Method and apparatus for aggregated transmission of srs

Abstract

The method can be implemented by a wireless transmit / receive unit (WTRU). The method can include receiving a reference signal (RS) transmission configuration and determining a set of aggregated transmission parameters to perform an aggregated RS transmission. The determining can be based on the RS transmission configuration. The set of aggregated RS transmission parameters can be transmitted to other WTRUs in an aggregated group or one or more of a network. An indication of transmitting the aggregated RS can be received. An indication of transmitting the aggregated RS to other WTRUs in an aggregated group can be transmitted. The aggregated RS can be transmitted using the determined set of transmission parameters and the RS transmission configuration.

Description

[0001] Cross-reference to related applications This application claims the benefit of U.S. Provisional Application No. 63 / 570,879, filed March 28, 2024, the entire contents of which are incorporated herein by reference. Background Technology

[0002] 5G and above applications are expanding in many verticals, such as XR, industrial IoT, and intelligent transportation systems. These new scenarios present new service requirements with reasonable resource and power efficiency, such as ultra-high UL data rates, ultra-low latency, and high reliability. Some services, such as XR and VR / AR, may even require tight synchronization between data streams from different devices running a single application layer (e.g., gloves, glasses, etc.). Summary of the Invention

[0003] This document describes a Wireless Transmit / Receive Unit (WTRU). A WTRU may include a processor. The processor may be configured to receive a Reference Signal (RS) transmission configuration and determine an aggregated transmission parameter set to perform an aggregated RS transmission. The determination may be based on the RS transmission configuration. The processor may be configured to transmit the aggregated RS transmission parameter set to other WTRUs in an aggregation group or to one or more WTRUs in a network, receive an instruction for transmitting the aggregated RS transmission, transmit the instruction to transmit the aggregated RS transmission to other WTRUs in the aggregation group, and transmit the aggregated RS transmission using the determined transmission parameter set and RS transmission configuration.

[0004] The aggregated RS transmission parameter set may include a subset of aggregated WTRUs, transmission resources, antenna port mappings, or one or more of the transmission power of each WTRU in the aggregated group.

[0005] The processor can be configured to allocate transmission power across one or more WTRUs in an aggregation group based on received path loss information, the maximum transmit power of each WTRU in the aggregation group, or one or more power scaling factors associated with the aggregation RS transmission.

[0006] The aggregated RS transmission parameter set can include antenna port mapping.

[0007] The processor can be configured to determine the antenna port mapping from the antenna ports of different WTRUs in the aggregation group to the corresponding RS ports based on the received configuration indicating the RS port allocation scheme used for aggregation transmission.

[0008] The processor can be configured to receive a set of non-aggregated transmission parameters to perform a non-aggregated RS transmission, receive an additional indication of whether to send an aggregated RS transmission or a non-aggregated RS transmission, and determine, based on the additional indication, whether to use the set of aggregated transmission parameters or the set of non-aggregated transmission parameters to perform the transmission.

[0009] Indications used to send aggregated RS transmissions may include one or more of the RS resource identifier (ID), radio network temporary identifier (RNTI), or indication source.

[0010] Indicators for sending aggregated RS transmissions may include RS resource IDs. The RS resource IDs may correspond to a set of RS resources configured for the aggregated group transmission mode. The RS may be a sounding reference signal (SRS).

[0011] The processor can be configured to select a set of RS resources based on the received aggregation configuration, where the aggregation configuration indicates the RS usage pattern associated with the aggregation group to determine the set of transmission parameters.

[0012] The processor can be configured to determine the set of transmission parameters by selecting a subset of WTRUs for aggregated RS transmissions based on one or more of collocation indications received from the group coordinator, synchronization timing indications, or indications supporting antenna ports.

[0013] The method can be implemented by a Wireless Transmit / Receive Unit (WTRU). The method may include receiving a reference signal (RS) transmission configuration and determining an aggregated transmission parameter set to perform aggregated RS transmission. The determination may be based on the RS transmission configuration. The aggregated RS transmission parameter set may be transmitted to other WTRUs in the aggregation group or to one or more units in the network. Instructions for transmitting aggregated RS transmissions may be received. Instructions for transmitting aggregated RS transmissions to other WTRUs in the aggregation group may be transmitted. The determined transmission parameter set and RS transmission configuration can be used to transmit aggregated RS transmissions.

[0014] The aggregated RS transmission parameter set may include a subset of aggregated WTRUs, transmission resources, antenna port mappings, or one or more of the transmission power of each WTRU in the aggregated group.

[0015] The method may include allocating transmission power across WTRUs based on received path loss information, the maximum transmit power of each WTRU, or one or more power scaling factors associated with aggregated RS transmissions.

[0016] The aggregated RS transmission parameter set can include antenna port mapping.

[0017] The method may include determining the antenna port mapping from the antenna ports of different WTRUs in the aggregation group to the corresponding RS ports based on the configuration of the received RS port allocation scheme indicating the aggregation transmission.

[0018] The method may include receiving a set of non-aggregated transmission parameters to perform a non-aggregated RS transmission, receiving an additional indication of whether to send an aggregated RS transmission or a non-aggregated RS transmission, and determining, based on the additional indication, whether to use an aggregated transmission parameter set or a non-aggregated transmission parameter set to perform the transmission.

[0019] Indications used to send aggregated RS transmissions may include one or more of the RS resource identifier (ID), radio network temporary identifier (RNTI), or indication source.

[0020] Indicators for sending aggregated RS transmissions may include RS resource IDs. The RS resource IDs may correspond to a set of RS resources configured for the aggregated group transmission mode. The RS may be a sounding reference signal (SRS).

[0021] The method may include selecting a set of RS resources based on the received aggregation configuration. The aggregation configuration may indicate the RS usage pattern associated with the aggregation group to determine the set of transmission parameters.

[0022] The method may include determining a set of transmission parameters by selecting a subset of WTRUs for aggregated RS transmissions based on one or more of a co-location indication received from a group coordinator, a synchronization timing indication, or an indication of an antenna port support.

[0023] A wireless transmit / receive unit (WTRU) may include a processor and memory. The processor and memory can be configured to receive a configuration as part of an aggregation group. The processor and memory can be configured to determine a set of transmission parameters to perform aggregated SRS transmissions. This determination can be based on the received configuration. The processor and memory can also be configured to transmit the aggregated SRS transmission parameter set.

[0024] The processor and memory can be configured to receive instructions for transmitting aggregated SRS. The processor and memory can be configured to transmit aggregated SRS transmission instructions. The processor and memory can be configured to transmit aggregated SRS using a set of transmission parameters and a received configuration.

[0025] The received configuration may include one or more SRS resource configurations and / or SRS set configurations. The received configuration may include one or more transports configured using an aggregation scheme and / or transports associated with the SRS. The received configuration may include one or more indications regarding other member WTRUs.

[0026] The determined set of transmission parameters may include one or more of the selected WTRU subset, the selected SRS set, antenna port mapping, and / or transmit power. Attached Figure Description

[0027] Figure 1A This is a system diagram illustrating an example communication system in which one or more of the disclosed embodiments may be implemented.

[0028] Figure 1B This illustrates that, according to an embodiment, it is possible to Figure 1A The system diagram shown is of an example wireless transmit / receive unit (WTRU) used in the communication system.

[0029] Figure 1C This illustrates that, according to an embodiment, it is possible to Figure 1A The system diagram shows an example radio access network (RAN) and an example core network (CN) used in the communication system shown.

[0030] Figure 1D This illustrates that, according to an embodiment, it is possible to Figure 1A The system diagram shows another example RAN and another example CN used in the communication system shown.

[0031] Figure 2 An example scenario for transmitting aggregated reference signals (RS) (e.g., (SRS)) is shown.

[0032] Figure 3 An example method for transmitting aggregated reference signals (RS) (e.g., (SRS)) is shown. Detailed Implementation

[0033] Figure 1A This diagram illustrates an example communication system 100 in which one or more of the disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, and broadcasting to multiple wireless users. The communication system 100 enables multiple wireless users to access this content by sharing system resources, including wireless bandwidth. For example, the communication system 100 may employ one or more channel access methods, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal FDMA (OFDMA), Single Carrier FDMA (SC-FDMA), Zero Tail Unique Word DFT Spread Spectrum OFDM (ZT UWDTS-s OFDM), Unique Word OFDM (UW-OFDM), Resource Block Filtered OFDM, Filter Bank Multicarrier (FBMC), etc.

[0034] like Figure 1AAs shown, the communication system 100 may include wireless transceiver units (WTRUs) 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, Public Switched Telephone Network (PSTN) 108, Internet 110, and other networks 112. However, it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, and 102d may be any type of device configured to operate and / or communicate in a wireless environment. For example, WTRUs 102a, 102b, 102c, and 102d (any of which may be referred to as a “station” and / or “STA”) may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, cellular phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated processing chains), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. Any of WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as WTRUs. Furthermore, any descriptions herein that refer to UEs may equally apply to WTRUs (and vice versa). For example, the WTRU can be configured to execute any procedure or process described herein that is performed by the UE (and vice versa).

[0035] The communication system 100 may also include base station 114a and / or base station 114b. Each of base stations 114a and 114b may be any type of device configured to wirelessly interface with at least one of WTRUs 102a, 102b, 102c, and 102d to facilitate access to one or more communication networks (e.g., CN 106 / 115, Internet 110, and / or other networks 112). For example, base stations 114a and 114b may be base transceiver stations (BTS), node Bs, eNodeBs, home node Bs, home eNodeBs, gNBs, NRNodeBs, site controllers, access points (APs), wireless routers, etc. Although base stations 114a and 114b are each described as a single element, it should be understood that base stations 114a and 114b may include any number of interconnected base station and / or network elements.

[0036] Base station 114a may be part of RAN 104 / 113, and may also include other base stations and / or network elements (not shown), such as base station controllers (BSCs), radio network controllers (RNCs), relay nodes, etc. Base station 114a and / or base station 114b may be configured to transmit and / or receive radio signals on one or more carrier frequencies, which may be referred to as cells (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage of radio services to a specific geographic area, which may be relatively fixed or may change over time. A cell may also be divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Therefore, in an embodiment, base station 114a may include three transceivers, i.e., one transceiver per sector of the cell. In an embodiment, base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in a desired spatial direction.

[0037] Base stations 114a and 114b can communicate with one or more of WTRUs 102a, 102b, 102c, and 102d via air interface 116. Air interface 116 can be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). Any suitable radio access technology (RAT) can be used to establish air interface 116.

[0038] More specifically, as described above, the communication system 100 can be a multiple access system and can employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, base stations 114a and WTRUs 102a, 102b, and 102c in RAN 104 / 113 can implement radio technologies such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which can establish air interfaces 115 / 116 / 117 using Wideband CDMA (WCDMA). WCDMA can include communication protocols such as High-Speed ​​Packet Access (HSPA) and / or evolved HSPA (HSPA+). HSPA can include High-Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High-Speed ​​UL Packet Access (HSUPA).

[0039] In the embodiment, base station 114a and WTRUs 102a, 102b, 102c can implement radio technologies such as evolved UMTS terrestrial radio access (E-UTRA), which can use Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-A Pro) to establish air interface 116.

[0040] In the embodiment, base station 114a and WTRUs 102a, 102b, 102c can implement radio technologies such as NR radio access, which can establish air interface 116 using new radio (NR).

[0041] In this embodiment, base station 114a and WTRUs 102a, 102b, and 102c can implement multiple radio access technologies. For example, base station 114a and WTRUs 102a, 102b, and 102c can jointly implement LTE radio access and NR radio access, for example, using the dual connectivity (DC) principle. Therefore, the air interface used by WTRUs 102a, 102b, and 102c can be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., eNBs and gNBs).

[0042] In other embodiments, base station 114a and WTRUs 102a, 102b, and 102c can implement radio technologies such as IEEE 802.11 (i.e., Wi-Fi), IEEE 802.16 (i.e., WiMAX), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Provisional Standard 2000 (IS-2000), Provisional Standard 95 (IS-95), Provisional Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data Rate GSM Evolution (EDGE), and GSM EDGE (GERAN).

[0043] For example, Figure 1ABase station 114b can be a wireless router, home node B, home eNodeB, or access point, and can utilize any suitable RAT to facilitate wireless connectivity in a local area, such as commercial locations, homes, vehicles, campuses, industrial facilities, air corridors (e.g., for use by drones), roads, etc. In one embodiment, base station 114b and WTRUs 102c and 102d can implement radio technologies such as IEEE 802.11 to establish a wireless local area network (WLAN). In another embodiment, base station 114b and WTRUs 102c and 102d can implement radio technologies such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, base station 114b and WTRUs 102c and 102d can utilize cellular-based RATs (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or femtocell. Figure 1A As shown, base station 114b can be directly connected to Internet 110. Therefore, it is not required that base station 114b access Internet 110 via CN 106 / 115.

[0044] RAN 104 / 113 can communicate with CN 106 / 115, which can be any type of network configured to provide voice, data, application, and / or Voice over Internet Protocol (VoIP) services to one or more of WTRUs 102a, 102b, 102c, and 102d. Data can have different Quality of Service (QoS) requirements, such as different throughput requirements, latency requirements, fault tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. CN 106 / 115 can provide call control, billing services, location-based services, prepaid calling, internet connectivity, video distribution, and / or perform advanced security functions such as user authentication. Although in Figure 1A Although not shown, it should be understood that RAN 104 / 113 and / or CN 106 / 115 can communicate directly or indirectly with other RANs using the same RAT as RAN 104 / 113 or a different RAT. For example, in addition to connecting to RAN 104 / 113, which may utilize NR radio technology, CN 106 / 115 can also communicate with another RAN (not shown) using GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0045] CN 106 / 115 can also serve as a gateway for WTRU 102a, 102b, 102c, 102d to access PSTN 108, the Internet 110, and / or other networks 112. PSTN 108 may include a circuit-switched telephone network providing Common Old-Style Telephone Service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices using common communication protocols such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and / or Internet Protocol (IP) from the TCP / IP Internet Protocol suite. Network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, network 112 may include another CN connected to one or more RANs, which may use the same RAT as RAN 104 / 113 or a different RAT.

[0046] Some or all of the WTRUs 102a, 102b, 102c, and 102d in the communication system 100 may include multi-mode capabilities (e.g., WTRUs 102a, 102b, 102c, and 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). For example... Figure 1A The WTRU 102c shown can be configured to communicate with a base station 114a that can employ cellular-based radio technology and with a base station 114b that can employ IEEE 802 radio technology.

[0047] Figure 1B This is a system diagram illustrating example WTRU 102. (See diagram below.) Figure 1B As shown, WTRU 102 may include a processor 118, a transceiver 120, a transmitting / receiving element 122, a speaker / microphone 124, a keyboard 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power supply 134, a Global Positioning System (GPS) chipset 136, and / or other peripheral devices 138, etc. It should be understood that WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with the embodiments.

[0048] Processor 118 may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. Processor 118 may perform signal encoding / decoding, data processing, power control, input / output processing, and / or any other functions that enable WTRU 102 to operate in a wireless environment. Processor 118 may be coupled to transceiver 120, and transceiver 120 may be coupled to transmitting / receiving element 122. Although Figure 1B While processor 118 and transceiver 120 are described as separate components, it should be understood that processor 118 and transceiver 120 may be integrated together in an electronic package or chip.

[0049] Transmitting / receiving element 122 can be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) via air interface 116. For example, in one embodiment, transmitting / receiving element 122 can be an antenna configured to transmit and / or receive RF signals. In another embodiment, transmitting / receiving element 122 can be a transmitter / detector, for example, configured to transmit and / or receive IR, UV, or visible light signals. In yet another embodiment, transmitting / receiving element 122 can be configured to transmit and / or receive both RF and optical signals. It should be understood that transmitting / receiving element 122 can be configured to transmit and / or receive any combination of wireless signals.

[0050] Although the transmitting / receiving element 122 is in Figure 1B While described as a single element, WTRU 102 may include any number of transmitting / receiving elements 122. More specifically, WTRU 102 may employ MIMO technology. Therefore, in an embodiment, WTRU 102 may include two or more transmitting / receiving elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals via air interface 116.

[0051] Transceiver 120 can be configured to modulate signals to be transmitted by transmitting / receiving element 122 and demodulate signals received by transmitting / receiving element 122. As described above, WTRU 102 can have multi-mode capability. Therefore, for example, transceiver 120 may include multiple transceivers to enable WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0052] The processor 118 of WTRU 102 can be coupled to a speaker / microphone 124, a keyboard 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) unit or an organic light-emitting diode (OLED) display unit) and can receive user input data therefrom. The processor 118 can also output user data to the speaker / microphone 124, keyboard 126, and / or display / touchpad 128. Furthermore, the processor 118 can access and store information from any type of suitable memory (e.g., non-removable memory 130 and / or removable memory 132). Non-removable memory 130 may include random access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. Removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital storage (SD) card, etc. In other embodiments, the processor 118 can access and store information from memory that is not physically located on WTRU 102 (e.g., on a server or home computer (not shown)).

[0053] The processor 118 can receive power from the power supply 134 and can be configured to distribute and / or control power to other components in the WTRU 102. The power supply 134 can be any suitable device for powering the WTRU 102. For example, the power supply 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0054] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) about the current location of the WTRU 102. In addition to, or instead of, information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) via air interface 116, and / or determine its location based on the timing of signals received from two or more nearby base stations. It should be understood that the WTRU 102 may acquire location information using any suitable location determination method while remaining consistent with the embodiments.

[0055] The processor 118 may be further coupled to other peripheral devices 138, which may include one or more software and / or hardware modules providing additional features, functions, and / or wired or wireless connectivity. For example, peripheral devices 138 may include accelerometers, electronic compasses, satellite transceivers, digital cameras (for photos and / or video), Universal Serial Bus (USB) ports, vibration devices, television transceivers, hands-free headsets, Bluetooth® modules, FM radio units, digital music players, media players, video game player modules, internet browsers, virtual reality and / or augmented reality (VR / AR) devices, activity trackers, etc. Peripheral devices 138 may include one or more sensors, which may be gyroscopes, accelerometers, Hall effect sensors, magnetometers, orientation sensors, proximity sensors, temperature sensors, time sensors; geolocation sensors; altimeters, light sensors, touch sensors, magnetometers, barometers, attitude sensors, biosensors, and / or humidity sensors.

[0056] WTRU 102 may include a full-duplex radio, for which the transmission and reception of some or all signals (e.g., associated with a specific subframe of both UL (e.g., for transmission) and downlink (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit 139 to reduce and / or substantially eliminate self-interference via hardware (e.g., a choke) or via signal processing (e.g., a separate processor (not shown) or via processor 118). In embodiments, WTRU 102 may include a half-duplex radio, for which the transmission and reception of some or all signals (e.g., associated with a specific subframe of either UL (e.g., for transmission) or downlink (e.g., for reception) may be concurrent and / or simultaneous.

[0057] Figure 1C This is a system diagram illustrating RAN 104 and CN 106 according to an embodiment. As described above, RAN 104 can communicate with WTRUs 102a, 102b, and 102c via air interface 116 using E-UTRA radio technology. RAN 104 can also communicate with CN 106.

[0058] RAN 104 may include eNode-Bs 160a, 160b, and 160c; however, it should be understood that RAN 104 may include any number of eNode-Bs while remaining consistent with the embodiments. eNode-Bs 160a, 160b, and 160c may each include one or more transceivers for communicating with WTRUs 102a, 102b, and 102c via air interface 116. In the embodiments, eNode-Bs 160a, 160b, and 160c may implement MIMO technology. Therefore, for example, eNode-B 160a may use multiple antennas to transmit and / or receive radio signals from WTRU 102a.

[0059] Each of the eNode-B 160a, 160b, and 160c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, and user scheduling in the UL and / or DL, etc. Figure 1C As shown, eNode-B 160a, 160b, and 160c can communicate with each other via the X2 interface.

[0060] Figure 1C The CN 106 shown may include a Mobility Management Entity (MME) 162, a Serving Gateway (SGW) 164, and a Packet Data Network (PDN) Gateway (or PGW) 166. While each of the foregoing elements is described as part of CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0061] The MME 162 can connect to each eNode-B 162a, 162b, 162c in RAN 104 via the S1 interface and can be used as a control node. For example, the MME 162 can be responsible for authenticating users of WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a specific serving gateway during the initial attachment of WTRUs 102a, 102b, 102c, etc. The MME 162 can provide control plane functions for handover between RAN 104 and other RANs (not shown) employing other radio technologies (such as GSM and / or WCDMA).

[0062] The SGW 164 can connect to each eNode B 160a, 160b, or 160c in RAN 104 via the S1 interface. The SGW 164 can typically route and forward user data packets to / from WTRUs 102a, 102b, or 102c. The SGW 164 can perform other functions, such as anchoring the user plane during inter-eNode B handover; triggering paging when DL data is available for WTRUs 102a, 102b, or 102c; and managing and storing the context of WTRUs 102a, 102b, or 102c.

[0063] The SGW 164 can connect to the PGW 166, which can provide WTRU 102a, 102b, and 102c with access to packet-switched networks such as Internet 110, to facilitate communication between WTRU 102a, 102b, 102c and IP-enabled devices.

[0064] CN 106 can facilitate communication with other networks. For example, CN 106 can provide WTRU 102a, 102b, and 102c with access to a circuit-switched network such as PSTN 108 to facilitate communication between WTRU 102a, 102b, and 102c and traditional landline communication equipment. For example, CN 106 may include, or be able to communicate with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between CN 106 and PSTN 108. Furthermore, CN 106 can provide WTRU 102a, 102b, and 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0065] Despite WTRU in Figure 1A-1D While described as a wireless terminal, it is conceivable that, in some representative embodiments, such a terminal may use (e.g., temporarily or permanently) a wired communication interface with a communication network.

[0066] In a representative embodiment, the other network 112 may be a WLAN.

[0067] In an Infrastructure Basic Services Set (BSS) mode, a WLAN may have an Access Point (AP) for the BSS and one or more Stations (STAs) associated with the AP. The AP may access or interface with a Distributed System (DS) or another type of wired / wireless network, carrying traffic into and / or out of the BSS. Traffic originating outside the BSS destined for a STA can be delivered to the AP via it. Traffic originating from a STA destined for a destination outside the BSS can be sent to the AP for delivery to the appropriate destination. For example, traffic between STAs within the BSS can be sent via the AP, where the source STA can send traffic to the AP, and the AP can deliver traffic to the destination STA. Traffic between STAs within the BSS can be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic can be sent between source and destination STAs (e.g., directly between them) using Direct Link Establishment (DLS). In some representative embodiments, the DLS may use 802.11e DLS or 802.11z Tunneled DLS (TDLS). A WLAN using the Standalone BSS (IBSS) mode may not have an access point (AP), and STAs within the IBSS or using the IBSS (e.g., all STAs) can communicate directly with each other. The IBSS communication mode is sometimes referred to as the "self-organizing" communication mode in this document.

[0068] When operating in 802.11ac infrastructure mode or a similar mode, the AP can transmit beacons on a fixed channel (e.g., the primary channel). The primary channel can be of a fixed width (e.g., a 20 MHz bandwidth) or dynamically set via signaling. The primary channel can be the operating channel of the BSS and can be used by the STA to establish a connection with the AP. In some representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) can be implemented, for example in an 802.11 system. For CSMA / CA, each STA, including the AP, can sense the primary channel. If a particular STA senses / detects and / or determines that the primary channel is busy, that STA can back off. A single STA (e.g., only one station) can transmit at any given time within a given BSS.

[0069] High-throughput (HT) STAs can communicate using a 40MHz wide channel, for example, by combining a primary 20MHz channel with adjacent or non-adjacent 20MHz channels.

[0070] Very High Throughput (VHT) STAs can support channels with widths of 20MHz, 40MHz, 80MHz, and / or 160MHz. 40MHz and / or 80MHz channels can be formed by combining consecutive 20MHz channels. A 160MHz channel can be formed by combining eight consecutive 20MHz channels, or by combining two non-consecutive 80MHz channels, which can be referred to as an 80+80 configuration. For the 80+80 configuration, after channel coding, the data passes through a segment resolver, which splits the data into two streams. Each stream can be processed separately using Inverse Fast Fourier Transform (IFFT) and time-domain processing. These streams can be mapped onto the two 80MHz channels, and the data can be transmitted by the transmitting STA. At the receiver of the receiving STA, the operation of the 80+80 configuration described above can be reversed, and the combined data can be sent to the Media Access Control (MAC).

[0071] 802.11af and 802.11ah support operating modes below 1 GHz. The channel operating bandwidth and carrier in 802.11af and 802.11ah are reduced compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV Blank (TVWS) spectrum, while 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz using non-TVWS. According to a representative embodiment, 802.11ah can support metering-type control / machine-type communications, such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support (e.g., only support) certain and / or limited bandwidths. MTC devices may include batteries with a battery life exceeding a threshold (e.g., to maintain very long battery life).

[0072] WLAN systems that can support multiple channels and channel bandwidths (e.g., 802.11n, 802.11ac, 802.11af, and 802.11ah) include a channel that can be designated as the primary channel. The bandwidth of the primary channel can be equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be set and / or limited by one of the STAs operating in the BSS, with the STA supporting a minimum bandwidth operating mode. In the 802.11ah example, for STAs that support (e.g., only support) the 1MHz mode (e.g., MTC type devices), the primary channel can be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes. Carrier Sense and / or Network Allocation Vector (NAV) settings can depend on the status of the primary channel. If the primary channel is busy, for example due to STAs (supporting only the 1MHz operating mode) sending to the AP, the entire available band can be considered busy, even if most of the band remains idle and may be available.

[0073] In the United States, the available frequency band for 802.11ah is from 902MHz to 928MHz. In South Korea, the available frequency band is from 917.5MHz to 923.5MHz. In Japan, the available frequency band is from 916.5MHz to 927.5MHz. The total available bandwidth for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0074] Figure 1D This is a system diagram illustrating RAN 113 and CN 115 according to an embodiment. As described above, RAN 113 can communicate with WTRUs 102a, 102b, and 102c via air interface 116 using NR radio technology. RAN 113 can also communicate with CN 115.

[0075] RAN 113 may include gNBs 180a, 180b, and 180c; however, it should be understood that RAN 113 may include any number of gNBs while remaining consistent with the embodiments. gNBs 180a, 180b, and 180c may each include one or more transceivers for communicating with WTRUs 102a, 102b, and 102c via air interface 116. In the embodiments, gNBs 180a, 180b, and 180c may implement MIMO technology. For example, gNBs 180a and 180b may utilize beamforming to transmit signals to and / or receive signals from gNBs 180a, 180b, and 180c. Therefore, for example, gNB 180a may use multiple antennas to transmit and / or receive radio signals from WTRU 102a. In embodiments, gNBs 180a, 180b, and 180c can implement carrier aggregation technology. For example, gNB 180a can transmit multiple component carriers (not shown) to WTRU 102a. A subset of these component carriers can be on unlicensed spectrum, while the remaining component carriers can be on licensed spectrum. In embodiments, gNBs 180a, 180b, and 180c can implement Coordinated Multipoint (CoMP) technology. For example, WTRU 102a can receive coordinated transmissions from gNBs 180a and 180b (and / or gNB 180c).

[0076] WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using transmissions associated with scalable digitization. For example, OFDM symbol spacing and / or OFDM subcarrier spacing can vary for different transmissions, different cells, and / or different portions of the radio transmission spectrum. WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using subframes or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing different numbers of OFDM symbols and / or continuously varying lengths of absolute time).

[0077] gNBs 180a, 180b, and 180c can be configured to communicate with WTRUs 102a, 102b, and 102c in standalone and / or non-standalone configurations. In standalone configuration, WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c without simultaneously accessing other RANs (e.g., eNode-Bs 160a, 160b, and 160c). In standalone configuration, WTRUs 102a, 102b, and 102c can utilize one or more gNBs 180a, 180b, and 180c as mobility anchors. In standalone configuration, WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using signals in unlicensed frequency bands. In a non-standalone configuration, WTRUs 102a, 102b, and 102c can communicate / connect with gNBs 180a, 180b, and 180c, while also communicating / connecting with another RAN such as eNode-Bs 160a, 160b, and 160c. For example, WTRUs 102a, 102b, and 102c can implement DC principles to communicate substantially simultaneously with one or more gNBs 180a, 180b, and 180c, as well as one or more eNode-Bs 160a, 160b, and 160c. In a non-standalone configuration, eNode-Bs 160a, 160b, and 160c can be used as mobility anchors for WTRUs 102a, 102b, and 102c, and gNBs 180a, 180b, and 180c can provide additional coverage and / or throughput for serving WTRUs 102a, 102b, and 102c.

[0078] Each of gNBs 180a, 180b, and 180c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, user scheduling in UL and / or DL, network slicing support, dual connectivity, interoperability between NR and E-UTRA, routing user plane data to User Plane Functions (UPF) 184a and 184b, and routing control plane information to Access and Mobility Management Functions (AMF) 182a and 182b, etc. Figure 1D As shown, gNB 180a, 180b, and 180c can communicate with each other via the Xn interface.

[0079] Figure 1DThe CN 115 shown may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. Although each of the foregoing elements is described as part of the CN 115, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0080] AMF 182a and 182b can connect to one or more gNBs 180a, 180b, and 180c in RAN 113 via the N2 interface and can be used as control nodes. For example, AMF 182a and 182b can be responsible for authenticating users of WTRU 102a, 102b, and 102c, supporting network slicing (e.g., handling different PDU sessions with different requirements), selecting specific SMF 183a and 183b, managing registration areas, terminating NAS signaling, mobility management, etc. AMF 182a and 182b can use network slicing to customize CN support for WTRU 102a, 102b, and 102c based on the service type used by WTRU 102a, 102b, and 102c. For example, different network slices can be established for different use cases (e.g., services relying on Ultra Reliable Low Latency (URLLC) access, services relying on Enhanced Massive Mobile Broadband (eMBB) access, services for Machine Type Communication (MTC) access, etc.). AMF 162 can provide control plane functions for handover between RAN 113 and other RANs (not shown) that employ other radio technologies such as LTE, LTE-A, LTE-A Pro and / or non-3GPP access technologies such as WiFi.

[0081] SMFs 183a and 183b can connect to AMFs 182a and 182b in CN 115 via the N11 interface. SMFs 183a and 183b can also connect to UPFs 184a and 184b in CN 115 via the N4 interface. SMFs 183a and 183b can select and control UPFs 184a and 184b, and configure the routing of services through UPFs 184a and 184b. SMFs 183a and 183b can perform other functions, such as managing and allocating WTRU IP addresses, managing PDU sessions, controlling policy enforcement and QoS, and providing downlink data notifications. PDU session types can be IP-based, non-IP-based, Ethernet-based, etc.

[0082] UPF 184a and 184b can be connected to one or more gNBs 180a, 180b, and 180c in RAN 113 via the N3 interface. This interface can provide WTRU 102a, 102b, and 102c with access to a packet-switched network (e.g., Internet 110) to facilitate communication between WTRU 102a, 102b, 102c and IP-enabled devices. UPF 184 and 184b can perform other functions such as routing and forwarding packets, enforcing user plane policies, supporting multi-destination PDU sessions, handling user plane QoS, buffering downlink packets, and providing mobility anchoring.

[0083] CN 115 can facilitate communication with other networks. For example, CN 115 may include, or be able to communicate with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) serving as an interface between CN 115 and PSTN 108. Furthermore, CN 115 can provide WTRUs 102a, 102b, and 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In an embodiment, WTRUs 102a, 102b, and 102c can be connected to local data networks (DNs) 185a and 185b via UPFs 184a and 184b through their N3 interfaces and the N6 interface between UPFs 184a and 184b and DNs 185a and 185b.

[0084] Given Figure 1A-1D as well as Figure 1A-1D As described in the corresponding descriptions herein, one or all of the functions described for one or more of the WTRU 102a-d, base station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF183a-b, DN 185a-b, and / or any other device described herein (one or more) may be performed by one or more emulation devices (not shown). An emulation device may be one or more devices configured to emulate one or more of the functions described herein. For example, an emulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0085] Simulation devices can be designed to perform one or more tests on other devices in laboratory and / or carrier network environments. For example, one or more simulation devices can perform one or more or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices within the communication network. One or more simulation devices can perform one or more or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. Simulation devices can be directly coupled to another device for testing and / or testing purposes that can be performed using over-the-air wireless communication.

[0086] One or more emulation devices may perform one or more functions, including all functions, rather than being implemented / deployed as part of a wired and / or wireless communication network. For example, emulation devices may be used in test scenarios outside of deployment (e.g., testing) wired and / or wireless communication networks and / or test laboratories to implement testing of one or more components. One or more emulation devices may be test equipment. Emulation devices may transmit and / or receive data using direct RF coupling and / or wireless communication via RF circuitry (e.g., which may include one or more antennas).

[0087] 5G and above applications are likely to expand across multiple verticals, including extended reality (XR), industrial IoT (IoT), and intelligent transportation systems. Such scenarios may present new service requirements, such as ultra-high uplink (UL) data rates, ultra-low latency, and high reliability, while maintaining reasonable resource and power efficiency. Some services, including XR and virtual reality / augmented reality (VR / AR), may require tight synchronization between data streams from multiple devices operating within a single application layer, such as gloves, glasses, and / or other devices.

[0088] Wireless Transmit / Receive Units (WTRUs) in a network can be grouped to assist each other and / or perform collaborative tasks and processes, forming aggregation groups. Groups can be defined statically or dynamically based on the proximity of WTRUs, support for aggregation and / or collaboration features, or shared data interests among WTRUs (e.g., WTRUs belonging to the same set of users, subscribers, and / or devices). The tasks performed by WTRUs within an aggregation group may involve communication protocol aspects in both higher-layer and lower-layer protocol stacks. In some cases, collaboration may aim to collect and regroup distributed knowledge and / or decisions to improve overall system performance. In other cases, WTRUs may delegate tasks on behalf of another WTRU. Networks can use WTRU aggregation to dynamically route uplink and / or downlink data using multiple Uu links and sidelinks between WTRUs, taking into account data transmission power, channel conditions, and / or Quality of Service (QoS) requirements. This approach enables efficient group management while maintaining QoS and / or Quality of Experience (QoE) of service. Aggregation and / or collaboration can also involve WTRUs relaying data to the network or another WTRU.

[0089] Lower-layer aggregation (e.g., Media Access Control (MAC) and / or Physical (PHY) layer aggregation) allows the network to leverage combined gains at lower layers to enhance system performance. Furthermore, Physical Downlink Shared Channel (PDSCH) and / or Physical Uplink Shared Channel (PUSCH) transmissions can be performed on the same resources to reduce resource overhead and enhance WTRU antenna capabilities. For example, joint transmissions utilizing a Single-Frequency Network (SFN) can enable multiple WTRUs to transmit the same signal on the same resources, thereby increasing received power at the gNodeB (gNB) and improving decoding performance due to combined gains at lower layers. On the downlink (DL) side, WTRUs can receive transmissions and combine processed signals before decoding, or decode and subsequently exchange results. Hybrid Automatic Repeat Request (HARQ) retransmissions can be avoided as long as transmissions are successful on at least one WTRU, reducing latency and eliminating unnecessary retransmissions. WTRUs can also employ distributed transmit and / or receive techniques similar to Distributed Multiple-Input Multiple-Output (MIMO) to balance channel diversity among WTRUs (e.g., by transmitting and / or receiving different data layers). WTRUs in an aggregated group can be viewed as a single logical device, where interactions and configurations are managed within the group (e.g., via a group coordinator (GC)).

[0090] In the current 3GPP standard, networks can schedule and prepare Uu transmissions based on measured reference signals (RS) to estimate channel quality between WTRUs and gNBs. The sounding reference signal (SRS) can be used as an uplink reference signal for uplink channel estimation and can also be used for downlink estimation and / or beam management. Reference signal (RS) transmission (e.g., sounding reference signal (SRS)) can be configured individually for each WTRU, and the WTRU can be configured via Radio Resource Control (RRC) to receive one or more sets of SRS resources, which indicate how to transmit the SRS (e.g., timing, frequency, and / or cyclic shift).

[0091] Enhancements to the transmission of aggregated WTRUs may include implementing joint and / or aggregated SRS transmissions, thereby allowing the network to obtain improved channel measurements of the aggregated WTRUs. This specification may describe methods for supporting SRS transmissions applicable to WTRUs operating as individual units within an aggregated group. This specification may further describe in detail methods for determining SRS transmission parameters for an aggregate of WTRUs to coordinate transmissions and prevent ambiguity (e.g., antenna-to-port mapping and / or transmit power allocation for multiple WTRUs).

[0092] Under existing standards, when WTRUs perform aggregated transmissions, each WTRU can send SRS independently, and the corresponding aggregated channel may not be directly measured by the network. Therefore, the network may lack accurate measurement of aggregated transmissions. Furthermore, WTRU aggregation can be managed on the WTRU side (e.g., by the GC), and the network may be unaware of the ongoing aggregation configuration, which can be dynamically modified and / or updated.

[0093] Furthermore, from the WTRU's perspective, SRS transmission may involve internal implementation components (e.g., antenna-to-SRS port mapping and / or SRS power control) that may require joint management by WTRUs across aggregated groups. Without coordination, ambiguity may arise regarding the sharing of SRS ports and / or resources among WTRUs. Therefore, coordination among WTRUs may be necessary to facilitate proper SRS transmission.

[0094] The method for determining and utilizing aggregation-specific transmission parameters for SRS transmissions can be based on a set of configurations and / or information related to WTRUs within the aggregation group.

[0095] A Wireless Transmit / Receive Unit (WTRU) can receive pre-configured portions of an aggregation group. The configuration may include one or more Sound Reference Signal (SRS) resources and / or sets, specifying the resource configuration and the number of ports configured. Additionally and / or alternatively, the WTRU can be configured to utilize aggregation schemes associated with the SRS (e.g., non-single-frequency network (non-SFN) transmissions), such as uplink (UL) permission with SRS indication. The WTRU can also receive (e.g., from the Group Coordinator (GC)) indications about other WTRUs in the aggregation group, including information about the number of supported antenna ports, supported aggregation schemes, and / or co-location indications (e.g., relative positions and / or synchronization timings between WTRUs).

[0096] A WTRU can determine a set of transport parameters to perform aggregated SRS transports based on received configurations and indications. Transport parameters may include SRS resources and / or set identifiers (IDs) based on the aggregated transport, which can be determined based on the configured aggregated transport and associated SRS indications. Additionally and / or alternatively, a WTRU can determine a subset of WTRUs to perform aggregated SRS transports. A WTRU can select a set of WTRUs based on WTRU configurations within an aggregated group. For example, for an SRS configured with four transport (TX) ports and associated with a non-SFN transport, a WTRU could select two WTRUs, each with two TX ports, that are not co-located and support non-SFN aggregated transports.

[0097] The WTRU can determine the mapping between the antenna ports of a selected subset of WTRUs and the configured SRS ports. For example, the WTRU can map two antenna ports of a first WTRU to the first two SRS ports, and two antenna ports of a second WTRU to the third and fourth SRS ports. Additionally and / or alternatively, the WTRU can determine aggregated SRS transmission power parameters based on the WTRU's SRS transmit power. The WTRU can determine the transmit power of another WTRU's ports based on its transmit power control, thereby distributing power equally among the WTRUs.

[0098] The WTRU can send aggregated SRS resources and / or a set of transmission parameters (e.g., port mappings and / or transmission power) to a defined subset of WTRUs and / or to the network. Upon receiving an indication to send aggregated SRS, the WTRU can send an SRS transmission indication to the WTRUs determined for the aggregated transmission. The WTRU can receive the indication via MAC activation or downlink control information (DCI) commands for semi-persistent and / or aperiodic SRS, and can send the indication via sidelink MAC (SL-MAC) or sidelink control information (SCI), respectively.

[0099] WTRUs can transmit SRS using a defined set of aggregation transmission parameters and a received configuration. This coordination among WTRUs enables the transmission of a reference signal (RS) that correctly represents the aggregated UL channel, allowing the network to perform accurate measurements and improve scheduling. WTRUs can collect and process information from multiple sources to determine the transmission parameters used for aggregation configuration and avoid ambiguity in transmission allocation. For example, WTRUs can determine which SRS is used as the reference for incoming transmissions and / or assess the antenna and power capabilities of WTRUs within the aggregation group.

[0100] WTRU groups can form aggregate groups, which may include GCs. GCs can manage certain group functions and centralize information that may be unavailable to the network. Aggregate groups can be pre-defined or dynamically updated. Aggregate groups can consist of WTRUs that share common data interests, belong to the same user and / or subscriber, are part of the same set of devices, and / or are very close to each other. Example use cases may include XR, IoT, and / or wearable devices.

[0101] For WTRU aggregation in UL transmit and downlink (DL) receive, a WTRU can perform UL transmit and / or DL ​​receive with the support of one or more auxiliary WTRUs to utilize WTRU diversity gain in transmit and / or receive. WTRUs can be configured for aggregation and can be allocated SRS resources and / or aggregates based on their capabilities. WTRUs can report their aggregation configuration and / or support to the network, for example, via WTRU capability indications, Radio Resource Control (RRC) (re)configuration, UL MAC Control Element (MAC-CE), and / or Physical (PHY) level indications. Additionally and / or alternatively, a WTRU can report its aggregation configuration and / or support to another WTRU using sidelink (SL) transmissions (e.g., PC5-RRC, PC5-MAC, and / or SCI indications).

[0102] The WTRU can receive configuration parameters for operation in aggregation mode. Based on the WTRU's capabilities and / or aggregation support, the configuration may include aggregation-related requirements, parameters, and / or settings. In one example, the WTRU can receive aggregation configuration from the network as part of an RRC (re)configuration. Additionally and / or alternatively, the WTRU can receive aggregation configuration from another WTRU (e.g., a GC) via SL transmission (e.g., PC5-RRC).

[0103] In one example, a WTRU can receive one or more configurations. These configurations can include transmission modes. A WTRU can be configured to support or enable one or more transmission modes. Different transmission modes can include a first transmission mode, where a WTRU can transmit SRS for transmission using only its own antenna and antenna port (e.g., without aggregation). A second transmission mode can allow a WTRU to transmit SRS using aggregation of WTRUs, meaning multiple WTRUs can participate in transmitting SRS. This mode can conserve a portion of the WTRU's transmission power and / or enable joint transmission among WTRUs to improve channel quality. A third transmission mode can allow a WTRU to delegate SRS transmission to other WTRUs, meaning the WTRU may not be part of the WTRU group performing SRS transmission. This mode can conserve the transmission power and energy of the delegated WTRU while allowing the network to gain knowledge of its SRS via the transmission of auxiliary WTRUs.

[0104] In one example, a WTRU can be configured to support one or more transport modes (e.g., based on its hardware, software, and / or implementation capabilities, or by belonging to and / or being configured to support a WTRU category of a feature). In another example, a WTRU can be configured to support one or more transport modes for different transports or transport types (e.g., using a first transport mode for a first SRS set or SRS resource and a second transport mode for another SRS set or SRS resource).

[0105] WTRUs can be configured to use one or more aggregation transmission techniques. In one example, multiple WTRUs can simultaneously transmit the same signal on the same time and / or frequency resources, causing these signals to be added at the gNB. This transmission method can be called SFN transmission. The benefits of SFN transmission may include enhanced received signal strength at the gNB, and the channel can benefit from diversity across different sources. In another example, multiple WTRUs can transmit different parts of the transmission, and the network can combine received transmissions to reconstruct the complete transmission. For example, WTRUs can be configured to transmit transmissions at different layers. WTRUs can still act as a single logical entity and, from the network's perspective, can be viewed as different ports and / or layers of a single transmission.

[0106] The WTRU can be configured with indications regarding aggregation groups. The WTRU can receive a list of WTRUs within the aggregation group (e.g., including their WTRU IDs). Additionally and / or alternatively, the WTRU can receive indications of the presence and / or ID of a GC, if applicable. The WTRU can receive indications from the aggregation group that it is a valid and / or supported cell. Furthermore, the WTRU can receive information about other WTRUs within the group, including the number of antenna ports available for transmission and / or reception, transmit power and / or maximum transmit power, aggregation feature support (e.g., transmission mode, transmission scheme, and / or aggregation port mapping combination), synchronization status and / or time alignment, battery level and / or energy settings, correlation and / or orthogonality with the WTRU, and / or relative or absolute location. The WTRU can also receive a priority list of WTRUs (e.g., indicating which WTRUs can preferentially participate in aggregation transmissions) and / or a list of non-preferred WTRUs that can be ultimately selected for aggregation transmissions.

[0107] WTRUs can be configured to follow certain requirements regarding how aggregation can be performed and / or how WTRUs can be grouped. For example, WTRUs can receive configurations regarding grouping requirements, such as correlation thresholds, maximum distance thresholds, and / or synchronization and / or time alignment thresholds.

[0108] In one example, a WTRU can be configured with SRS resources and / or sets. A WTRU can be configured individually using SRS resources and / or sets (e.g., receiving configuration from the network as part of its RRC configuration). In one example, a WTRU can receive configuration from the network (e.g., using SI, RRC, MAC, and / or PHY level indications). In another example, a WTRU can receive configuration from another WTRU using SL communication (e.g., SL-RRC, SL-MAC, and / or SCI indications) or other WTRU inter-communication systems.

[0109] SRS resource set configuration may include an SRS resource set ID, one or more SRS resources, and / or resource type (e.g., whether the SRS resource set is periodic, semi-persistent, and / or aperiodic, and the corresponding configuration). SRS resource set configuration may also include usage (e.g., whether the SRS is used for beam management, codebook-based transmission, non-codebook transmission, and / or antenna switching). In one example, it may include a new usage indicating that the SRS is being used for aggregated transmission. Furthermore, the configuration may include power control parameters (e.g., target received power value (p0), power scaling (alpha), and / or reference path loss). In one example, the power control parameters may include one set of values ​​for non-aggregated transmission and another set of values ​​for aggregated transmission. The configuration may also indicate whether the SRS resource set supports or allows aggregated transmission (e.g., using binary flags).

[0110] SRS resource configuration may include SRS resource ID, the number of SRS ports, and / or spatial relation information for SRS. The WTRU may be pre-configured with SRS resources, including spatial relation information (e.g., spatialRelationInfo or spatialRelationInfoPos), which can be received from higher-level configurations, pre-configurations, MAC spatial reference update commands, and / or RSs of the DCI activating the SRS resources and / or sets. The RS can be an SSB, CSI-RS, and / or SRS. Furthermore, the configuration may include information about resources allocated for SRS transmissions, including resource mappings, transmission combs, time and / or frequency indications, and / or other transmission-related parameters.

[0111] A WTRU can receive SRS resources and / or aggregate configurations as part of a WTRU group (e.g., not for a specific individual WTRU). A WTRU can receive SRS resources and / or aggregate configurations for a group (e.g., configurations with an indication of the group and / or aggregate ID). In this case, SRS transmission can be left to the WTRU group to determine and configure how the WTRUs in the group manage SRS transmission.

[0112] The determination of transmission parameters for aggregated SRS can be discussed. A WTRU can determine its own SRS set and / or resources, transmission mode, and transmission parameters. A source WTRU or an assisted WTRU can receive its own SRS configuration and determine whether and / or how to perform SRS transmission aggregation for its SRS set and / or resources. A WTRU can determine the SRS set and / or resources, transmission mode, and transmission parameters for another WTRU. A WTRU operating as a group coordinator or assisted WTRU can receive the SRS configuration of another WTRU (e.g., an assisted WTRU) and determine whether and / or how the assisted WTRU performs SRS transmission aggregation. A WTRU can determine the SRS set and / or resources, transmission mode, and transmission parameters for a WTRU group. A WTRU operating as a group coordinator can receive the SRS configuration applicable to the WTRU group and determine whether, which, and / or how the WTRUs in the group perform SRS transmission aggregation.

[0113] The WTRU can determine whether to use the aggregated transmission mode to transmit SRS. The WTRU can determine one, more, or a combination of the following: the set of SRS and / or resources using the aggregated transmission mode, the WTRUs participating in the aggregated transmission mode, the aggregated antenna port mapping (e.g., the mapping between the antenna ports and SRS ports of the WTRUs in the aggregate), the transmit power for different aggregated SRS ports, and the WTRUs associated with different SRS resources within the resource set.

[0114] The determination of the foregoing aspects is described below, but it should be understood that criteria can be combined and some determination steps can be jointly determined. WTRU can determine whether to use aggregated transmissions for some UL RS transmissions (e.g., based on received configuration and / or indications).

[0115] WTRU can determine the transport mode for some SRS resources or sets based on one or more conditions. If a first condition is met, WTRU can determine to use a first transport mode (e.g., not using aggregation); if a second condition is met, a second transport mode (e.g., using aggregation) is used, and so on. WTRU can determine to use different transport modes for different SRS transports. A first transport mode can be used for some SRS sets and / or SRS resources, and a second transport mode can be used for some other SRS sets and / or SRS resources, both of which are configured and / or active simultaneously.

[0116] The WTRU can be configured and / or determined to measure one or more quality parameters (e.g., SINR, RSSI, RSRP, CQI) on one or more configured and / or determined signals and / or channels. The WTRU can receive configurations (e.g., via SIB, RRC, MAC-CE, DCI) that may include one or more thresholds associated with the measurement. The WTRU can measure one or more quality parameters with respect to received or detected DL signals and / or channels (e.g., SSB, PDCCH, PDSCH, or DL ​​RS such as DL DMRS and / or CSI-RS). If the measured quality parameter is above a first threshold, the WTRU can determine to use a first transmission mode, or if the measured quality parameter is below a second threshold, it can determine to use a second transmission mode. The WTRU can determine the transmission mode of a given SRS by measuring the DL channel associated with it (e.g., when the WTRU receives a configuration with SRS resources indicating spatial relationships of DL RSs, the WTRU can use measurements on that DL RS to determine the SRS transmission mode). WTRU can also use measurements of QCL signals and / or channels (e.g., sent by networks with similar spatial conditions) as RSs indicated in spatial relational configurations.

[0117] A WTRU can determine the transmission mode to use based on a configuration received and / or determined by the WTRU. The WTRU can determine or receive a configuration indicating that it is part of a WTRU aggregation group for transmitting at least some control, data, or RS transmissions, having a corresponding WTRU ID, data information (e.g., data stream, QoS stream, queue), and RS ID within the group. As part of an aggregation group, the WTRU can receive a configuration indicating that the group's SRS will be transmitted using aggregation. When the received configuration indicates that the SRS will be transmitted using aggregation as part of an RS (e.g., based on an explicit indication in the SRS configuration), the WTRU can determine to use a second transmission mode (e.g., using aggregation) for the SRS set or resource. When the SRS configuration explicitly indicates the transmission mode used for the SRS (e.g., using a new field in the SRS resource or set configuration), the WTRU can determine to use a transmission mode (e.g., third-mode delegated transmission). When the SRS resource set is set to aggregate or delegated, the WTRU can use the aggregation mode. When an SRS is used directly or indirectly as a reference (e.g., as a reference to a reference) to transmit data configured to be sent using aggregation (e.g., if the WTRU is configured and / or instructed to transmit via DCI or RRC, where the SRS is in TCI state, QCL state, or spatial transformation), the WTRU may determine to use a second transmission mode (e.g., using aggregation) for the SRS set or resource. When the WTRU is configured with QoS associated with the aggregated transmission (e.g., based on latency, reliability, or data rate) and the WTRU has or expects data in the UL buffer (associated with the QoS requiring aggregation), the WTRU may determine to use a second transmission mode (e.g., using aggregation) for the SRS set or resource.

[0118] A WTRU can determine whether to use one transport mode or another for an SRS resource or set based on the SRS port configuration (TX and RX). A WTRU can be configured with an SRS set indicating four SRS TX ports, where the WTRU individually supports (e.g., only supports) two TX ports and supports four TX ports when aggregated with another WTRU. The WTRU can then determine to use the aggregated transport mode for that SRS set. Alternatively, a WTRU can be configured with an SRS set indicating two SRS TX ports, supporting both SRS TX ports individually or with another WTRU, and can determine to use a second transport mode (using aggregation).

[0119] A WTRU can be configured and / or determined to estimate its location in the network and / or relative to the serving cell. The WTRU can use its location to determine the transmission mode of the SRS. The WTRU can be configured and / or determined to use GNSS-based positioning, network-based positioning, and / or positioning based on another WTRU. The WTRU can be configured or determined to estimate its relative or absolute location relative to its serving cell. The WTRU can use synchronization signals and / or time alignment indications to estimate its distance to the serving cell. The WTRU can be configured with or determined with respect to thresholds for distance and / or location. If the WTRU is determined or indicated to be outside the cell edge (e.g., if the distance to the serving cell is below a first threshold), the WTRU can determine to use a first transmission mode; or if it is determined or indicated to be at the cell edge (e.g., if the distance to the serving cell is above a second threshold), it will use a second transmission mode.

[0120] The WTRU may have low battery power or be configured in power-saving mode. The WTRU may determine whether to use aggregation for transmission based on its power-saving mode configuration.

[0121] When no relevant configuration is available and / or no specific criteria for determining the transport mode are met, the WTRU may default to using one of the transport modes. The WTRU can be configured (e.g., pre-configured) with a default transport mode. For example, the WTRU may be pre-configured to use a transport mode that utilizes aggregation (e.g., a second transport mode).

[0122] WTRU can select WTRUs in the group to perform UL RS transfers (e.g., based on their capabilities).

[0123] A WTRU can determine a set and / or group of WTRUs based on one or more conditions to perform aggregated transports of some SRS sets and / or resources. A WTRU can select WTRUs from a configured and / or determined list of WTRUs (e.g., WTRUs in an aggregated group) to perform aggregated transports. A WTRU can select WTRUs from a portion of WTRUs that are not configured into the current aggregated group to perform aggregated transports. A WTRU can select WTRUs from both configured and unconfigured portions of WTRUs to perform aggregated transports.

[0124] If the first condition is met, the WTRU can select a first WTRU set to perform the aggregated transport; if the second condition is met, it can select a second WTRU set to perform the aggregated transport, and so on. The WTRU can determine which WTRU set to use for different SRS transports. The first WTRU set can be used for some SRS sets and / or SRS resources, while the second WTRU set can be used for some other SRS sets and / or SRS resources, both of which can be configured and / or active simultaneously.

[0125] A WTRU can select a WTRU to perform aggregated transmissions of some SRS sets and / or SRS resources based on one or more of the following: A WTRU can determine the transmission mode to use based on a configuration received and / or determined by the WTRU. A WTRU can determine or receive a configuration indicating that it is part of a WTRU aggregation group for transmitting at least some control, data, or RS transmissions, having a corresponding WTRU ID, data information (e.g., data stream, QoS stream, queue), and RSID within the group. A WTRU can select a WTRU from the WTRUs in the configured aggregation group. For SRS sets and / or resources, a WTRU can select a WTRU configured to perform aggregated transmissions of the considered SRS sets and / or resources, or aggregated transmissions of data payloads or control messages, using the SRS sets and / or resources as direct or indirect references.

[0126] A WTRU can select WTRUs to perform aggregated transmissions based on its own capabilities. A WTRU can receive WTRU capabilities from other WTRUs (e.g., based on information received directly by the WTRU using a PC5 connection, from another WTRU such as a group coordinator, or from the network). A WTRU can receive information about supported characteristics related to aggregation with another WTRU, such as supported aggregation transmission schemes, supported channels and / or signals for aggregation, the maximum number of WTRUs supported in the aggregated transmission, supported aggregation antenna port combinations, and / or the number of supported TX and RX ports. A WTRU can select WTRUs that support aggregated SRS transmissions. A WTRU can select WTRUs that support the configured aggregation transmission mode (e.g., supporting SFN transmissions when SFN transmissions are configured, or supporting non-SFN and / or independent port transmissions when non-SFN and / or independent port transmissions are configured). A WTRU can select WTRUs for which the total number of WTRUs in its aggregation is less than or equal to the maximum number of supported WTRUs in the aggregated transmission. A WTRU can select other WTRUs that support the same number of TX and RX ports as itself (e.g., so that the antenna port configurations of two WTRUs can be identical). A WTRU can be selected based on the number of TX and RX ports it supports, such that the total number of TX and / or RX ports equals or exceeds a certain value. This value can be the number of ports indicated in the SRS configuration. A WTRU can also select other WTRUs that support aggregated antenna port combinations, which are configured and / or determined to be used for SRS sets and / or resources.

[0127] A WTRU can be configured and / or informed, or can determine, the correlation between its Uu channels. Correlation information can indicate the level of correlation between WTRUs (e.g., highly correlated, loosely correlated, or uncorrelated). WTRUs can select WTRUs for aggregation based on correlation values ​​and RSs used to measure correlation (e.g., RSs directly or indirectly used as references to SRS sets and / or resources). A WTRU can select another WTRU whose Uu channels for two of its WTRUs have very high correlation with a given RS. A WTRU can select another WTRU whose Uu channels for two of its WTRUs have no correlation with a given RS. WTRUs can determine which correlation criterion to use for WTRU selection based on the aggregation transmission scheme of the transmission. A WTRU configured with aggregation transmission using SFN transmission can select WTRUs with high correlation (e.g., above a threshold). A WTRU configured with aggregation transmission where ports are independent (e.g., distributed MIMO) can select WTRUs with no correlation and / or low correlation (e.g., below a threshold).

[0128] WTRUs can be selected based on their location. A WTRU can select WTRUs within a given relative distance or proximity (e.g., based on a configured threshold for the maximum distance between WTRUs). This maximum distance may be beneficial for ensuring good SL signal quality between WTRUs or for ensuring cooperative positioning of WTRUs. A WTRU can also select WTRUs close to the gNB (e.g., within a configured maximum distance threshold).

[0129] A WTRU can select another WTRU based on synchronization considerations. A WTRU can select another WTRU if it can adjust its transmission timing to match the timing of other WTRUs. A WTRU can select another WTRU with the same configured time alignment parameters.

[0130] A WTRU can select other WTRUs based on its priority. A WTRU can receive a list of WTRU priorities, which sorts the WTRUs according to the order of aggregated transmissions. The WTRU can then select WTRUs from those meeting other criteria (if any) based on the priority order. A WTRU can have a list of non-preferred WTRUs that it avoids for aggregated transmissions.

[0131] It should be understood that even if the proposed criteria can be used as a filter to select WTRUs that do not meet some criteria, WTRUs can still perform selection and / or prioritization among the WTRUs that meet the requirements. A WTRU can select from the set of WTRUs that meet the requirements the WTRU with the highest priority in the received and / or determined WTRU priority list. A WTRU can select from the set of WTRUs that meet the requirements the WTRU with the strongest correlation of its signal (e.g., in the case where a WTRU delegates some transmission ports to maximize the similarity between channels). A WTRU can select from the set of WTRUs that meet the requirements the WTRU that supports the highest number of TX and / or RX ports to minimize the number of WTRUs in the aggregation and avoid overhead between WTRUs.

[0132] The WTRU can determine the set of transmission parameters for aggregated SRS transmissions. The WTRU can determine the set of transmission parameters for aggregated transmissions with a given set of SRS and / or resources for a given WTRU set and / or group. Transmission parameters may include one or more of the following. The WTRU can determine the set of aggregated antenna port combinations based on SRS configuration and WTRU capabilities.

[0133] The WTRU can determine the mapping between antenna ports of the WTRU set and / or group and SRS ports used for aggregated transmissions of SRS. In non-aggregated transmissions, the WTRU itself determines the antenna port-to-SRS port mapping (e.g., depending on the internal implementation) and applies the same mapping for both SRS and transmissions using SRS as a reference. One antenna port can be mapped to a first SRS port transmitted on one of the SRS resources, while another antenna port can be mapped to a second SRS port transmitted on another SRS resource. Multiple antenna ports of the WTRU can be mapped to SRS ports using a given SRS resource. The WTRU can receive configurations of different SRS ports indicating different SRS resources, cyclic shifts, frequency spacing (combining), frequency offsets, etc., thereby identifying and separating different SRS ports. In aggregated SRS transmissions, different WTRUs should know how to map their antenna ports to SRS ports (e.g., how to share SRS ports across WTRUs).

[0134] The WTRU can receive an SRS configuration indicating a given number of TX and / or RX ports (e.g., in the case of DL probing using channel reciprocity). If the WTRU does not know the mapping, there may be ambiguity regarding which SRS port the WTRU should transmit on, which could result in unwanted overlapping transmissions.

[0135] The WTRU can determine that all WTRUs in the group apply independent overlap mappings between their antenna ports and SRS ports. In this option, all WTRUs can transmit simultaneously on the SRS resources of each port. Each WTRU can use its own internal mapping (e.g., the same as a regular non-aggregated mapping). This option may be advantageous for SFN transmissions where WTRUs jointly transmit SRS, allowing the gNB to perform channel estimation on the actual combination of UL signals and thus determine the aggregated channel more accurately.

[0136] The WTRU can determine that the antenna ports of different WTRUs are mapped to separate SRS ports. For example, the two antenna ports of the first WTRU in the group can be mapped to the first two SRS ports, and the two antenna ports of the second WTRU in the group can be mapped to the third and fourth SRS ports. In this option, the WTRU can use the resources associated with different SRS ports to transmit individually. This option may be beneficial for gNB to estimate individual channels and be able to schedule precoding or multilayer transmissions.

[0137] A WTRU can determine to use all or some of the antenna ports of one or more WTRUs in a group for aggregated transmission. A WTRU can determine to use all antenna ports of WTRUs in a group (e.g., when WTRUs have the same number of antenna ports and are also the same as the SRS ports in an SFN transmission). A WTRU can determine to use only one of two or more antenna ports for each WTRU in a group (e.g., based on the signal quality of the WTRU signal or the WTRU battery level).

[0138] The WTRU can determine the aggregated antenna port mapping across multiple WTRUs based on SRS resource configuration. The WTRU can determine that SRS transmissions of ports configured to be simultaneous can be mapped to different WTRUs (e.g., so that each WTRU can transmit at full power). The WTRU can also determine that SRS transmissions of ports configured in different time slots can be mapped to the same WTRU.

[0139] The WTRU can determine the converged antenna port mapping based on SRS usage. The WTRU can determine that an SRS resource set configured with usage="antennaSwitching", "codebook", or "nonCodebook" is configured to use a different WTRU and / or WTRU port for each SRS port. The WTRU can determine that an SRS resource set configured with usage="beamManagement" can be associated with mappings that have overlapping ports across WTRUs.

[0140] A WTRU can determine the aggregation mapping (e.g., overlapping mapping, separation mapping, or a combination of both) of WTRUs in a group based on one or more of the following: A WTRU can determine the mapping from antenna ports to SRS ports of a group based on the correlation of the WTRUs' Uu channels. A WTRU can be configured and / or informed, or can determine, the correlation and / or orthogonality between the WTRUs' Uu channels. When WTRUs have high correlation or low orthogonality, a WTRU can determine to use an overlapping mapping across WTRUs. When WTRUs have no correlation and / or have low correlation or high orthogonality, a WTRU can determine to use a separation mapping across WTRUs.

[0141] WTRUs can determine the mapping from antenna ports to SRS ports of a group based on the aggregation transmission scheme. WTRUs configured with aggregation transmissions using SFN transmissions can choose to use overlapping mappings. WTRUs configured with aggregation transmissions where ports are independent (e.g., distributed MIMO) can choose to use separate mappings.

[0142] The WTRU can determine its antenna port mapping based on the number of SRS ports configured for the SRS. A WTRU receiving an SRS configuration indicating 4 TX ports and two WTRUs in a group, each with 2 TX antenna ports, can determine that the WTRUs use separate mappings to have sufficient total TX ports in the aggregation. If the WTRU is configured with a 2-TX-port SRS set and / or resources, and all WTRUs in the group support 2 TX ports, the WTRUs can choose overlapping mappings.

[0143] The WTRU can determine its antenna port mapping based on received and / or determined configurations. The WTRU can receive configurations indicating whether to use overlapping or separate mappings for selected types of aggregated transmissions (e.g., at least for aggregated SRS transmissions). The WTRU can receive and / or determine configurations indicating the thresholds and conditions to which different mappings are applied (e.g., thresholds regarding correlation and / or orthogonality that the WTRU needs for orthogonality criteria).

[0144] WTRUs can determine antenna port mapping based on their signal quality. Two WTRUs with similar RSRP or signal quality can be mapped to the same port to have similar contributions or conditions, and overlapping mapping is beneficial.

[0145] WTRUs can determine antenna port mapping based on their synchronization or time alignment. WTRUs with the same time alignment parameters can be mapped to the same SRS port, while WTRUs with different time alignment parameters can be mapped to different ports.

[0146] It is understood that even if the proposed criteria can be used as a filter for downselecting ports, WTRUs can still perform selection and / or prioritization among WTRUs or WTRU ports that meet the requirements. WTRUs can prioritize WTRUs or WTRU ports with RSRP higher than SRS ports to maximize signal quality for aggregated transmissions. WTRUs can prioritize WTRUs or WTRU ports based on their correlation with themselves (e.g., in the case of SFN transmissions, prioritizing the WTRU port with the strongest correlation). In the case of non-SFN transmissions, WTRUs can prioritize WTRUs with the lowest correlation to increase diversity.

[0147] WTRU can determine the format of the aggregated port mapping based on the selected WTRUs, their capabilities, and the transmission mode. WTRU can determine the mapping format of the antenna ports of WTRUs in the group. WTRU can determine the individual antenna port-to-SRS port mapping of WTRUs in the group based on the number of ports supported by WTRUs in the group, the number of SRS ports, and the determined port mapping.

[0148] Each WTRU can be mapped to an antenna port index vector with an SRS port length to indicate which port of the WTRU is used for which SRS port. For example, WTRU1: [1, 2, -1, -1] means that the first antenna port of WTRU1 is mapped to the first SRS port, the second antenna of WTRU1 is mapped to the second SRS port, and WTRU1 does not have antenna ports mapped to the third and fourth SRS ports because the "-1" value is used to indicate that no mapping exists, although other ways of indicating such non-existence are not excluded.

[0149] Each WTRU can be mapped to a set of SRS port indices. For example, WTRU2:{3,4} means that the antenna port of WTRU2 is mapped to SRS ports 3 and 4. If no further information is determined or stored in the mapping signaling, WTRU2 can determine for itself how to map its antenna port to the received SRS ports.

[0150] The WTRU can determine, for example, the number of SRS ports and / or the number of antenna ports used for that mapping, to its antenna ports based on, for example, the number of SRS ports and / or a defined port mapping. As an example of a mapping format, each WTRU can be mapped to a set of SRS port indices and multiple antenna ports to be used. For example, WTRU2 with two antenna ports: {3, 4} means that two antenna ports of WTRU2 are mapped to SRS ports 3 and 4. If no further information is defined or stored in the mapping signaling, WTRU2 can determine for itself how to map two of its antenna ports to the received SRS ports.

[0151] A WTRU can determine the number of ports that it should map to SRS ports. A WTRU can indicate to another WTRU that it has been allocated two ports for a given SRS resource and / or set. The other WTRU can then autonomously map its ports to SRS ports based on the SRS resource and / or set configuration. If the SRS resource and / or set is configured with two TX ports, and another WTRU receives a configuration to map two ports to the SRS resource and / or set, then the WTRU should map its two TX ports to the two SRS ports.

[0152] The WTRU can determine which WTRU is mapped to which SRS resource. In this case, the WTRU uses the SRS resource ID for indication and can perform its own internal mapping between its antenna port and all SRS ports based on the configuration of the SRS group and / or resources. Each WTRU then covers all ports, and the WTRU transmits SRS through overlap and / or simultaneous transmission.

[0153] A WTRU can determine, based on the transmission mode associated with an SRS as an SFN transmission (e.g., configured and / or determined by a scheduling instruction received by the WTRU for a transmission using that SRS as a reference), that it and another WTRU will each map their two TX ports to two SRS ports of an SRS resource and / or set. The WTRU can then send a configuration to the other WTRU indicating the corresponding SRS resource and / or set, and that it should map two of its TX ports to SRS ports. Alternatively, a WTRU can determine, based on the transmission mode associated with an SRS as a non-SFN transmission (e.g., configured and / or determined by a scheduling instruction received by the WTRU for a transmission using that SRS as a reference), that it and another WTRU will each map their two TX ports to different SRS ports of an SRS resource and / or set comprising four TX ports. The WTRU determines which SRS port each WTRU should map to, ensuring no ambiguity or overlap. For example, a WTRU might choose ports {0, 1} for itself and ports {2, 3} for another WTRU. Then, the WTRU can indicate the SRS resources and / or sets and the corresponding port mappings to another WTRU (e.g., 2 ports will be mapped to SRS ports {2, 3}).

[0154] The WTRU can determine the aggregated SRS transmit power configuration based on a defined port mapping, aggregation transmission scheme, and WTRU capabilities and / or WTRU power control. The WTRU can determine parameters for transmit power or transmit power control applicable to WTRUs in the aggregation group associated with the aggregated SRS, based on, for example, the transmit power parameters of the assisted WTRU and the aggregation port mapping. To perform joint or distributed transmission of the configured SRS, the WTRUs need to be aligned on their respective power contributions to signal transmission. In normal NR operation, SRS transmit power is equally distributed across the ports of a single WTRU.

[0155] The WTRU can determine the actual transmission power to be used for aggregated SRS transmissions (e.g., based on its own transmit power control behavior and other WTRU power capabilities such as maximum transmit power). The WTRU can determine the total transmit power (e.g., the sum of transmit power from all WTRUs used for aggregated SRS transmissions) based on its own SRS transmit power control behavior (e.g., using regular SRS power control behavior). The WTRU can determine the total transmit power based on transmit power control behavior specific to aggregated SRS transmissions (e.g., some of these parameters are given for the group, not WTRU-specific, such as using average path loss values ​​or dedicated and / or configured power scaling factors for aggregation). The WTRU can determine the transmit power for each aggregated SRS port. The WTRU can determine the total transmit power for aggregated SRS transmissions and share a linear value of the total SRS transmit power across aggregated SRS ports by dividing the total SRS transmit power by the number of ports. The WTRU can determine the transmit power for each port based on the maximum transmit power of each WTRU and / or the path loss of the WTRU. The WTRU can determine the transmit power of each port to compensate for the path loss between the WTRU and the gNB, so that each port makes an equal contribution on the network side. The individual port contribution is determined based on the total power of the WTRU and the path loss of the WTRU.

[0156] Each WTRU can determine the transmit power for aggregated SRS transmissions for each WTRU in the group, and each WTRU can also distribute power for SRS transmissions across its ports. A WTRU can determine the total transmit power for aggregated SRS transmissions and divide it by the number of WTRUs. Each WTRU can also individually determine its transmit power (e.g., based on its maximum transmit power and / or its power contribution corrected for path loss). Each WTRU can determine the transmit power for each port to compensate for path loss between the WTRU and the gNB, ensuring that each WTRU makes an equal contribution on the network side, where the individual WTRU contribution is determined based on the total power of the WTRU and the WTRU's path loss.

[0157] A WTRU can determine one or more SRS transmit power control loop parameters (e.g., maximum output power, target power (p0), power scaling factor (alpha), path loss) for use by the WTRU to aggregate SRS transmissions based on its own power loop. The WTRU can determine these parameters to effectively configure other WTRUs to follow a similar power control algorithm, ensuring that different WTRUs apply the same behavior in SRS transmit power. The WTRU can determine a common maximum transmit power applicable to SRS transmissions for each WTRU and / or port, and the WTRU can determine this value based on its own maximum transmit power (e.g., the same as it or divided by the number of WTRUs). Using the values ​​of the assisted WTRUs as a reference, other transmission parameter values, such as the power scaling factor (alpha) or path loss values ​​used as references, can be determined and shared.

[0158] WTRUs can determine an offset, which is applied to their regular transmit power calculations to compensate for the portion of the aggregated transmission. For each aggregated transmission with 2 WTRUs and 2 transmit ports, the WTRUs can determine to apply a -3dB offset to the SRS transmit power. For WTRUs in the group, having power control parameters for aggregated SRS transmissions is equivalent to having a new dedicated power control for that SRS. WTRUs can have a set of regular power control behaviors and / or parameters for non-aggregated transmissions, and another set of behaviors and / or parameters for aggregated transmissions. WTRUs can have multiple sets of SRS power control behaviors and / or parameters for different SRS aggregations (e.g., if the parameters are determined based on values ​​from one WTRU or based on parameters from the WTRU group).

[0159] WTRUs can determine which transmit power rule or parameter to determine (e.g., transmit power per WTRU or per port, or power control parameters) based on the aggregation transmission scheme used for transmission, the determined aggregation port mapping, the capabilities of the WTRUs, their power profiles, and the Uu channel quality of the WTRUs. When the transmission scheme associated with the aggregated SRS is SFN, the WTRU can determine the average shared power across different WTRUs, as similar receive power contributions on the network side may be beneficial for coherent reception of the aggregated signal. WTRUs can determine to use different target powers for WTRUs in the aggregation group based on the Uu channel quality of the WTRUs and their power profiles. WTRUs can determine higher target powers for WTRUs with strong power profiles and lower target powers for WTRUs with limited battery capacity. WTRUs can also determine target powers based on the path loss from the WTRU to the network to avoid requiring strong transmit power from WTRUs with lower channel quality.

[0160] The WTRU can determine the transmit power or power control parameters per port based on a defined aggregated port mapping. The WTRU can determine that when two antenna ports (e.g., across the WTRU) are mapped to a single SRS port and another SRS port is mapped to a single antenna port, the antenna port mapped to the common SRS port may have a different transmit power (e.g., -3dB) than the antenna port with a single antenna port.

[0161] A WTRU can determine the association between SRS resources of an SRS resource set and WTRUs in an aggregated group (e.g., based on a defined port mapping or SRS usage). A WTRU can determine how to distribute the different SRS resources of the SRS resource set among WTRUs in the group (e.g., based on SRS configuration, such as usage). WTRUs can uniformly share the SRS resources of the SRS resource set among WTRUs in subgroups of an aggregated WTRU. WTRUs can also uniformly share the SRS resources of the SRS resource set among defined SRS ports. When different SRS resources correspond to different SRS ports (e.g., when usage is set to antennaSwitching), WTRUs can use a defined aggregated SRS port mapping to associate and / or assign SRS resources to WTRUs.

[0162] When an SRS is configured for usage=beamManagement and different SRS resources in the SRS resource set correspond to different spatial filters from WTRUs, different WTRUs in the aggregation scenario can have their own spatial filters and scan them individually using the SRS resource set. WTRUs can determine which resources in the resource set to allocate to each WTRU and / or associate with each WTRU (e.g., based on the number of spatial filters supported by each WTRU in the aggregation group). WTRUs can individually allocate and / or associate portions of SRS resources from the SRS resource set, corresponding to the number of spatial filters supported by each WTRU. WTRUs can allocate and / or associate overlapping SRS resources from the SRS resource set to different WTRUs in the group, thereby generating combined spatial filters on overlapping resources.

[0163] A WTRU can determine the format for SRS resource allocation and / or association with other WTRUs based on defined resource sharing. A WTRU can indicate to another WTRU the set of SRS resource IDs corresponding to its allocated portion (e.g., using SL RRC, SL MAC, or SCI). WTRUs can determine the preceding aspects sequentially, or some aspects can be jointly determined as part of a single determination step.

[0164] A WTRU can first determine that a given set of SRSs and / or resources will use an aggregated transmission mode, and then jointly determine which WTRUs and their corresponding antenna ports (e.g., because the number of ports and supported combinations can be part of the WTRU selection process). A WTRU can first determine that a given set of SRSs and / or resources will use an aggregated transmission mode, and then jointly determine transmission power parameters and which WTRUs are in the aggregated transmission based on the WTRU's power configuration (e.g., based on the available or maximum power of each WTRU) to avoid selecting WTRUs that do not have sufficient transmit power to match the transmission. A WTRU can first determine that it will perform a transmission with aggregation with some other WTRUs (e.g., based on the received configuration or indication), and then determine which SRS resources and / or sets are suitable for that WTRU group (e.g., based on the number of supported ports in the group).

[0165] The WTRU can request UL RS configuration based on an aggregation configuration. The WTRU can first determine the total number of antenna ports to be used for aggregation (e.g., based on WTRU capacity and the number of antennas in the group), and then send an indication to the network including that aggregation configuration. The WTRU can send this configuration to the network as an RRC configuration or a WTRU capacity indication. This indication is intended to trigger and / or request the network to configure and / or reconfigure the WTRU with an SRS configuration that includes the total number of supported ports.

[0166] A WTRU can first indicate its own two-antenna-port capability to the network, then determine that, through aggregation, it can jointly support up to four antenna ports with other WTRUs, and send this indication to the network as an updated or additional WTRU capability. The WTRU can then receive a new SRS configuration set where the number of ports is greater than the number it supports without aggregation (e.g., four ports). When the configured number of ports exceeds its own capability, the WTRU can determine that the SRS resources and / or sets are implicitly configured for aggregation.

[0167] A WTRU can send a defined set of parameters to another WTRU and the network. A WTRU can also send a defined set of transmission parameters for SRS transmission to another WTRU. A WTRU can send aggregated SRS transmission parameters using side-link RRC configuration or reconfiguration (e.g., for semi-static aggregation configuration). A WTRU can also send aggregated SRS transmission parameters using side-link MAC (e.g., MAC CE) configuration or SLPHY-level configuration (e.g., in SCI).

[0168] WTRUs can send aggregated SRS transport parameters to the GC. WTRUs can be configured (e.g., as part of an aggregation) to report aggregation-related configurations and decisions to the group coordinator of the aggregation group. The GC may have already been instructed via group configuration. In this case, the WTRU report may include transport parameters for all WTRUs (e.g., selected WTRUs) associated with the aggregation of SRS transports and individually identified (e.g., via their WTRU IDs). WTRUs can send aggregated SRS transport parameters to WTRUs participating in the aggregated SRS transport. WTRUs can be configured (e.g., as part of an aggregation) to report the determined configuration to selected WTRUs in the aggregation group. WTRUs can report to selected WTRUs individually using dedicated unicast transports for each WTRU, where the report may include only the transport parameters required by that WTRU. WTRUs can send transport parameters to all WTRUs using multicast and / or broadcast transports, where individual configurations are indicated by the corresponding WTRU ID.

[0169] If the source and / or assisted WTRU is not the WTRU performing the decision and is not part of the selected WTRU group (e.g., when SRS transmission is fully delegated), the WTRU determining the transmission parameters can still report to the source and / or assisted WTRU that it is not part of the transmission group. The WTRU may indicate the SRS resource and / or set configuration as part of the aggregation. When SRS resources and / or sets are typically configured for WTRUs in the group, the configuration may include the SRS resource and / or set ID. The configuration may include part or all of the SRS resource and / or set configuration received by the WTRU (e.g., SRS periodicity, time and frequency resources, offset, scrambling, ID). The configuration may indicate the gNB (e.g., cell ID) corresponding to the received SRS configuration. The WTRU may indicate a determined list of WTRUs in the aggregation group participating in the aggregated SRS transmission. The WTRU may indicate a determined aggregation port mapping (e.g., using the previously described format). The WTRU may indicate determined transmit power parameters used for transmission by other WTRUs. Parameters may include total transmit power, transmit power per WTRU, transmit power per port, and power control behavior parameters (e.g., path loss, offset, scaling factor).

[0170] A WTRU can use the parameters described above to indicate a change in the aggregation configuration to another WTRU. A WTRU may have already determined a first set of aggregation parameters, sent this set to other WTRUs in the aggregation, and then determined a second set of parameters (an update in the configuration) based on the newly received configuration or indication, and sent this second set to other WTRUs in the aggregation. In this second determination of the parameter sets, the WTRU may determine that one or more WTRUs in the aggregation group configured for aggregated transmission of the SRS are no longer part of that SRS aggregation. The WTRU can then send an indication to these WTRUs that they are no longer part of the aggregation for the corresponding SRSID.

[0171] The WTRU can receive a first set of parameters for aggregated transmissions of the SRS, and also a second set of parameters (e.g., based on the SRS ID) for aggregated transmissions of the same SRS. The WTRU can then update the parameter set based on the most recently received parameters.

[0172] In some examples, WTRUs may share their SRS resource and / or set configurations. A WTRU may send its SRS resource and / or set configurations received from the network, where the SRS resources and / or sets are specifically configured for that WTRU (e.g., WTRU-specific RRC configurations, similar to regular ones). A WTRU may send SRS resource and / or set configurations to aggregated WTRUs, limited to the SRS resources and / or sets configured and / or determined as part of the aggregation scheme.

[0173] The WTRU can send SRS resource and / or set configurations it receives from the network, where the SRS resources and / or sets are configured for the WTRU group. The WTRU can receive these SRS configurations as part of the group and can configure them for the group (e.g., using configurations indicating their applicability to the group). In this case, when indicating which SRS resources and / or sets to apply the aggregate configuration, the WTRU can indicate the corresponding SRS ID from the group configuration.

[0174] Each WTRU can receive SRS resources and / or set configurations individually from the network (e.g., using WTRU-specific RRC configurations), but the network can configure WTRUs using common SRS resources and / or sets. A WTRU can first send its SRS resources and / or set configurations to another WTRU, and the receiving WTRU can establish a mapping and / or correspondence (e.g., mapping SRS IDs) between the SRS configuration received from the network and from the WTRU. In this way, WTRUs can then share (e.g., share only) the SRS ID when indicating the SRS configuration, and the WTRU receiving the SRS ID can use the established mapping to retrieve the correct SRS configuration from its own configuration.

[0175] The WTRU can send a defined set of transmission parameters for SRS transmission to the network. The WTRU can send aggregated SRS transmission parameters using RRC configuration or reconfiguration (e.g., for semi-static aggregation configuration). The WTRU can also send aggregated SRS transmission parameters using MAC (e.g., UL MAC CE) configuration or SL PHY-level configuration (e.g., in UCI).

[0176] In the example, (e.g., for each determined aggregated SRS resource and / or set transmission), the WTRU may indicate the SRS resource and / or set configuration that is part of the aggregate. The configuration can be referenced using the SRS resource and / or set ID. The WTRU may indicate a determined list of WTRUs participating in the aggregated SRS transmission for which the WTRU was selected. The WTRU may indicate a determined aggregated port mapping for antenna port-to-SRS port mapping (e.g., using the format described above). The WTRU may indicate determined transmit power parameters used for transmission by other WTRUs. As described above, these parameters may include total transmit power, transmit power per WTRU, transmit power per port, and power control behavior parameters (e.g., offset and / or scaling factors).

[0177] WTRUs can instruct other WTRUs to perform SRS transmissions based on received activation and / or triggering. In one aspect of the solution, a WTRU can receive an instruction to perform a transmission of SRS resources and / or sets, determined and / or configured to be performed using aggregation. Upon receiving such an instruction, the WTRU can send (e.g., forward) a similar instruction to WTRUs in the aggregation group. For example, a WTRU receives a configuration for periodic SRS transmissions (e.g., via RRC) and sends periodic transmission parameters (e.g., resources and / or periodicity) (e.g., via SL RRC) to WTRUs in the aggregation group. As another example, a WTRU receives a configuration for semi-persistent SRS transmissions (e.g., via RRC) and receives an instruction to activate the transmission (e.g., via a MAC instruction). The WTRU can send the activation instruction (e.g., using an SL MAC instruction). As another example, a WTRU receives a non-periodic SRS transmission configuration (e.g., via RRC) and receives a transmission command to perform an SRS transmission (e.g., via a MAC and / or DCI instruction). The WTRU can send the transmission command (e.g., using an SL MAC and / or SCI instruction).

[0178] In one aspect of the solution, a WTRU instructed to transmit SRS using an aggregated transmission mode can transmit the instructed SRS using determined and / or received aggregated transmission parameters. The WTRU can use a combination of configurations received (e.g., received from the network or shared by another WTRU) for SRS resource and / or set configurations (e.g., for resource and / or scheduling indications) and determined and / or received sets of aggregated parameters (e.g., for antenna and / or power configurations). In some examples, based on determined and / or received port mappings, the WTRU can transmit (e.g., transmit only) on a portion of the configured SRS ports or resources when other ports are mapped to another WTRU. The WTRU can use determined and / or received transmit power configurations instead of conventional SRS power control behavior to determine the transmit power to be applied to the SRS transmission. WTRUs (e.g., auxiliary WTRUs) participating in aggregated SRS transmissions can send SRS transmissions including an indication of their WTRU ID and / or antenna port ID as part of the SRS (e.g., as an implicit indication, such as scrambling transmission or applying an offset or cyclic shift corresponding to their WTRU and / or port ID). Adding this indication to the SRS transmission avoids the need for WTRUs to report aggregation configurations to the network, where the network detects mappings and WTRU selections when directly receiving the SRS.

[0179] A WTRU can be configured with multiple sets of parameters (e.g., power control parameters and / or port mappings) for transmitting SRS resources and / or sets (e.g., when transmitting with or without aggregation). A WTRU (e.g., an auxiliary WTRU) can receive some sets of parameters from another WTRU (e.g., an assisted WTRU or a GC). Alternatively, a WTRU may have already determined some sets of parameters itself (e.g., a GC or an assisted and / or source WTRU). A WTRU can be configured, stored, and / or has determined multiple sets of transmission parameters for different aggregation configurations (e.g., a WTRU can assist multiple WTRUs in an SRS transmission, or different SRS resources and / or sets can have different transmission parameters applied). A WTRU can determine one of the parameter sets to use based on received indications for SRS transmissions (e.g., via DCI, MAC, and / or RRC) and based on whether the SRS is configured, determined, and / or indicated to be transmitted with or without aggregation. A WTRU can determine one of the parameter sets to use based on an upcoming transmission. For example, the WTRU can receive a transport permission where the transport is configured to use SRS as a reference and the transport is configured to use aggregation. The WTRU can then determine the SRS transport configuration to use that corresponds to the aggregated transport configuration.

[0180] The WTRU can use the determined set of parameters for SRS transmissions for aggregated transmissions based on the SRS indication in the received permission. In one aspect of the solution, a WTRU configured and / or whose parameter set for the aggregated SRS transmission (e.g., aggregated port mapping) has been determined can receive a transmission indication (e.g., permission) configured with an SRS as a reference for a spatial filter or codebook, for which the WTRU is configured and / or previously transmitted along with the aggregated SRS transmission. The WTRU can reuse some or all of the parameter set to transmit other signals or channels, such as PUSCH, DMRS, or any transmission that uses the aggregated SRS as a reference for its transmission.

[0181] The WTRU can reuse the same transport configuration as the aggregated SRS transport configuration for permitted transports (e.g., for transports of the data payload PUSCH and associated RSs such as PUSCH DMRS). The WTRU can send and / or forward permission to WTRUs in the aggregation, or send transport indications that include necessary information from the permission, such as scheduling information. The indications may also include data and / or signals to be transmitted by the WTRU. The indications may include the SRS ID, which will be used as a reference and is a reference to the set of parameters and / or transport modes that will be used by other WTRUs for transport.

[0182] WTRUs can use different sets of parameters (e.g., not using aggregation) to send permitted transmissions, while SRSs use aggregation to configure and / or send. WTRUs may determine to use different sets of parameters based on indications received in the permission (e.g., indicating that the transmission should not be performed using aggregation) or whether the time between the received and / or decoded permission and the actual transmission is insufficient to forward and / or send the necessary information to other WTRUs.

[0183] The WTRU can determine the transmission mode and / or parameter set to be used for a given transmission based on the SRS indication in the permission. The SRS indication may include explicit or implicit indications of using aggregation. The WTRU may receive indications for aggregation or non-aggregation in conjunction with the SRS indication (e.g., bit flags). The WTRU may be configured with dual SRS IDs, corresponding to the same SRS resource and / or set, but with or without aggregation, and when the WTRU receives an SRS ID, it determines the transmission mode and / or parameter set based on the received SRS ID. The WTRU can determine to use aggregated SRS parameters for a given transmission when it receives a DCI for the permitted transmission, which is scrambled with a specific RNTI indicating the aggregation used (e.g., aggregation group-RNTI, which may be specific to each aggregation group or aggregation configuration). The WTRU can then use the set of parameters for the aggregation used for the SRS indicated in the permission.

[0184] WTRUs can be (pre-)configured as part of an aggregated group, having a first set of transport parameters for an SRS set (e.g., using non-aggregated transport) and a second set of transport parameters for the same SRS set (e.g., using aggregated transport configuration, including inter-WTRU port mapping and other WTRU IDs).

[0185] The WTRU can receive a transmission command (e.g., via a DCI authorized by bearer scheduling) from the network indicating the use of a SRI for transmission and scheduling resources. Based on whether the RNTI used for the DCI is an aggregation group RNTI or another WTRU's RNTI, whether the DCI is sent in resources reserved for aggregation scheduling, and / or an explicit indication in the DCI, the WTRU can determine that the SRI is used for aggregation transmission with another WTRU.

[0186] A WTRU can send scheduling commands, the corresponding SRI, and transport parameters to other WTRUs. The WTRU can use the transport parameters associated with the aggregate transport mode of the received SRI to transmit on the indicated resource (e.g., PUSCH, PUSCHDMRS).

[0187] WTRU actions and / or steps may receive the following (pre)configurations as part of an aggregation group: one or more SRS resource and / or set configurations, including resource configurations and the number of ports configured thereon; transmissions configured with aggregation schemes (e.g., non-SFN transmissions) and associated with SRS (e.g., UL permission with SRS indication); and indications regarding other member WTRUs (e.g., received from GC), such as the number of supported antenna ports and aggregation schemes, and / or indications regarding co-location among WTRUs (e.g., location and / or synchronization timing).

[0188] WTRU actions and / or steps can determine a set of transmission parameters based on received configurations and indications to perform aggregated SRS transmissions. Determination may include the SRS resources and / or set IDs to be transmitted with the aggregation (e.g., based on the configured aggregated transmission and associated SRS indications).

[0189] A WTRU can determine a subset of WTRUs to perform aggregated SRS transport. A WTRU can select a set of WTRUs based on the WTRU configuration in a group. For example, for an SRS configured with 4 TX ports and associated with non-SFN transport, a WTRU can select two WTRUs each with 2 TX ports, which are not co-located and support non-SFN aggregated transport.

[0190] The WTRU can determine the mapping between the antenna ports of a subset of WTRUs and the configured SRS ports. The WTRU can map the two antenna ports of the first WTRU to the first two SRS ports, and map the two antennas of the second WTRU to the third and fourth SRS ports.

[0191] A WTRU can determine the aggregated SRS transmission power parameter based on its SRS transmit power. A WTRU can also determine the transmit power of another WTRU port based on its transmit power control and by distributing power evenly among WTRUs.

[0192] WTRU actions and / or steps can send aggregated SRS resources and / or a set of transport parameters (e.g., port mapping, transport power) to a defined subset of WTRUs and the network.

[0193] Upon receiving an instruction to transmit an aggregated SRS, the WTRU may send an SRS transmission instruction to the WTRU determined for the aggregated transmission. The WTRU may receive the instruction via MAC activation and / or DCI commands for semi-persistent and / or aperiodic SRS, and / or send the instruction via SL-MAC and / or SCI respectively.

[0194] WTRU actions and / or steps can be sent using a defined set of transmission parameters and a received configuration.

[0195] Figure 2 Example scenario 200 is illustrated, in which WTRU A 206a, as part of aggregation group 204, can receive RS configuration 208 from network 202. WTRU A 206a can then send RS configuration and / or aggregation transmission parameters 210 to other WTRUs in the group (e.g., WTRU B 206b and / or WTRU C 206c). When RS is triggered and / or configured to be sent on behalf of WTRU A 206a and / or aggregation group 204, WTRU B 206b and / or WTRU C 206c can further send RS. RS transmission 212 can then be sent to network 202.

[0196] Figure 3 An example method 300 for transmitting aggregate probe reference signals (SRS) is shown, including a method for determining whether to transmit the SRS transmission using determined aggregated SRS transmission parameters or regular parameters.

[0197] The WTRU can determine the set of transmission parameters to use based on the SRS indication. The WTRU can use non-aggregated transmission to receive a (pre-)configured first set of transmission parameters, including SRS resources and / or sets, spatial filters, and port configurations. The WTRU can also use aggregated transmission to receive a second set of transmission parameters, including SRS resources, associated SRS set IDs and / or spatial filters corresponding to SRS IDs, mappings between WTRU ports and aggregated SRS ports, power control parameters, and corresponding WTRU IDs.

[0198] A WTRU may receive transport commands from the network (e.g., a DCI carrying a scheduler) and / or from another WTRU (e.g., a scheduler forwarded via an SCI), indicating the SRI used for transporting and scheduling resources. The WTRU may determine the set of transport configurations used for the transport based on one or more conditions. Determination may include the SRS ID in the SRI used for aggregated transport with another WTRU, the RNTI used for the DCI being an aggregated group-RNTI and / or the RNTI of another WTRU, and / or having an explicit indication in the DCI and / or SCI.

[0199] WTRU can transmit on permitted resources (e.g., PUSCH and / or PUSCH DMRS) using a defined set of transmission parameters associated with the aggregate transmission mode of the indicated SRS.

[0200] At 302, aggregation can be used to configure WTRU. At 304, WTRU can receive SRS configuration and WTRU instructions, which may include details about available SRS resources, port mappings, and other aggregation-related parameters.

[0201] In section 306, the WTRU can determine the transmission parameters for aggregated SRS transmissions based on the received SRS configuration and WTRU indication. These parameters define how SRS resources are allocated among WTRUs within the aggregation group.

[0202] At 308, the WTRU can send specific transmission parameters to the aggregated WTRU in the group. At 310, the WTRU can receive SRS transmission instructions or commands.

[0203] In step 312, the WTRU can determine whether the SRS is configured for aggregation transmission. If it is determined in step 312 that the SRS is not configured for aggregation, then in step 314, the WTRU can use the received SRS configuration to send the SRS.

[0204] If it is determined in 312 that SRS is configured for aggregation, then in 316, the WTRU can send an SRS transmission indication or command to the aggregation WTRU. In 318, the WTRU can send SRS using the SRS configuration and the determined aggregation transmission parameters.

Claims

1. A wireless transceiver unit (WTRU), comprising: Processor and memory, wherein the processor and memory are configured as follows: Receive Reference Signal (RS) transmission configuration; Determine the set of aggregated transport parameters to perform aggregated RS transport, wherein the determination is based on RS transport configuration; Send the aggregated RS transmission parameter set to one or more other WTRUs or networks in the aggregated group; Receive an instruction for sending aggregated RS transmissions; Send the instruction to send the aggregated RS transmission to other WTRUs in the aggregation group; and The aggregated RS transmission is sent using a defined set of transmission parameters and RS transmission configuration.

2. The WTRU according to claim 1, wherein, The aggregated RS transmission parameter set includes one or more of the following: a subset of aggregated WTRUs, transmission resources, antenna port mappings, or transmission power of each WTRU in the aggregated group.

3. The WTRU according to claim 2, wherein, The processor is configured to distribute transmission power across one or more WTRUs in an aggregation group based on received path loss information, the maximum transmit power of each WTRU in the aggregation group, or one or more power scaling factors associated with the aggregation RS transmission.

4. The WTRU according to claim 2, wherein, The aggregated RS transmission parameter set includes antenna port mapping.

5. The WTRU according to claim 4, wherein, The processor is configured to determine the antenna port mapping from the antenna ports of different WTRUs in the aggregation group to the corresponding RS ports based on the received configuration indicating the RS port allocation scheme for aggregated RS transmissions.

6. The WTRU according to claim 1, wherein, The processor is configured to: Receive a set of non-aggregated transmission parameters to perform non-aggregated RS transmission; Receive additional instructions indicating whether to send aggregated or non-aggregated RS transmissions; and Based on additional instructions, determine whether to use an aggregated or non-aggregated set of transport parameters to perform the transport.

7. The WTRU according to claim 1, wherein, Indications used to send aggregated RS transmissions include one or more of the RS resource identifier (ID), radio network temporary identifier (RNTI), or indication source.

8. The WTRU according to claim 7, wherein, The indication for sending aggregated RS transmissions includes an RS resource ID, which corresponds to a set of RS resources configured for the aggregated group transmission mode, and RS is a sounding reference signal (SRS).

9. The WTRU according to claim 1, wherein, The processor is configured to: The set of RS resources is selected based on the received aggregation configuration, where the aggregation configuration indicates the RS usage pattern associated with the aggregation group to determine the set of transmission parameters.

10. The WTRU according to claim 1, wherein, The processor is configured to determine a set of transmission parameters by selecting a subset of WTRUs for aggregated RS transmissions based on one or more of a co-location indication received from the group coordinator, a synchronization timing indication, or an indication to support the antenna port.

11. A method implemented by a wireless transmit / receive unit (WTRU), the method comprising: Receive Reference Signal (RS) transmission configuration; Determine the set of aggregated transport parameters to perform aggregated RS transport, wherein the determination is based on RS transport configuration; Send the aggregated RS transmission parameter set to one or more other WTRUs or networks in the aggregated group; Receive an instruction for sending aggregated RS transmissions; Send the instruction to send the aggregated RS transmission to other WTRUs in the aggregation group; and The aggregated RS transmission is sent using a defined set of transmission parameters and RS transmission configuration.

12. The method according to claim 11, wherein, The aggregated RS transmission parameter set includes at least one of the following: a subset of aggregated WTRUs, transmission resources, antenna port mapping, or transmission power of each WTRU in the aggregated group.

13. The method of claim 12, further comprising distributing transmission power across WTRUs based on one or more of received path loss information, maximum transmit power per WTRU, or power scaling factors associated with aggregated RS transmissions.

14. The method according to claim 12, wherein, The aggregated RS transmission parameter set includes antenna port mapping.

15. The method of claim 14, further comprising determining, based on the received configuration indicating an RS port allocation scheme for aggregated RS transmissions, an antenna port mapping from the antenna ports of different WTRUs in the aggregation group to the corresponding RS ports.

16. The method of claim 11, further comprising: Receive a set of non-aggregated transmission parameters to perform non-aggregated RS transmission; Receive additional instructions, indicating whether to send aggregated RS transmissions or non-aggregated RS transmissions; and Based on additional instructions, determine whether to use an aggregated or non-aggregated set of transport parameters to perform the transport.

17. The method according to claim 11, wherein, Indications used to send aggregated RS transmissions include one or more of the RS resource identifier (ID), radio network temporary identifier (RNTI), or indication source.

18. The method according to claim 17, wherein, The indication for sending the aggregated RS includes an RS resource ID, which corresponds to a set of RS resources configured for the aggregated group transmission mode, and an RS is a sounding reference signal (SRS).

19. The method of claim 11, further comprising selecting a set of RS resources based on a received aggregation configuration, wherein the aggregation configuration indicates an RS usage pattern associated with an aggregation group to determine a set of transmission parameters.

20. The method of claim 11, further comprising determining a set of transmission parameters by selecting a subset of WTRUs for aggregated RS transmissions based on one or more of a co-location indication received from a group coordinator, a synchronization timing indication, or an indication of support for antenna ports.

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