Channel state information (CSI) determination and reporting associated with multiple CSI resources

Abstract

Systems, methods, and instrumentalities are disclosed herein for determining and reporting channel state information (CSI) for multiple CSI resources. A device (e.g., wireless transmit / receive unit (WTRU)) may receive, from a network entity, configuration information that indicates a first CSI resource and a second CSI resource. The device may determine a first oversampling index associated with the first CSI resource and a second oversampling index associated with the second CSI resource. The device may determine, based on the first oversampling index, a first set of codewords associated with the first CSI resource. The device may determine, based on the second oversampling index, a second set of codewords associated with the second CSI resource. The device may select a codeword from at least one of the first set of codewords or the second set of codewords. The device may send, to the network entity, a CSI report that indicates the selected codeword.

Description

CHANNEL STATE INFORMATION (CSI) DETERMINATION AND REPORTING ASSOCIATED WITH MULTIPLE CSI RESOURCESCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 553,224, filed February 14, 2024 the contents of which is incorporated by reference herein.BACKGROUND

[0001] Mobile communications using wireless communication continue to evolve. A fifth generation may be referred to as 5G. A previous (legacy) generation of mobile communication may be, for example, fourth generation (4G) long term evolution (LTE).SUMMARY

[0002] Systems, methods, devices, and instrumentalities are described herein related to channel state information (CSI) determination and reporting for multiple CSI resources.

[0003] A device (e.g., a wireless transmit / receive unit (WTRU)) may receive, from a network entity, configuration information that indicates a first channel state information (CSI) resource and a second CSI resource. The device may determine a first oversampling index associated with the first CSI resource and a second oversampling index associated with the second CSI resource. The device may determine, based on the first oversampling index, a first set of codewords from a codebook of codewords associated with the first CSI resource. The device may determine, based on the second oversampling index, a second set of codewords from a codebook of codewords associated with the second CSI resource. The device may select a codeword from at least one of the first set of codewords or the second set of codewords. The device may send a CSI report to the network entity. The CSI report may indicate the selected codeword.

[0004] The first oversampling index may be a shared oversampling index. The device may determine the second set of codewords associated with the second CSI resource by using the first oversampling index as the second oversampling index. The shared oversampling index may be determined based on: a first rank value associated with the first CSI resource being greater than a second rank value associated with the second CSI resource; the first CSI resource being an initial CSI resource in a CSI resource set; or the first CSI resource being a last CSI resource in the CSI resource set.

[0005] The device may determine a first channel quality metric associated with the first CSI resource and a second channel quality metric associated with the second CSI resource. On a condition that the first channel quality metric satisfies a threshold, the device may select a first codeword from the first set of codewords. On a condition that the second channel quality metric satisfies the threshold, the device may select a second codeword from the second set of codewords.

[0006] The first channel quality metric may include a rank value associated with the first CSI resource, reference signal received power (RSRP) value associated with the first CSI resource, or signal to interference noise ratio (SINR) value associated with the first CSI resource. The second channel quality metric may include a rank value associated with the second CSI resource, an RSRP value associated with the second CSI resource, or an SINR value associated with the second CSI resource.

[0007] The first set of codewords may be different from the second set of codewords. The device may select a first codeword from the first set of codewords and a second codeword from the second set of codewords. The device may determine a co-phasing coefficient associated with the first codeword and the second codeword. The CSI report may further indicate the co-phasing coefficient.

[0008] The first set of codewords associated with the first CSI resource may include a number of codewords. The device may determine the number of codewords based on a number of antenna ports associated with the first CSI resource.

[0009] The device may identify a first codeword in the first set of codewords. The device may identify a second codeword in the second set of codewords. The first set of codewords may comprise the second codeword. The device may determine a payload size associated with the first codeword and the second codeword. On a condition that the payload size exceeds allocated resources for CSI reporting, the device may select the first codeword and the second codeword from the first set of codewords.

[0010] The device may determine a channel quality indicator (CQI) based on the first CSI resource and the second CSI resource, and wherein the CSI report further indicates the CQI.

[0011] The device may select a first codeword and a second codeword from the first set of codewords. The CSI report may further indicate that the first codeword and the second codeword are from the first set of codewords. The CSI report may further indicate a number of codewords selected from the first set of codewords. The CSI report may further indicate an index associated with the first codeword. The CSI report may further indicate an index associated with the second codeword.

[0012] The device may determine a first rank value associated with the first CSI resource and a second rank value associated with the second CSI resource. The device may, on a condition that the first rank value is above a rank threshold, select a first codeword from the first set of codewords. On a condition thatthe second rank value is above the rank threshold, the device may select a second codeword from the second set of codewords.

[0013] The first set of codewords may be different from the second set of codewords. The device may select a first codeword from the first set of codewords and a second codeword from the second set of codewords. The device may determine a co-phasing coefficient associated with the first codeword and the second codeword. The CSI report may further indicate the co-phasing coefficient.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Furthermore, like reference numerals in the figures indicate like elements, and wherein:

[0015] FIG. 1 A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented.

[0016] FIG. 1 B 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.

[0017] FIG. 1 C 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. 1 A according to an embodiment.

[0018] FIG. 1 D 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.

[0019] FIG. 2 illustrates an example codebook.

[0020] FIG. 3 illustrates an example of selecting a first set of codewords based on common oversampling indices (Ols) for CSI resources in a CSI resource set.

[0021] FIG. 4 illustrates an example of selecting a first set of codewords based on independent Ols for each CSI resource in a CSI resource set.

[0022] FIG. 5 illustrates an example flowchart for codeword selection.DETAILED DESCRIPTION

[0023] 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), orthogonalFDMA (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.

[0024] As shown in FIG. 1 A, 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 I nternet 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 “ST A”, may be configured to transmit and / or receive wireless signals and may include a user equipment (WTRU), 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 (loT) 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.

[0025] 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 I nternet 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.

[0026] 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 configured to 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 acombination 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.

[0027] 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).

[0028] 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).

[0029] 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).

[0030] 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).

[0031] 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).

[0032] 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, CDMA2000 1X, 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.

[0033] The base station 114b in FIG. 1 A 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. 1 A, 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.

[0034] 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, which may 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.

[0035] 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 commoncommunication 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.

[0036] 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.

[0037] FIG. 1 B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1 B, 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.

[0038] 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. 1 B depicts the processor 118 and the transceiver 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.

[0039] 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 willbe appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0040] Although the transmit / receive element 122 is depicted in FIG. 1 B 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.

[0041] 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.

[0042] 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).

[0043] 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.

[0044] 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 willbe appreciated that the WTRU 102 may acquire location information by way of any suitable locationdetermination method while remaining consistent with an embodiment.

[0045] 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.

[0046] 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 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)).

[0047] FIG. 1 C 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.

[0048] 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.

[0049] 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 ofusers in the UL and / or DL, and the like. As shown in FIG. 1 C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0050] The CN 106 shown in FIG. 1 C 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] Although the WTRU is described in FIGS. 1 A-1 D 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.

[0056] In representative embodiments, the other network 112 may be a WLAN.

[0057] A WLAN in Infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) for the BSS and one or more stations (ST As) 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 802.11 z tunneled DLS (TDLS). A WLAN using an Independent BSS (I BSS) 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.

[0058] 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 fixed width (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.

[0059] 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.

[0060] 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 MHzchannels, 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).

[0061] Sub 1 GHz modes of operation are supported by 802.11af and 802.11ah. The channel operating bandwidths, and carriers, are reduced in 802.11 af and 802.11 ah relative to those used in 802.11 n, and 802.11ac. 802.11 af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11 ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non- TVWS spectrum. According to a representative embodiment, 802.11 ah 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).

[0062] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.11 n, 802.11 ac, 802.11af, and 802.11 ah, 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 ST As in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA, from among all ST As in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.11 ah, the primary channel may be 1 MHz wide for ST As (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other ST As 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.

[0063] In the United States, the available frequency bands, which may be used by 802.11 ah, 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 802.11 ah is 6 MHz to 26 MHz depending on the country code.

[0064] FIG. 1 D 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

[0065] 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).

[0066] 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).

[0067] 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.

[0068] 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. 1 D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0069] The CN 115 shown in FIG. 1 D 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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 UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0074] In view of Figures 1A-1 D, 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-b, 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.

[0075] 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.

[0076] 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.

[0077] As used herein, a codebook may refer to a set of discrete Fourier transform (DFT)-beams, codewords, basis-beams for selection of a PMI. A DFT-beam may refer to a vector of complex numbers. A DFT-beam may be referred to as a basis-beam, codeword, or a PMI. PMI may refer to a set of one or more DFT-beams, basis-beams, codeword(s).

[0078] A codebook may refer to a set of DFT-beams. A codeword may refer to a single entry in the codebook. For example, a codeword may be synonymous with the term DFT-beam, basis-beam, and / or PMI.

[0079] DFT-oversampling may refer to an integer number used to oversample or increase the number of DFT-beams, basis-beams, and / or codewords in a codebook. A DFT-oversampling index may refer to an integer value greater than or equal to zero and / or less than the DFT-oversampling.

[0080] A channel state information (CSI) reference signal (RS) (CSI-RS) may refer to a reference signal used for sounding the DL channel. CSI-RS ports may refer to the single-polarized or dual-polarized antenna ports used for transmission of the CSI-RS for DL channel sounding.

[0081] A CSI resource may refer to the time / frequency resources used for transmission of the CSI-RS from a number of CSI-RS ports. A CSI resource set may refer to a collection of one or more CSI resources.

[0082] A specification (e.g. , fifth generation new radio (5G NR) specifications) may support codebookbased downlink (DL) CSI determination and reporting. For example, the specification(s) may support two types of CSI (e.g., sometimes referred to as Type-I and Type-ll CSI). In both Type-I and Type-ll CSI, the precoding matrix indicator (PMI) or a set of codeword(s) may be selected (e.g., from the same codebook). A difference between Type-I and Type-ll PMI is the number of codewords or DFT-beams selected from the codebook. In Type-I Mode 1 , a single codeword may be selected from the codebook. In Type-ll Mode 2, one or more (e.g., up to four) codewords may be selected from the codebook as a wideband PMI. In Type- ll Mode 2, a (e.g., one) codeword may be selected (e.g., for each sub-band) and reported from the one or more (e.g., four) codewords. The codebook used for selection or determination of a PMI may have a total of N1N2O1O2codewords. In Type-I mode 1 PMI determination, the WTRU may select a (e.g., one) codeword out of the N1N20102available codewords in the codebook. In type-ll, the WTRU may select more than one codeword out of the N1N20102codewords in the codebook as the PMI. In Type-ll, the WTRU may determine and report combining coefficients (e.g., to combine all the DFT-beams or codewords). The gNB may update or correct the reported PMI. The gNB may apply the corrected PMI across the antenna ports to generate a beam for downlink transmission.

[0083] Feature(s) associated with codebooks are provided herein.

[0084] The number of dual-polarized antenna ports on the first and second dimension of an antenna panel at the gNB may beand N2, respectively. In this case, the total number of antenna ports is2N1N2. The oversampling values for the first and second dimension may beand O2, respectively. In some examples (e.g., as per NR specifications), the DFT-beam, basis-beam, beam-vector, or a (e.g. , each) codeword in the codebook (e.g., each of the 16 codewords in Figure 1) may be determined using equation (2), where m = (), ■■■ , N2O2- l and / = (), ••• , N1O1- 1.

[0085] FIG. 2 illustrates an example of a codebook for N1 =N2=O1 =02=2.

[0086] FIG. 2 illustrates an example of a codebook for an antenna panel with= N2= 2 dualpolarized antennas and O1= O2- 2 DFT-oversampling values. The range of the DFT-oversampling values is 0, ••• , O - 1 and 0, ••• , O2- 1. A (e.g., each) codeword in the codebook of codeword may be associated with a (e.g., single) I and m value.

[0087] PMI may be determined.

[0088] Determination of Type-1 PMI may be a single-step process. Determination of a Type-ll PMI may be a multi-step (e.g., two-step) process. In Type-ll PMI determination, the WTRU may determine a first set of codewords from the codebook. The WTRU may determine a second set of codewords based on (e.g., from) the first set of codewords. The second set of codewords may be the determined PMI. The determination of the first set of codewords from a codebook of codewords and the determination of the second set of codewords from the first set of codewords are described herein using examples.

[0089] To determine a Type-ll PMI, the WTRU may determine DFT-oversampling indices, or a value in the range of DFT-oversampling values (e.g., an integer number from 0 to O±- 1 and 0 to O2- 1). The WTRU may identify the first set of codewords associated with the determined DFT-oversampling indices. The WTRU may select a second set of codewords from the first set of codewords. The second set of codewords may include two or more codewords. The determined second set of codeword may be the (e.g., actual) determined PMI.

[0090] In some examples (e.g., in 5G NR), resources for PMI or CSI determination may be configured in the sets. For example, a resource set may include more than one CSI resource. For example, in Type-ll CSI, the resource set may include a (e.g., only one) resource (e.g., which may be up to thirty-two ports). The number of CSI resources in a CSI resource set may be increased to increase the number of CSI RS ports (e.g., where each CSI resource may be mapped to different antenna ports). The resources may betransmited at different times (e.g., but same frequency), at different frequencies (e.g., but same time), or at the same frequency and the same time (e.g., but multiplexed in code or power domain).

[0091] The complexity of searching a PMI and the overhead of reporting the selected PMI may depend on the number of codewords (e.g., the number of antenna ports and oversampling value) in the defined codebook. With an increase in the number of antenna ports, the search complexity and reporting overhead may increase. Existing specification (s) may support (e.g., only support) PMI determination based on a (e.g., single) CSI resource.

[0092] A WTRU may determine a PMI across multiple CSI resources in a CSI resource set. The WTRU may determine a PMI with reduced complexity and report the PMI with smaller overhead.

[0093] Feature(s) described herein are associated with PMI determination across multiple CSI resources in a CSI resource set with reduced complexity and reporting overhead.

[0094] A WTRU may receive CSI configuration information (e.g., a CSI configuration). The CSI configuration information may include indication(s) for one or more of the following: two or more CSI resources in a resource set (e.g., a first channel state information (CSI) resource and a second CSI resource); Type-A or Type-B CSI; a codebook configuration (e.g., number of codewords (DFT beams) in the PMI, for example, the number of codewords to select from a codebook of codewords; DFT- oversampling, for example, oversampling value(s) to oversample the codewords in the codebook; and / or the like); oversampling indice(s) (Ol(s)) determination, for example, common Ol(s) determination (e.g., Ol(s) are determined based on a single CSI resource and are used as common Ol(s) across all CSI resources in the CSI resource set) or independent Ol(s) determination (e.g., independent Ol(s) are determined for each CSI resource in the CSI resource set). Type-A may refer to a single CSI (e.g., rank, PMI, and / or channel quality information (CQI)) for all CSI resource in the CSI resource set, and Type-B may refer to a single CSI for a subset of CSI resource in the CSI resource set. For Type-B, a UE may also be configured with a CQI and / or rank offset(s) value(s).

[0095] A WTRU may do one or more of the following. The WTRU may determine a rank value across the CSI resources (e.g., all the CSI resources) in the CSI resource set.

[0096] The WTRU may determine one or more DFT-oversampling indice(s) (e.g., a first oversampling index associated with the first CSI resource and a second oversampling index associated with the second CSI resource). The WTRU may determine shared (e.g., common) Ol(s). For example, the WTRU may determine Ol(s) in a (e.g., single) CSI resource in the CSI resource set and use it as shared (e.g., common) Ol(s) across the CSI resources (e.g., all CSI resources) in the CSI resource set. For example, Ol(s) may be determined based on a CSI resource with the highest rank value (e.g., if a first rank value associated with the first CSI resource is greater than a second rank value associated with the second CSI resource, the Olassociated with the first CSI resource may be used for both CSI resources). The Ol(s) may be commonly used across the CSI resources (e.g., all CSI resources) in the CSI resource set. Ol(s) may be determined based on a first (e.g., initial) or last CSI resource in the CSI resource set (e.g., and may be commonly used across all CSI resources in the CSI resource set).

[0097] The WTRU may determine independent Ol(s). For example, the WTRU may determine Ol(s) for each CSI resource in the CSI resource set. The WTRU may determine a first set of codewords (e.g., where the first set of codewords includes a plurality of subsets). One or more of the following may apply. The number of subsets in the first set of codewords may be equal to the number of CSI resources in the CSI resource set. The number of codewords in each subset may be the same. A (e.g., each) subset of codewords in the first set of codewords may be associated with a CSI resource in the CSI resource set. A (e.g., each) subset of codewords may be drawn from a codebook of codewords associated with the CSI resource in the CSI resource set. A (e.g., each) subset of codewords may be drawn from a codebook based on the determined Ol(s) for the CSI resource in the CSI resource set. For example, the WTRU may determine, based on the first oversampling index, a first set of codewords from a codebook of codewords associated with the first CSI resource and determine, based on the second oversampling index, a second set of codewords from a codebook of codewords associated with the second CSI resource.

[0098] The WTRU may determine a second set of codewords from the first set of codewords. For example, the WTRU may select a codeword from at least one of the first set of codewords or the second set of codewords. One or more of the following may apply. The number of codewords in the second set may be equal to the configured number of codewords in the PMI. For Type-A CSI, the WTRU may determine the second set of codewords. At least one codeword may be selected from a (e.g., each) subset of codewords in the first set of codewords. For Type-B CSI, the WTRU may determine the second set of codewords. Zero, one, or more than one codeword may be selected from a (e.g., each) subset of codewords in the first set of codewords.

[0099] The WTRU may modify the selected second set of codewords. One or more of the following may apply. The WTRU may increase or decrease the number of codewords in the second set of codewords that are selected from a subset of codewords in the first set of codewords, for example, if the difference in (e.g., between) a rank, a CQI, or both a rank and a CQI before and after modification of the second set of codewords is less than or equal to a configured, indicated, or fixed CQI (e.g., CQI value) and / or rank offset(s) (e.g., rank offset value).

[0100] For example, the WTRU may determine a second set of codewords that includes three codewords (e.g., where two codewords are selected from a first subset of codewords in the first set of codewords and one codeword is selected from a second subset of codewords in the first set of codewords).The WTRU may modify the second set of codewords (e.g., by selecting all three codewords from the first subset of codewords in the first set of codewords or all three codewords from the second subset of codewords in the first set of codewords), for example, if the difference in (e.g., between) a rank, a CQI, or both a rank and a CQI before and after modification of the second set of codewords is less than a configured, indicated, or fixed CQI and / or rank offset (e.g., if the difference between the rank before modification and after modification is less than a rank offset threshold value).

[0101] The number of codewords in the second set of codewords (e.g., after modifying the second set of codewords) may remain the same as the number of codewords in the second set of codewords before modification of the second set of codewords.

[0102] For independent Ol(s) determination, the WTRU may determine one or more co-phasing value(s) for co-phasing for one or more codeword(s) in the second set of codeword(s) selected from different subset(s) of codewords in the first set of codewords.

[0103] The WTRU may determine a CQI value for (e.g., all) CSI resources in the CSI resource set. The WTRU may send a CSI report which includes indications for rank, CQI, and PMI (or PMI information). The PMI (or PMI information) may include one or more of the following. The PMI may include number of codewords selected from a (e.g., each) subset in the first set of codewords and included in the second set of codewords. The PMI may indicate the selected codewords. For example, the PMI may include index of each codeword selected from a (e.g., each) subset in the first set of codewords and included in the second set of codewords. For Type-B, the PMI may include indices of subsets in the first set of codewords from which at least one codeword is selected in the second set of codewords, or indices of subsets in the first set of codewords from which zero codewords are selected in the second set of codewords.

[0104] The CSI report may indicate (e.g., include) co-phasing information. For example, for independent QI (s), the CSI report may include co-phasing value(s) for the codeword(s) selected from two or more subset of codewords in the first set of codewords. For example, if the first set of codewords is different from the second set of codewords, the WTRU may select a first codeword from the first set of codewords and a second codeword from the second set of codewords, and determine a co-phasing coefficient associated with the first codeword and the second codeword.

[0105] Example configurations are provided herein.

[0106] A WTRU may be semi-statically and / or dynamically (e.g., by RRC, MAC-CE, and / or DCI) configured for CSI measurement and reporting. The CSI configuration may include one or more of the following. The CSI configuration may indicate CSI resources. The CSI configuration may indicate one or more CSI measurement resource set(s) (e.g., where each set includes a plurality of CSI resource(s)).

[0107] The CSI configuration may indicate the number of antenna ports, CSI-RS ports, or ports mapped to the CSI resource set. The CSI configuration may indicate an association of different antenna ports with different CSI resources in the CSI resource set. For example, sixty-four antenna ports may be mapped to a CSI resource set (e.g., where the CSI resource set has two CSI resources).

[0108] For example, the first set of thirty-two antenna ports (e.g., the odd-numbered antenna ports or the first thirty-two antenna ports) may be mapped to the first CSI resource in the CSI resource set. The second set of thirty-two antenna ports (e.g., the even-numbered antenna ports or the second thirty-two antenna ports) antenna ports may be mapped to the second CSI resource in the CSI resource set.

[0109] The CSI configuration may indicate a type of CSI to determine.

[0110] A WTRU may be configured to determine and report Type-A or Type-B CSI. For Type-A CSI (e.g., if Type-A CSI is configured), the WTRU may determine and report a CSI (e.g., rank, PMI, and / or CQI) across CSI resources (e.g., all CSI resources) in the CSI resource set. For Type-B CSI (e.g., if Type-B CSI is configured), the WTRU may determine and report a CSI across a subset of the CSI resources in the CSI resource set. If Type-B CSI is configured, the WTRU may be configured with a CQI offset value(s) or a CQI threshold(s) and / or a rank offset value(s) or a rank threshold(s).

[0111] The CSI configuration may indicate codebook configuration information.

[0112] The WTRU may be configured with information related to the CSI-RS ports or antenna ports layout on an antenna-array at the gNB (e.g., used for transmission of the CSI resources). For example, the WTRU may be configured with an indication that the gNB is using a rectangular antenna array. The WTRU may be configured with an indication that the gNB is using dual-polarized antenna setup. The WTRU may be configured with the number of antenna-ports in a first and a second dimension of the antenna array.

[0113] The WTRU may be configured with oversampling values (e.g., DFT-oversampling) in a first and / or second dimension (e.g., to increase the number of codewords in a codebook of codewords).

[0114] The WTRU may be configured for a codebook type (e.g., Type-ll, Enhanced Type-ll, portselection Type-ll, enhanced port-selection Type-ll, etc.). The codebook type may be used by the WTRU for selection of one or more codewords or a PMI.

[0115] The WTRU may be configured for selection of the codewords (e.g., a PMI). The WTRU may be configured to report one or more codewords selected from a codebook.

[0116] The WTRU may be configured to report a PMI with a number of codewords or DFT-beams. The number of codewords in the PMI may be configured per resource or across all resources. For example, the WTRU may be configured with the number of codewords to select from codebooks associated with all theCSI resources in the CSI resource set. The number of codewords to select from a codebook associated with one or more CSI resources in the CSI resource set.

[0117] The WTRU may be configured to report a PMI with four codewords. The WTRU may be configured with a CSI resource set having four CSI resources (e.g., as described herein). The WTRU may be configured to select a (e.g., one) codeword from a codebook associated with a single CSI resource in the CSI resource set.

[0118] The WTRU may be configured to select and report a PMI with Q number of codewords (e.g., where Q is the number of codewords to select from a codebook associated with a single CSI resource in the CSI resource set, NQ is the total number of codewords to select, and N is the total number of CSI resources in the CSI resource set).

[0119] The configuration information may include feature(s) associated with determining oversampling indices (Ol).

[0120] A WTRU may be configured to determine Ol(s) based on common oversampling indices determination or independent Ol (s) determination.

[0121] The configuration information may include feature(s) associated with determining CSI.

[0122] The WTRU may determine a rank. For example, the WTRU may determine a (e.g., single) rank for each CSI resource in the CSI resource set. The WTRU may determine a (e.g., single) rank value based on all the CSI resources in the CSI resource set (e.g., the rank value across all the CSI resources in the CSI resource set is the sum of rank values determined based on each CSI resource).

[0123] The WTRU may determine PMI for multiple CSI resources.

[0124] In some examples (e.g., in the existing 5G NR specifications), a Type-ll CSI resource set may have (e.g., may only have) one CSI resource. If the number of CSI resources in the CSI resource set is more than one, the WTRU may determine the Ol(s) for PMI determination.

[0125] The WTRU may perform Ol(s) selection.

[0126] The WTRU may determine Ol(s) in a (e.g., single) CSI resource in the CSI resource set. The WTRU may use the Ol (s) as common Ol (s) across all CSI resources in the CSI resource set.

[0127] the WTRU may determine Ol (s) based on a CSI resource with the highest rank value. The WTRU may use the Ol (s) as common Ol (s) across all CSI resources in the CSI resource set for selection of the first set of codewords.

[0128] The WTRU may determine Ol(s) based on a first or last CSI resource in the CSI resource set. The WTRU may use the Ol (s) as common Ol(s) across all CSI resources in the CSI resource set for selection of the first set of codewords.

[0129] The WTRU may determine independent Ol(s) for each CSI resource in the CSI resource set.

[0130] of the WTRU may determine a first set of codewords.

[0131] After selection of the Ol(s), the WTRU may determine the first set of codewords from the codebook of codewords. The PMI, or the second set of codewords may be selected from the first set of codewords.

[0132] The WTRU may determine a first set of codewords. One or more of the following may apply. A (e.g., each) subset of codewords in the first set of codewords may be associated with a CSI resource in the CSI resource set.

[0133] A (e.g., each) subset of codewords may be drawn from a codebook based on the determined Ol(s) for the CSI resource in the CSI resource set.

[0134] An example of the first set of codewords based on common Ol (s) selection across all the CSI resources in the CSI resource set is illustrated in FIG. 3.

[0135] An example of the first set of codewords based on independent Ol (s) selection for each CSI resources in the CSI resource set is illustrated in FIG. 4.

[0136] The number of subsets in the first set may be less than or equal to the number of CSI resources in the CSI resource set.

[0137] For example, the WTRU may consider a subset of the CSI resources in the CSI resource set for the CSI determination. The subset of CSI resources in the CSI resource set may be determined based on a channel quality metric (e.g., RSRP, SINR, and / or rank values). For example, CSI resources with their RSRP, SINR, and / or rank values greater than or equal to a configured, indicated, or fixed RSRP, SINR, and / or rank thresholds are considered. For example, on a condition that a first channel quality metric satisfies a threshold, the WTRU may select a first codeword from the first set of codewords and on a condition that a second channel quality metric satisfies the threshold, the WTRU may select a second codeword from the second set of codewords.

[0138] The number of codewords in a subset may be related to the number of CSI-RS or antenna ports in the associated CSI resource. The WTRU may determine a number of codewords in a set of codewords based on a number of antenna ports associated with the CSI resource. For example, the number of codewords in a subset may be equal to the number of antenna ports (e.g., CSI-RS ports if the gNB is using a single-polarized antennas for transmission of the associated CSI resource in the CSI resource set).

[0139] The number of codewords in a subset may be equal to half the number of antenna ports (e.g., CSI-RS ports if the gNB is using a dual-polarized antennas for transmission of the associated CSI resource in the CSI resource set).

[0010] A (e.g., each) subset of codewords may be drawn from a codebook of codewords associated with the CSI resource in the CSI resource set.

[0141] FIG. 3 illustrates an example of selection of a first set of codewords based on common Ol(s) for all CSI resources in the CSI resource set. FIG. 4 illustrates an example of selection of a first set of codewords based on independent Ol(s) for each CSI resources in the CSI resource set.

[0142] FIG. 5 illustrates an example flowchart for codeword selection. As shown, at 502, a device (e.g., a wireless transmit / receive unit (WTRU)) may receive, from a network entity, configuration information that indicates a first channel state information (CSI) resource and a second CSI resource. At 504, the device may determine a first oversampling index associated with the first CSI resource and a second oversampling index associated with the second CSI resource. At 506, the device may determine, based on the first oversampling index, a first set of codewords from a codebook of codewords associated with the first CSI resource. At 508, the device may determine, based on the second oversampling index, a second set of codewords from a codebook of codewords associated with the second CSI resource. At 510, the device may select a codeword from at least one of the first set of codewords or the second set of codewords. At 512, the device may send a CSI report to the network entity. The CSI report may indicate the selected codeword.

[0143] The WTRU may determine PMI.

[0144] The WTRU may determine a PMI, second set of words, DFT-beams from the first set of codewords, etc. One or more of the following may apply.

[0145] The determined number of codewords in the second set of codewords may be equal to the configured number of codewords in the PMI.

[0146] If Type-A CSI is configured, the WTRU may determine the second set of codewords (e.g., where at least one codeword is selected from each subset of codewords in the first set of codewords).

[0147] The restriction of selecting at least one codewords form each subset may ensure that the WTRU determines a PMI or a second set of codewords of a proper dimension.

[0148] For example, the gNB may configure the WTRU with four CSI resources in a CSI resource set (e.g., where each resource has thirty-two CSI-RS ports and the total number of CSI-RS ports are one hundred and twenty-eight across all CSI resources in the CSI resource set). The WTRU may select at least one codewords from a (e.g., each) subset (e.g., from each of the four subsets of codewords in the first set of codewords), for example, to ensure that a second set of codewords or a PMI of dimension one hundred and twenty-eight ports is determined and reported.

[0149] For example, the gNB may configure the WTRU with four CSI resources in a CSI resource set. A (e.g., each) resource may have thirty-two CSI-RS ports. The total number of CSI-RS ports may be one hundred and twenty-eight across all CSI resources in the CSI resource set. The WTRU may be configured to select one or more (e.g., two) CSI resources (e.g., two subsets of codewords in the first set of codewords) based on a configured, indicated, or fixed RSRP, SINR, and / or rank threshold(s). The selection may be configured to be based on the best (e.g., first two best) resources with the highest RSRP, SINR, and / or rank. The WTRU may select the two CSI resources (or the two subset of CSI resources in the CSI resource set). The WTRU may select at least one codewords from each subset (e.g., from each of the selected two out of four subset of codewords in the first set of codewords), for example, to ensure that a second set of codewords or a PM I of dimension sixty-four ports is determined and reported.

[0150] Type-ll CSI may be associated with a higher reporting overhead. The overhead may increase (e.g., further) if the number of CSI resources in a CSI resource set increases. To reduce the overhead of Type-ll CSI (e.g., if the number of CSI resources in a CSI resource set is large), Type-B CSI may be used.

[0151] If Type-B CSI is configured, the WTRU may determine the second set of codewords. Zero, one, or more than one codeword may be selected from a (e.g., each) subset of codewords in the first set of codewords. One or more of the following may apply.

[0152] A WTRU may select one or more codewords from a subset of codewords in the first set of codewords if (e.g., only if) the associated rank, RSRP, and / or SINR value of the CSI resource associated with the subset of codewords is larger than a configured, indicated, or fixed rank, RSRP, and / or SINR threshold.

[0153] The WTRU may modify the selected second set of codewords. One or more of the following may apply.

[0154] The WTRU may increase or decrease the number of codewords in the second set of codewords that are selected from a subset of codewords in the first set of codewords, for example, if the difference in (e.g., between) a rank, a CQI , or both a rank and a CQI before and after modification of the second set of codewords is less than or equal to a configured, indicated, or fixed CQI (e.g., CQI value) and / or rank offset(s) (e.g., rank offset value).

[0155] For example, the WTRU may determine a second set of codewords that includes three codewords (e.g., where two codewords are selected from a first subset of codewords in the first set of codewords and one codeword is selected from a second subset of codewords in the first set of codewords). The WTRU may modify the second set of codewords by selecting all three codewords from the first subset of codewords in the first set of codewords or all three codewords from the second subset of codewords in the first set of codewords, for example, if the difference in (e.g., between) a rank, a CQI, or both a rank anda CQI before and after modification of the second set of codewords is less than a configured, indicated, or fixed CQI and / or rank offset (e.g., if the difference between the rank before modification and after modification is less than a rank offset threshold value).

[0156] The WTRU may increase or decrease the number of codewords in the second set of codewords that are selected from a subset of codewords in the first set of codewords, for example, if the difference in (e.g., between) payload size before and after modification of the second set of codewords is less than or equal to a configured, indicated, or fixed payload.

[0157] For example, the WTRU may identify a first codeword in the first set of codewords. The WTRU may identify a second codeword in the second set of codewords. The first set of codewords may include the second codeword. The WTRU may determine a payload size associated with the first codeword and the second codeword. If the payload size exceeds allocated resources for CSI reporting, the WTRU may select the first codeword and the second codeword from the first set of codewords.

[0158] In another example, the WTRU may determine a second set of codewords that includes three codewords (e.g., where two codewords are selected from a first subset of codewords in the first set of codewords and one codeword is selected from a second subset of codewords in the first set of codewords). The WTRU may determine the payload size. The WTRU may compare the payload size to the allocated uplink resources for reporting the CSI. If the allocated uplink resources for reporting the CSI is not sufficient, the WTRU may modify the second set of codewords by selecting all three codewords from the first subset of codewords in the first set of codewords or all three codewords from the second subset of codewords in the first set of codewords.

[0159] The WTRU may increase or decrease the number of codewords in the second set of codewords based on the allocated uplink resources for CSI reporting.

[0160] For example, the WTRU may determine a second set of codewords having one or more codewords. The WTRU may reduce the number of codewords in the second set of codewords if the allocated uplink resources for reporting the second set of codewords are not sufficient.

[0161] The WTRU may modify the second set of codewords (e.g., based on the modification example shown earlier) or increase or decrease the number of codewords in the second set of codewords based on a target CSI omission.

[0162] For example, the WTRU may determine a second set of codewords having one or more codewords. The WTRU may determine the portions of the CSI report to be omitted from reporting due to limited uplink resources for CSI reporting. The WTRU may reduce the number of codewords in the second set of codewords (e.g., so that a smaller portion of the CSI omission can be reduced and a larger portion of the CSI can be reported).

[0163] The number of codewords in the second set of codewords after modifying the second set of codewords may remain the same as the number of codewords in the second set of codewords before modification of the second set of codewords.

[0164] To determine the second set of codewords from the first set of codewords, a WTRU may select equal number of codewords from each subset in the first set of codewords. One or more of the following may apply.

[0165] A WTRU may select equal number of codewords from each subset in the first set of codewords.

[0166] A WTRU may select Q number of codewords from a single subset and in the remaining subsets. The indices of the remaining (N-1)Q codewords may be the same as the indices of the Q codewords selected in the single subset.

[0167] Feature(s) associated with co-phasing codewords selected from different CSI resources are provided herein.

[0168] If the WTRU determines a first set of codewords using independent Ol(s) determination, the (e.g., all) codewords included in a subset of codewords in the first set of codewords may be orthogonal to each other (e.g., but codewords in different subsets may not be orthogonal to each other). An example of non- orthogonal codewords in two different subsets is provided in FIG. 4.. An example of orthogonal codewords in two different subsets is provided in FIG.3. A co-phasing coefficient value may be used to co-phase two codewords in the second set of codewords drawn from two subsets with different Ol(s).

[0169] For independent Ol(s) determination, the WTRU may determine one or more co-phasing value(s) for co-phasing for one or more codeword(s) in the second set of codeword(s) selected from different subset(s) of codewords in the first set of codewords.

[0170] For example, as illustrated in FIG. 4, two codewords from two different subset of codewords in the first set of codewords may not be orthogonal to each other. The WTRU may determine a (e.g., single) value for two codewords associated with two different subsets of codewords in the first set of codewords or a (e.g., single) co-phasing value for multiple codewords associated with two different subsets of codewords in the first set of codewords.

[0171] A WTRU may determine CQI.

[0172] In some examples (e.g., 5G NR), a CQI value may be determined based on a (e.g., single) CSI resource. For a CSI resource set with multiple CSI resources, the WTRU may determine a (e.g., single) CQI value across all or a subset of CSI resources in the CSI resource set.

[0173] Feature(s) associated with CSI reporting are provided herein.

[0174] The WTRU may send a CSI report that includes indications for rank, CQI, and PMI (or PMI information). The PMI (or PMI information) may include one or more of the following. The PMI may include the indices of subsets in the first set of codewords from which at least one codeword is selected in the second set of codewords, or indices of subsets in the first set of codewords from which zero codewords are selected in the second set of codewords. This indicator may be absent in the CSI report, if CSI (e.g., PMI or second set of codewords) determination is configured across all CSI resources in the CSI resource set (e.g., a Type-A CSI with no resource selection). This indicator may be present in the CSI report, if CSI (e.g., PMI or second set of codewords) determination is configured across all CSI resources in the CSI resource set and Type-B CSI is configured.

[0175] For a (e.g., each) subset of codewords in the first set of codewords, from which at least one codeword is selected in the second set of codewords, the PMI may include the number of codewords selected from the subset.

[0176] For example, the first set of codewords may have four subsets (e.g., and each subset has two codewords). The second set may have three codewords (e.g., where two codewords are selected from the first subset and one codeword is selected from the second subset and where zero codewords are selected from the third and fourth subset). A WTRU may send an indicator that has multiple two sub-indicators (e.g., where the first sub-indicator indicates the number of codewords selected from the first subset and the second sub-indicator indicates the number of codewords selected from the second subset).

[0177] The CSI report (e.g., in PMI) may include the index of a (e.g., each) codeword selected from a (e.g., each) subset in the first set of codewords and included in the second set of codewords.

[0178] For example, the first set of codewords may have four subsets. A (e.g., each) subset may have two codewords. The second set may have three codewords (e.g., where two codewords are selected from the first subset and one codeword is selected from the second subset and where zero codewords are selected from the third and fourth subset). The WTRU may send an indicator (e.g., with two sub-indicators). The first sub-indicator indicates the indices of the two codewords in the first subset and the second subindicator indicates the index of one codeword in the second subset.

[0179] For Type-B, the CSI report (e.g., in PMI) may include the number of selected codewords (e.g., the number of codewords in the second set of codewords).

[0180] The CSI report (e.g., in PMI) may include co-phasing information. For example, for independent Ol(s), the co-phasing information may include co-phasing value(s) for the codeword(s) selected from two or more subset of codewords in the first set of codewords.

[0181] A WTRU may receive a CSI configuration. The CSI configuration may include indications for two or more CSI resources in a resource set.

[0182] The WTRU may do one or more of the following. The WTRLI may receive CSI-RS in each of one or more CSI resources.

[0183] The WTRU may determine one or more of report quantity(ies), codebook type (s), and / or codebook parameter(s) based on the number of CSI resources in the CSI resource set. One or more of the following may apply.

[0184] The WTRU may determine one or more report quantity(ies). The WTRU may determine (e.g., only determine) rank, PMI, and / or CQI for one or more CSI resources in the resource set based on a configured, indicated, or a fixed number of CSI resources in the resource set.

[0185] For example, the WTRU may determine report quantity(ies) to be rank and CQI if the number of CSI resources in the resource set is larger than a configured, indicated, or fixed threshold.

[0186] For example, the WTRU may determine report quantity(ies) to be rank, PMI, and CQI if the number of CSI resources in the CSI resource set is smaller than a configured, indicated, or fixed threshold.

[0187] For example, the WTRU may determine report quantity(ies) to be a minimum rank or minimum CQI value across all CSI resources in the CSI resource set if the number of CSI resources in the resource set is larger than a configured, indicated, or fixed threshold.

[0188] The WTRU may determine one or more codebook type(s) for determination of the report quantity(ies) in one or more CSI resources in the CSI resource set based on the number of CSI resources in the CSI resource set.

[0189] For example, the WTRU may determine to use a first codebook (e.g., NR Type-I) for determination of the report quantity(ies) if the number of CSI resources in the CSI resource set is greater than a configured, indicated, or fixed threshold.

[0190] The WTRU may determine to use a second codebook (e.g., NR Type-ll) codebook for determination of the report quantity(ies) if the number of CSI resources in the CSI resource set is less or equal to a configured, indicated, or fixed threshold.

[0191] The WTRU may determine to use a first and a second codebooks (e.g., NR Type-I and Type-ll) for determination of the report quantity(ies) if the number of CSI resources in the CSI resource set is between two configured, indicated, or fixed thresholds.

[0192] The WTRU may determine more than one set of report quantities (e.g., PMI_1 , CQI_1 , and PMI_2, CQI_2) using a plurality of codebooks (e.g., Type-I and Type-ll) for each CSI resource in the CSI resource set.

[0193] The WTRU may determine one or more codebook parameter(s) for the determined codebook type(s) and for determination of the report quantity(ies) based on the number of CSI resources in the CSI resource set.

[0194] For example, the WTRU may use a higher or a lower resolution codebook (e.g., higher or smaller DFT-oversampling values, where DFT-oversampling quantifies the resolution of a codebook) based on the number of CSI resources.

[0195] The WTRU may use higher DFT-oversampling value(s) if the number of CSI resources in the CSI resource set is less than a configured, indicated, or fixed threshold.

[0196] The WTRU may use a smaller DFT-oversampling value(s) if the number of CSI resources in the CSI resource set is higher than a configured, indicated, or fixed threshold.

[0197] The WTRU may use a higher degree of CSI compression (e.g., higher value of compression parameters), and a smaller degree of CSI compression (e.g., smaller values of compression parameters) if the number of CSI resources in the CSI resource set is higher, lower than a configured, indicated, or fixed threshold, respectively.

[0198] The WTRU may determine and report the report quantity(ies) for one or more CSI resources in the CSI resource set.

[0199] For example, the WTRU may report a set of report quantity(ies) determined using a plurality of codebook type and / or codebook parameters.

[0200] The WTRU may report the worst report quantity(ies) (e.g., the minimum rank and / or minimum CQI) among the report quantities of all the CSI resources in the CSI resource set.

[0201] The WTRU may report a report quantity(ies) for each CSI resource in the CSI resource set.

[0202] The WTRU may dynamically or semi-statically receive the number of CSI resources (e.g.,Nr-csi) in the resource set and CSI configuration of each resource (e.g., by MAC-CE, RRC, DCI). The CSI configuration of a resource may indicate the codebook type as follows.

[0203] Codebook Type-I may be determined based on at least one of the following. Codebook Type-I may be determined if the number of ports in one or more CSI resource(s) is greater than a threshold (e.g., PCSI-RS)- Codebook Type-I may be determined If the number of horizontal ports in one or more CSI resource(s) is greater than a threshold (e.g., W1t / l). Codebook Type-I may be determined If the number of vertical ports in one or more CSI resource(s) is greater than a threshold (e.g., W2t / l). Codebook Type-I may be determined If the number of horizontal oversampling in one or more CSI resource(s) is greater than a threshold (e.g., Of'1). Codebook Type-I may be determined if the number of vertical oversampling in one or more CSI resource(s) is greater than a threshold (e.g., O1).

[0204] Codebook Type-ll may be determined based on at least one of the following. Codebook Type-ll may be determined if the number of selected beams in codebook Type-ll, configured is less than a predefined threshold in MAC-CE, RRC or DCI (e.g. Ltype-n). Codebook Type-ll may be determined if the combination of the number of selected beams in codebook Type-ll (e.g., LType-n) and any codebook parameter(s) (e.g., NltN2, Ovand O2) is less than a predefined thresholdsNr, N2, Oltand O2).

[0205] The WTRU may determine subband CSI and / or wideband CSI (e.g., based on the number of CSI resources in the resource set and thresholds of number of CSI resources). For example, the WTRU may determine a wideband CSI, if the number of a resource CSI in a resource set is less than a threshold (e.g., Nlrt—hclsih 1 i e Ni'lr— csi < — Nirt—hlcsi ■'

[0206] The WTRU may determine a wideband CSI, if the number of a resource CSI in a resource set is greater than a threshold (e.g.,

[0207] The WTRU may determine both subband CSI or wideband CSI, if

[0208] The WTRU may dynamically or semi-statically receive the number of CSI resources (e.g.,Nr-csi) inresource set and CSI configuration of each resource (e.g., by MAC-CE, RRC, DCI). The CSI configuration may indicate the codebook parameters as follows.

[0209] If the number of DFT oversampling of the CSI resources is greater than a threshold, a (e.g., one) precoding matrix may be indicated by the PMI corresponding to M' subbands out of M subbands (e.g., where M’ < M).

[0210] If the number of DFT oversampling of the CSI resources is less than a threshold, a (e.g., one) precoding matrix may be indicated by the PMI corresponding to subbands out of M subbands (e.g., where M' < M).

[0211] Determi nation (s) may be made per CSI resource set.

[0212] A WTRU may receive a (e.g., single) report quantity configuration that may be applicable to the entire set of CSI resources configured in a resource set. The WTRU may receive an indication instructing the WTRU to associate a CSI resource with a quantity report, for example, through one or more of a semistatic (e.g., RRC), dynamic (e.g., DCI or MAC CE, etc.).

[0213] The WTRU may determine CSI report quantity associated to the received CSI-RSs in a (e.g., each) CSI resource (e.g., in an implicit manner). If a WTRU is configured with more than one CSI resource per CSI resource set, the WTRU may determine report quantities based on a parameter of CSI configuration, for example, number of CSI-RS resources in a configured CSI resource set, total number ofCSI ports or RSs supported by the configured CSI resources in a resource set, slot index (first, last, etc.), total number of CSI symbols in configured CSI-RS resources in a set, etc.

[0214] Examples described herein may be based on use of the number of CSI resources in a set. A person of ordinary skill in the art will appreciate that the same approach may be applied while considering another parameter, characteristic, or feature of the CSI configuration.

[0215] A WTRU may determine one or more of report quantity(ies), codebook type(s), and / or codebook parameter(s) based on the number of CSI resources in the CSI resource set. One or more of the following may apply.

[0216] The WTRU may determine report quantity(ies). For example, the WTRU may determine (e.g., only determine) rank, PMI, and / or CQI for one or more CSI resources in the resource set based on a configured, indicated, or a fixed number of CSI resources in the resource set.

[0217] For example, the WTRU may determine report quantity(ies) to be rank and CQI if the number of CSI resources in the resource set is larger than a configured, indicated, or fixed threshold.

[0218] The WTRU may determine report quantity(ies) to be rank, PMI, and CQI if the number of CSI resources in the CSI resource set is smaller than a configured, indicated, or fixed threshold.

[0219] The WTRU may determine report quantity(ies) to be a minimum rank or minimum CQI value across all CSI resources in the CSI resource set if the number of CSI resources in the resource set is larger than a configured, indicated, or fixed threshold.

[0220] The WTRU may determine a codebook type. The WTRU may determine one or more codebook type(s) for determination of the report quantity(ies) in one or more CSI resources in the CSI resource set based on the number of CSI resources in the CSI resource set.

[0221] For example, the WTRU may determine to use a first codebook (e.g., NR Type-I) for determination of the report quantity(ies) if the number of CSI resources in the CSI resource set is greater than a configured, indicated, or fixed threshold.

[0222] The WTRU may determine to use a second codebook (e.g., NR Type-ll codebook) for determination of the report quantity(ies) if the number of CSI resources in the CSI resource set is less or equal to a configured, indicated, or fixed threshold.

[0223] The WTRU may determine to use a first and a second codebooks (e.g., NR Type-I and Type-ll) for determination of the report quantit(ies) if the number of CSI resources in the CSI resource set is between two configured, indicated, or fixed thresholds.

[0224] The WTRU may determine more than one set of report quantities (e.g., PMI_1 , CQI_1, and PMI_2, CQI_2) using a plurality of codebooks (e.g., Type-I and Type-ll) for each CSI resource in the CSI resource set.

[0225] The WTRU may determine one or more codebook parameters. For example, the WTRU may determine codebook parameter(s) for the determined codebook type(s) and for determination of the report quantity(ies) based on the number of CSI resources in the CSI resource set.

[0226] For example, the WTRU may use a higher or a lower resolution codebook (e.g., higher or smaller DFT-oversampling values, where DFT-oversampling quantifies the resolution of a codebook) based on the number of CSI resources.

[0227] For example, the WTRU may use higher DFT-oversampling value(s) if the number of CSI resources in the CSI resource set is less than a configured, indicated, or fixed threshold.

[0228] The WTRU may use a smaller DFT-oversampling value(s) if the number of CSI resources in the CSI resource set is higher than a configured, indicated, or fixed threshold.

[0229] The WTRU may use a higher degree of CSI compression (e.g., higher value of compression parameters), and a smaller degree of CSI compression (e.g., smaller values of compression parameters) if the number of CSI resources in the CSI resource set is higher, lower than a configured, indicated, or fixed threshold, respectively.

[0230] Determi nation (s) may be made per CSI resource.

[0231] A WTRU may receive one or more (e.g., a plurality of) report quantity configurations to support having different report quantity configuration per resource. If more than one report quantity is supported, the WTRU may receive an indication to associate a CSI resource with a quantity report, for example, through one or more of a semi-static signaling (e.g., RRC) and / or dynamic signaling (e.g., DCI or MAC CE, etc.).

[0232] The WTRU may determine a CSI report quantity associated with the received CSI-RSs in a (e.g., each) CSI resource in an implicit manner. For example, if a WTRU is configured with more than one CSI resource per CSI resource set, the WTRU may determine report quantities per CSI resource based on a parameter of the configured CSI resource (e.g., number of CSI ports, RSs, slot index, number of CSI symbols in a CSI resource, etc.).

[0233] Examples described herein may be based on use of the number of CSI ports in a CSI resource. A person of ordinary skill in the art will appreciate that the same approach may be applied by considering another parameter, characteristic, or feature of the CSI configuration.

[0234] A WTRU may determine one or more of report quantity(ies), codebook type(s), and / or codebook parameter(s) correspond to a CSI resource based on the number of CSI ports per CSI resource. One or more of the following may apply.

[0235] A WTRU may determine one or more report quantity(ies): The UE may determine (e.g., only determines) rank, PMI and / or CQI for a CSI resources in the resource set based on a configured, indicated, or a fixed number of CSI ports for the CSI resource.

[0236] The WTRU may determine report quantity(ies) to be rank and CQI if the number of CSI ports in a CSI resource is larger than a configured, indicated, or fixed threshold.

[0237] The WTRU may determine report quantity(ies) to be rank, PMI, and CQI if the number of CSI ports in a CSI resource is smaller than a configured, indicated, or fixed threshold.

[0238] The WTRU may determine a codebook type. The WTRU may determine one or more codebook type(s) for determination of the report quantity(ies) corresponding to a CSI resources in the CSI resource set based on the number of CSI ports in a CSI resource.

[0239] For example, the WTRU may determine to use a first codebook (e.g., NR Type-1) for determination of the report quantity(ies) if the number of CSI ports in the CSI resource is greater than a configured, indicated, or fixed threshold.

[0240] The WTRU may determine to use a second codebook (e.g., NR Type-ll codebook) for determination of the report quantity(ies) if the number of CSI ports in the CSI resource is less or equal to a configured, indicated, or fixed threshold.

[0241] The WTRU may determine to use a first and a second codebooks (e.g., NR Type-I and Type-ll) for determination of the report quantity(ies) if the number of CSI ports in the CSI resource is between two configured, indicated, or fixed thresholds.

[0242] The WTRU may determine more than one set of report quantities (e.g., PMI_1 , CQI_1, and PMI_2, CQI_2) using a plurality of codebooks (e.g., Type-I and Type-ll) for each CSI resource in the CSI resource set.

[0243] The WTRU may determine one or more codebook parameters. The WTRU may determine codebook parameter(s) for the determined codebook type(s) and for determination of the report quantity(ies) based on the number of CSI ports in the CSI resource.

[0244] For example, the WTRU may use a higher or a lower resolution codebook (e.g., higher or smaller DFT-oversampling values, where DFT-oversampling quantifies the resolution of a codebook) based on the number of CSI resources.

[0245] The WTRU may use higher DFT-oversampling value(s) if the number of CSI port in the CSI resource is less than a configured, indicated, or fixed threshold.

[0246] The WTRU may use a smaller DFT-oversampling value(s) if the number of CSI ports in the CSI resource is higher than a configured, indicated, or fixed threshold.

[0247] The WTRU may use a higher degree of CSI compression (e.g., higher value of compression parameters), and a smaller degree of CSI compression (e.g., smaller values of compression parameters) if the number of CSI ports in the CSI resource is higher, lower than a configured, indicated, or fixed threshold, respectively.

[0248] The WTRU may determine and report that report quantity(ies) for one or more CSI resources in the CSI resource set. For example, the WTRU may report a set of report quantity(ies) determined using a plurality of codebook type and / or codebook parameters. The WTRU may report the worst report quantity(ies) (e.g., the minimum rank and / or minimum CQI) among the report quantities of all the CSI resources in the CSI resource set. The WTRU may report a report quantity(ies) for each CSI resource in the CSI resource set.

[0249] Although features and elements described above are described in particular combinations, each feature or element may be used alone without the other features and elements of the preferred embodiments, or in various combinations with or without other features and elements.

[0250] Although the implementations described herein may consider 3GPP specific protocols, it is understood that the implementations described herein are not restricted to this scenario and may be applicable to other wireless systems. For example, although the solutions described herein consider LTE, LTE-A, New Radio (NR) or 5G specific protocols, it is understood that the solutions described herein are not restricted to this scenario and are applicable to other wireless systems as well. For example, while the system has been described with reference to a 3GPP, 5G, and / or NR network layer, the envisioned embodiments extend beyond implementations using a particular network layer technology. Likewise, the potential implementations extend to all types of service layer architectures, systems, and embodiments. The techniques described herein may be applied independently and / or used in combination with other resource configuration techniques.

[0251] The processes described herein may be implemented in a computer program, software, and / or firmware incorporated in a computer-readable medium for execution by a computer and / or processor. Examples of computer-readable media include, but are not limited to, electronic signals (transmitted over wired and / or wireless connections) and / or computer-readable storage media. Examples of computer- readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as, butnot limited to, internal hard disks and removable disks, magneto-optical media, and / or optical media such as compact disc (CD)-ROM disks, and / or digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, terminal, base station, RNC, and / or any host computer.

[0252] It is understood that the entities performing the processes described herein may be logical entities that may be implemented in the form of software (e.g., computer-executable instructions) stored in a memory of, and executing on a processor of, a mobile device, network node or computer system. That is, the processes may be implemented in the form of software (e.g., computer-executable instructions) stored in a memory of a mobile device and / or network node, such as the node or computer system, which computer executable instructions, when executed by a processor of the node, perform the processes discussed. It is also understood that any transmitting and receiving processes illustrated in figures may be performed by communication circuitry of the node under control of the processor of the node and the computer-executable instructions (e.g., software) that it executes.

[0253] The various techniques described herein may be implemented in connection with hardware or software or, where appropriate, with a combination of both. Thus, the implementations and apparatus of the subject matter described herein, or certain aspects or portions thereof, may take the form of program code (e.g., instructions) embodied in tangible media including any other machine-readable storage medium wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the subject matter described herein. In the case where program code is stored on media, it may be the case that the program code in question is stored on one or more media that collectively perform the actions in question, which is to say that the one or more media taken together contain code to perform the actions, but that - in the case where there is more than one single medium - there is no requirement that any particular part of the code be stored on any particular medium. In the case of program code execution on programmable devices, the computing device generally includes a processor, a storage medium readable by the processor (including volatile and non-volatile memory and / or storage elements), at least one input device, and at least one output device. One or more programs that may implement or utilize the processes described in connection with the subject matter described herein, e.g., through the use of an API, reusable controls, or the like. Such programs are preferably implemented in a high level procedural or object oriented programming language to communicate with a computer system. However, the program(s) can be implemented in assembly or machine language, if desired. In any case, the language may be a compiled or interpreted language, and combined with hardware implementations.

[0254] Although example embodiments may refer to utilizing aspects of the subject matter described herein in the context of one or more stand-alone computing systems, the subject matter described herein is not so limited, but rather may be implemented in connection with any computing environment, such as a network or distributed computing environment. Still further, aspects of the subject matter described herein may be implemented in or across a plurality of processing chips or devices, and storage may similarly be affected across a plurality of devices. Such devices might include personal computers, network servers, handheld devices, supercomputers, or computers integrated into other systems such as automobiles and airplanes.

[0255] In describing preferred embodiments of the subject matter of the present disclosure, as illustrated in the Figures, specific terminology is employed for the sake of clarity. The claimed subject matter, however, is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish a similar purpose.

Claims

CLAIMSWhat is Claimed:1 . A wireless transmit / receive unit (WTRU) comprising: a processor configured to: receive, from a network entity, configuration information that indicates a first channel state information (CSI) resource and a second CSI resource; determine a first oversampling index associated with the first CSI resource and a second oversampling index associated with the second CSI resource; determine, based on the first oversampling index, a first set of codewords from a codebook of codewords associated with the first CSI resource; determine, based on the second oversampling index, a second set of codewords from a codebook of codewords associated with the second CSI resource; select a codeword from at least one of the first set of codewords or the second set of codewords; and send a CSI report to the network entity, wherein the CSI report indicates the selected codeword.

2. The WTRU of claim 1, wherein the first oversampling index is a shared oversampling index, and wherein the processor being configured to determine, based on the second oversampling index, the second set of codewords associated with the second CSI resource comprises the processor being configured to use the first oversampling index as the second oversampling index.3 . The WTRU of claim 2, wherein the shared oversampling index is determined based on: a first rank value associated with the first CSI resource being greater than a second rank value associated with the second CSI resource; the first CSI resource being an initial CSI resource in a CSI resource set; or the first CSI resource being a last CSI resource in the CSI resource set.

4. The WTRU of claim 1 , wherein the processor is further configured to determine a first channel quality metric associated with the first CSI resource and a second channel quality metric associated with the second CSI resource, and the processor being configured to select the codeword from at least one of the first set of codewords or the second set of codewords comprises the processor being configured to: on a condition that the first channel quality metric satisfies a threshold, select a first codeword from the first set of codewords; andon a condition that the second channel quality metric satisfies the threshold, select a second codeword from the second set of codewords.

5. The WTRU of claim 4, wherein the first channel quality metric comprises a rank value associated with the first CSI resource, reference signal received power (RSRP) value associated with the first CSI resource, or signal to interference noise ratio (SINR) value associated with the first CSI resource, and wherein the second channel quality metric comprises a rank value associated with the second CSI resource, an RSRP value associated with the second CSI resource, or an SINR value associated with the second CSI resource.

6. The WTRU of claim 1 , wherein the first set of codewords is different from the second set of codewords, the processor being configured to select the codeword from at least one of the first set of codewords or the second set of codewords comprises the processor being configured to select a first codeword from the first set of codewords and a second codeword from the second set of codewords, and wherein the processor is further configured to determine a co-phasing coefficient associated with the first codeword and the second codeword, wherein the CSI report further indicates the co-phasing coefficient.

7. The WTRU of claim 1 , wherein the first set of codewords associated with the first CSI resource comprises a number of codewords, wherein the processor is further configured to determine the number of codewords based on a number of antenna ports associated with the first CSI resource.

8. The WTRU of claim 1 , wherein the processor being configured to select the codeword from at least one of the first set of codewords or the second set of codewords comprises the processor being configured to: identify a first codeword in the first set of codewords; identify a second codeword in the second set of codewords, wherein the first set of codewords comprises the second codeword; determine a payload size associated with the first codeword and the second codeword; and on a condition that the payload size exceeds allocated resources for CSI reporting, select the first codeword and the second codeword from the first set of codewords.

9. The WTRU of claim 1, wherein the processor is further configured to determine a channel quality indicator (CQI) based on the first CSI resource and the second CSI resource, and wherein the CSI report further indicates the CQI.

10. The WTRU of claim 1 , wherein the processor being configured to select the codeword from at least one of the first set of codewords or the second set of codewords comprises the processor being configured to select a first codeword and a second codeword from the first set of codewords, and wherein the CSI report further indicates at least one of: that the first codeword and the second codeword are from the first set of codewords; a number of codewords selected from the first set of codewords; an index associated with the first codeword; or an index associated with the second codeword.

11. A method comprising: receiving, from a network entity, configuration information that indicates a first channel state information (CSI) resource and a second CSI resource; determining a first oversampling index associated with the first CSI resource and a second oversampling index associated with the second CSI resource; determining, based on the first oversampling index, a first set of codewords from a codebook of codewords associated with the first CSI resource; determining, based on the second oversampling index, a second set of codewords from a codebook of codewords associated with the second CSI resource; selecting a codeword from at least one of the first set of codewords or the second set of codewords; and sending a CSI report to the network entity, wherein the CSI report indicates the selected codeword.

12. The method of claim 11 , wherein the first oversampling index is a shared oversampling index, and wherein determining, based on the second oversampling index, the second set of codewords associated with the second CSI resource comprises using the first oversampling index as the second oversampling index.13 . The method of claim 12, wherein the shared oversampling index is determined based on: a first rank value associated with the first CSI resource being greater than a second rank value associated with the second CSI resource; the first CSI resource being an initial CSI resource in a CSI resource set; or the first CSI resource being a last CSI resource in the CSI resource set.

14. The method of claim 11 , wherein the method further comprises determining a first channel quality metric associated with the first CSI resource and a second channel quality metric associated with the second CSI resource, and selecting the codeword from at least one of the first set of codewords or the second set of codewords comprises: on a condition that the first channel quality metric satisfies a threshold, selecting a first codeword from the first set of codewords; and on a condition that the second channel quality metric satisfies the threshold, selecting a second codeword from the second set of codewords.

15. The method of claim 14, wherein the first channel quality metric comprises a rank value associated with the first CSI resource, reference signal received power (RSRP) value associated with the first CSI resource, or signal to interference noise ratio (SINR) value associated with the first CSI resource, and wherein the second channel quality metric comprises a rank value associated with the second CSI resource, an RSRP value associated with the second CSI resource, or an SINR value associated with the second CSI resource.

16. The method of claim 11 , wherein the first set of codewords is different from the second set of codewords, selecting the codeword from at least one of the first set of codewords or the second set of codewords comprises selecting a first codeword from the first set of codewords and a second codeword from the second set of codewords, and wherein the method further comprises determining a co-phasing coefficient associated with the first codeword and the second codeword, wherein the CSI report further indicates the co-phasing coefficient.

17. The method of claim 11 , wherein the first set of codewords associated with the first CSI resource comprises a number of codewords, wherein the method further comprises determining the number of codewords based on a number of antenna ports associated with the first CSI resource.

18. The method of claim 11 , wherein selecting the codeword from at least one of the first set of codewords or the second set of codewords comprises: identifying a first codeword in the first set of codewords; identifying a second codeword in the second set of codewords, wherein the first set of codewords comprises the second codeword; determining a payload size associated with the first codeword and the second codeword; andon a condition that the payload size exceeds allocated resources for CSI reporting, selecting the first codeword and the second codeword from the first set of codewords.

19. The method of claim 11 , wherein the method further comprises determining a channel quality indicator (CQI) based on the first CSI resource and the second CSI resource, and wherein the CSI report further indicates the CQI.

20. The method of claim 11 , wherein selecting the codeword from at least one of the first set of codewords or the second set of codewords comprises selecting a first codeword and a second codeword from the first set of codewords, and wherein the CSI report further indicates at least one of: that the first codeword and the second codeword are from the first set of codewords; a number of codewords selected from the first set of codewords; an index associated with the first codeword; or an index associated with the second codeword.

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