Sidelink communication

Abstract

Methods for transmitting channel state information and / or position information between nodes in a network. In particular, procedures and systems for sidelink groupcast transmissions in a cellular network.

Description

Technical Field

[0001] The following disclosure relates to sidelink communication, and in particular to reporting the channel quality or location of such communication. Background Technology

[0002] Wireless communication systems such as third-generation (3G) mobile phone standards and technologies are well-known. Such 3G standards and technologies have been developed by the 3rd Generation Partnership Project (3GPP). Third-generation wireless communication has generally been developed to support macrocell mobile phone communication. Communication systems and networks have evolved towards broadband and mobile systems.

[0003] In a cellular wireless communication system, user equipment (UE) connects to a radio access network (RAN) via a radio link. The radio access network includes a set of base stations providing radio links to UEs located in cells covered by base stations, and an interface to a core network (CN) that provides overall network control. As will be understood, the radio access network and the core network each perform their respective functions relevant to the overall network. For convenience, the term "cellular network" will be used to refer to the combined radio access network and core network, and will be understood to refer to the corresponding systems used to perform the disclosed functions.

[0004] The 3rd Generation Partnership Project developed the so-called Long Term Evolution (LTE) system, namely the Evolved Universal Mobile Telecommunications System Territorial Radio Access Network (E-UTRAN), for mobile access networks, in which one or more macro cells are supported by base stations called eNodeBs or eNBs (evolved NodeBs). More recently, LTE has further evolved into the so-called 5G or NR (New Radio) system, in which one or more cells are supported by base stations called gNBs. NR is proposed to use the Orthogonal Frequency Division Multiplexing (OFDM) physical transport format.

[0005] In traditional cellular communication networks, all signaling occurs between each mobile device and the base station, rather than directly between mobile devices, even when they are within each other's wireless communication range. This can lead to inefficient use of wireless transmission resources and potentially increase the use of base station resources. Sidelink communication allows mobile devices to communicate directly, rather than through base stations, potentially improving the utilization of both wireless and base station resources. Sidelink communication is considered particularly valuable for machine-to-machine communication, especially vehicle-to-vehicle (V2V) and vehicle-to-everything (V2X) communication.

[0006] There are three main categories of sidechain communication—unicast, multicast, and broadcast. Unicast transmission refers to one-to-one transmission between user equipment. Multicast transmission is one-to-many transmission, but only user equipment within the group can receive the transmission. Broadcast transmission is one-to-many transmission, and the receivers cannot be controlled.

[0007] Transmitters can use Channel State Information (CSI) for link adaptation, allowing them to select appropriate modulation and coding schemes (MCS) and use other parameters such as transmit power. CSI can also be used to aid in correct beamforming when using multiple antennas or spatial multiplexing.

[0008] In Frequency Division Duplex (FDD) systems, channel state information (CSO) is typically estimated at the receiver using reference symbols transmitted by the transmitter. The CSO is then transmitted back to the transmitter for use. The same process can be used in Time Division Duplex (TDD) systems, or the user equipment (UE) can estimate the CSO using return transmissions from the receiver UE. However, this method assumes channel reciprocity, which may not be the case due to hardware variations in the UE. Therefore, it is more common to employ a method where the receiver estimates the CSO and then sends it to the transmitter.

[0009] Multicast communication presents particular challenges for channel state information estimation because the number of links increases exponentially with the number of user devices in the group. To date, no effort has been made to address this problem of providing channel state information estimation in multicast scenarios.

[0010] Sharing location information among user equipment can also be beneficial. For example, location information can be used for user grouping, relay / cooperation management, group leader selection, and / or power control. Typically, the term "location" refers to the absolute location of a user equipment, which other user equipment (or base stations or other nodes) can use to calculate distance and direction. The word "location" will be used herein as a general term for information relating to location, distance, and / or position. In multicast systems, location information can be particularly useful because it can be used to define the behavior of sidechain receivers. For example, receivers may not need to transmit hybrid automatic repeat request feedback beyond a certain distance from the transmitter.

[0011] The following disclosure relates to various improvements to cellular wireless communication systems, particularly sidelink communication in such systems. Summary of the Invention

[0012] This overview is provided to introduce the selection of concepts in a simplified form, which will be further described in the detailed description below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0013] A method for determining channel state information in a multicast system is provided, the method comprising the steps of: sending a signal including a channel state information reference signal from a first user equipment (User Equipment) of a group of User Equipment (User Equipment) as a multicast message to all other User Equipment (User Equipment) in the group; and sending a signal including channel state information from each User Equipment (User Equipment) in the group that received the channel state information reference signal to the first User Equipment.

[0014] The transmission resources used for channel state information reference signals and / or channel state information are allocated by the base station.

[0015] One indication of the allocated resources is sent from the base station to the first user equipment, and the channel state information reference signal sent by the first user equipment includes an indication of the allocated resources for transmitting channel state information.

[0016] One indication of the resource allocation is sent from the base station to each user equipment in the group.

[0017] The method further includes the step of sending the channel state information from the first user equipment to the base station.

[0018] The method is initiated by a request from the first user equipment to the base station.

[0019] The method is initiated by the base station.

[0020] The transmission resources for the channel state information reference signal and / or channel state information are selected by the first user equipment.

[0021] The channel state information is sent by each user equipment as a unicast message to the first user equipment.

[0022] The channel state information is sent by each user equipment as a multicast message to all other user equipment in the group that includes the first user equipment.

[0023] The method further includes the second user equipment in the group sending a signal including a channel state information reference signal to all other user equipment in the group; and all user equipment in the group except the second user equipment sending channel state information to all other user equipment in the group in a multicast message.

[0024] The signal, which includes channel state information, also includes an indication of the location of the transmitting user equipment.

[0025] The user equipment receiving the location information uses this information to perform directional transmission to the relevant user equipment.

[0026] The first user equipment sends the location information to the base station.

[0027] A method for determining channel state information in a multicast system is also provided, the method comprising the steps of: in response to a channel state information reference signal received from a first user equipment in the group, sending a message to each user equipment in the group, instructing each user equipment to report channel state information to a base station; in response to the message, the first user equipment sending the channel state information reference signal to the other user equipment in the group; and each user equipment that receives the channel state information reference signal sending channel state information to the base station.

[0028] A method for sharing location information among user equipment is also provided, the method comprising sending a sidelink control information message from a first user equipment in a group of user equipment to at least one other user equipment in the group, characterized in that the sidelink control information includes the location of the first user and utilizes the location for user grouping, relay / cooperation management, group leader selection and / or power control. Attached Figure Description

[0029] Further details, aspects, and embodiments of the invention will be described by way of example only with reference to the accompanying drawings. Elements in the drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For ease of understanding, the same reference numerals have been included in the various drawings.

[0030] Figure 1 The selected elements of the cellular communication system are displayed.

[0031] Figures 2 to 5 The various message flows in the group transmission system are displayed. Detailed Implementation

[0032] Those skilled in the art will recognize and understand that the details of the described examples are merely illustrative of some embodiments, and that the teachings set forth herein are applicable to various alternative settings.

[0033] Figure 1 This diagram illustrates three base stations (e.g., eNB or gNB, depending on the specific cellular standard and terminology) that make up a cellular network. Typically, each base station is deployed by a cellular network operator to provide geographic coverage for user equipment in that area. The base stations form a radio area network (RAN). Each base station provides radio coverage for user equipment in its area or cell. The base stations interconnect via an X2 interface and connect to the core network via an S1 interface. As will be understood, only basic details are shown to illustrate key characteristics of a cellular network. A PC5 interface is provided between user equipment for sidelink (SL) communication. Figure 1 The related interface and component names are for illustrative purposes only; different systems operating on the same principles may use different naming conventions.

[0034] Each base station contains the hardware and software to implement radio area network functions, including communication with the core network and other base stations, transmission of control and data signals between the core network and user equipment, and maintaining wireless communication with the user equipment associated with each base station. The core network includes the hardware and software to implement network functions, such as overall network management and control, and routing of cells and data.

[0035] For sidelink communication between transmitting and receiving user equipment, the receiving user equipment receives data on the Physical Sidelink Shared Channel (PSSCH) and receives sidelink control information (SCI) on the Physical Sidelink Control Channel (PSCCH). Feedback (positive / negative acknowledgment) signals can be provided from the receiving user equipment to the transmitting user equipment on the Physical Sidelink Feedback Channel (PSFCH).

[0036] Two operating modes are proposed for the allocation of resources (i.e., time / frequency resources) for sidelink communication. Mode 1 (first mode) is applied when the user equipment (UE) is within the base station's coverage area and resources are allocated by the base station. Mode 2 (second mode) is used when the UE is outside the base station's coverage area and the UE autonomously selects and uses resources, typically employing a pre-transmission listening process.

[0037] User equipment (UE) reserves resources for transmission by sending sidelink control information messages that indicate the resources to be used. The sidelink control information informs the receiver (which can be a single UE in unicast, a group of UEs in multicast, or all reachable UEs in broadcast) of the expected transmission details.

[0038] As mentioned above, no effort has been made to date to provide channel state information estimation for multicast systems. Estimating the channel state information for a group of N users with N*(N-1) / 2 pairs of links is even more challenging. Therefore, managing all signaling and reporting can result in significant network load. The following disclosure provides a method for implementing channel state information estimation in multicast systems.

[0039] Typically, omnidirectional transmission is used for sidechain multicast transmission because the locations of group members are different and unknown. However, if the transmitter user equipment knows the locations of group members, directional transmission can achieve significant power savings. In some applications, such as vehicle-to-vehicle, the relative positions of user equipment can be structured (e.g., vehicles are restricted to roads), enabling simple location indication that can be carried in channel state information messages for directional transmission.

[0040] To improve the Quality of Service (QoS) of sidelink channels, a hybrid automatic repeat request (HRP) procedure can be used. Resources used for transmitting HRP feedback can be used for channel state information transmission from receiver to transmitter. In the example, a channel state information reference signal can be included in a multicast transmission over the physical sidelink shared channel, allowing it to be received by user equipments (UEs) in the group. Receiving UEs can each use the channel state information reference signal (or other methods) to determine channel state information (e.g., channel quality indicator, rank indicator, precoding indicator, reference signal received power, or received signal strength indicator) for the channel between the transmitter and the corresponding UE. The UEs can then use feedback resources corresponding to the physical sidelink shared channel to transmit the channel state information to the transmitter UE.

[0041] In the case where a base station or central node (e.g., a group leader or designated user equipment) coordinates a group, that base station / node will benefit from having channel state information on all N*(N-1) links so that it can perform resource allocation, interference management, link adaptation, power control, etc. In contrast, each member in the group only needs to upload channel state information on (N-1) links. It is also beneficial for the central node / base station to keep the channel state information up-to-date for all links, so that scheduling and port physical layer management can be performed in real time based on the current state. Therefore, continuous updates for N*(N-1) links may be required. This disclosure aims to reduce the number of transmissions to maintain channel state information, potentially reducing N transmissions, thereby reducing signaling overhead and resource utilization. In the example of a specific node performing channel state information acquisition for itself, the number of channel state information reference signal transmissions can be reduced from N-1 to a single multicast transmission. If applied to all group members, the aforementioned N*(N-1) transmissions can be reduced to N multicast transmissions.

[0042] Figure 2 This demonstrates the process of determining channel state information in a multicast system operating in Mode 1. The group in this example has three members, but the principle can be extended to any number of members.

[0043] In step 21, the Tx (transmitting) user equipment initiates a channel state information acquisition process with a message to the base station; however, this process can also be initiated by the base station. In step 22, the base station allocates resources for the channel state information reference signal and channel state information report, and sends the allocation to the Tx user equipment (e.g., in a channel state information or downlink control information message). In an alternative example, the allocation is sent directly from the base station to all members of the group. The base station may send user equipment-specific downlink control information to each group member or it may send a group common downlink control information indication. In the group common downlink control information, the user equipment can determine implicit resource mappings to reduce overhead. Sending resource indications only to the Tx user equipment for distribution to other group members may be advantageous, for example, when not all group members are connected to the same base station.

[0044] In step 23, the Tx user equipment sends the channel state information reference signal (with corresponding sidelink control information, physical sidelink control channel, and physical sidelink shared channel) as a multicast transmission to all group members. If only channel state information reporting resources are indicated to the Tx user equipment in step 22, they are also indicated in the transmission.

[0045] In step 24, each group member sends channel state information to the Tx user equipment on the indicated resources, and in step 25, the Tx user equipment may optionally send channel state information to the base station. The Tx user equipment and the base station (if the channel state information was sent to it) can then use the channel state information for future transmissions from the Tx user equipment. Channel state information acquisition still consumes resources, so the use of on-demand channel state information acquisition can be limited to conserve resources. On-demand channel state information acquisition can be triggered by a node in the group or by a control node according to a specified configuration. Similarly, pre-configured periodic channel state information acquisition can be disabled. In other examples, a specific channel state information reference signal may not be required, and the user equipment may determine the channel state information based on other parameters, such as the received power of a reference signal that can be directly obtained from received transmissions.

[0046] In some cases, traffic may be considered strictly periodic. In such cases, channel state information can be collected periodically, aligned with known data transmissions.

[0047] Including reference signal and channel state information reports in existing data (physical side link shared channel), feedback (physical side link feedback channel), or control (physical side link control channel) channels, rather than in separate channels, may be effective.

[0048] As described above, channel state information acquisition can be initiated by a Tx user equipment. In this case, the channel state information request may include the group ID of the desired group for channel state information acquisition (since the user equipment may be a member of more than one group), so this may not be implicit. Indicating a group enables the base station to allocate resources from the appropriate pool for the indicated group. When sending the indication for resource allocation, the base station may include a group identifier so that the user equipment knows which group the resources will be used for.

[0049] Figure 3 This shows an example of channel state information acquisition in a multicast system running in mode 2.

[0050] In step 30, the Tx user equipment selects resources and transmits a channel state information reference signal in a physical sidelink shared channel (with corresponding sidelink control information, physical sidelink control channel, and physical sidelink shared channel) as a multicast transmission on the selected resources. In step 31, group members determine the channel state information and report the allocated physical sidelink shared channel (or physical sidelink feedback channel) to the Tx user equipment. Resources used for channel state information reporting can be allocated by the Tx user equipment based on its own perception and indicated to other group members in the sidelink control information (or as a reward in the physical sidelink shared channel containing the channel state information reference signal). This process is expected to have good latency and duplex characteristics for the Tx user equipment, but resource availability from other group member locations cannot be considered. Alternatively, each group member can select resources for its channel state information response upon receiving the channel state information reference signal. This process adds latency because the resource selection process delays the response transmission, but may allow for better resource selection.

[0051] The benefits of accurate channel state information may vary for different user equipment within a group. For example, a platoon leader may transmit significantly more data to platoon members than it returns. Similarly, in an infotainment group where group members broadcast media to each other, transmission is highly asymmetric. In these examples, the platoon leader or transmitter will benefit more from accurate channel state information than other members. Channel state information acquisition can therefore be configured to allow only a subset of the group to acquire it when needed.

[0052] In the above description, the channel state information report has already been sent in the transmission from the relevant group member to the Tx user equipment. However, the report can also be sent as a multicast transmission or sent to the base station via the Uu uplink interface. The method chosen may vary depending on the specific circumstances. For example, if the base station has already triggered channel state information acquisition, the report can be sent to the base station, or if the user equipment has triggered channel state information acquisition, the report can be sent to that user equipment.

[0053] Each channel state information report can be transmitted using unicast physical sidelink shared channel data transmission, so that the physical sidelink shared channel contains only channel state information reports and can therefore be very short. To reduce multiplexing and duplexing problems due to a potentially large number of reports, it may be preferable to multiplex the channel state information reports in the frequency domain, allowing Tx user equipment to receive multiple reports simultaneously. Since the channel state information report messages are small and physical sidelink shared channel allocation is typically at the sub-channel granularity (i.e., one or more physical resource blocks in the frequency domain), the sub-channel carrying the reports on the physical sidelink shared channel can be shared by multiple users, whose reports are transmitted within the sub-channel at the physical resource block granularity. Downlink control information or sidelink control information messages can be used to indicate the resources to be used.

[0054] In another option, channel state information reports for multicast can be sent on the physical sidelink feedback channel. This can be attractive because physical sidelink feedback channel resources are typically (pre)configured, thus reducing the overhead associated with using the physical sidelink shared channel. Physical sidelink feedback channel resources are usually located in the last few time slot symbols, which can reduce duplex issues, and resource gains can be achieved when the physical sidelink feedback channel resources are not fully utilized for positive / negative acknowledgment feedback, thereby enabling data multiplexing into the shared channel.

[0055] Physical sidelink feedback channel resources are (pre)configured and can be activated or presumed to be activated to carry channel state information reports when performing channel state information acquisition (e.g., when receiving / indicating channel state information reference signals). Each user equipment can therefore implicitly or explicitly determine the allocation of channel state information reports in the physical sidelink feedback channel based on the allocation in the sidelink control information. Specific formats for channel state information reports on the physical sidelink feedback channel can be defined to allow multiplexing of channel state information reports and positive / negative acknowledgment feedback.

[0056] When using a physical sidelink feedback channel for channel state information (CSI) reporting, group members can use the feedback resources associated with the physical sidelink shared channel carrying the CSI reference signal. Resource indications can be sent in sidelink control information or carried in the message triggering the CSI report. If a group member cannot simultaneously include both the CSI report and the required data feedback in the physical sidelink feedback channel corresponding to the physical sidelink shared channel for the CSI reference signal, the CSI report can be sent first. Data feedback, along with feedback for subsequent transmissions, can then be sent together in the next feedback opportunity. The feedback format may need to be modified to transmit feedback for two transport blocks in a single message. Using the physical sidelink feedback channel for CSI information and reserving subsequent transmissions for dual transport block feedback provides efficient resource utilization because no additional resources need to be reserved for CSI reporting, and existing feedback mechanisms can be used for delayed feedback.

[0057] Figure 4 An example is shown where multicast transmission is used to transmit channel state information reports. As described above, a Tx user equipment can send a channel state information reference signal in a multicast transmission, which is received by the Rx (receiving) user equipments in the group. Each Rx user equipment calculates the channel state information for the link from the Tx user equipment to itself and sends a channel state information report in the multicast physical-side link-shared channel. Therefore, all members of the group receive information about the channel state information for all links from the Tx user equipment (assuming all Rx user equipments are within range of each other). Such a system may make the most sense in a system operating in Mode 2, but it is also applicable in Mode 1 operation. The use of multicast channel state information reports allows each user equipment to report to all user equipments with a single message, saving N-2 messages. The total number of messages for sharing channel state information reports among all user equipments in the group is N.

[0058] Can be repeated Figure 4The process involves transmitting a Channel State Information Reference (CSSR) signal in a multicast transmission so that all group members receive information about all links. Group members take turns (i.e., each sends sequentially) transmitting a CSSR in a multicast transmission, and all user equipment (UEs) transmit their CSSR reports in the same transmission. In this process, each transmission can include a CSSR (measured by the Rx user) as a pilot and a CSSR report from the Tx user equipment as data. Therefore, receiving a shared channel on a physical-side link allows for both measurement and reporting. The first UE to send the CSSR may not yet have any CSSR to send. Therefore, once all UEs have sent their CSSRs and received all responses, all UEs have CSSR on all links (assuming all UEs are within range of each other). A similar process can be used to share the locations of group members and the distances between UEs. The order in which UEs send CSSRs and reports can be pre-configured and implicitly known to each UE (e.g., based on each member's user ID), so each group member knows when to send their CSSR and reports. Alternatively, each member can perform resource monitoring and allocation, thus sending a channel state information reference signal and reporting on its first recognizable opportunity. Each member continues to attempt until it successfully sends a channel state information reference signal and reports. This scheme requires members to adapt to conditions and may require rapid updates to the channel state information report before transmission. In each iteration, a member can transmit all channel state information reports or only new reports to reduce overhead. New reports can be defined as those not included in the currently reported channel state information or those less than a defined time. Similarly, channel state information reports can be transmitted as differences from previous reports rather than complete, absolute details.

[0059] Figure 5 An example is shown where a base station coordinates channel state information reports to be sent directly to the base station via the Uu uplink interface. The channel state information acquisition process can be initiated by a member of the group via message 51 to the base station, or the base station can initiate the process. The base station can directly schedule each user equipment (UE) using message 52 of the Uu downlink control information, instructing the UE to report the channel state information status of the incoming channel state information reference signal 53, which is sent by the Tx UE in response to message 52 from the base station.

[0060] As scheduled by Uu downlink control information message 52, each Rx user equipment (UE) sends a channel state information report to the base station via messages on the Uu uplink interface. Uu downlink control information message 52 can be an independent message for each UE, or a group-wide common Uu downlink control information message that can be used for all or a subset of a group. Tx UE receives Uu downlink control information message 52. Alternatively, it can send Uu downlink control information message 52. Then, the base station can send a channel state information report to the Tx UE in message 55.

[0061] The channel state information acquisition process can also be coordinated to calculate multiple links and combine reports into a single response from each user equipment to the base station.

[0062] In one variant, each member can receive channel state information reports and aggregate them to forward to other members of the group, as in a multicast transmission. Members can send all information or process versions based on system configuration or settings provided by downlink control information messages to reduce overhead. In an example where a user equipment sends a channel state information report to a Tx user equipment in a unicast transmission, the Tx user equipment can aggregate responses and send them to the base station. Similarly, when the base station receives channel state information reports, it can aggregate them and send them to the Tx user equipment or any group member. Each group member can aggregate and transmit reports during the iteration process. For example (mathematically imprecise), if several users in a group are reporting channel state information with a given channel quality, it can be approximated by a single channel with lower quality. If two users have a channel that results in a 10% block error rate, the group block error rate is 1 - (1 - 0.10)² = 19%. Therefore, instead of reporting two channel state reports implying a 10% block error rate, they can be aggregated into a lower channel state report implying a 19% block error rate. Any other suitable mechanism can be used to convey useful information, such as a histogram of feedback data.

[0063] As mentioned above, comparable processes can be used to share location information, which is useful in multicast systems. For example, multicast transmissions can be configured so that only members within a (pre-)configured distance need to send hybrid automatic repeat request feedback. Location information can be used in any process that requires it.

[0064] The techniques and processes described in this paper can be used to perform location acquisition, which can then be distributed in the same manner as discussed for channel state information.

[0065] As the reader will understand, location relates to the absolute location of a user equipment (UE) and can be used by other UEs (or base stations or other nodes) to calculate distance and direction. The word "location" will be used throughout this document as a general term for position, distance, and / or location. Position may be the preferred indicator because it conveys more information, but distance can be more easily quantified to reduce overhead. For example, 2 bits can be used to represent four distance ranges: near, medium, far, and ultra-far. However, distance does not convey direction (although direction can also be quantified, for example, 2 bits can represent four segments, each 90 degrees). Furthermore, distance and direction are UE-specific, while location is useful for all UEs.

[0066] User equipment (UE) can send its location information in a sidelink control information message used for multicast transmission, enabling all UEs in the group to know the absolute and relative location of the sending UE. Location can be transmitted in a defined coordinate system (e.g., geodesics) or by mapping to a predefined set of locations, such as a region ID in Long Term Evolution (LTE). Location transmission can be performed together with channel state information acquisition or as a separate process using the methods described herein. For example, during channel state information acquisition, downlink control information and / or sidelink control information messages can include an indication of whether location (or distance / direction) should be reported along with a channel state information report. More granularity can be provided by using two bits to indicate any combination of channel state information and / or location acquisition requests. Combining location and channel state information transmission can reduce overall overhead because some processes (e.g., message headers) are reused. Channel state information and location are also likely to change together, so updating both simultaneously is prudent.

[0067] When channel state information reports are transmitted via unicast, location information (i.e., position, distance, and / or direction) can be reported as payload in the channel state information report. Since the channel state information report is expected to be small, sufficient space is also expected to accommodate the location information. If a physical sidelink feedback channel is used, a data format may need to be defined to carry the required combination (feedback, channel state information, and / or location). If a user equipment (UE) reports location information to the base station, the UE can report all locations or a processed set (e.g., maximum distance, farthest UE, UE in a specific area). When using multicast transmission for channel state information reporting, location information can be sent within the sidelink control information. When transmitting channel state information to the base station via the Uu uplink, the UE can report its location information to the base station through its channel state information report. The base station can then send the location information or information derived from it (e.g., maximum distance, farthest UE, UE in a specific area) to any member of the group.

[0068] The preceding description has been given in the context of sidelink communication in cellular systems, but the principles described here also apply to any group of wireless nodes communicating in a group (e.g., mobile devices, integrated access and backhaul nodes, relays, etc.).

[0069] Although no device or apparatus constituting part of the network is shown in detail, it may at least include a processor, a storage unit, and a communication interface, wherein the processor unit, storage unit, and communication interface are configured to perform methods of any aspect of the invention. Further options and choices are described below.

[0070] The signal processing functions of embodiments of the present invention, particularly gNBs and user equipment, can be implemented using computing systems or architectures known to those skilled in the art. For a given application or environment, a computing system such as a desktop computer, laptop computer, handheld computing device (PDA, mobile phone, PDA, etc.), mainframe, server, client, or any other type of specialized or general-purpose computing device may be desirable or suitable. The computing system may include one or more processors, which can be implemented using general-purpose or special-purpose processing engines, such as microprocessors, microcontrollers, or other control modules.

[0071] The computing system may also include main memory, such as random access memory (RAM) or other dynamic memory, for storing information and instructions to be executed by the processor. Such main memory can also be used to store temporary variables or other intermediate information during the execution of instructions to be executed by the processor. The computing system may also include read-only memory (ROM) or other static storage devices for storing static information and instructions for the processor.

[0072] The computing system may also include an information storage system, which may include, for example, media drives and removable storage interfaces. Media drives may include drives or other mechanisms to support fixed or removable storage media, such as hard disk drives, floppy disk drives, magnetic tape drives, optical disc drives, optical disc (CD) or digital video drive (DVD) read or write drives (R or RW), or other removable or fixed media drives. Storage media may include, for example, hard disks, floppy disks, magnetic tapes, optical discs, CDs or DVDs, or other fixed or removable media read and written by media drives. Storage media may include computer-readable storage media having specific computer software or data stored therein.

[0073] In alternative embodiments, the information storage system may include other similar components for allowing computer programs or other instructions or data to be loaded into the computing system. Such components may include, for example, removable storage units and interfaces, such as program boxes and box interfaces, removable memory (e.g., flash memory or other removable memory modules) and memory slots, as well as other removable storage units and interfaces that allow software and data to be transferred from the removable storage units to the computing system.

[0074] The computing system may also include a communication interface. This communication interface is used to allow the transfer of software and data between the computing system and external devices. Examples of communication interfaces may include modems, network interfaces (such as Ethernet or other NIC cards), communication ports (such as Universal Serial Bus (USB) ports), PCMCIA slots, and cards. The software and data transferred via the communication interface are in the form of signals, which can be electronic, electromagnetic, optical, or other signals that can be received by the communication interface medium.

[0075] In this document, the terms "computer program product," "computer-readable medium," etc., are generally used to refer to tangible media, such as memory, storage devices, or storage units. These and other forms of computer-readable media may store one or more instructions for use by a processor, including a computer system, to cause the processor to perform specified operations. Such instructions, commonly referred to as "computer program code" (which may be grouped as computer programs or other groups), when executed, enable a computing system to perform the functions of embodiments of the present invention. Note that code may directly cause a processor to perform specified operations, be compiled to perform such operations, and / or be combined with other software, hardware, and / or firmware elements (e.g., libraries for performing standard functions) to perform such operations.

[0076] The non-transitory computer-readable medium may include at least one selected from the group consisting of: hard disk, CD-ROM, optical storage device, magnetic storage device, read-only memory, programmable read-only memory, erasable programmable read-only memory, EPROM, electrically erasable programmable read-only memory, and flash memory. In embodiments using software-implemented elements, the software may be stored in the computer-readable medium and loaded into the computing system using, for example, a removable storage drive. The control module (in this example, software instructions or executable computer program code), when executed by a processor in the computer system, causes the processor to perform the functions of the invention as described herein.

[0077] Furthermore, the inventive concept can be applied to any circuit used to perform signal processing functions within a network element. It is also conceivable that, for example, semiconductor manufacturers can incorporate the inventive concept into the design of standalone devices, such as microcontrollers or application-specific integrated circuits (ASICs) for digital signal processors (DSPs), and / or any other subsystem elements.

[0078] It should be understood that, for clarity, the above description refers to embodiments of the invention with reference to a single processing logic. However, the inventive concept can also be implemented by a number of different functional units and processors to provide signal processing functionality. Therefore, references to specific functional units are to be regarded only as references to appropriate means of providing the described functionality, and not as indicating a strict logical or physical structure or organization.

[0079] Various aspects of the present invention can be implemented in any suitable form, including hardware, software, firmware, or any combination thereof. The present invention can optionally be implemented, at least in part, as computer software running on one or more data processors and / or digital signal processors or configurable module components such as FPGA devices.

[0080] Therefore, the elements and components of embodiments of the present invention can be implemented physically, functionally, and logically in any suitable manner. In fact, the function may be implemented in a single unit, in multiple units, or as part of other functional units. Although the invention has been described in conjunction with some embodiments, it is not intended to limit it to the specific forms set forth herein. Rather, the scope of the invention is limited only by the appended claims. Furthermore, although features appear to have been described in conjunction with specific embodiments, those skilled in the art will recognize that various features of the described embodiments can be combined according to the invention. In the claims, the term "comprising" does not exclude the presence of other elements or steps.

[0081] Furthermore, although listed separately, multiple means, elements, or method steps can be implemented, for example, by a single unit or processor. Moreover, while individual features may be included in different claims, these features may be advantageously combined, and inclusion in different claims does not imply that such combination of features is infeasible and / or advantageous. Furthermore, including a feature in one claim class does not imply limitation on that class, but rather indicates that the feature is equally applicable to other claim classes where appropriate.

[0082] Furthermore, the order of features in the claims does not imply that these features must be performed in any particular order, and in particular, the order of steps in a method claim does not imply that these steps must be performed in that order. On the contrary, these steps may be performed in any suitable order. Moreover, singular references do not exclude plural forms. Therefore, references to "an," "a," "first," "second," etc., do not exclude plural forms.

[0083] Although the invention has been described in conjunction with some embodiments, it is not intended to limit it to the specific forms set forth herein. Rather, the scope of the invention is limited only by the appended claims. Furthermore, although features appear to have been described in conjunction with specific embodiments, those skilled in the art will recognize that various features of the described embodiments can be combined according to the invention. In the claims, the terms "comprising" or "including" do not exclude the presence of other elements.

Claims

1. A method for determining channel state information in a multicast system, characterized in that, The method includes the step of: sending a channel state information reference signal from a first user equipment in a group of user equipments as a multicast message to all other user equipments in the group; And each user equipment in the group receiving the channel state information reference signal sends a signal including channel state information to the first user equipment; wherein the transmission resources of the channel state information reference signal and / or the channel state information are allocated by the base station or the first user equipment, and when the channel state information report is sent via unicast transmission, the channel state information includes information related to the user equipment's location, direction, and / or distance, wherein the user equipment's location is reported as the payload of the channel state information report; and, when the channel state information report is sent via multicast transmission, the location information is sent via sidelink control information, the multicast system supports each user equipment to send the channel state information reference signal and the channel state information report in turn, and each user equipment in the group obtains the channel state information about all other user equipment; wherein each channel state information report Multicast transmissions are all performed on the Physical Side Link Shared Channel (PSSCH). Each multicast transmission enables all user equipment (User Equipment) to obtain channel state information for all links from each sending User Equipment to all receiving User Equipment. The multicast channel state information reporting process is executed sequentially by each User Equipment within the group in a predetermined order. Each User Equipment sequentially sends a channel state information reference signal during the multicast transmission, and then all User Equipment sends the corresponding channel state information report in multicast format. Each transmission includes the channel state information reference signal and the previously received channel state information report as data. Receiving one multicast PSSCH transmission is sufficient to achieve the measurement and sharing of channel state information. Furthermore, the transmission order is determined through pre-configuration or resource monitoring. Each channel state information report includes new or updated channel state information data, or differential data relative to the previous channel state information report.

2. The method as described in claim 1, characterized in that, One indication of resource allocation is sent from the base station to the first user equipment, and the channel state information reference signal sent by the first user equipment includes information for indicating the resource allocation.

3. The method as described in claim 1, characterized in that, An instruction to allocate resources is sent from the base station to each user equipment in the group.

4. The method as described in claim 1, characterized in that, It also includes the step of sending the channel state information from the first user equipment to the base station.

5. The method as described in claim 1, characterized in that, The method is initiated by a request from the first user equipment to the base station.

6. The method as described in claim 1, characterized in that, The method is initiated by the base station.

7. The method as described in claim 1, characterized in that, The transmission resources for the channel state information reference signal and / or the channel state information are selected by the first user equipment.

8. The method as described in claim 1, characterized in that, The channel state information is sent by each user equipment as a unicast message to the first user equipment.

9. The method as described in claim 1, characterized in that, When a channel state information report is sent via multicast transmission, the channel state information is sent as a multicast message by each user equipment to all other user equipment in the group that includes the first user equipment.

10. The method as described in claim 9, characterized in that, Also includes: The second user equipment in the group sends a signal including a channel state information reference signal to all other user equipment in the group; All user equipment in the group except the second user equipment sends channel state information to all other user equipment in the group in a multicast message.

11. The method as described in claim 1, characterized in that, The signal including channel state information also includes an indication of the location of the user equipment that sent the channel state information.

12. The method as described in claim 11, characterized in that, The user equipment receiving the location information uses the location of the user equipment that sent the channel state information to perform directional transmission to the user equipment that sent the channel state information.

13. The method as described in claim 12, characterized in that, The first user equipment sends the location information to the base station.

14. A method for determining channel state information in a multicast system, characterized in that, The method includes the steps of: a base station sending a message to each user equipment in the group in response to a channel state information reference signal received from a first user equipment in the group, instructing each user equipment to report channel state information to the base station; In response to the message, the first user equipment sends a channel state information reference signal to the other user equipments in the group; each user equipment receiving the channel state information reference signal sends channel state information to the base station; wherein, the transmission resources of the channel state information reference signal and / or the channel state information are allocated by the base station or the first user equipment, and when the channel state information report is sent via unicast transmission, the channel state information includes information related to the user equipment's location, orientation, and / or distance; wherein, the user equipment's location is reported as the payload of the channel state information report; and, when the channel state information report is sent via multicast transmission, the location information is sent via sidelink control information, and the multicast system supports each user equipment to take turns sending the channel state information reference signal and the channel state information report, and each user equipment in the group obtains the channel state information about all other user equipments; In this system, the multicast transmission of each channel state information report takes place on the Physical Side Link Shared Channel (PSSCH). Each multicast transmission enables all user equipment (UEs) to obtain channel state information for all links from each sending UE to all receiving UEs. The multicast channel state information reporting process is executed sequentially by each UE within the group in a predetermined order. Each UE sequentially sends a channel state information reference signal during the multicast transmission, and then all UEs send the corresponding channel state information report in multicast format. Each transmission includes the channel state information reference signal and previously received channel state information reports as data. Receiving one multicast PSSCH transmission is sufficient to achieve the measurement and sharing of channel state information. Furthermore, the transmission order is determined through pre-configuration or resource monitoring. Each channel state information report includes new or updated channel state information data, or differential data relative to previous channel state information reports.

15. A method for sharing location information among user equipments, the method comprising: a first user equipment in a group of user equipments sending a sidelink control information message and a channel state information reference signal to at least one other user equipment in the group; each user equipment in the group receiving the channel state information reference signal sending a signal including channel state information to the first user equipment, characterized in that... When transmitting channel state information reports via multicast, location information is sent in the sidelink control information, and the location information is used for user grouping, relay / cooperation management, group leader selection, and / or power control. The transmission resources for the channel state information reference signal and / or the channel state information are allocated by the base station or the first user equipment. When transmitting the channel state information report via unicast, the channel state information includes information related to the user equipment's location, direction, and / or distance. The user equipment's location is reported as the payload in the channel state information report. Furthermore, when transmitting the channel state information report via multicast, the location information is sent via the sidelink control information. The multicast system supports each user equipment taking turns sending the channel state information reference signal and the channel state information report, and each user equipment in the group obtains information about the channel state of all other user equipment. The information is distributed as follows: Each channel state information report is multicast transmitted on the Physical Side Link Shared Channel (PSSCH). Each multicast transmission enables all user equipment (UEs) to obtain channel state information for all links from each sending UE to all receiving UEs. The multicast channel state information reporting process is executed sequentially by each UE within the group in a predetermined order. Each UE sequentially sends a channel state information reference signal during the multicast transmission, followed by all UEs sending their corresponding channel state information reports in multicast format. Each transmission includes the channel state information reference signal and previously received channel state information reports as data. Receiving one multicast PSSCH transmission enables the measurement and sharing of channel state information. The transmission order is determined through pre-configuration or resource monitoring. Each channel state information report includes new or updated channel state information data, or differential data relative to previous channel state information reports.

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