Method for 3tx channel sounding

Abstract

NOT VISIBLE DUE TO STATUS OF PATENT

Description

METHOD FOR 3TX CHANNEL SOUNDING CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to United States Provisional Patent Application No.63 / 553,201 filed in the United States of America on February 14, 2024, the entire contents of which are incorporated herein by reference. BACKGROUND

[0002] Mobile devices may be limited to 2TX because of the device size restrictions for mobile wireless transmit / receive units (WTRUs). Throughput gain from 4TX and 8TX UL may be rarely realized in practice. SUMMARY

[0003] A wireless transmit / receive unit (WTRU) may perform one or more operations (e.g., channel sounding) for 3 antenna ports with an N>3 antenna port sounding reference signal (SRS) resource. The WTRU may determine a mapping from 3 antenna ports (Aps) to 4 SRS ports. The WTRU may apply a scaling factor to determine the transmission power per SRS port.

[0004] A wireless transmit / receive unit (WTRU) may receive configuration information comprising one or more sounding reference signal (SRS) resources with four SRS ports per SRS resource. The configuration information comprises tdm port configuration. The WTRU may determine the association between an AP and one or more SRS ports. The WTRU may determine the association between the AP and one or more SRS ports based on a preconfigured mapping. The WTRU may transmit an SRS using three antenna ports (APs). The three antenna ports may be mapped to the four SRS ports in an SRS resource of the one or more SRS resources. The WTRU may determine a transmission power split for each of the one or more SRS ports. The WTRU may transmit a physical uplink shared channel (PUSCH) with a precoder indicated in a grant.

[0005] A WTRU may receive configuration information. The configuration information may indicate a plurality of sounding reference signal (SRS) ports (e.g., for channel sounding). The configuration information may include SRS resource configuration and / or at least one power scaling value. The WTRU may determine an association between a plurality of antenna ports (Aps) and the plurality of SRS ports, for example, based on the SRS resource configuration. A first AP of the plurality of APs may be mapped to a first SRS port of the plurality of SRS ports. A second SP of the plurality of Aps may be mapped to a second SRS port of the plurality of SRS ports. A third AP of the plurality of Aps may be mapped to a third SRS port and to a fourth SRS port of the plurality of SRS ports. The WTRU may determine a first transmission power for the first SRSport based on a (e.g., linear) value. The WTRU may determine a second transmission power for the SRS port based on the (e.g., linear) value. The WTRU may determine a third transmission power for the third SRS port based on the (e.g., linear) value and / or at least one power scaling value. The WTRU may determine a fourth transmission power for the fourth SRS port based on the (e.g., linear) value and / or the at least one power scaling value. The WTRU may transmit an SRS transmission (e.g., over the plurality of SRS ports) in accordance with the respective transmission power per SRS port.

[0006] The SRS configuration may include fixed mapping, one or more parameters of SRS resource configuration, an AP-SRS port association index value, and / or one or more patterns. The WTRU may determine the association based on one or more of the fixed mapping, the one or more parameters of SRS resource configuration, the AP-SRS port association index value, and / or the one or more patterns. The fixed mapping may include static association information to associate the plurality of APs with the plurality of SRS ports. The association may be determined based on the static association information.

[0007] The WTRU may receive an indication to activate and / or deactivate one or more patterns that associate the plurality of APs with the plurality of SRS ports. The association may be determined based on one or more activated and / or deactivated patterns. The indication may be received via a medium access control (MAC) control entity (CE).

[0008] The (e.g., linear) value may include a respective (e.g., linear) value associated with each AP. The WTRU may apply a second scaling value to determine each respective (e.g., linear) value.

[0009] The plurality of APs may include a first AP group and / or a second AP group. Each respective (e.g., linear) value may be determined based on the first AP group and / or the second AP group.

[0010] The WTRU may send a report that indicates capability information associated with the plurality of APS. The WTRU may receive the configuration information in response to the capability information.

[0011] The WTRU may determine the transmission power for the third SRS port based on the at least one power scaling value and / or the (e.g., linear) value. The WTRU may determine a third scaling value based on the at least one power scaling value. The WTRU may determine the transmission power for the fourth SRS port based on the third scaling value.

[0012] The WTRU being configured to determine the transmission power for the respective first and second SRS port may include the WTRU being configured to divide the (e.g., linear) value by the number of APs of the plurality of APs.

[0013] A WTRU may receive configuration information. The configuration information may indicate a plurality of SRS ports (e.g., for channel sounding). The configuration information may include SRS resourceconfiguration and at least one power scaling value. The WTRU may determine an association between a plurality of antenna ports and a plurality of SRS ports based on the SRS resource configuration information. The WTRU may determine a transmission power per SES port. The WTRU may determine a (e.g., linear) value based on a total transmission power. The transmission power for each SRS port may be determined based on the (e.g., linear) value and / or the at least one power scaling value. The WTRU may determine transmission power (e.g., over the plurality of SRS ports) in accordance with the respective transmission power per SRS port. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG.1A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented.

[0015] FIG.1B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG.1A according to an embodiment.

[0016] FIG.1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG.1A according to an embodiment.

[0017] FIG.1D is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG.1A according to an embodiment.

[0018] FIG.2a is a diagram illustrating an example of a mapping of 3 WTRU antenna ports to SRS ports with power scaling factor.

[0019] FIG.2b is a diagram illustrating an example of a mapping of 3 WTRU antenna ports to SRS ports with alpha and / or beta.

[0020] FIG.3 is a diagram illustrating an example of a special case without power splitting. DETAILED DESCRIPTION

[0021] FIG.1A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 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 OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0022] As shown in FIG.1A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104 / 113, a CN 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a “station” and / or a “STA”, may be configured to transmit and / or receive wireless signals and may include a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a WTRU.

[0023] The communications systems 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or the other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a gNB, a NR NodeB, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0024] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or the base station 114b may be configuredto transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the 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 desired spatial directions.

[0025] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0026] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115 / 116 / 117 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink (DL) Packet Access (HSDPA) and / or High-Speed UL Packet Access (HSUPA).

[0027] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0028] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access , which may establish the air interface 116 using New Radio (NR).

[0029] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC)principles. Thus, the air interface utilized by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., a eNB and a gNB).

[0030] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA20001X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0031] The base station 114b in FIG.1A may be a wireless router, Home Node B, Home eNode B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR etc.) to establish a picocell or femtocell. As shown in FIG.1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106 / 115.

[0032] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106 / 115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not shown in FIG.1A, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, whichmay be utilizing a NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0033] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or the other networks 112. The PSTN 108 may include circuit- switched telephone networks that provide plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and / or the internet protocol (IP) in the TCP / IP internet protocol suite. The networks 112 may include wired and / or wireless communications networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0034] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG.1A may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0035] FIG.1B is a system diagram illustrating an example WTRU 102. As shown in FIG.1B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0036] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG.1B depicts the processor 118 and thetransceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0037] The transmit / receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0038] Although the transmit / receive element 122 is depicted in FIG.1B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0039] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit / receive element 122 and to demodulate the signals that are received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11, for example.

[0040] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and / or the removable memory 132. The 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. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0041] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 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, and the like.

[0042] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable location- determination method while remaining consistent with an embodiment.

[0043] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and / or Augmented Reality (VR / AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0044] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the 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 either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the downlink (e.g., for reception)).

[0045] FIG.1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0046] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a.

[0047] Each of the eNode-Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, and the like. As shown in FIG.1C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0048] The CN 106 shown in FIG.1C 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 are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0049] The MME 162 may be connected to each of the eNode-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0050] The SGW 164 may be connected to each of the eNode Bs 160a, 160b, 160c in the RAN 104 via the S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring user planes during inter- eNode B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0051] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0052] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers.

[0053] Although the WTRU is described in FIGS.1A-1D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[0054] In representative embodiments, the other network 112 may be a WLAN.

[0055] A WLAN in Infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have an access or an interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic in to and / or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and / or referred to as peer-to- peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802.11e DLS or an 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an “ad- hoc” mode of communication.

[0056] When using the 802.11ac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixedwidth (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented, for example in in 802.11 systems. For CSMA / CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0057] High Throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHz wide channel.

[0058] Very High Throughput (VHT) STAs may support 20MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz, and / or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above described operation for the 80+80 configuration may be reversed, and the combined data may be sent to the Medium Access Control (MAC).

[0059] Sub 1 GHz modes of operation are supported by 802.11af and 802.11ah. The channel operating bandwidths, and carriers, are reduced in 802.11af and 802.11ah relative to those used in 802.11n, and 802.11ac.802.11af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support Meter Type Control / Machine- Type Communications, such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and / or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0060] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel which may be designated as the primary channel.The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.11ah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP, the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0061] In the United States, the available frequency bands, which may be used by 802.11ah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11ah is 6 MHz to 26 MHz depending on the country code.

[0062] FIG.1D is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0063] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 108b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0064] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing varying number of OFDM symbols and / or lasting varying lengths of absolute time).

[0065] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration WTRUs 102a, 102b, 102c may communicate with / connect to gNBs 180a, 180b, 180c while also communicating with / connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In the non-standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for servicing WTRUs 102a, 102b, 102c.

[0066] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards User Plane Function (UPF) 184a, 184b, routing of control plane information towards Access and Mobility Management Function (AMF) 182a, 182b and the like. As shown in FIG.1D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0067] The CN 115 shown in FIG.1D 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. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0068] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as 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, and / or the like. The AMF 162 may provide a control plane function for switching between the 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.

[0069] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating WTRU IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernet-based, and the like.

[0070] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

[0071] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0072] In view of Figures 1A-1D, and the corresponding description of Figures 1A-1D, one or more, or all, of the functions described herein with regard to one or more of: WTRU 102a-d, Base Station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-ab, UPF 184a-b, SMF 183a-b, DN 185a-b, and / or any other device(s) described herein, may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0073] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and / or in an operator network environment. For example, the one or more emulation devices may perform the 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 in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and / or may performing testing using over-the-air wireless communications.

[0074] The one or more emulation devices may perform the one or more, including all, functions while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in a testing scenario in a testing laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0075] Uplink transmission on 3 antennas may described herein (e.g., in association with multiple input multiple output (MIMO) WID. An objective may be to improve uplink throughout by specifying codebook- based transmission with 3TX at the WTRU side.

[0076] One or more mobile devices may be (e.g., mostly) limited to 2TX, for example, because of the device size restrictions for mobile WTRUs. Even though one or more other releases (e.g., Release 18) may support 4TX and / or 8TX uplink (UL), the throughput gain from 4TX and / or 8TX may be rarely realized in practice. It may be agreed that 3TX represents a viable value proposition considering current technologyand / or consumer demands. Therefore, the intention (e.g., in Rel-19) may be to specify 3TX for the restricted case of codebook-based transmission without Full Power Transmission (FPTX), and / or without introducing one or more (e.g., any) enhancements to the SRS resources.

[0077] 3TX may improve the throughput (e.g., in comparison to 2TX) and / or may be more feasible to implement and / or deploy on mobile devices with the current state of technology (e.g., compared to 4TX). The specification (e.g., 3GPP Technical Specification (TS) 38.211) may support 2, 4, and / or 8TX implementations for codebook-based transmission (e.g., the specification may not support WTRUs with 3TX). Scope may restrict SRS resource enhancements, so a specification may not be expected for a (e.g., new) 3 port SRS resource. To enable this, the network may require one or more (e.g., all) of the following. The network may require a procedure for sounding the channel over the 3TX reusing existing SRS resources (e.g., 1, 2, 4, 8 port SRS). The network may require a codebook of precoders for 3TX which the receiver may use to determine the optimal precoder based on the sounding procedure. The network may require a method for the network to indicate to the WTRU the determined precoder for the UL codebook- based transmission.

[0078] The (e.g., current) specification may not support a 3 port SRS resource and / or NR may not have one or more (e.g., any) methods for 3TX channel sounding in codebook-based configuration. Embodiments described herein may address what is the procedure for a WTRU with 3TX to perform one or more operations (e.g., channel sounding). For example, SRS can be used for (e.g., direct) channel sounding, beam management, and / or antenna switching; the association may be applicable in one or more (e.g., all) operations. Embodiments described herein may be applied for one or more (e.g., any) combinations of (e.g., odd number of) APs to associate with and / or map to (e.g., even number of) SRS ports.

[0079] Embodiments described herein may relate to a method for 3TX channel sounding with N>3 ports SRS resource. For example, embodiments may relate to a WTRU configured to determining the 3TX SRS resource and / or power allocation (e.g., for channel sounding). A WTRU may receive configuration information. The configuration information may indicate a plurality of SRS ports (e.g., for channel sounding). The configuration information may include SRS resource configuration and at least one power scaling value. The WTRU may determine an association between a plurality of antenna ports and a plurality of SRS ports based on the SRS resource configuration information. The WTRU may determine a transmission power per SRS port. The WTRU may determine a (e.g., linear) value based on a total transmission power. For example, a (e.g., linear) value may indicate that the units are in Watts (e.g., as opposed to dBm). The transmission power for each SRS port may be determined based on the (e.g., linear) value and / or the at least one powerscaling value. The WTRU may transmit an SRS transmission (e.g., over the plurality of SRS ports) in accordance with the respective transmission power per SRS port. For example, the SRS transmission may be a single SRS transmission (e.g., the four SRS ports may correspond to a single SRS resource). The WTRU may determine the transmitted signal per antenna port as a function of the SRS resource configuration (e.g., each antenna port can have a different cyclic shift, and / or different transmit power, as described herein).

[0080] A WTRU may be configured with one or more SRS resources with 4SRS ports per SRS resource. For example, the WTRU may receive configuration information that indicates a plurality of sounding reference signal (SRS) ports (e.g., for channel sounding). The configuration information may include SRS resource configuration information and / or at least one power scaling value.

[0081] The WTRU may transmit an SRS using 3 antenna ports (APs) mapped to the 4 SRS ports in an SRS resource of the one or more SRS resources. The WTRU may determine an association between a plurality of antenna ports (APs) and the plurality of SRS ports, for example, based on the SRS resource configuration information. A first AP of the plurality of APs may be mapped to a first SRS port of the plurality of SRS ports. A second AP of the plurality of APs may be mapped to a second SRS port of the plurality of SRS ports. A third AP of the plurality of APs may be mapped to a third SRS port and to a fourth SRS port of the plurality of SRS ports. For example, the WTRU may map each of a first and a second AP to a respective first and second SRS port, and / or may map a third AP to the two remaining SRS ports (e.g., to both a third SRS port and a fourth SRS port). Each AP may be associated with an index. When the WTRU transmits one or more (e.g., multiple) SRS resources (e.g., periodic SRS case), the WTRU may cycle the index of the AP that maps to two SRS ports. The SRS resource configuration may indicate a pattern for the order of the mapped antenna port index. The WTRU may determine (e.g., implicitly) the index of the antenna port that is mapped to two SRS ports, for example, based on one or more of: CellID, slot index, SRS resource index, SRS resource set index, and / or repetition index. The WTRU may receive a fixed mapping of APs to SRS ports. The SRS resource configuration may indicate a fixed index of the AP mapped to two SRS ports, for example, for periodic SRS. In aperiodic SRS case, for example, an aperiodic SRS resource may be configured with a fixed index of the AP mapped to two SRS ports, and / or the triggering command may indicate the index of the aperiodic SRS resource. Additionally or alternatively, the triggering command may indicate the index of the AP mapped to two SRS ports. For example, the SRS configuration information may include fixed mapping, one or more parameters of SRS resource configuration, an AP-SRS port association index value, and / or one or more patterns. The WTRU may determine the association based on one or more of the fixed mapping, the one or more parameters of SRSresource configuration, the AP-SRS port association index value, and / or the one or more patterns. The fixed mapping may include static association information to associate the plurality of APs with the plurality of SRS ports. The association may be determined based on the static association information.

[0082] When the WTRU transmits the SRS over the 4 SRS ports, for example, the WTRU may determine the power per SRS and / or may transmit the SRS over one or more (e.g., each) SRS port using the respective power determined for the port. For example, the WTRU may determine a first transmission power for the first SRS port based on a (e.g., linear) value. The WTRU may determine a second transmission power for the second SRS port based on the (e.g., linear) value. The WTRU may determine a third transmission power for the third SRS port based on the (e.g., linear) value and / or at least one power scaling value. The WTRU may determine a fourth transmission power for the fourth SRS port based on the (e.g., linear) value and / or the at least one power scaling value. The WTRU may transmit an SRS transmission (e.g., over the plurality of SRS ports) in accordance with the respective transmission power per SRS port. For example, the SRS transmission may be a single SRS transmission (e.g., the four SRS ports may correspond to a single SRS resource). The WTRU may determine the transmitted signal per antenna port as a function of the SRS resource configuration (e.g., each antenna port can have a different cyclic shift, and / or different transmit power, as described herein).

[0083] The WTRU may receive a value of α as part of the SRS resource set configuration for scaling. The WTRU may calculate a (e.g., linear) value of the transmit power (Plin) according to the SRS power control formula. The WTRU may split Plin across the number of APs (for the example of 3 APs, the WTRU may calculate Plin / 3). The WTRU may transmit on the 1stand 2ndSRS port according to the split (e.g., linear) value per AP (for the example of 3 APs, the power for each of these SRS ports is Plin / 3). The WTRU may transmit on the 3rdand 4thSRS port according to a scaling of the split (e.g., linear) value per AP, where the WTRU may scale it by α onto the third SRS port, and by (1- α) onto the fourth SRS port (for the example of 3APs, the power of the 3rdSRS port is α*Plin / 3 and the power of the 4thSRS port is (1- α)*Plin / 3). For example, the (e.g., linear) value may include a respective (e.g., linear) value associated with each AP. The WTRU may apply a second scaling value to determine each respective (e.g., linear) value.

[0084] The following are definitions of common terms that may be used in the disclosure.

[0085] Hereinafter, ‘a’ and ‘an’ and similar phrases are to be interpreted as ‘one or more’ and ‘at least one’. Similarly, any term which ends with the suffix ‘(s)’ is to be interpreted as ‘one or more’ and ‘at least one’. The term ‘may’ is to be interpreted as ‘may, for example’.

[0086] A symbol ‘ / ’ (e.g., forward slash) may be used herein to represent ‘and / or’, where for example, ‘A / B’ may imply ‘A and / or B’.

[0087] Herein, the terms prediction and estimation may be used interchangeably.

[0088] Herein, the terms candidate cell, neighbor cell, and target cell may be used interchangeably.

[0089] Herein, the terms source cell, current cell, and serving cell may be used interchangeably.

[0090] A WTRU may transmit and / or receive a physical channel and / or reference signal according to at least one spatial domain filter. The term beam may be used herein to refer to a spatial domain filter.

[0091] The WTRU may transmit a physical channel and / or signal using the same spatial domain filter as the spatial domain filter used for receiving a reference signal (RS) (such as a channel state information RS (CSI-RS)) and / or a synchronization signal (SS) block. The WTRU transmission may be referred to as target, and the received RS and / or SS block may be referred to as reference and / or source. In examples, the WTRU may transmit the target physical channel and / or signal according to a spatial relation with a reference to such RS and / or SS block.

[0092] The UE may transmit a first physical channel and / or signal according to the same spatial domain filter as the spatial domain filter used for transmitting a second physical channel and / or signal. The first and second transmissions may be referred to as target and reference (or source), respectively. In examples, the WTRU may transmit the first (e.g., target) physical channel and / or signal according to a spatial relation with a reference to the second (e.g., reference) physical channel and / or signal.

[0093] A spatial relation may be implicit, configured by radio resource control (RRC) and / or signaled by medium access control control element (MAC CE) and / or downlink control information (DCI). For example, a WTRU may (e.g., implicitly) transmit physical uplink shared channel (PUSCH) and demodulated RS (DM- RS) of PUSCH according to the same spatial domain filter as an SRS indicated by an SRS resource indicator (SRI) indicated in DCI and / or configured by RRC. In examples, a spatial relation may be configured by RRC for an SRI and / or signaled by MAC CE for a physical uplink control channel (PUCCH). Such spatial relation may (e.g., also) be referred to as a beam indication.

[0094] The WTRU may receive a first (e.g., target) downlink channel and / or signal according to the same spatial domain filter or spatial reception parameter as a second (e.g., reference) downlink channel and / or signal. For example, such association may exist between a physical channel such as physical downlink control channel (PDCCH) and / or physical downlink shared channel (PDSCH) and its respective DM-RS. At least when the first and second signals are reference signals, such association may exist when the WTRU is configured with a quasi-colocation (QCL) assumption type D between corresponding antenna ports. Suchassociation may be configured as a transmission configuration indicator (TCI) state. A WTRU may be indicated an association between a CSI-RS and / or SS block and a DM-RS by an index to a set of TCI states configured by RRC and / or signaled by MAC CE. Such indication may (e.g., also) be referred to as a beam indication.

[0095] Herein, a transmission and reception point (TRP) may be interchangeably used herein with one or more of transmission point (TP), reception point (RP), radio remote head (RRH), distributed antenna (DA), base station (BS), a sector (e.g., of a BS), and / or a cell (e.g., a geographical cell area served by a BS). Herein, the term Multi-TRP may be interchangeably used with one or more of MTRP, M-TRP, and / or multiple TRPs.

[0096] A UE may be configured with (and / or may receive configuration of) one or more TRPs to which the WTRU may transmit and / or from which the WTRU may receive. The WTRU may be configured with one or more TRPs for one or more cells. A cell may be a serving cell, secondary cell.

[0097] A WTRU may be configured with at least one RS for the purpose of channel measurement. This RS may be denoted as a Channel Measurement Resource (CMR) and / or may include a CSI-RS, SSB, and / or other downlink RS transmitted from the TRP to a WTRU. A CMR may be configured and / or associated with a TCI state. A WTRU may be configured with a CMR group where CMRs transmitted from the same TRP may be configured. Each group may be identified by a CMR group index (e.g., group 1). A WTRU may be configured with one CMR group per TRP, and / or the WTRU may receive a linkage between one CMR group index and another CMR group index, and / or between one RS index from one CMR group and another RS index from another group.

[0098] A WTRU may be configured with (and / or receive configuration of) one or more pathloss (PL) reference groups (e.g., sets) and / or one or more SRS groups, SRS resource indicator (SRI) and / or SRS resource sets.

[0099] A PL reference group may correspond to and / or may be associated with a TRP. A PL reference group may include, identify, correspond to, and / or be associated with one or more TCI states, SRIs, reference signal sets (e.g. CSI-RS set, SRI sets), CORESET index, and / or reference signals (e.g. CSI-RS, SSB).

[0100] A WTRU may receive a configuration (e.g., any configuration described herein). The configuration may be received from a gNB and / or TRP. For example, the WTRU may receive configuration of one or more TRPs, one or more PL reference groups and / or one or more SRI sets. A WTRU may (e.g., implicitly) determine an association between a RS set / group and a TRP. For example, if the WTRU is configured withtwo SRS resource sets, the WTRU may determine to transmit to TRP1 with SRS in the first resource set, and / or to TRP2 with SRS in the second resource set. The configuration may be via RRC signaling.

[0101] In the examples and embodiments described herein, TRP, PL reference group, SRI group, and SRI set may be used interchangeably. The terms set and group may be used interchangeably herein.

[0102] A property of a grant and / or assignment may include one or more of the following. A property of a grant and / or assignment may include a frequency allocation. A property of a grant and / or assignment may include an aspect of time allocation, such as a duration. A property of a grant and / or assignment may include a priority. A property of a grant and / or assignment may include a modulation and coding scheme. A property of a grant and / or assignment may include a transport block size. A property of a grant and / or assignment may include one or more (e.g., a number of) spatial layers. A property of a grant and / or assignment may include one or more (e.g., a number of) transport blocks. A property of a grant and / or assignment may include a TCI state, CRI, and / or SRI. A property of a grant and / or assignment may include one or more (e.g., a number of) repetitions. A property of a grant and / or assignment may include whether the repetition scheme is Type A or Type B. A property of a grant and / or assignment may include whether the grant is a configured grant type 1, type 2 or a dynamic grant. A property of a grant and / or assignment may include whether the assignment is a dynamic assignment or a semi-persistent scheduling (configured) assignment. A property of a grant and / or assignment may include a configured grant index and / or a semi-persistent assignment index. A property of a grant and / or assignment may include a periodicity of a configured grant and / or assignment. A property of a grant and / or assignment may include a channel access priority class (CAPC). A property of a grant and / or assignment may include one or more (e.g., any) parameters provided in a DCI, by MAC or by RRC for the scheduling the grant and / or assignment.

[0103] An indication by DCI may include one or more of the following. An indication by DCI may include an explicit indication by a DCI field and / or by radio network temporary identifier (RNTI) used to mask cyclical redundancy check (CRC) of the PDCCH. An indication by DCI may include an implicit indication by a property such as DCI format, DCI size, Coreset and / or search space, aggregation level, first resource element of the received DCI (e.g., index of first Control Channel Element), where the mapping between the property and the value may be signaled by RRC and / or MAC, and / or the like.

[0104] Herein, downlink reception may be used interchangeably with Rx occasion, PDCCH, PDSCH, and / or SSB reception. Herein, uplink transmission may be used interchangeably with Tx occasion, PUCCH, PUSCH, PRACH, and / or SRS transmission. Herein, RS may be used interchangeably with one or more of RS resource, RS resource set, RS port, and / or RS port group. Herein, RS may be used interchangeablywith one or more of SSB, CSI-RS, SRS, and / or DM-RS. Herein, time instance may be used interchangeably with slot, symbol, and / or subframe.

[0105] The term antenna port may be used to represent a transmission antenna used for UL transmission of a signal at the WTRU. The WTRU may use antenna ports to transmit reference signals (e.g., SRS and / or DMRS), and / or for transmitting physical channels (e.g., PUCCH, PUSCH). The WTRU may be equipped with one or more (e.g., multiple) antenna elements. An antenna port may represent one or more (e.g., multiple) antenna elements.

[0106] An SRS port may be specified in NR, and / or may map to a physical time / frequency resource. In NR, for example, the WTRU may be configured with a number of SRS ports equal to the number of antenna ports reported by the WTRU in its capability. The SRS port may be used by the WTRU to transmit pilot sequences (e.g., reference signals) to a cell on preconfigured time / frequency resources.

[0107] The WTRU may determine which out of N SRS port indices may be used to transmit the signal from the WTRU antenna ports (APs) where N is greater than the number of APs. For example, the case of N>3 may be considered, where 3 is the number of antenna ports at the WTRU; it may be generalized for a number of APs other than 3. For example, term X (e.g., as described herein) may be the number of APs at the WTRU.

[0108] The WTRU may receive configuration information that indicates a plurality of sounding reference signal (SRS) ports (e.g., for channel sounding). The configuration information may include SRS resource configuration information and / or at least one power scaling value. For example, the WTRU may receive a configuration with N SRS ports greater than the number of WTRU APs. The WTRU may send a report that indicates capability information associated with the plurality of APS. The WTRU may receive the configuration information in response to the capability information. The WTRU may report a capability of X=3 AP. Based on the WTRU capability, for example, the WTRU may receive a configuration of an SRS resource set which includes one or more SRS resources. The SRS resource set may be applicable for channel sounding with SRS resource usage set to codebook. With codebook usage, the SRS resources may be used by the network to determine precoders from a codebook for the PUSCH transmission. If an N=X port resource is specified, for example, the network may configure the WTRU with a 3 port resource, and / or the WTRU may map one or more (e.g., each) AP one-to-one to an SRS port. If (e.g., only) N>X port SRS resources are available, for example, the WTRU may (e.g., need to) determine which SRS ports are used for transmitting the X AP. In examples, there may be no N=X port SRS resource specified, so eachSRS resource in the set may be configured with N SRS ports with N>X. In examples (e.g., as described herein), N=4 SRS ports may be configured with X=3 AP.

[0109] The WTRU may determine the association between an AP and one or more SRS ports. The WTRU may determine an association between a plurality of antenna ports (APs) and the plurality of SRS ports, for example, based on the SRS resource configuration information. A first AP of the plurality of APs may be mapped to a first SRS port of the plurality of SRS ports. A second AP of the plurality of APs may be mapped to a second SRS port of the plurality of SRS ports. A third AP of the plurality of APs may be mapped to a third SRS port and to a fourth SRS port of the plurality of SRS ports.

[0110] The WTRU may transmit over the 4 SRS ports. The WTRU may determine a mapping from the 3 APs to the 4 SRS ports to determine the routing of the signal output from the APs to the ports of the SRS resource. The WTRU may map the first and / or second AP to a respective first and / or second SRS port, and / or may map the third AP to the remaining third and / or fourth respective SRS ports. The WTRU may receive, as part of the SRS resource set configuration, a mapping that identifies the indices of the associated AP and SRS port.

[0111] If the WTRU transmits in one or more (e.g., multiple) SRS resources (e.g., periodic SRS configuration), for example, the WTRU may change the index of the AP that is mapped to the 2 SRS ports according to a predefined rule / mapping / pattern to cycle the index. The SRS resource configuration may include a pattern which indicates the order of the AP index mapping to the SRS ports for every symbol / slot. For example, the pattern may indicate that the order is {(s1, AP1, SRS1 and SRS2), (s2, AP2, SRS1 and SRS2)}. The WTRU, in the first transmission symbol s1, may map AP1 to the 1stand 2ndSRS ports, and / or may map AP2 and AP3 to the 3rdand 4thSRS ports, respectively. In the second transmission in s2, the WTRU may map AP2 to the 1stand 2ndSRS ports, and AP1 and AP3 to the 3rdand 4thSRS ports. In examples, the same two SRS ports may be mapped to AP1 and AP2 in different time slots. The pattern may (e.g., also) indicate different SRS port indices mapped to AP1 and / or AP2. The WTRU may determine the mapping of the remaining 2 APs as one-to-one over the remaining SRS ports after the first AP is mapped. For example, the SRS configuration information may include fixed mapping, one or more parameters of SRS resource configuration, an AP-SRS port association index value, and / or one or more patterns. The WTRU may determine the association based on one or more of the fixed mapping, the one or more parameters of SRS resource configuration, the AP-SRS port association index value, and / or the one or more patterns. The fixed mapping may include static association information to associate the plurality ofAPs with the plurality of SRS ports. The association may be determined based on the static association information.

[0112] The pattern may be (e.g., explicitly) configured as part of the SRS resource configuration. The mapping may be configured for the SRS resource set, and / or the WTRU may apply the same mapping to one or more (e.g., all) SRS resources in the resource set. Additionally or alternatively, the mapping may be configured per SRS resource in the set, and / or the WTRU may apply one or more different mappings as a function of the SRS resource index.

[0113] Additionally or alternatively, more than one pattern may be configured, and / or the WTRU may determine the mapping based on one or more parameters of the SRS resource configuration. The WTRU may determine the pattern as a function of one or more of the following. The WTRU may determine the pattern as a function of transmission comb or comb index. For example, the N ports may be transmitted over two different comb indices, and each comb index may be associated with one of the patterns. The WTRU may determine the pattern as a function of sequence number, sequence group index, cyclic shift index. For example, each sequence number / sequence group index may be associated with a different pattern. For example, the first AP may be configured with a cyclic shift, and the cyclic shift is associated to one of the pattern applied over the 3 APs. The WTRU may determine the pattern as a function of the hop index if frequency hopping is configured. For example, for each transmission of the WTRU in a different hop, the WTRU may transmit on a different mapping pattern. The WTRU may determine the pattern as a function of the repetition index if repetition is configured. For example, for each transmission in a different repetition index of the same SRS resource, the WTRU may transmit on a different mapping pattern. The WTRU may determine the pattern as a function of the SRS port groups if the SRS ports are transmitted in TDM. For example, an SRS resource may be configured with a TDM pattern where SRS ports 1 and 2 are in a first group transmitted in slot 1, and SRS ports 3 and 4 are in a second group transmitted in slot 2. The WTRU may apply a pattern associated to one of the port groups. For example, one AP may be mapped to the two SRS ports in a first port group, and / or in a second port group. The WTRU may determine the pattern as a function of CellID, TRP ID, coresetPoolIndex. For example, the WTRU may apply a different pattern depending on the target receiving point. The WTRU may switch to a different pattern when it transmits to a receiving point with a different CellID, TRP ID, coresetPoolIndex.

[0114] Additionally or alternatively, the WTRU may receive a preconfigured mapping with a fixed index of the AP mapped to two SRS ports. For example, in periodic SRS case, the WTRU may be configured with the index of AP1 and AP2 mapped to SRS ports 1 and 2, and AP3 may be mapped to SRS port index 3and 4. The WTRU may use the same mapping for one or more (e.g., all) transmissions of the same SRS resource. The WTRU may transmit the SRS resource (e.g., always) with the same mapping for one or more (e.g., all) configured time slots.

[0115] Additionally or alternatively, more than one pattern may be configured, and / or the WTRU may determine the mapping based on receiving a dynamic command to activate and / or deactivate a pattern. The WTRU may receive a MAC-CE which indicates the activation and / or deactivation command of a pattern associated an SRS resource set and / or SRS resource. For example, the WTRU may receive an indication to activate and / or deactivate one or more patterns that associate the plurality of APs with the plurality of SRS ports. The association may be determined based on one or more activated and / or deactivated patterns. The indication may be received via a medium access control (MAC) control entity (CE).

[0116] In the aperiodic case, for example, the WTRU may receive a triggering command in a grant which includes the index of an SRS resource, and / or the WTRU may transmit an SRS after a time offset from the triggering command. The index of the aperiodic SRS resource may be associated with one fixed mapping, and / or with one of the time offset that may be indicated for the triggered SRS resource. Different aperiodic SRS resources may be configured with different mappings, and / or the network may trigger different mappings by sending a different aperiodic SRS resource index in the triggering command. For example, SRS resource 1 may be associated to a first mapping, and / or SRS resource 2 may be associated to a second mapping. The SRS resource 1 may be triggered if the network requests mapping 1, and SRS resource 2 may be triggered if the network requests mapping 2. Additionally or alternatively, the triggering command may (e.g., also) include a mapping rule from the AP index to SRS ports for the triggered aperiodic SRS resource index. For example, the network may trigger aperiodic SRS resource number 1, and / or an additional command indicates if AP1 is mapped to SRS ports 1 and 2, and / or if AP2 is mapped to SRS ports 1 and 2. The triggering command may (e.g., also) indicate the index of the SRS ports that AP1 is mapped to (e.g., SRS ports 1 and 2, and / or SRS ports 3 and 4). After determining the mapping of APs to SRS ports, for example, the WTRU may determine the transmission power of the SRS resource.

[0117] A WTRU may determine the transmission power split per SRS port. In NR, for example, the WTRUmay determine the transmission power in the transmission power in dBm, ^^SRS,^,^,^^^^, ^^^, ^^^, using theSRS power control formula (e.g., as described in 3GPP TS 38.213,behavior with respect to Sounding reference signals) given by [1] ^ ^PCMAX, f , c( i ), ^ ^ ^ ^ ^where ^^CMAX,^,^^^^^ may be the WTRU maximum output power for carrier f of serving cell c in SRS transmission occasion i, ^^O_SRS,^,^,^^^^^^ may be a configured target received power for BWP b of SRS resource set index ^^^, be the configured number of RBs for SRS transmission, ^^ maybe the subcarrier spacing, may be the configured fractional pathloss compensation factor,^^^^^,^,^^^^ௗ^ may be the measured on RS ^^ௗ, and ℎ^,^,^^^^, ^^^ may be the lthpower control may the total power that the WTRU may use to transmit one or more (e.g., all) the SRS ports of the resource.

[0118] For example, when N=X=4, the procedure in NR may be as follows. The WTRU may convert thedBm value to the linear equivalent value, ^^^SRS,^,^,^^^^, ^^^, ^^^, and / or may split the (e.g., linear) value equallyacross the N configured SRS ports. For example, if N=4, the WTRU may transmit on each of the 4 SRS portswith an equal power of ^^^SRS,^,^,^^^^, ^^^, ^^^ / 4. For example, the WTRU being configured to determine thetransmission power for the first and second SRS port may include the WTRU being configured todivide the (e.g., linear) value by the number of APs of the plurality of APs.

[0119] In the (e.g., special) case where N=8 with tdm configuration, the WTRU may transmit the SRS ports in different tdm’d groups of SRS ports (e.g., group 1 with SRS ports 1-4 in symbol 1, and group 2 withSRS ports 5-8 in symbol 2), and / or the WTRU may split ^^^SRS,^,^,^^^^, ^^^, ^^^ equally across the SRS portsper symbol. For example, in this case, N=8 with tdm, the WTRU may transmit on each of the ports in group1 with ^^^SRS,^,^,^^^^, ^^^, ^^^ / 4, and / or each of the ports in group 2 with ^^^SRS,^,^,^^^^, ^^^, ^^^ / 4.

[0120] In examples, the WTRU may have X=3 APs which may be less than the number of configured SRS ports N. Therefore, the split of transmission power across SRS ports may require an enhancement such that the WTRU can determine the transmission power across the N SRS ports using its 3 APs.

[0121] In examples, the WTRU may report a capability of X=3 APs, and / or receive a scaling factor, α, as part of the SRS resource set configuration. The WTRU may (e.g., also) determine the mapping of APs to SRS ports using one of the methods described herein, where the 1stand 2ndAPs are mapped to a respective 1stand 2ndSRS port, and the 3rdAP is mapped to the 3rdand 4thSRS port. In examples, the WTRU may follow may perform one or more of the following. The WTRU may calculate the transmissionpower in dBm using the power control formula and / or may obtain ^^SRS,^,^,^^^^, ^^^, ^^^. The WTRU maycalculate the (e.g., linear) value ^^^SRS,^,^,^^^^, ^^^, ^^^. The WTRU may split the transmitted power equallyacross the X APs, ^^^SRS,^,^,^^^^, ^^^, ^^^ / X. The WTRU may transmit on the 1st and 2nd SRS ports with atransmission power per SRS port according to the (e.g., linear) value split across APs. This may yield atransmission power of ^^^SRS,^,^,^^^^, ^^^, ^^^ / X for each of the 1st and 2nd SRS ports. The WTRU may transmiton the 3rdand 4thSRS ports with a transmission power per SRS port according to a scaled value of the (e.g., linear) value, wheremay scale it by α on the 3rdSRS port, and by (1- α) on the 4thSRSport. This may yields a transmission power of α ∗ ^^^SRS,^,^,^^^^, ^^^, ^^^ / X and ^1 െ α^ ∗ ^^^SRS,^,^,^^^^, ^^^, ^^^ / X for the 3rdand 4thSRS ports, respectively.

[0122] In examples, the WTRU may have X=3 AP, so the WTRU may calculate the split value as^^^SRS,^,^,^^^^, ^^^, ^^^ / 3 for the 1st and 2nd SRS port, and α ∗ ^^^SRS,^,^,^^^^, ^^^, ^^^ / 3 and ^1 െα^ ∗ ^^^SRS,^,^,^^^^, ^^^, ^^^ / 3 for the 3rd and 4th SRS ports, respectively.

[0123] FIG.2a is a diagram illustrating an example of a mapping of 3 WTRU antenna ports to SRS ports with power scaling factor 200. The WTRU may perform the SRS power control procedure (e.g., at 202a)which produces the (e.g., linear) value, ^^^^^^^^ ൌ ^^^SRS,^,^,^^^^, ^^^, ^^^. The WTRU may be configured with afixed mapping of X=3 APs to N=4 SRS ports where AP1210 and AP2212 map to the 1st and 2nd SRS ports, respectively, and AP3214 maps to the 3rd and 4th SRS ports (e.g., 3rdSRS port 220 and / or 4thSRS port 222). For example, AP1210a may map to 1stSRS port 216a. For example, AP2212a may map to 2nd SRS port 218a. For example, AP3214a may map to 3rdSRS port 220a and 4thSRS port 222a. The value α may enable the WTRU to split the transmission power for AP3 that maps to two SRS ports. For example, at 202a, the WTRU may determine, via a SRS power control, Plin per AP. At 204a, the WTRU may determine Plin of 1 / 3 for AP1210a. At 206a, the WTRU may determine Plin of 1 / 3 for AP2212. At 208, the WTRU may determine Plin of 1 / 3 for AP3214a. The Plin determined for AP1210a, AP2212a, and / or AP3214a may differ (e.g., as described herein).

[0124] Additionally or alternatively, the WTRU may not split Plin equally across one or more (e.g., all) APs.Another scaling factor, β, may be configured such that the WTRU may split Plin according to ^^௫ ∗ Plin perAP. The power splitting procedure after the SRS power control procedure may be instead replaced by thefollowing: The WTRU may split the transmitted power across the X APs with ^^௫ ∗ ^^^SRS,^,^,^^^^, ^^^, ^^^.Separate β values may be configured per AP (β1,β2,β3) where ∑௫ ^^௫ = 1. For example, the WTRU maydetermine for the transmission power on the SRS ports corresponding to AP1 scaled by ^^^ ∗ Plin, to AP2scaled by ^^ଶ ∗ Plin, and to AP3 scaled by ^^ଷ ∗ Plin. For example, thedetermine thetransmission power for the third SRS port based on the at least one power scaling value and / or the (e.g., linear) value. The WTRU may determine a third scaling value based on the at least one power scaling value. The WTRU may determine the transmission power for the fourth SRS port based on the third scaling value.For example, there may be a (e.g., single) power scaling value (e.g., alpha) that is (pre)configured. The WTRU may determine the power scaling per port as a function of alpha. For example, the WTRU may use alpha to determine the power scaling for the third SRS port and / or the fourth SRS port. The power per SRS port (e.g., third SRS port and / or fourth SRS port) may be different.

[0125] FIG.2b is a diagram illustrating an example of a mapping of 3 WTRU antenna ports to SRS ports with alpha and / or beta 250. At 204b, the WTRU (e.g., via SRS power control 202b) may determine Plin value based on β1. For example, the Plin value based on β1 may be ¼ (e.g., instead of 1 / 3). At 206b, the WTRU may determine Plin value based on β2. The WTRU (e.g., via SRS power control 202b) may determine Plin of ¼ for AP2212b (e.g., instead of 1 / 3). At 208b, the WTRU (e.g., via SRS power control 202b) may determine Plin based on β3. For example, the WTRU (e.g., via SRS power control 202) may determine Plin of ½ for AP3214b (e.g., instead of 1 / 3). β values may be configured per AP group. For example, AP1 and AP2 may be configured in the same group based on WTRU capability (e.g., APs on the same panel, same polarization, etc…). For example, the plurality of APs may include a first AP group and / or a second AP group. Each respective (e.g., linear) value may be determined based on the first AP group and / or the second AP group.

[0126] Embodiments described herein may be associated with a (e.g., special) case with tdm port configuration. One or more procedures described herein may include the case where the SRS resource is configured with N ports without the tdm transmission. An SRS resource can be configured with a tdm option on and / or a TDM factor s which indicates the number of SRS ports per slot. For example, with s=2, the WTRU may transmit N / 2 ports in slot 1, and N / 2 ports in slot 2. If the tdm is configured, for example, the WTRU may receive an α value configuration across one or more (e.g., all) slots, and / or separate α values may be configured per slot. The α value may (e.g., also) be configured per port group which may be defined per slot or across slot. For example, 1 AP may map to one port group, where the port group includes of the 3rdand 4thSRS ports. The SRS ports in the port group may be (e.g., both) transmitted in slot 1, and / or transmitted in different slots.

[0127] Embodiments described herein may be associated with a (e.g., special case) without powersplitting (α ൌ 1 or α ൌ 0^. If α ൌ 1 or α ൌ 0, the WTRU may perform the procedure of powersplitting by X number of APs, ^^^SRS,^,^,^^^^, ^^^, ^^^ / X, and / or in the next procedure the WTRU may notallocate (e.g., any) power to one of the N SRS ports. FIG.3 illustrates this case for two different mapping patterns in such a scenario.

[0128] FIG.3 is a diagram illustrating an example of a special case without power splitting. FIG.3 depicts an example of turning off an antenna port with two different mapping patterns. An antenna port may beturned off to direct the signal towards the best antenna port(s). For example, if channel quality is poor on one antenna port due to blockage and / or orientation, the mapping pattern may change. One option may be to preconfigure the patterns. Additionally or alternatively, one or more (e.g., multiple) patterns may be cycled. The WTRU may cycle through different patterns as a function of a hopping sequence (e.g., as a function of time index where a first slot may use mapping pattern 325, and / or a second slot may use mapping pattern 350). A WTRU may be configured with one or more mapping patters to associate a plurality of APs with a plurality of SRS ports. For example, a WTRU may configured with a first mapping pattern 325 and / or a second mapping pattern 350. In the first mapping pattern, AP1302a may be mapped to first SRS port 308a; AP2304a may be mapped to 2ndSRS port 310a; and / or AP3306a may be mapped to the 3rdSRS port 312a and 4thSRS port 314a. The WTRU may allocate at least a portion (e.g., all) of AP3’s 306a power to the 3rdSRS port 312a. In the second mapping pattern, AP1302b may be mapped to the 1stSRS port 308b and 2ndSRS port 310b; AP2304b may be mapped to 3rdSRS port 312b; and / or AP3 may be mapped to 4thSRS port 314b. The WTRU may allocate at least a portion (e.g., all) of AP1’s 302b power to the 2ndSRS port 310b. As described herein, these may be two exemplary mapping patterns that can be configured (e.g.,. explicitly); and / or the WTRU may cycle through different patterns according to one or more rules (e.g., as described herein).

[0129] Examples described herein may consider the case where two of the APs are mapped one-to-one to SRS ports, and a third AP is mapped to 2 SRS ports. Equivalently, for the case without power splitting (e.g., if α is not configured), the WTRU may receive a configuration with mapping patterns that associates the X APs with a one-to-one mapping to a subset of the N antenna ports which yields mapping patterns such as shown in Figure 3.

[0130] Embodiments described herein may be associated with a (e.g., special) case with SRS ports aggregated from one or more (e.g., multiple) SRS resource sets. In examples, the WTRU may receive an SRS resource set configuration with one or more SRS resources, where each SRS resource has N ports. In examples, the WTRU may receive a configuration where the N SRS ports are distributed across one or more (e.g., multiple) SRS resources such that the N SRS ports are equal to X AP. The APs of the WTRUs may be mapped one-to-one to the N SRS ports, and / or the WTRU may determine to apply one of the mapping patterns / rules (e.g., described herein) across the N SRS ports from the different SRS resources. The WTRU may transmit over one or more (e.g., multiple) SRS resources where the number of SRS ports aggregated over one or more (e.g., all) resources is equal to N. For example, for the X=3 AP case, the WTRU may transmit an SRS with 1 port, and an SRS with 2 ports. AP1 of the WTRU may be mapped tothe SRS resource with 1 port, and AP2 and AP3 may be mapped to the first and second port of the SRS resource with 2 ports.

[0131] In examples, the WTRU may be configured with one or more (e.g., multiple) SRS resource sets, where the resources within each SRS resource set are configured with the same number of SRS ports. For example, the first resource set may include 1-port SRS resources, and / or the second resource set may include 2-port SRS resources. If the two sets are configured with periodic SRS resources, for example, the WTRU may transmit the resources from each set according to the configured periodicity. If one or more of the sets are configured with aperiodic SRS resources, for example, the SRS resources may be triggered individually from each set with a dynamic triggering command received in a grant. The WTRU may (e.g., also) receive in the configuration one SRI per resource set, where the SRI is a bit that indicates one of the SRS resources in the set. For example, a resource set may be configured with two SRS resources, and SRI=0 may indicate the first SRS resource, and SRI=1 may indicate the second SRS resource. When the WTRU receives a grant for a PUSCH, for example, the grant may include one SRI per SRS resource set, which may indicate to the WTRU the index of the two SRS resources from the two SRS resource sets that aggregate to a 3 port SRS. The WTRU may transmit the PUSCH over the WTRU’s 3 APs with the same UL spatial filter that is indicated by the two SRIs. For example, the first SRI may indicate the spatial filter for the first AP, and / or the second SRI may indicate the spatial filter for the 2ndand 3rdAP.

[0132] In examples, the WTRU may be configured with one SRS resource set, where the resources within the SRS resource sets are configured with different number of SRS ports. For example, one or more SRS resources in the set are 1-port SRS, and one or more resources in the set are 2-port SRS. If the set is configured with periodic SRS resources, the WTRU may transmit the resources from the set according to the configured periodicity. If the set is configured with aperiodic SRS, the WTRU may receive a triggering command that may be linked to one, and / or to a pair of SRS resources from the set. The WTRU may transmit the one or more SRS resources associated to the triggering command. The WTRU may receive a configuration of the pair of SRS resources as a function of the WTRU reported capability of X APs. The total number of ports N across the pair of resources may aggregate to X APs. For example, the WTRU may receive a command to trigger a transmission of a 1-port SRS resource and a 2-port SRS resource. The WTRU may determine a fixed association of the APs to SRS ports that is associated to the triggering command (e.g., AP1 to the 1-port SRS resource, and AP2 and AP3 to the 2-port SRS resource). When the WTRU receives a grant for a PUSH, for example, the grant may include one SRI for the SRS resource set, where the SRI may indicate the associated pair of SRS resources from the set that aggregate to thenumber of X APs. The WTRU may transmit the PUSCH over the WTRU’s 3 APS with the same UL spatial filter that is indicated by the single SRI.

[0133] A WTRU may transmit a PUSCH with a precoder indicated in a grant. Based on the SRS sounding procedure described, for example, the network may calculate / determine a precoder for a 3-port transmission based on the received SRS port measurements. The 3-port precoder may be determined from one or more codebooks of 3-port precoders. The WTRU may receive a TPMI in a grant that indicates the index of the precoder from the codebooks, and / or the WTRU may transmit a PUSCH that is precoded according to the TPMI.

Claims

CLAIMS:

1. A wireless transmit / receive unit (WTRU) comprising: a processor configured to: receive configuration information that indicates a plurality of sounding reference signal (SRS) ports, wherein the configuration information comprises SRS resource configuration information and at least one power scaling value; determine an association between a plurality of antenna ports (APs) and the plurality of SRS ports based on the SRS resource configuration information, wherein a first AP of the plurality of APs is mapped to a first SRS port of the plurality of SRS ports, a second AP of the plurality of APs is mapped to a second SRS port of the plurality of SRS ports, and a third AP of the plurality of APs is mapped to a third SRS port and to a fourth SRS port of the plurality of SRS ports; determine a first transmission power for the first SRS port based on a value; determine a second transmission power for the second SRS port based on the value; and determine a third transmission power for the third SRS port based on the value and at least one power scaling value; determine a fourth transmission power for the fourth SRS port based on the value and the at least one power scaling value; and transmit an SRS transmission in accordance with the respective transmission power per SRS port.

2. The WTRU of claim 1, wherein the SRS configuration information comprises fixed mapping, one or more parameters of SRS resource configuration, an AP-SRS port association index value, or one or more patterns, and wherein the processor is configured to determine the association based on one or more of the fixed mapping, the one or more parameters of SRS resource configuration, the AP-SRS port association index value, or the one or more patterns.

3. The WTRU of claim 2, wherein the fixed mapping comprises static association information to associate the plurality of APs with the plurality of SRS ports, and wherein the association is determined based on the static association information.

4. The WTRU of claim 2, wherein the processor is configured to receive an indication to active or deactivate one or more patterns that associate the plurality of APs with the plurality of SRS ports, and wherein the association is determined based on the one or more activated or deactivated patterns.

5. The WTRU of claim 4, wherein the indication is received via a medium access control (MAC) control entity (CE).

6. The WTRU of claim 1, wherein the value comprises a respective value associated with each AP, and wherein the processor is configured to apply a second scaling value to determine each respective value.

7. The WTRU of claim 6, wherein the plurality of APs comprises a first AP group and a second AP group, and wherein each respective value is determined based on the first AP group or the second AP group.

8. The WTRU of claim 1, wherein the processor is configured to send a report that indicates capability information associated with the plurality of APs, and wherein the configuration information is received in response to the capability information.

9. The WTRU of claim 1, wherein the processor is configured to determine the transmission power for the third SRS port based on the at least one power scaling value and the value, and wherein the processor is configured to determine a third scaling value based on the at least one power scaling value, wherein the processor is configured to determine the transmission power for the fourth SRS port based on the third scaling value.

10. The WTRU of claim 1, wherein the processor being configured to determine the transmission power for the respective first and second SRS port comprises the processor being configured to divide the value by the number of APs of the plurality of APs.

11. A method performed by a wireless transmit / receive unit (WTRU), the method comprising:receiving configuration information that indicates a plurality of sounding reference signal (SRS) ports, wherein the configuration information comprises SRS resource configuration information and at least one power scaling value; determining an association between a plurality of antenna ports (APs) and the plurality of SRS ports based on the SRS resource configuration information, wherein a first AP of the plurality of APs is mapped to a first SRS port of the plurality of SRS ports, a second AP of the plurality of APs is mapped to a second SRS port of the plurality of SRS ports, and a third AP of the plurality of APs is mapped to a third SRS port and to a fourth SRS port of the plurality of SRS ports; determining a first transmission power for the first SRS port based on a value; determining a second transmission power for the second SRS port based on the value; and determining a third transmission power for the third SRS port based on the value and at least one power scaling value; determining a fourth transmission power for the fourth SRS port based on the value and the at least one power scaling value; and transmitting an SRS transmission in accordance with the respective transmission power per SRS port.

12. The method of claim 11, wherein the SRS configuration information comprises fixed mapping, one or more parameters of SRS resource configuration, an AP-SRS port association index value, or one or more patterns, and wherein the processor is configured to determine the association based on one or more of the fixed mapping, the one or more parameters of SRS resource configuration, the AP-SRS port association index value, or the one or more patterns.

13. The method of claim 12, wherein the fixed mapping comprises static association information to associate the plurality of APs with the plurality of SRS ports, and wherein the association is determined based on the static association information.

14. The method of claim 12, further comprising receiving an indication to active or deactivate one or more patterns that associate the plurality of APs with the plurality of SRS ports, and wherein the association is determined based on the one or more activated or deactivated patterns.

15. The method of claim 14, wherein the indication is received via a medium access control (MAC) control entity (CE).

16. The method of claim 11, wherein the value comprises a respective value associated with each AP, and wherein the method further comprises applying a second scaling value to determine each respective value.

17. The method of claim 16, wherein the plurality of APs comprises a first AP group and a second AP group, and wherein each respective value is determined based on the first AP group or the second AP group.

18. The method of claim 11, further comprising sending a report that indicates capability information associated with the plurality of APs, and wherein the configuration information is received in response to the capability information.

19. The method of claim 11, further comprising determining the transmission power for the third SRS port based on the at least one power scaling value and the value, and wherein the third scaling value is determined based on the at least one power scaling value, wherein the transmission power for the fourth SRS port is determined based on the third scaling value.

20. The method of claim 11, wherein determining the transmission power for the respective first and second SRS port comprises dividing the value by the number of APs of the plurality of APs.

21. A wireless transmit / receive unit (WTRU) comprising: a processor configured to: receive configuration information that indicates a plurality of sounding reference signal (SRS) ports for channel sounding, wherein the configuration information comprises SRS resource configuration and at least one power scaling value; determine an association between a plurality of antenna ports (APs) and a plurality of SRS ports based on the SRS resource configuration information;determine a transmission power per SRS port, wherein the processor is configured to determine a value based on a total transmission power, wherein the transmission power for each SRS port is determined based on the value or the at least one power scaling value; and transmit an SRS transmission in accordance with the respective transmission power per SRS port.

22. A method performed by a wireless transmit / receive unit (WTRU), the method comprising: receiving configuration information that indicates a plurality of sounding reference signal (SRS) ports for channel sounding, wherein the configuration information comprises SRS resource configuration and at least one power scaling value; determining an association between a plurality of antenna ports (APs) and a plurality of SRS ports based on the SRS resource configuration information; determining a transmission power per SRS port, wherein the processor is configured to determine a value based on a total transmission power, wherein the transmission power for each SRS port is determined based on the value or the at least one power scaling value; and transmitting an SRS transmission in accordance with the respective transmission power per SRS port.