Method for energy saving transmitter operation and related receiver operation

Abstract

A method for a WTRU may include receiving configuration information including a linear state associated with at least one reference signal (RS); receiving at least one RS; determining at least one linear setting for the received at least one RS; reporting at least one linear metric relating to at least one measurement of the received at least one RS; receiving an indication to receive a downlink (DL) transmission using a first one of the linear states; and receiving the DL transmission using the linear setting determined for the RS associated with the first linear state indicated in the linear states among the received at least one RS.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 396,060, filed on August 8, 2022, the contents of which are incorporated herein by reference. Background Art

[0003] In wireless communications, it is desirable to minimize or reduce network power consumption for both transmission and reception. Such reductions are beneficial for lowering operating costs and environmental sustainability.

[0004] Compared to earlier systems, the design of 5G NR is very efficient from the perspective of minimizing network transmissions when there is no data to communicate. For example, the always-on cell-specific reference signal (CRS) is not used in 5G NR. However, there is still potential to reduce energy consumption. For example, when the network is not transmitting during other activities (such as baseband (digital) processing for reception or beamforming), the network still consumes energy. In addition, even when the WTRU is not being served during a given period, such "idle" power consumption is not negligible in dense networks. If the network can "turn off" these activities when not transmitting to the WTRU, energy consumption can be reduced. Summary of the invention

[0005] An effective way to reduce network energy consumption is to reduce power amplifier (PA) power or the associated bias current, especially since the PA may account for the highest percentage of gNB energy consumption. However, one problem that arises when operating either at low bias current or above the saturation point is nonlinear intermodulation byproducts. Allowing the PA to operate without such nonlinear components can significantly improve the power efficiency of the PA, thereby reducing power and energy waste and dissipated heat. The present disclosure describes embodiments for enabling PAs to operate with higher power efficiency, including methods related to reducing nonlinear losses by compensating using digital pre-distortion (DPD) at the transmitter and / or digital post-distortion (DPoD) at the receiver.

[0006] A method may include receiving information about a first linear reference signal, a first linear state associated with the first linear reference signal, and a first quasi-co-located reference signal. The method may include determining a first linear setting applicable to the first linear state and the first quasi-co-located reference signal. The first linear setting may correspond to a digital post-distortion (DPoD) parameter. The method may include receiving information about a second linear reference signal, a second linear state associated with the second linear reference signal, and a second quasi-co-located reference signal. Each of the first quasi-co-located reference signal and the second quasi-co-located reference signal may be a channel state information reference signal (CSI-RS) or a synchronization signal block (SSB). The method may include determining a second linear setting applicable to the second linear state and the second quasi-co-located reference signal. The method may include reporting whether the first linear setting or the second linear setting meets minimum performance. The method may include receiving an indication of a first linear state and an associated first quasi-co-located reference signal or a second linear state and an associated second quasi-co-located reference signal applicable to physical downlink control channel (PDCCH) reception or physical downlink shared channel (PDSCH) reception. The method may include receiving information on a PDCCH or PDSCH using a first linearity setting under the condition that the indication is for a first linearity state and an associated first quasi-co-sited reference signal. The method may include receiving information on a PDCCH or PDSCH using a second linearity setting under the condition that the indication is for a second linearity state and an associated second quasi-co-sited reference signal.

[0007] A method for a WTRU may include: receiving configuration information including linear states associated with at least one reference signal (RS); receiving at least one RS; determining at least one linear setting for the at least one received RS; reporting at least one linearity metric related to at least one measurement of the at least one received RS; receiving an indication to receive a downlink (DL) transmission using a first linear state among the linear states; and receiving a DL transmission using the linear setting determined for an RS among the at least one received RS that is associated with the first linear state indicated among the linear states. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] A more detailed understanding may be obtained from the following description given by way of example in conjunction with the accompanying drawings, in which like reference numerals indicate like elements, and in which:

[0009] Figure 1A is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented;

[0010] Figure 1B is an example of an embodiment in which Figure 1AA system diagram of an example wireless transmit / receive unit (WTRU) for use within an illustrated communication system;

[0011] Figure 1C is an example of an embodiment in which Figure 1A A system diagram of an example Radio Access Network (RAN) and an example Core Network (CN) used within the illustrated communication system;

[0012] Figure 1D is an example of an embodiment in which Figure 1A A system diagram of another example RAN and another example CN used within the illustrated communication system;

[0013] Figure 2 The position of the IMD3 tone relative to the M1 / M2 pilot signal is shown;

[0014] Figure 3 An example is shown in which a WTRU receives a reference signal and adjusts a receiver configuration to compensate for distortion measured on the reference signal; and

[0015] Figure 4 An example is shown in which a WTRU receives at least one reference signal, reports a linearity metric related to the at least one reference signal, receives at least one linearity state, and applies at least one linearity setting associated with the at least one linearity state. DETAILED DESCRIPTION

[0016] Figure 1A 1 is a diagram illustrating an example communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through sharing of system resources (including wireless bandwidth). For example, the communication system 100 may employ one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), zero tail unique word discrete Fourier transform spread OFDM (ZT-UW-DFT-S-OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, and filter bank multi-carrier (FBMC), etc.

[0017] like Figure 1AAs shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network (CN) 106, a public switched telephone network (PSTN) 108, the Internet 110 and other networks 112, but it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 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 (STA)) may be configured to send and / or receive wireless signals and may include user equipment (UE) such as a WTRU, a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated process chain environment), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0018] The communication system 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, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node B, an evolved Node B (eNB), a Home Node B, a Home evolved Node B, a next generation Node B such as a gNode B (gNB), a new radio (NR) Node B, a site controller, an access point (AP), a wireless router, and the like. Although the base stations 114a, 114b are each depicted as a single element, it should be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0019] The base station 114a may be part of the RAN 104, 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), and a relay node. The base station 114a and / or the base station 114b may be configured to send 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 a licensed spectrum, an unlicensed spectrum, or a combination of a licensed spectrum and an unlicensed spectrum. A cell may provide coverage of wireless services to a specific geographic area, which may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Therefore, in one embodiment, the base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In one 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 send and / or receive signals in a desired spatial direction.

[0020] 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).

[0021] More specifically, as noted above, the communication system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, and SC-FDMA, among others. For example, the base station 114a in the RAN 104 and the WTRUs 102a, 102b, 102c may implement a radio technology, such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), that may use Wideband CDMA (WCDMA) to establish the air interface 116. 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 ​​Uplink (UL) Packet Access (HSUPA).

[0022] In one 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) that may establish the air interface 116 using Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-A Pro).

[0023] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology (such as NR radio access) that may establish the air interface 116 using NR.

[0024] In one 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 together implement LTE radio access and NR radio access, for example using dual connectivity (DC) principles. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to / from multiple types of base stations (e.g., eNBs and gNBs).

[0025] 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), GSM Enhanced Data Rates for Evolution (EDGE), GSM EDGE (GERAN), etc.

[0026] Figure 1AThe base station 114b in may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in local areas such as commercial venues, homes, vehicles, campuses, industrial facilities, sky corridors (e.g., for use by drones), and roads. 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 one 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 a femtocell. As Figure 1A As shown, the base station 114 b may have a direct connection to the Internet 110. Therefore, the base station 114 b may not need to access the Internet 110 via the CN 106.

[0027] The RAN 104 may be in communication with the CN 106, 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 different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not described in detail in the specification, the CN 106 may be 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. Figure 1A Although not shown in the figure, it will be appreciated that the RAN 104 and / or the CN 106 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104, which may utilize NR radio technology, the CN 106 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0028] The CN 106 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP) in the TCP / IP Internet protocol suite. The networks 112 may include wired communication networks and / or wireless communication 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 or a different RAT.

[0029] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication 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 via different wireless links). Figure 1A The illustrated WTRU 102c 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.

[0030] Figure 1B is a system diagram illustrating an example WTRU 102. Figure 1B As shown, the WTRU 102 may include, among other things, 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. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0031] 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 associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), any other type of integrated circuit (IC), state machine, etc. The processor 118 may perform signal decoding, 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. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, but it is understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0032] The send / receive element 122 may be configured to send a signal to a base station (e.g., base station 114a) or receive a signal from a base station via an air interface 116. For example, in one embodiment, the send / receive element 122 may be an antenna configured to send and / or receive an RF signal. In one embodiment, the send / receive element 122 may be a transmitter / detector configured to send and / or receive, for example, an IR, UV or visible light signal. In another embodiment, the send / receive element 122 may be configured to send and / or receive both an RF signal and an optical signal. It should be understood that the send / receive element 122 may be configured to send and / or receive any combination of wireless signals.

[0033] Although the transmit / receive element 122 Figure 1B Although depicted as a single element in the figure, 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.

[0034] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. For example, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0035] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an 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 a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a 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, and a secure digital (SD) memory card, among others. In other embodiments, the processor 118 may access information from and store data in a memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0036] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control 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, etc.

[0037] 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 from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by any suitable location-determination method while remaining consistent with an embodiment.

[0038] The processor 118 may also be coupled to other peripherals 138, which may include one or more software modules 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 electronic compass, a satellite transceiver, a digital camera (for photos and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, Modules, frequency modulation (FM) radio units, digital music players, media players, video game player modules, Internet browsers, virtual reality and / or augmented reality (VR / AR) devices and activity trackers, etc. The peripheral device 138 may include one or more sensors. The sensor may be one or more of the following: a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geographic location sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and a humidity sensor, etc.

[0039] The WTRU 102 may include a full-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for UL (e.g., for transmission) and DL (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit for reducing and / or substantially eliminating self-interference via hardware (e.g., a choke) or via signal processing performed by a processor (e.g., a separate processor (not shown) or via the processor 118). In one embodiment, the WTRU 102 may include a half-duplex radio for which transmission and reception of some or all signals (e.g., associated with specific subframes for UL (e.g., for transmission) or DL ​​(e.g., for reception)) may be concurrent and / or simultaneous.

[0040] Figure 1C 1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with an embodiment. As noted above, the RAN 104 may employ 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.

[0041] The RAN 104 may include evolved Node-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of evolved Node-Bs while remaining consistent with an embodiment. The evolved Node-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 evolved Node-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the evolved Node-B 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0042] Each of the evolved Node 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, and scheduling of users in the UL and / or DL, among other things. Figure 1C As shown, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0043] Figure 1C The illustrated CN 106 may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. Although the foregoing elements are depicted as part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0044] The MME 162 may be connected to each of the evolved Node-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, and selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c. 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.

[0045] The SGW 164 may be connected to each of the evolved Node-Bs 160a, 160b, 160c in the RAN 104 via an 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 the user plane during an inter-evolved Node-B handover, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, and managing and storing the context of the WTRUs 102a, 102b, 102c.

[0046] 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.

[0047] 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 be in communication 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 other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers.

[0048] Although the WTRU Figures 1A to 1D Although described as a wireless terminal, it is contemplated that in certain representative embodiments such a terminal may (eg, temporarily or permanently) employ a wired communications interface with a communications network.

[0049] In a representative embodiment, the other network 112 may be a WLAN.

[0050] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for a BSS and one or more stations (STAs) associated with the AP. The AP may have access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic to and / or carries traffic away from the BSS. Traffic originating from outside the BSS and destined for the STA may arrive through the AP and may be delivered to the STA. Traffic originating from the STA and destined for a target outside the BSS may be transmitted to the AP to be delivered to the corresponding target. Traffic between STAs within the BSS may be transmitted through the AP, for example, wherein the source STA may transmit traffic to the AP, and the AP may deliver traffic to the target STA. Traffic between STAs within the BSS may be considered and / or referred to as point-to-point traffic. Point-to-point traffic may be transmitted between the source STA and the destination STA (e.g., directly between them) using a direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunnel DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs (eg, all STAs) within or using the IBSS may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad hoc" communication mode.

[0051] When using the 802.11ac infrastructure operating mode or a similar operating mode, the AP may send beacons on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a dynamically set width. The primary channel may be an operating channel of the BSS and may be used by the STA to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access / collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. For CSMA / CA, a STA (e.g., each STA) (including the AP) may listen to the primary channel. If the primary channel is listened / 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.

[0052] High throughput (HT) STAs may communicate using a 40 MHz wide channel (eg, via a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels) to form a 40 MHz wide channel.

[0053] Very high throughput (VHT) STA can support 20MHz, 40MHz, 80MHz and / or 160MHz wide channels. 40MHz channels and / or 80MHz channels can be formed by combining continuous 20MHz channels. 160MHz channels can be formed by combining 8 continuous 20MHz channels, or by combining two non-continuous 80MHz channels (this can be called 80+80 configuration). For 80+80 configuration, after channel coding, the data can pass through a segment parser that can divide the data into two streams. Each stream can be processed by inverse fast Fourier transform (IFFT) and time domain processing separately. These streams can be mapped to two 80MHz channels, and the data can be sent by the transmitter STA. At the receiver of the receiver STA, the above-mentioned operation for the 80+80 configuration can be reversed, and the combined data can be transmitted to the medium access control (MAC).

[0054] 802.11af and 802.11ah support operating modes below 1GHz. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support meter type control / machine type communication (MTC), such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support for (e.g., only support for) certain bandwidths and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain very long battery life).

[0055] WLAN systems that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include channels that can be designated as primary channels. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA (which supports the minimum bandwidth operating mode) from all STAs operating in the BSS. In the example of 802.11ah, for STAs (e.g., MTC-type devices) that support (e.g., only support) a 1MHz mode, the primary channel may be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the state of the primary channel. If the primary channel is busy, for example, because a STA (which only supports a 1MHz operating mode) is transmitting to the AP, all available bands may be considered busy even if most of the available bands remain idle.

[0056] In the United States, the available frequency band for 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0057] Figure 1D1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with an embodiment. As noted above, the RAN 104 may employ NR 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.

[0058] The RAN 104 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 104 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, the gNBs 180a, 180b may utilize beamforming to send signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may, for example, use multiple antennas to send wireless signals to and / or receive wireless signals from the WTRU 102a. In one 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 an unlicensed spectrum, while the remaining component carriers may be on a licensed spectrum. In one embodiment, the gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNB 180a and gNB 180b (and / or gNB 180c).

[0059] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with parameter sets that may be scalable. For example, 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 the gNBs 180a, 180b, 180c using subframes or Transmission Time Intervals (TTIs) of varying or scalable lengths (e.g., containing varying numbers of OFDM symbols and / or varying absolute time lengths over time).

[0060] 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 a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c while also not accessing other RANs (e.g., such as the eNodeBs 160a, 160b, 160c). In a standalone configuration, the WTRUs 102a, 102b, 102c may use one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate / connect with the gNBs 180a, 180b, 180c while also communicating / connecting with another RAN, such as the eNode-Bs 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNode-Bs 160a, 160b, 160c may act as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0061] Each of the gNBs 180a, 180b, 180c may be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, support of network slicing, interworking between DC, NR and E-UTRA, routing of user plane data towards a user plane function (UPF) 184a, 184b and routing of control plane information towards an access and mobility management function (AMF) 182a, 182b, etc. Figure 1D As shown, gNBs 180a, 180b, and 180c may communicate with each other via an Xn interface.

[0062] Figure 1D The CN 106 shown may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and possible data networks (DNs) 185a, 185b. Although the foregoing elements are depicted as part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0063] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via the N2 interface and may act as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRU 102a, 102b, 102c, support of network slicing (e.g., handling of different protocol data unit (PDU) sessions with different requirements), selecting a specific SMF 183a, 183b, management of registration areas, termination of non-access stratum (NAS) signaling, mobility management, etc. The AMF 182a, 182b may use network slicing in order to customize CN support for the WTRU 102a, 102b, 102c based on the type of services utilized by the WTRU 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, and services for MTC access. The AMF 182a, 182b may provide a control plane function for switching between the RAN 104 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.

[0064] The SMF 183a, 183b may be connected to the AMF 182a, 182b in the CN 106 via the N11 interface. The SMF 183a, 183b may also be connected to the UPF 184a, 184b in the CN 106 via the N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b, and configure traffic routing through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions such as managing and allocating UE (e.g., WTRU) IP addresses, managing PDU sessions, controlling policy enforcement and QoS, and providing DL data notifications. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0065] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via the 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 DL packets, and providing mobility anchoring, etc.

[0066] The CN 106 may facilitate communications with other networks. 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 other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to the DNs 185a, 185b through the UPFs 184a, 184b via the N3 interfaces to the UPFs 184a, 184b and the N6 interfaces between the UPFs 184a, 184b and the local DNs 185a, 185b.

[0067] Given that Figures 1A to 1D as well as Figures 1A to 1D Corresponding to the description of the present invention, one or more or all of the functions described herein with reference to one or more of the following items may be performed by one or more simulation devices (not shown): WTRU102a to 102d, base station 114a to 114b, evolved Node B 160a to 160c, MME 162, SGW 164, PGW 166, gNB180a to 180c, AMF 182a to 182b, UPF 184a to 184b, SMF 183a to 183b, DN 185a to 185b and / or any other device described herein. The simulation device may be one or more devices configured to mimic one or more or all of the functions described herein. For example, the simulation device can be used to test other devices and / or simulate network and / or WTRU functions.

[0068] The simulation device may be designed to implement one or more tests of other devices in a laboratory environment and / or in an operator network environment. For example, one or more simulation devices may perform one or more functions 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. One or more simulation devices may perform one or more functions or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. A simulation device may be directly coupled to another device for the purpose of testing and / or performing tests using over-the-air wireless communications.

[0069] One or more simulation devices can perform one or more (including all) functions without being implemented / deployed as part of a wired and / or wireless communication network. For example, the simulation device can be used in a test scenario in a test lab and / or a non-deployed (e.g., testing) wired and / or wireless communication network to implement testing of one or more components. One or more simulation devices can be test equipment. Direct RF coupling and / or wireless communication via RF circuits (e.g., which can include one or more antennas) can be used by the simulation device to send and / or receive data.

[0070] The following abbreviations and acronyms may be used for reference:

[0071] ACK

[0072] BLER Block Error Rate

[0073] BWP Bandwidth Section

[0074] CAP channel access priority

[0075] CAPC channel access priority category

[0076] CCA Clear Channel Assessment

[0077] CCE Control Channel Element

[0078] CE Control Elements

[0079] CG configuration authorization or cell group

[0080] CP cyclic prefix

[0081] CP-OFDM Conventional OFDM (depends on cyclic prefix)

[0082] CQI Channel Quality Indicator

[0083] CRC Cyclic Redundancy Check

[0084] CSI channel state information

[0085] CW contention window

[0086] CWS contention window size

[0087] CO channel occupancy

[0088] DAI Downlink Assignment Index

[0089] DCI downlink control information

[0090] DFI downlink feedback information

[0091] DG Dynamic Authorization

[0092] DL Downlink

[0093] DM-RS Demodulation Reference Signal

[0094] DRB Data Radio Bearer

[0095] eLAA Enhanced License Assisted Access

[0096] FeLAA further enhances license-assisted access

[0097] HARQ Hybrid Automatic Repeat Request

[0098] LAA License Assisted Access

[0099] LBT listens first and speaks later

[0100] LTE LTE Long Term Evolution, e.g. from 3GPP LTE Release 8 and higher

[0101] NACKNegative ACK

[0102] NES Network Energy Saving

[0103] MCS modulation and decoding scheme

[0104] MIB Master Information Block

[0105] MIMO Multiple Input Multiple Output

[0106] NR New Radio

[0107] OFDM Orthogonal Frequency Division Multiplexing

[0108] PHY physical layer

[0109] PID Process ID

[0110] PEI Paging Early Indication

[0111] PO paging time

[0112] PRACH Physical Random Access Channel

[0113] PSS primary synchronization signal

[0114] RA Random Access (or procedure)

[0115] RACH Random Access Channel

[0116] RAN Radio Access Network

[0117] RAR Random Access Response

[0118] RCU Radio Access Network Central Unit

[0119] RF Radio Front End

[0120] RLF Radio Link Failure

[0121] RLM Radio Link Monitoring

[0122] RMSI remaining system information

[0123] RNTI Radio Network Identifier

[0124] RO RACH Timing

[0125] RRC Radio Resource Control

[0126] RRM Radio Resource Management

[0127] RS reference signal

[0128] RSRP reference signal received power

[0129] RSSI Received Signal Strength Indicator

[0130] SDU Service Data Unit

[0131] SI system information

[0132] SIB System Information Block

[0133] SRS sounding reference signal

[0134] SS sync signal

[0135] SSB Synchronous Signal Block

[0136] SSS auxiliary synchronization signal

[0137] SWG switching gap (in independent subframe)

[0138] SPS semi-persistent scheduling

[0139] SUL Supplementary Uplink

[0140] SN Auxiliary Node

[0141] TB transfer block

[0142] TBS transport block size

[0143] TRP send / receive point

[0144] TSC Time Sensitive Communications

[0145] TSN Time Sensitive Network

[0146] UL Uplink

[0147] URLLC ultra-reliable low-latency communication

[0148] WBWP wide bandwidth part

[0149] WLAN Wireless Local Area Network and Related Technologies (IEEE 802.xx Domain)

[0150] 3GPP Third Generation Partnership Project

[0151] NR supports beamforming with many ports (up to 64 transmit and receive ports), and energy consumption increases with the number of ports utilized. In implementation, not all WTRUs need to use the maximum number of ports. If the network can adapt the number of ports to only the number that is needed, energy consumption can be reduced.

[0152] NR R18 network energy saving aims to improve the operation of the cellular ecosystem to enable more efficient adaptation of network transmission and reception resources in the time, frequency, space and power domains with the potential support, feedback and assistance of the WTRU. This enables echo-friendly WTRU operation, which allows the deployment of greener network deployments, thereby allowing the reduction of emission costs and vertex costs of operating cellular networks. Unlike LTE, NR does not need to send synchronization signals or reference signals that are always on and supports adaptive bandwidth and MIMO functions. Although the initial work in R18 is not expected to affect traditional WTRUs, it is expected that this adaptation of network resources will enable higher efficiency in operating newer deployments and future generations.

[0153] The following terminology may be used and may be assumed through this disclosure. Channel state information (CSI) may include at least one of the following: channel quality index (CQI), rank indicator (RI), precoding matrix index (PMI), L1 channel measurement (e.g., RSRP, such as L1-RSRP, or SINR), CSI-RS resource indicator (CRI), SS / PBCH block resource indicator (SSBRI), layer indicator (LI), and / or any other measurement quantity measured by the WTRU from the configured CSI-RS or SS / PBCH block. Uplink control information (UC) may include: CSI, HARQ feedback for one or more HARQ processes, scheduling request (SR), link recovery request (LRR), CG-UCI, and / or other control information bits that may be transmitted on PUCCH or PUSCH. A channel condition may refer to any condition related to the state of a radio / channel that may be determined by a WTRU based on: WTRU measurements (e.g., L1 / SINR / RSRP, CQI / MCS, channel occupancy, RSSI, power headroom, exposure headroom); L3 / mobility-based measurements (e.g., RSRP, RSRQ); RLM status; and / or channel availability in unlicensed spectrum (e.g., whether a channel is occupied or whether a channel is deemed to have experienced consistent LBT failures based on a determination of an LBT procedure). A PRACH resource may refer to a PRACH resource (e.g., in terms of frequency), a PRACH opportunity (RO) (e.g., in terms of time), a preamble format (e.g., in terms of total preamble duration, sequence length, guard time duration, and / or in terms of length of a cyclic prefix), and / or a certain preamble sequence used to send a preamble in a random access procedure.

[0154] Attributes of the scheduling information (e.g., an uplink grant or a downlink assignment) may include at least one of the following: frequency allocation; aspects of time allocation, such as duration; priority; modulation and coding schemes; transport block size; number of spatial layers; number of transport blocks to be carried; TCI status or SRI; number of repetitions; and whether the grant is configured as grant type 1, type 2, or a dynamic grant.

[0155] The indication through the DCI may include at least one of the following: an explicit indication through a DCI field or through an RNTI used to mask the CRC of the PDCCH, or an implicit indication through attributes such as the DCI format, the DCI size, the core set or search space, the aggregation level, and an identifier of the first control channel resource used for the DCI (e.g., the index of the first CCE), where the mapping between the attributes and the values ​​may be signaled by RRC or MAC.

[0156] The terms network availability status and NES status are used interchangeably.

[0157] The WTRU may determine whether it can transmit or receive on certain resources based on a network availability state that reflects the power saving state of the gNB. The availability state may correspond to a network power saving state or a gNB activity level. The availability state may be uplink or downlink specific and may change from symbol to symbol, slot to slot, frame to frame, or on a longer duration granularity. The availability state may be determined by the WTRU or indicated by the network. The availability state may be, for example, "on", "off", "dormant", "micro-sleep", or "deep sleep". Such states may be abstracted by network configuration parameters and / or values. The "off" availability state may mean that the baseband hardware of the gNB is completely turned off. The "sleep" availability state may mean that the gNB wakes up periodically to send certain signals (e.g., presence signals, synchronization or reference signals) or receive certain uplink signals. In some availability states, some DL or UL resources are not available during certain time periods, and this may enable the network to turn off baseband processing and other activities. Some measurement resources (e.g., SSB or CSI-RS) may be available only in certain availability states.

[0158] Under certain conditions, the WTRU may also send a request (i.e., a wake-up request) to the network to modify the availability state to a state where resources are available to meet the WTRU's needs. Such a wake-up request may include a transmission that can be decoded by a low-complexity receiver at a gNB for which energy consumption requirements are minimal. In this document, wake-up request, turn-on request, or turn-on WTRU assistance information may be used interchangeably. In certain availability states (e.g., "micro-sleep" or "deep sleep"), a wake-up request may be used specifically and may refer to a physical uplink signal sent by the WTRU to request a change in the availability state. In addition, the turn-on request may be a physical layer or L2 indication from the WTRU to the network, which may be delivered as a MAC CE, UCI, RRC signaling, PUCCH, or RACH indication, and may include turn-on WTRU assistance information and / or a positioning report.

[0159] The WTRU may determine the availability state from, for example, the receipt of an availability state indication through L1 / L2 signaling (e.g., a group common DCI or indication), or may determine the availability state implicitly from the receipt of periodic DL signaling or the lack thereof. If the resource is applicable in the active availability state, the WTRU may determine whether the resource is applicable for transmission / reception and / or measurement for the determined network availability state.

[0160] The availability status applies to at least one transmit, receive or measurement resource. The availability status may apply to at least one time period, such as a time slot or a time symbol. The availability status may apply to a serving cell, a cell group, a frequency band, a bandwidth portion, a TRP, a set of spatial elements, or a frequency range within a bandwidth portion.

[0161] After receiving downlink signaling that changes the availability state of a cell or TRP, the WTRU considers the active availability state associated with the cell, carrier, TRP, or band to be in "off", "deep sleep", or "micro sleep" state. For example, the WTRU may receive an off command on broadcast signaling, RRC signaling, DCI (e.g., group common DCI), or DL ​​MAC CE. The WTRU may determine the availability state based on the receipt of an availability state indication from, for example, L1 / L2 signaling (e.g., group common DCI or indication).

[0162] The WTRU may implicitly assume a certain availability state (e.g., "off," "deep sleep," "micro sleep," or "dormant") associated with a cell, carrier, TRP, or frequency band based on at least one of the following.

[0163] The WTRU may implicitly assume a certain availability state based on receiving a command or signal indicating a change in the availability state (e.g., group common DCI or RRC signaling in connected mode). The WTRU may implicitly determine the availability state based on the reception of periodic downlink signaling. The WTRU may be configured or specified to associate an availability state with one or more downlink signal types (e.g., SSB, partial SSB, and / or one or more periods).

[0164] The WTRU may implicitly assume a certain availability state based on the gNB DTX state (e.g., whether the gNB is in active time or whether the associated activity timer is running).

[0165] The WTRU may implicitly assume an availability state based on the lack of detection of a presence indication. If no presence indication is detected at one or more presence indication occasions, the WTRU may determine an availability state associated with the cell (e.g., an "off" or "deep sleep" state). The WTRU may assume or change the availability state of the cell after multiple consecutive false detections or after a period of time (e.g., a timer) has expired after no presence signal was detected. After a period of time (e.g., a timer) associated with the availability state has expired, the WTRU may determine that the availability state is activated or deactivated. The WTRU may implicitly determine the availability state based on the lack of periodic downlink signaling received. For example, the WTRU may be configured with a signal quality threshold (e.g., an RSRP threshold) and if the WTRU does not detect a signal associated with an availability state with a signal strength above the threshold (e.g., a presence signal or SSB), the WTRU may assume that the availability state is not active and may assume a different availability state. The criterion may also be combined with the lack of detection of an identification sequence for the presence signal (e.g., detection of a PSS sequence).

[0166] The WTRU may implicitly assume an availability state based on the time of day. The WTRU may be configured to automatically assume an availability state (e.g., off, sleep, or dormant state) for a configured subset of cells (e.g., capacity boosting cells) based on the time of day. For example, the WTRU may determine that a capacity boosting cell has an availability state indicated as "on" during certain hours of the day, an availability state indicated as "deep sleep" during other configured hours, and an availability state indicated as "off" during a third set of configured hours of the day or night.

[0167] The WTRU may implicitly assume an availability state based on the availability state of an associated cell (e.g., another carrier of the same MAC entity, another carrier in the same cell group, another carrier in the same gNB, another sector in the same gNB, or a configured associated cell or capacity boosting cell).

[0168] The WTRU may implicitly assume a certain availability state based on detecting a signal containing only PSS or a simplified / reduced SSB signal.

[0169] The WTRU may implicitly assume a certain availability state based on the detection of RS signals (eg, CSI-RS, PRS, TRS) or the absence of detection of RS signals.

[0170] The WTRU may implicitly assume a certain availability state based on the RRC state of the WTRU (idle, inactive or connected mode).

[0171] The WTRU may implicitly assume a certain availability state based on whether a page has been received (possibly within a configured time window).

[0172] The WTRU may implicitly assume a certain availability state based on whether it has received system information (e.g., periodic SI or a subset of SIBs (possibly within a configured time window).

[0173] The WTRU may be configured to monitor for indications that may characterize a level of network activity (e.g., availability status). Network activity may be associated with a gNB and / or a cell. The WTRU may assume the same availability status for all cells that are part of the same gNB (e.g., cells of the same MAC entity). The network activity indication (e.g., presence indication) may include a channel (e.g., PDCCH) and / or a signal (e.g., sequence). The activity indication may indicate an activity level (e.g., reduced activity) that the WTRU may expect from the associated gNB and / or cell. The activity indication may include activity information of other gNBs or cells. The activity indication may be a PDCCH that includes group common signaling. For example, the network may send a group common DCI to a group of WTRUs (e.g., WTRUs in a serving cell) to indicate a change in activity status or activity level in the uplink and / or downlink. The CRC of the PDCCH may be scrambled with a dedicated "activity indication RNTI". The WTRU may be configured with at least one search space associated with a monitoring opportunity for an activity indication PDCCH. The indication may include a sleep entry signal (e.g., a predetermined sequence). When the WTRU detects this sequence, the WTRU may expect a reduced activity level for a specific time period. The WTRU may activate C-DRX for the indicated time period. Alternatively, two sequences may be used to indicate normal activity and reduced activity.

[0174] The signaling or activity indication within the PDCCH may include at least one of the following.

[0175] Signaling or activity indication within the PDCCH may include an expected activity level (e.g., availability status) of the associated gNB / cell within a particular time interval. The activity level may be predetermined and / or configured, and may, for example, include normal activity and reduced activity. The signaling may indicate the activity level. For example, a bit "1" may indicate normal activity, while a bit "0" may indicate reduced activity.

[0176] For each activity level (e.g., availability state), the signaling or activity indication within the PDCCH may include defined transmission and reception properties. For example, during reduced activity, it may not be desirable for the WTRU to monitor certain PDCCH search spaces (including all SSs), and / or receive certain types of PDSCH (including all PDSCHs), and / or transmit PUCCH / PUSCH, and / or perform certain measurements.

[0177] The signaling or activity indication within the PDCCH may include a set of configurations that may be associated with an activity level and may be used / applied when indicating the activity level, e.g., SS configuration, CSI reporting configuration, index of transmitted SSBs, etc. Each set of configurations may have attributes associated with the activity level, e.g., a label that may be set to "reduced activity".

[0178] Signaling or activity indication within the PDCCH may be signaled in a portion of the PDCCH or activity indication and may include a time interval in which the activity level is assumed. A bitmap may be used to indicate the time interval, wherein each bit in the bitmap may be associated with a specific duration (e.g., a time slot or frame). For example, a bit "1" may indicate regular activity, while a bit "0" may indicate reduced activity on the associated frame. The time interval may be indicated by the start time and length of the interval. The start time may be defined, for example, the start time may be determined by adding a fixed offset to the time the indication is received. The length of the interval may be configured or signaled in the indication PDCCH.

[0179] The signaling or activity indication within the PDCCH may be predetermined to include the time interval within which the activity level is assumed.

[0180] In the event that the current serving cell or capacity enhancement cell is turned off or another condition is met, the WTRU may be configured or predefined with an alternative serving cell to perform initial access, mobility, or cell reselection. The WTRU may be configured according to each broadcast of dedicated signaling for a list of fallback or alternative serving cells, or according to each serving cell or according to each gNB. For example, the WTRU may initiate a cell reselection or mobility process to an alternative serving cell associated with the cell or gNB from which the shutdown indication was received. In one example, the shutdown or sleep indication may dynamically indicate to the WTRU (e.g., through dedicated or broadcast signaling) which cell to fall back or connect to. In one example, the fallback cell may be predefined as a master node cell when the WTRU is in dual connectivity. The fallback / alternative cell may be configured or predefined as a cell associated with a different RAT or frequency band. For example, the WTRU may fall back to an LTE or FR1 cell associated with the cell or gNB from which the shutdown indication was received (e.g., when the WTRU is in CA or DC using multiple RATs or multiple frequency bands).

[0181] If an uplink or downlink resource or signal is applicable in an active availability state, the WTRU may determine that the resource or signal is applicable for transmission / reception and / or measurement for the determined network availability state. The WTRU may determine that a subset of measurement resources and / or signals (e.g., SSB, CSI-RS, TRS, PRS) are not applicable in certain availability states. The WTRU may determine that a subset of uplink or downlink resources (e.g., PRACH, PUSCH, PUCCH) are not applicable in certain availability states. The WTRU may send some uplink signals (e.g., SRS, pSRS, PRACH, UCI) only in a subset of network availability states.

[0182] One way to save energy in the network is for the gNB to reduce the bias current of the power amplifier (PA). However, reducing the bias current may have the effect of increasing the nonlinear response of the amplifier. Losses caused by nonlinearity may be compensated by digital pre-distortion (DPD) at the transmitter and / or digital post-distortion (DPoD) at the receiver. It is recommended that the WTRU provide feedback to the gNB to help set the DPD. It is also recommended that the WTRU support DPoD to compensate for in-band distortion.

[0183] The losses incurred by operating the PA of a base station in a nonlinear region may include intermodulation distortion products, including 3rd, 5th, and 7th order products. Nonlinear losses may be proportional to PA power, and the additional input power of the PA may go more into the lossy modulation byproducts rather than into the modulated subcarrier, especially when the signal amplitude is closer to the PA saturation point. Such losses may cause the PA to operate in a power-inefficient manner, where much of the consumed PA energy is wasted and the system is also degraded due to carrier leakage out of band. Much of the additional power may also be dissipated as heat, which results in additional nonlinearity in the PA operation. The network may compensate for such losses by applying DPD.

[0184] If the network changes the bias current of the power amplifier and / or the corresponding DPD setting of the transmitter, the amount of distortion observed at the receiver and therefore the required DPoD setting may also change. It may be complex or infeasible for a WTRU to properly adjust its DPoD and maintain its receiver performance using existing procedures.

[0185] The following example procedure enables the WTRU to maintain its receiver performance when operating in a system where the distortion characteristics of the transmitted signal vary.

[0186] In one embodiment, the WTRU may receive a reference signal and adjust the configuration of its receiver to compensate for the distortion measured on the reference signal. For example, the WTRU may set the parameters of a digital post-distortion (DPoD) module. The WTRU may also receive an indication of the state of the transmitter that generates the reference signal in terms of its linearity characteristics. Such a state may be referred to as a "linearity state". The linearity state may be associated with transmitter implementation aspects such as at least the amount of current fed to the power amplifier, a specific digital pre-distortion setting, the transmit power, and the antenna beam. Once the WTRU has successfully adjusted its receiver to correct for the nonlinearity caused by the specific transmitter configuration summarized by the linearity state, the WTRU may reuse the same receiver configuration for subsequent transmissions with the same linearity state. The WTRU may reuse the same receiver configuration only when the linearity state and the spatial filter (e.g., identified by the transition configuration indicator (TCI) state) are the same.

[0187] Alternatively, the linearity state of the transmitter may be assessed by the WTRU using measurements of specific intermodulation products caused by transmitter nonlinearities under certain conditions as described further below.

[0188] The WTRU may quantify the linearity status by measuring the difference in power level, amplitude and / or phase of the linear RS as well as the measurement of the tones corresponding to intermodulation byproducts of a certain order.

[0189] Digital pre-distortion (DPD) algorithms are based on one or two loopbacks that use amplifier output feedback to verify amplifier linearity in both amplitude and phase. In modern multi-panel and active antenna systems (AAS) where there are multiple amplifiers integrated with antenna elements, linearity becomes a more complex problem to solve. Beams are created by coherently combining a set of amplifiers and panels with different input weights, and each amplifier can then contribute its own imperfections to the final transmitted signal. Recalibration of the AAS during field operations can be a difficult task. Based on these considerations, the DPD algorithm may require external feedback to correct for such additional distortion effects from multiple amplifiers and on multiple beams.

[0190] A potential implementation may be to have the WTRU feed back signal linearity measurements to the network (ie, base station), for example based on measuring training reference tone signals and / or associated by-products.

[0191] The method for linear measurement can be the measurement of third-order intermodulation products D3 and D4, and has a pair of tones (RS), which can be called RS1 (M1) and RS2 (M2) that are close enough in the frequency domain so that M1, M2, D3, D4 fall within the WTRU's frequency band and measurement channel. Figure 2The relationship of M1, M2, D3, D4 in the frequency domain is shown. The frequencies of the intermodulation byproducts (or a subset thereof) may fall within the measurement band of the WTRU, while a second subset may fall outside the measurement band of the WTRU (e.g., outside the bandwidth part (BWP) of the WTRU). The WTRU may measure such byproducts that fall within the active BWP of the WTRU.

[0192] The M1 and M2 tones may be selected to be close enough to each other so that the third intermodulation product may be close enough to fall within the measurement channel of the device.

[0193] For example, if M1=F1 and M2=F2, where F1 and F2 may be located at the NR subcarrier level of the channel selection parameter system, then D3 and D4 may be located at the following positions: D3(F1, F2)=2F1-F2 and D4(F1, F2)=2F2-F1.

[0194] In one embodiment, the base station may configure a set of tone pairs in the frequency domain that may cover a specific bandwidth that may be measured by the WTRU. Additionally, the measurement configuration may be accompanied by time domain gaps, which will allow D3, D4 intermodulation product detection under better conditions.

[0195] Alternatively, to avoid gaps, the base station may puncture everything around the REs (ie, data carrying REs) located at the D3, D4 positions of each M1, M2 tone pair.

[0196] In one embodiment, the M1, M2 signals may be scrambling sequences (RS types) that may be detected without creating any specific gaps. The sequence may be configured or determined based on cell attributes (e.g., PCI or SSB index). The D3, D4 products may be detected and measured under certain conditions or by puncturing everything around the D3, D4 locations in the frequency domain.

[0197] In terms of PA linearity, the ratio between the (M1, M2) and (D3, D4) measured powers may serve as a qualifier. For example, a differential power between these two measurements below X dB may indicate an unacceptable level of nonlinearity in the base station PA. For example, the WTRU may feed back to the gNB the difference between M1 and D3 and the difference between M2 and D4 in dB. The WTRU may also feed back the difference of the 5th order byproducts under some conditions, for example, when they are in-band or if the difference between M1 and D3 is greater than a threshold or if the difference between the 3rd order tone and the 5th order tone is greater than a dB threshold.

[0198] Such measurements of type (D3, D4) may need to be made over bursts of type (M1, M2) signals and averaged accordingly. Bursts may be needed to accumulate more measurement power and have a better assessment of the presence of (D3, D4). For example, the WTRU may report the difference between the non-linear metrics of a consecutive set of measured training tones. The WTRU may report the difference between the (M1-D3) gaps of two consecutive training tones and / or indicate a preference for which tone results in a smaller gap.

[0199] When a non-linear condition is detected by a measurement, the WTRU may be configured to report the measurement. Thus, the measurement may be configured to be reported or triggered based on a (M1, M2) / (D3, D4) type ratio threshold. The measured quantity may be a dB ratio referenced to (M1, M2), or an absolute value of (D3, D4) expressed in dBm.

[0200] The measurement may be semi-statically configured and activated by a MAC-CE or DCI command. For example, semi-persistent measurement of non-linear measurements may be activated / deactivated by a MAC CE. For each occasion, a burst of measurement pilot signals may be generated by the base station. In this case, the measurement may be reported in absolute values ​​(dB or dBm) or as a linear / non-linear indicator.

[0201] In order to perform such measurements, the WTRU may have to be in connected mode. The measurements may be initiated on a specific beam, which may be the WTRU serving beam. Alternatively, the WTRU may be commanded to perform per-beam measurements on a set of beams, which may be a subset of the beams already reported by the WTRU. These measurements may be done in a time-division order and may require gaps for non-serving beams. There may be a limited number of linear measurements that the WTRU may perform and therefore a system-wide approach may be required.

[0202] Alternatively, a one-time measurement may be configured. This may be activated by the DCI and reported as an absolute value or as a linearity / non-linearity indicator based on a comparison of the measurement result with a linearity threshold.

[0203] The signal design may follow the ZP-CSI-RS and NZP-CSI-RS models and thus the WTRU assumptions for the NZP-LIN-Mi-RS and ZP-LIN-Mi-RS pairs and for the ZP-LIN-Di-RS pair may be clear and may avoid collisions with other transmissions. Depending on the WTRU channel bandwidth, there may be multiple Mi and Di pairs.

[0204] The ZP-LIN-Mi-RS pairs and ZP-LIN-Di-RS pairs may need to be configured in neighboring cells or beams that linearly overlap with the measured cell / beam. The configured measurement signals and locations may be beam specific and linked to the TCI status.

[0205] When multiple measurement pairs are configured in a beam, the WTRU may report the most significant non-linearity. Alternatively, the average of the linear measurements may be reported. In one example, the WTRU may report the highest significant value and the difference of the remaining measurement pairs.

[0206] Alternatively, the WTRU may report subband nonlinearity for each subband or for designated subband-related pairs.

[0207] In one example, the network may configure a set of Mi pairs for each carrier / beam and may command the WTRU to perform measurements only on one pair or a subset of the pairs.

[0208] When intra-band carrier aggregation is configured together with non-linear measurements, the linear tones / RS used for the measurements can span one carrier, or two or more carriers, depending on the base station decision and its RF front-end architecture.

[0209] In one embodiment, the base station may apply pre-distortion to the transmitted signal based on non-linear properties measured / detected and reported by the WTRU. The pre-distortion method may be based on a look-up table (LUT) where different vectors describing the non-linear characteristics of the PA for various amplitude levels may be obtained / stored based on measurements. In one example, measurements for the LUT may be done using the RS during the initial access procedure and feedback provided by the WTRU. The gNB may also periodically update the LUT, for example based on changes in the assigned BWP and / or PAPR value of the transmitted signal. The WTRU may feed back to the gNB a vector of a measure of non-linearity used to reduce the received signal.

[0210] The WTRU may use one of the following embodiments to determine the linearity state applicable for a particular reception.

[0211] In one embodiment, the linearity state index may be implicitly or explicitly indicated in the DCI associated with the reception. For example, a new field may indicate the linearity index.

[0212] In one embodiment, the linear state index applicable to a configured authorization may be configured as part of the configured authorization configuration.

[0213] In one embodiment, the linearity state may be indicated by a MAC CE. For example, the MAC CE may indicate an association between a linearity state and a TCI state. When a PDCCH or PDSCH is received, the WTRU may set its receiver according to the linearity state associated with the TCI state applicable to the PDCCH or PDSCH. In one embodiment, the linearity state index may be configured by RRC as part of an extended TCI state.

[0214] In one embodiment, the WTRU may determine the linearity status by measuring the reference training tone and / or associated byproducts (e.g., if the intermodulation byproducts are measured to have a strength above a threshold, or if they are within a certain dB of the level of the received reference tone).

[0215] In one embodiment, the WTRU may be configured to perform measurements on an RS assigned to measure linear properties of a received signal. The linear properties may indicate the level of nonlinearity introduced on the transmitted / received signal due to distortion caused by the PA and / or other active components in the transmitter / receiver chain. Other types of distortion introduced on the signal may be considered severe, but may not be nonlinear. These distortions may be due to multiplicative noise (such as phase noise generated by an oscillator during up / down conversion) and / or additive noise (such as channel noise). Distortion that introduces new spectral components that were not originally present in the signal is nonlinear distortion. The new spectral components may appear in-band and / or out-of-band of the signal. The WTRU may be configured with a dedicated RS for measuring / detecting nonlinearity caused by the PA and another RS ​​for measuring distortion caused by other losses (e.g., phase noise).

[0216] In one example, the WTRU may be configured to measure and / or look for spectral regrowth (e.g., intra-band / inter-band intermodulation) to determine the linearity / non-linearity of a transmitted signal. The level and location of the measured spectral regrowth may be used as an indication of the degree of linearity / non-linearity of the transmitted / received signal. The greater the level of measured spectral regrowth, the lower / higher the degree of linearity / non-linearity of the signal.

[0217] In an example where channel conditions may be assumed to be ideal (e.g., flat fading, line-of-sight propagation, etc.), the WTRU may be configured to measure the error vector magnitude (EVM) on the dedicated RS to determine the level of linearity / non-linearity of the transmitted / received signal. The WTRU may perform the EVM measurement after equalization and mitigation of other RF distortions (e.g., phase noise), and determine the degree of linearity / non-linearity of the signal based on the measured EVM level.

[0218] The WTRU may estimate whether the PA bias is changed and adapt accordingly.

[0219] The WTRU may be configured with a linear RS pattern for DPD training and / or DPoD adjustment (e.g., via semi-static or RRC signaling), where the WTRU continuously reports changes to observed linear state metrics. For each linear RS training pattern, the WTRU may be configured with associated RS resources to measure associated measurement gaps, where the measurement gap is the period between linear RS in the pattern, and / or the expected number of RS opportunities for each pattern. The WTRU may receive a MAC CE to activate or deactivate reporting associated with the linear RS training pattern. The WTRU may alternatively assume that the linear RS training mode is active until deactivated by semi-static or RRC signaling.

[0220] The WTRU may be configured to monitor one or more linear RSs (e.g., RS opportunities as part of a linear RS training pattern). When a linear state metric change (e.g., a change in power level, phase, or amplitude) greater than a configured or predetermined threshold is detected, the WTRU may determine that the PA of the serving cell is in a non-linear state. The WTRU may determine a linear state metric change based on the difference in linear state between measured linear RS opportunities, the difference in linear state between modulated RS and associated intermodulation byproducts, and / or measured channel conditions (e.g., measured RSRP less than a threshold).

[0221] In one embodiment, the WTRU may receive a first reference signal and a second reference signal and determine a nonlinearity metric by comparing the first reference signal and the second reference signal, as discussed below. When the difference in the nonlinearity metric between the first RS opportunity and the second RS opportunity is measured to be greater than or less than a threshold, the WTRU may determine that the PA of the serving cell is in a nonlinear state. The nonlinearity metric is discussed below.

[0222] In one embodiment, upon receiving a DL signal associated with the NES state, the WTRU may determine that the PA of the serving cell is in a non-linear state, including one or more of the following: an SSB or a subset of an SSB (e.g., a streamlined SSB or an SSB containing only the PSS), receiving a periodic presence of a DL signal (e.g., a reference signal) associated with the NES state, or measuring channel conditions associated with a DL signal that is below or above a configured threshold.

[0223] The WTRU may implicitly infer the NES mode and may apply DPoD.

[0224] The WTRU may determine whether to perform or activate the DPoD method based on detecting a linear state metric change greater than a threshold or detecting that the serving cell is in a non-linear state. As discussed below, upon detecting a linear state metric change greater than a threshold, the WTRU may report the linear state change and / or provide related assistance information. For a WTRU with DPoD capability, when it is determined that the serving cell is in a given availability state (e.g., after receiving an EVM request), the WTRU may perform or activate the DPoD method.

[0225] The WTRU may determine that a cell is in a given availability state when a linear state metric change greater than a threshold is detected, when it is determined that the PA of the serving cell is in a non-linear state, and / or when an indication associated with activating a linear RS training mode or linear RS resources is received (e.g., a MAC CE or RRC reconfiguration).

[0226] When a linearity state metric change greater than a threshold is detected or a serving cell is detected to be in a non-linear state, the WTRU may activate or deactivate reporting of measurements associated with the linearity state.

[0227] One or more network energy saving (NES) operation modes may be used, where a first NES operation mode may be a "normal mode" and a second NES operation mode may be a "energy saving mode". In the first NES operation mode (e.g., normal mode), the gNB may perform transmission / reception without one or more network energy saving schemes. In the second NES operation mode (e.g., energy saving mode), the gNB may perform transmission / reception with at least one network energy saving scheme.

[0228] The network energy saving (NES) process may include at least one of the following, but is not limited to: turning on / off transmission or reception at the gNB (e.g., turning on / off one or more downlink transmissions for all or a subset of time / frequency resources); changing the transmission power level in a dynamic or semi-static manner; turning on / off all or a subset of antenna ports at the gNB; relaxing the requirements on the transmit / receive antennas at the gNB (e.g., RF, EVM, etc.); and offloading the WTRU to a neighboring cell (or gNB).

[0229] Based on which subset of NES processes is used, determined, or configured for use, a different NES operating mode may be determined. For example, when a first NES operating mode is used, configured, or determined, a first subset of NES processes may be used, when a second NES operating mode is used, a second subset of NES processes may be used, and when a third NES operating mode is used, a third subset of NES processes may be used, wherein the subsets may include an empty set.

[0230] NES operational mode may be used interchangeably with network availability status, NES state, NES condition, NES configuration, NES mode, and NES situation.

[0231] The NES operation mode may be indicated or notified from the gNB to the WTRU. The WTRU may assume, expect or determine one or more of the following: EVM (error vector magnitude) level, where error types include amplitude, frequency / phase, timing and IQ offset (e.g., the EVM level when the WTRU is in a first NES operation mode (e.g., normal mode) may be better than the EVM level when the WTRU is in a second NES operation mode (e.g., power saving mode)); the non-linearity level of the power amplifier at the gNB transmitter; the coverage of the signal (e.g., SINR level); the distortion level of the signal transmitted from the gNB; the pre-distortion process used at the gNB (e.g., a first pre-distortion process may be used when the gNB is in the first NES operation mode, and a second pre-distortion process may be used when the gNB is in the second NES operation mode).

[0232] In this document, nonlinearity level, linearity level, nonlinearity quality, linearity quality, nonlinearity state, and linearity state are used interchangeably.

[0233] The WTRU may be configured, indicated, or determined to report one or more of nonlinear state related information (NLS), where the NLS may include one or more of the following: the level of one or more error types (e.g., amplitude, frequency / phase, timing, and IQ offset); the distortion level of the signal received from the gNB; whether the WTRU meets the indicated, determined, or configured EVM requirement level; the DPoD process used at the WTRU; the WTRU capability of NLS measurements and / or DPoD; and the EVM level, where the EVM level may be the current EVM level, the most recently measured EVM level, the target EVM level, the EVM level before DPoD, or the EVM level after DPoD. The WTRU may provide feedback indicating whether it is able to meet the EVM requirement (e.g., after receiving a linear RS).

[0234] The WTRU may report or be triggered to report one or more NLS when one or more of the following conditions are met.

[0235] The condition may be a determined NES operating mode. For example, when the WTRU is configured, instructed, or determined to operate in a first NES mode (e.g., normal mode), the WTRU may not report NLS. If the WTRU is configured, instructed, or determined to operate in a second mode (e.g., energy saving mode), the WTRU may report NLS.

[0236] The condition may be that the nonlinearity level of the received signal is below a threshold. The nonlinearity level of the received signal may be determined based on one or more of the following. The nonlinearity level of the received signal may be determined based on whether the EVM level is below or above a threshold. The threshold may be an EVM requirement determined or configured by the gNB. The nonlinearity level of the received signal may be determined based on an energy level detected in a certain resource that is below / above a threshold. The energy level may be referred to as at least one of: out-of-band emission, out-of-band leakage, adjacent carrier leakage, adjacent frequency resource leakage, adjacent RB leakage, and undesired band emission. The resource used for energy level detection or measurement may be at least one of: a frequency resource within an active BWP; a frequency resource adjacent to an active BWP (e.g., adjacent to an edge of an active BWP); a frequency resource adjacent to a carrier (e.g., adjacent to an edge of a carrier); and a guard band used, configured, or determined for a scheduled resource, an associated BWP, and / or an associated carrier. If the energy level detected in a particular resource is above a threshold, the WTRU may assume that the nonlinearity level at the gNB may need to be adjusted. The nonlinearity level of the received signal may be determined based on an error level for a particular modulation order. For example, the WTRU may track or measure the error level for each modulation order (e.g., QPSK, 16QAM, 64QAM) and if the error level for a particular modulation order (e.g., a higher modulation order such as 64QAM, 256QAM) is above a threshold (or greater than the error level for a lower modulation order), the WTRU may report the error level. The error level for a particular modulation order may be the number of HARQ NACKs for PDSCH / PUSCH transmissions associated with the particular modulation order for a particular time window.

[0237] The condition may be that the number of consecutive NACKs for PDSCH and / or PUSCH is below or above a threshold.

[0238] The condition may be that one or more thresholds mentioned in this document may be predetermined, (pre-)configured or indicated by the gNB.

[0239] Figure 3 An example is shown of a WTRU 300 receiving a reference signal (RS) from a gNB (or other WTRU, such as another base station or wireless network access point) 304 at or during relative time 302 and adjusting the configuration of a receiver on the WTRU or as part of a wireless network to compensate for distortion measured on the reference signal.

[0240] Still at or during relative time 302, the WTRU 300 may receive a configuration and / or indication for a first reference signal (linear reference signal (RS) #1) and an associated first linearity state (linearity state #1). The configuration may include a first quasi-co-located (QCL's) RS (e.g., CSI-RS or SSB) (QCL's RS #1). The WTRU 300 may receive the first linearity RS and calculate or otherwise determine a first linearity setting (linearity setting #1) applicable to the first linearity state (linearity state #1) and the QCL's RS / SSB (QCL's RS #1). The linearity setting may correspond to, for example, parameters of a DPoD module on the WTRU 300.

[0241] At or during the relative time 306, the WTRU 300 may receive a configuration for a second reference signal (linear RS #2) and an associated second linearity state (linear state #2) and a second QCL's RS / SSB or TCI state (QCL's RS #2). The WTRU 300 may receive the second linear RS and calculate or otherwise determine a second linearity setting (linear setting #2) applicable to the second linearity state (linear state #2) and the QCL's RS / SSB (QCL's RS #2). The WTRU 300 may report whether one or both of the (first and / or second) linearity settings meet the minimum performance requirements.

[0242] At or during the relative time 308, the WTRU 300 may receive an indication of a linearity state and RS / SSB of the QCL (e.g., RS#1 of the QCL) that may be applicable for PDCCH or PDSCH reception, for example, from an indicated generalized TCI state including the linearity state or from an indicated TCI state and linearity state indicated by a DCI or MAC CE. If the indication is for a first (or second) linearity state and RS / SSB RS#1 of the QCL (or RS / SSB RS#2 of the QCL), the WTRU 300 may receive information on the PDCCH or PDSCH using the first or (second) linearity setting and may apply the linearity setting (e.g., first linearity setting #1 and / or second linearity setting #2).

[0243] In one embodiment, the WTRU 300 may receive a reference signal (linear RS) and determine a nonlinearity metric based on the reference signal. The WTRU 300 may use this linear RS to estimate the power level of intermodulation byproducts and / or provide feedback to the gNB for DPD purposes. This may help the gNB adjust its digital predistortion parameters and / or inform the gNB what level of nonlinearity is acceptable for the WTRU 300. The WTRU 300 may report the value of the nonlinearity metric, possibly under the condition that the metric is below (or above) a configured threshold. The WTRU 300 may configure the linear RS and associated measurement resources per beam, per group of DL or UL spatial elements, per BWP and / or per TRP.

[0244] Still reference Figure 3 , the WTRU 300 may report the amplitude, power, and / or phase difference between the received linear RS and the associated intermodulation byproducts. The WTRU 300 may be configured to have a granularity for reporting such differences. For example, the WTRU 300 may be configured to use a certain number of bits to report feedback and establish a mapping between each codebook entry and the difference between the linear RS and the 3rd order intermodulation byproduct. For example, for a codebook size of 3 bits, the WTRU 300 may indicate to the gNB 304 that 000 corresponds to a difference of x dB between the modulated linear RS and the 3rd order modulation byproduct, 001 corresponds to a difference of y dB between the modulated linear RS and the 3rd order modulation byproduct, and so on. Conversely, such a mapping may be specified or determined based on a configured step size in dB.

[0245] In one embodiment, the WTRU 300 may receive a first reference signal and a second reference signal (e.g., RS#1 and RS#2), and determine a nonlinearity metric by comparing the first reference signal and the second reference signal. The nonlinearity metric may include at least one of the following: a phase difference or a function thereof (e.g., variance) between the first RS and the second RS; an error vector magnitude (EVM); or an indication of whether a linearity metric of the second RS (e.g., a level of intermodulation byproducts of a certain order) is higher than a linearity metric of the first RS and / or a difference.

[0246] The WTRU 300 may report the linearity state (e.g., including the power level, amplitude, and / or phase difference between the RS and the byproduct) of each linear RS in the pattern. Alternatively, the WTRU 300 may report the power level, amplitude, and / or phase difference only for the linear RS, where the difference is measured as the difference in linearity state between the last two consecutively received linear RSs.

[0247] The WTRU 300 may receive a configuration and / or indication for a first linear RS and a second linear RS. The WTRU 300 may determine a nonlinearity metric based on the received first linear RS and second linear RS. For example, the nonlinearity metric may be: a phase difference and / or an amplitude difference or a variance thereof between the first linear RS and the second linear RS; an EVM difference; a model-specific parameter (e.g., a memory polynomial parameter); or a measurement related to a difference in power or amplitude levels measured at the frequency of the linear RS and the associated intermodulation byproducts. The WTRU 300 may receive two signals that may allow the effects of linearity changes to be isolated only at the transmitter. The WTRU 300 may send a report of the nonlinearity metric (e.g., an RRC measurement report and / or assistance information for DPD setup) if the nonlinearity metric is above a configured threshold.

[0248] Figure 4 An example is shown of a WTRU 400 receiving a reference signal (RS) from a gNB (or other WTRU, such as another base station or wireless network access point) 404 at or during relative time 402 and adjusting a configuration of a receiver on the WTRU or as part of a wireless network to compensate for distortion measured on the reference signal, where the distortion may be a result of the gNB (or other transmitter) reducing the power of one or more power amplifiers of the gNB.

[0249] Still at or during relative time 402, the WTRU 400 may receive a configuration and / or indication for a first reference signal (linear reference signal (RS) #1) and an associated first linearity state (linearity state #1). The configuration may include a first quasi-co-located (QCL's) RS (e.g., CSI-RS or SSB) (QCL's RS #1). The WTRU 400 may receive the first linearity RS and determine or otherwise calculate a first linearity setting (linearity setting #1) applicable to the first linearity state (linearity state #1) and the QCL's RS / SSB (QCL's RS #1). The linearity setting may correspond to, for example, parameters of a DPoD module on the WTRU 400.

[0250] At or during relative time 406, the WTRU 400 may receive a configuration for a second reference signal (linear RS #2) and an associated second linearity state (linear state #2) and a second QCL's RS / SSB or TCI state (QCL's RS #2). The WTRU 400 may receive the second linear RS and determine or otherwise calculate a second linearity setting (linear setting #2) applicable to the second linearity state (linear state #2) and the QCL's RS / SSB (QCL's RS #2).

[0251] At or during the relative time 408, the WTRU 400 may determine or otherwise calculate and report to the gNB 404 or other devices in the wireless network a linearity metric associated with one or more linearity states (e.g., linearity state #1 and / or linearity state #2) and / or associated with one or more reference signals (e.g., RS#1, RS#2, RS#1 for QCL, and / or RS#2 for QCL). Examples of such linearity metrics include, but are not limited to: an indication of whether one or more reference signals (e.g., RS#1 and / or RS#2) are able to meet a minimum performance level taking into account a level of nonlinearity of each of the one or more reference signals; a ratio of intermodulation products associated with two or more reference signals (e.g., RS#1 and RS#2); and a phase difference and / or amplitude difference between two or more reference signals (e.g., RS#1 and RS#2).

[0252] At or during the relative time 410, the WTRU 400 may receive an indication of a linearity state (e.g., linearity state #1 or linearity state #2, which may be RS #1 of the QCL or RS #2 of the QCL), and the WTRU may configure itself to apply a linearity setting (e.g., linearity setting #1 or linearity setting #2) associated with the indicated QCL and / or linearity state, for example, to receive information on the PDCCH or PDSCH. For example, the WTRU 400 may receive an indication of a linearity state from an indicated generalized TCI state including a linearity state, or may receive an indication of a linearity state from an indicated TCI state and a linearity state indicated by a DCI or MAC CE. If the indication is for a first (or second) linearity state and RS / SSB RS #1 of the QCL (or RS / SSB RS #2 of the QCL), the WTRU 400 may receive information on the PDCCH or PDSCH using the first or (second) linearity setting, and may apply the linearity setting (e.g., first linearity setting #1 and / or second linearity setting #2).

[0253] In one embodiment, the WTRU 400 may receive a reference signal (linear RS) and determine a nonlinearity metric based on the reference signal. The WTRU 400 may use this linear RS to estimate the power level of intermodulation byproducts and / or provide feedback to the gNB 404 for DPD purposes. This may help the gNB 404 adjust its digital predistortion parameters and / or inform the gNB what level of nonlinearity is acceptable for the WTRU 400. The WTRU 400 may report the value of the nonlinearity metric, possibly under the condition that the metric is below (or above) a configured threshold. The WTRU 400 may configure the linear RS and associated measurement resources per beam, per group of DL or UL spatial elements, per BWP, and / or per TRP.

[0254] Still reference Figure 4 , the WTRU 400 may report the amplitude, power, and / or phase difference between the received linear RS and the associated intermodulation byproducts. The WTRU 400 may be configured to have a granularity for reporting such differences. For example, the WTRU 400 may be configured to use a certain number of bits to report feedback and establish a mapping between each codebook entry and the difference between the linear RS and the 3rd order intermodulation byproduct. For example, for a codebook size of 3 bits, the WTRU 400 may indicate to the gNB 404 that 000 corresponds to a difference of x dB between the modulated linear RS and the 3rd order modulation byproduct, 001 corresponds to a difference of y dB between the modulated linear RS and the 3rd order modulation byproduct, and so on. Conversely, such a mapping may be specified or determined based on a configured step size in dB.

[0255] In one embodiment, the WTRU 400 may receive a first reference signal and a second reference signal (e.g., RS#1 and RS#2), and determine a nonlinearity metric by comparing the first reference signal and the second reference signal. The nonlinearity metric may include at least one of the following: a phase difference or a function thereof (e.g., variance) between the first RS and the second RS; an error vector magnitude (EVM); or an indication of whether a linearity metric of the second RS (e.g., a level of intermodulation byproducts of a certain order) is higher than a linearity metric of the first RS and / or a difference.

[0256] The WTRU 400 may report the linearity state (e.g., including the power level, amplitude, and / or phase difference between the RS and the byproduct) of each linear RS in the pattern. Alternatively, the WTRU 400 may report the power level, amplitude, and / or phase difference only for the linear RS, where the difference is measured as the difference in linearity state between the last two consecutive received linear RSs.

[0257] The WTRU 400 may receive a configuration and / or indication for a first linear RS and a second linear RS. The WTRU 400 may determine a nonlinearity metric based on the received first linear RS and second linear RS. For example, the nonlinearity metric may be: a phase difference and / or an amplitude difference or a variance thereof between the first linear RS and the second linear RS; an EVM difference; a model-specific parameter (e.g., a memory polynomial parameter); or a measurement related to a difference in power or amplitude levels measured at the frequency of the linear RS and the associated intermodulation byproducts. The WTRU 400 may receive two signals that may allow the effects of linearity changes to be isolated only at the transmitter. The WTRU 400 may send a report of the nonlinearity metric (e.g., an RRC measurement report and / or assistance information for DPD setup) if the nonlinearity metric is above a configured threshold.

[0258] Although the features and elements are described above in specific combinations, it will be understood by those of ordinary skill in the art that each feature or element may be used alone or in any combination with other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (sent via a wired or wireless connection) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (such as built-in hard disks and removable disks), magneto-optical media, and optical media (such as CD-ROM disks and digital versatile disks (DVDs)). A processor associated with software may be used to implement a radio frequency transceiver for a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. A method for a WTRU, the method comprising: receiving configuration information including a linearity state associated with at least one reference signal; receiving at least one RS; determining at least one linear setting for the received at least one RS; reporting at least one linearity metric related to at least one received measurement of at least one RS; receiving an indication to receive a downlink (DL) transmission using a first one of the linearity states; as well as The DL transmission is received using a linearity setting determined for an RS of the at least one received RS associated with a first linearity state indicated in the linearity states.

2. The method according to claim 1, wherein: The DL transmission includes a Physical Downlink Control Channel (PDCCH) transmission and / or a Physical Downlink Shared Channel (PDSCH) transmission.

3. The method according to claim 1, wherein: The at least one linearity metric comprises an indication of whether a determined non-linearity of the received at least one RS is capable of meeting a minimum performance.

4. The method according to claim 1, wherein: The at least one linearity metric comprises an intermodulation product ratio, a phase difference and / or an amplitude difference between measurements of at least two received RSs.

5. The method according to claim 1, wherein: The linear setting corresponds to at least one parameter for digital post-distortion.

6. The method according to claim 1, wherein: At least two RSs of the received at least one RS are quasi-positioning RSs.

7. The method of claim 1, further comprising determining the at least one linearity metric by performing at least one measurement on the received at least one RS.

8. The method of claim 1, further comprising providing feedback to a base station regarding parameters used by the base station to digitally pre-compensate for distortion caused by a power amplifier.

9. The method of claim 1, further comprising providing feedback to a base station regarding digital predistortion parameters used by the base station.

10. A WTRU comprising a processing circuit configured to: receiving configuration information including a linearity state associated with at least one reference signal (RS); receiving at least one RS; determining at least one linear setting for the received at least one RS; reporting at least one linearity metric related to at least one received measurement of at least one RS; receiving an indication to receive a downlink (DL) transmission using a first one of the linearity states; as well as The DL transmission is received using a linearity setting determined for an RS of the at least one received RS associated with a first linearity state indicated in the linearity states.

11. The WTRU of claim 10 wherein: The DL transmission includes a Physical Downlink Control Channel (PDCCH) transmission and / or a Physical Downlink Shared Channel (PDSCH) transmission.

12. The WTRU of claim 10 wherein: The at least one linearity metric comprises an indication of whether a determined non-linearity of the received at least one RS is capable of meeting a minimum performance.

13. The WTRU of claim 10 wherein: The at least one linearity metric comprises an intermodulation product ratio, a phase difference and / or an amplitude difference between measurements of at least two received RSs.

14. The WTRU of claim 10 wherein: The linear setting corresponds to at least one parameter for digital post-distortion.

15. The WTRU of claim 10 wherein: At least two RSs of the received at least one RS are quasi-positioning RSs.

16. The WTRU of claim 10 wherein: The processing circuit is further configured to determine the at least one linearity metric by performing at least one measurement on the received at least one RS.

17. The WTRU of claim 10 wherein: The processing circuit is further configured to provide feedback to the base station regarding parameters used by the base station to digitally pre-compensate distortion caused by the power amplifier.

18. The WTRU of claim 10 wherein: The processing circuit is further configured to provide feedback to a base station regarding digital predistortion parameters used by the base station.

19. A non-transitory computer readable medium storing instructions that, when executed by a circuit, cause the circuit to: receiving configuration information including a linearity state associated with at least one reference signal (RS); receiving at least one RS; determining at least one linear setting for the received at least one RS; reporting at least one linearity metric related to at least one received measurement of at least one RS; receiving an indication to receive a downlink (DL) transmission using a first one of the linearity states; as well as The DL transmission is received using a linearity setting determined for an RS of the at least one received RS associated with a first linearity state indicated in the linearity states.

20. A method for a WTRU, the method comprising: transmitting configuration information including a linearity state associated with at least one reference signal (RS); Send at least one RS; receiving a linear setting for at least one RS transmitted; receiving at least one linearity metric related to at least one measurement of at least one RS transmitted; sending an indication to receive a downlink (DL) transmission using a first one of the linear states; and The DL transmission is sent.

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