number of required feedback resources corresponding to the sidelink transmission. The HARQ feedback option may be determined based on the number of required feedback resources. In an example, the SCI may include a parameter indicating the HARQ feedback option.

[0311] In an example, the wireless device may select the one or more feedback resources from the selected feedback resource group based on a mapping order. The SCI may indicate the mapping order. The mapping order may be a first mapping order starting from the feedback resource with the lowest index in the selected feedback resource group. The mapping order may be a second mapping order starting from the feedback resource with the highest index in the selected feedback resource group.

[0312] In an example, the wireless device may receive a sidelink transmission via a sidelink resource pool. The plurality of feedback resource groups corresponding to the sidelink transmission may be distributed within the sidelink resource pool. In an example, the plurality of feedback resource groups may be proportionally distributed among a plurality of subchannels within the sidelink resource pool.

[0313] In an example, the wireless device may select the one or more feedback resources from the selected feedback resource group based on a mapping between an index of the feedback resource in the selected one or more feedback resources and a subchannel index of the sidelink transmission. In an example, the SCI may indicate a PSFCH format.

[0314] Figure 37 A flowchart illustrating aspects of an exemplary embodiment of the present disclosure is provided. At 3710, a wireless device may receive a sidelink transmission. The sidelink transmission may include a transport block. At 3720, the wireless device may determine a feedback resource from a first feedback resource in response to the sidelink transmission indicating one of unicast and multicast with a first feedback operation, and may determine a feedback resource from a second feedback resource in response to the sidelink transmission indicating multicast with a second feedback operation. At 3730, the wireless device may transmit feedback for the transport block via the feedback resource.

[0315] According to an exemplary embodiment, a wireless device may receive a sidelink transmission. According to an exemplary embodiment, the sidelink transmission may include a transport block and at least one field indicating, for the transport block, one of: unicast; multicast with a first feedback operation; or multicast with a second feedback operation. According to an exemplary embodiment, in response to receiving the transport block, the wireless device may determine a feedback resource from feedback resources. According to an exemplary embodiment, the feedback resources may include a first feedback resource and a second feedback resource. According to an exemplary embodiment, the first feedback resource may be used for the unicast and multicast with the first feedback operation. According to an exemplary embodiment, the second feedback resource may be used for the multicast with the second feedback operation. According to an exemplary embodiment, the wireless device may transmit feedback for the transport block via the feedback resource.

[0316] According to an exemplary embodiment, a wireless device may receive a sidelink transmission including a transport block. According to an exemplary embodiment, the sidelink transmission may indicate one of the following for the transport block: unicast; multicast with a first feedback operation; or multicast with a second feedback operation. According to an exemplary embodiment, in response to receiving the transport block, the wireless device may determine a feedback resource from feedback resources. According to an exemplary embodiment, the feedback resource may include a first feedback resource and a second feedback resource. According to an exemplary embodiment, the first feedback resource may be used for the unicast and multicast with the first feedback operation. According to an exemplary embodiment, the second feedback resource may be used for the multicast with the second feedback operation. According to an exemplary embodiment, the wireless device may transmit feedback for the transport block via the feedback resource.

[0317] According to an exemplary embodiment, a wireless device may receive a sidelink transmission including a transport block. According to an exemplary embodiment, the wireless device may determine a feedback resource from feedback resources. According to an exemplary embodiment, the feedback resources may include a first feedback resource and a second feedback resource. According to an exemplary embodiment, the first feedback resource may be used in response to the sidelink transmission indicating one of a unicast and a multicast with a first feedback operation. According to an exemplary embodiment, the second feedback resource may be used in response to the sidelink transmission indicating a multicast with a second feedback operation. According to an exemplary embodiment, the wireless device may transmit feedback for the transport block via the feedback resource.

[0318] According to an exemplary embodiment, a wireless device may receive a sidelink transmission including a transport block. According to the exemplary embodiment, the wireless device may determine a feedback resource from a first feedback resource in response to the sidelink transmission indicating one of a unicast and a multicast with a first feedback operation, and may determine a feedback resource from a second feedback resource in response to the sidelink transmission indicating a multicast with a second feedback operation. According to the exemplary embodiment, the wireless device may transmit feedback for the transport block via the feedback resource.

[0319] According to an exemplary embodiment, the determining of the feedback resource may include determining the feedback resource from feedback resources including the first feedback resource and the second feedback resource.

Claims

1. A wireless communication method, comprising: transmitting, by the wireless device, a sidelink transmission comprising a transport block; and receiving feedback for the transport block via a feedback resource, in, The feedback resources come from: A first feedback resource indicates, in response to the sidelink transmission, one of the following: Unicast; or Multicast with first feedback operation, The first feedback resource is used for the unicast and the multicast with the first feedback operation; and A second feedback resource is provided, in response to the sidelink transmission indicating a multicast with a second feedback operation.

2. The method according to claim 1, wherein The feedback resource is one of a feedback resource pool. 3 . The method according to claim 2 , wherein the feedback resource pool comprises the first feedback resource and the second feedback resource.

4. The method of claim 2, wherein the determination of the feedback resources is in response to the transmission of the sidelink transmission. The method according to claim 2 , wherein the resources in the feedback resource pool are radio resources of a physical sidelink feedback channel.

6. The method according to claim 2, wherein the resources in the feedback resource pool are grouped into: a first set of said first feedback resources; and a second group of the second feedback resources.

7. The method according to claim 6, wherein: The first group includes the first feedback resource having a first index; and The second group includes the second feedback resource having a second index.

8. The method of claim 2, wherein the feedback resource is determined based on a mapping between an index of the feedback resource and a subchannel index of the sidelink transmission.

9. The method of claim 1, wherein: In the first feedback operation, the feedback information only includes negative acknowledgement (NACK); and In the second feedback operation, the feedback information includes ACK or NACK.

10. The method of claim 1, wherein the first feedback resource and the second feedback resource comprise overlapping radio resources. The method of claim 1 , comprising determining an index of the feedback resource.

12. The method according to claim 1, wherein the feedback resource is determined by: determining, based on a first rule, a first index of a first feedback resource from the first feedback resources for the unicast and the multicast with the first feedback operation; and A second index of a second feedback resource from the second feedback resources for the multicast with the second feedback operation is determined based on a second rule.

13. The method of claim 1 , wherein the sidelink transmission comprises sidelink control information (SCI) for the transport block, and The SCI indicates a number of required feedback resources corresponding to the sidelink transmission.

14. A wireless device comprising: one or more processors; as well as A memory storing instructions that, when executed by the one or more processors, cause the wireless device to perform the method of any one of claims 1 to 13.

15. A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform the method of any one of claims 1 to 13.

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