Methods, architectures, apparatuses and systems for constellation mode selection for non-linearity compensation

Abstract

Procedures, methods, architectures, apparatuses, systems, devices, and computer program products for constellation mode selection. A wireless transmit / receive unit, WTRU, receives configuration information from a network, determines, based on the received configuration information, a constellation mode, the constellation mode being a single mode in which a first constellation is used to generate an uplink signal, or a cascaded mode in which the first constellation and then a second constellation, obtained from the first constellation, are used to generate the uplink signal, reports, to the network, the determined constellation mode, and transmits, to the network, the uplink signal generated using the determined constellation mode.

Description

METHODS, ARCHITECTURES, APPARATUSES AND SYSTEMS FOR CONSTELLATION MODE SELECTION FOR NON-LINEARITY COMPENSATIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 540,441, filed 26 September 2023, which is incorporated herein by reference in its entirety.BACKGROUND

[0002] The present disclosure is generally directed to the fields of communications, software and encoding, including, for example, to methods, architectures, apparatuses, systems directed to constellation mode selection for non-linearity compensation.SUMMARY

[0003] In an aspect, the present principles are directed to a method at a wireless transmit / receive unit, WTRU, comprising receiving configuration information from a network, determining, based on the received configuration information, a constellation mode, the constellation mode being a single mode in which a first constellation is used to generate an uplink signal, or a cascaded mode in which the first constellation and then a second constellation, obtained from the first constellation, are used to generate the uplink signal, reporting, to the network, the determined constellation mode, and transmitting, to the network, the uplink signal generated using the determined constellation mode.

[0004] In an aspect, the present principles are directed to a w ireless transfer / receive unit, WTRU, comprising at least one processor configured to receive configuration information from a netw ork, determine, based on the received configuration information, a constellation mode, the constellation mode being a single mode in which a first constellation is used to generate an uplink signal, or a cascaded mode in which the first constellation and then a second constellation, obtained from the first constellation, are used to generate the uplink signal, report, to the network, the determined constellation mode, and transmit, to the network, the uplink signal generated using the determined constellation mode.

[0005] In an aspect, the present principles are directed to a wireless transfer / receive unit, WTRU, comprising determining, based on at least one measurement of a generated signal, a constellation mode, the constellation mode being a single mode in which a first constellation is used to generate an uplink signal, or a cascaded mode in which the first constellation and then a second constellation, obtained from the first constellation, are used to generate the uplink signal, reporting, to a network, the determined constellation mode, and transmitting, to the network, the uplink signal generated using the determined constellation mode.

[0006] In an aspect, the present principles are directed to a wireless transmit / receive unit. WTRU, comprising at least one processor configured to determine, based on at least one measurement ofa generated signal, a constellation mode, the constellation mode being a single mode in which a first constellation is used to generate an uplink signal, or a cascaded mode in which the first constellation and then a second constellation, obtained from the first constellation, are used to generate the uplink signal, report, to a network, the determined constellation mode, and transmit, to the network, the uplink signal generated using the determined constellation mode.

[0007] In an aspect, the present principles are directed to a method at a wireless transmit / receive unit, WTRU, comprising determining, based on a configured waveform to use for uplink transmissions, a constellation mode, the constellation mode being, for a first waveform, a single mode in which a first constellation is used to generate an uplink signal, or, for a second waveform, a cascaded mode in which the first constellation and then a second constellation, obtained from a first constellation, are used to generate the uplink signal, reporting, to a network, the determined constellation mode, and transmitting, to the network, the uplink signal generated using the determined constellation mode.

[0008] In an aspect, the present principles are directed to a wireless transfer / receive unit, WTRU, comprising at least one processor configured to determine, based on a configured waveform to use for uplink transmissions, a constellation mode, the constellation mode being, for a first waveform, a single mode in which a first constellation is used to generate an uphnk signal, or, for a second waveform, a cascaded mode in which the first constellation and then a second constellation, obtained from a first constellation, are used to generate the uphnk signal, report, to a network, the determined constellation mode, and transmit, to the network, the uplink signal generated using the determined constellation mode.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] A more detailed understanding may be had from the detailed description below, given by way of example in conjunction with drawings appended hereto. Figures in such drawings, like the detailed description, are examples. As such, the Figures (FIGs.) and the detailed description are not to be considered limiting, and other equally effective examples are possible and likely. Furthermore, like reference numerals ("ref") in the FIGs. indicate like elements, and wherein:

[0010] FIG. 1 A is a system diagram illustrating an example communications system;

[0011] FIG. IB is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1 A;

[0012] FIG. 1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 1A;

[0013] FIG. ID is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG. 1 A;

[0014] FIG. 2 illustrates an example two-sided AI / ML model for non-linearity mitigation of the present principles;

[0015] FIG. 3 illustrates a flow chart of a method according to a first main embodiment of the present principles; and

[0016] FIG. 4 illustrates a flow chart of a method according to a second main embodiment of the present principles.DETAILED DESCRIPTION

[0017] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of embodiments and / or examples disclosed herein. However, it will be understood that such embodiments and examples may be practiced without some or all of the specific details set forth herein. In other instances, well-known methods, procedures, components and circuits have not been described in detail, so as not to obscure the following description. Further, embodiments and examples not specifically described herein may be practiced in lieu of, or in combination with, the embodiments and other examples described, disclosed or otherwise provided explicitly, implicitly and / or inherently (collectively "provided") herein. Although various embodiments are described and / or claimed herein in which an apparatus, system, device, etc. and / or any element thereof carries out an operation, process, algorithm, function, etc. and / or any portion thereof, it is to be understood that any embodiments described and / or claimed herein assume that any apparatus, system, device, etc. and / or any element thereof is configured to carry' out any operation, process, algorithm, function, etc. and / or any portion thereof.

[0018] Example Communications System

[0019] The methods, apparatuses and systems provided herein are well-suited for communications involving both wired and wireless networks. An overview of various types of wireless devices and infrastructure is provided with respect to FIGs. 1A-1D, where various elements of the network may utilize, perform, be arranged in accordance with and / or be adapted and / or configured for the methods, apparatuses and systems provided herein.

[0020] FIG. 1A is a system diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 may employ one or more channelaccess methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), singlecam er FDMA (SC-FDMA), zero-tail (ZT) unique-word (UW) discreet Fourier transform (DFT) spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block- filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0021] As shown in FIG. 1A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104 / 113, a core network (CN) 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d. any of which may be referred to as a "station" and / or a "STA", may be configured to transmit and / or receive wireless signals and may include (or be) a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi- Fi device, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a UE.

[0022] The communications systems 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c. 102d, e.g.. to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or the networks 112. By way of example, the base stations 114a, 114b may be any of a base transceiver station (BTS), a Node-B (NB), an eNode-B (eNB), a Home Node-B (HNB), a Home eNode-B (HeNB), a gNode-B (gNB), a NR Node-B (NR NB). a site controller, an access point (AP). a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 1 14a, 114b may include any number of interconnected base stations and / or network elements.

[0023] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or the base station 114bmay be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in an embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each or any sector of the cell. For example, beamforming may be used to transmit and / or receive signals in desired spatial directions.

[0024] 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).

[0025] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 116 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink Packet Access (HSDPA) and / or High-Speed Uplink Packet Access (HSUPA).

[0026] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0027] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access, which may establish the air interface 116 using New Radio (NR).

[0028] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a. 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by WTRUs 102a, 102b,102c may be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., an eNB and a gNB).

[0029] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (Wi-Fi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 IX, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856). Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE). GSM EDGE (GERAN). and the like.

[0030] The base station 114b in FIG. 1 A may be a wireless router, Home Node-B, Home eNode- B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In an 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 any of a small cell, picocell or femtocell. As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106 / 115.

[0031] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106 / 115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not shown in FIG. 1A, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may be utilizing an NR radio technology7, the CN 106 / 115 may also be in communication with another RAN (not shown) employing any of a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or Wi-Fi radio technology.

[0032] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include circuit-switched telephone networks that provide plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and / or the internet protocol (IP) in the TCP / IP internet protocol suite. The networks 112 may include wired and / or wireless communications networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 114 or a different RAT.

[0033] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1 A 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.

[0034] FIG. IB is a system diagram illustrating an example WTRU 102. As shown in FIG. IB, the WTRU 102 may include a processor 1 18, a transceiver 120, atransmit / 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 elements / peripherals 138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0035] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller. Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG. IB depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together, e.g., in an electronic package or chip.

[0036] The transmit / receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in an embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In an embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0037] Although the transmit / receive element 122 is depicted in FIG. IB as a single element, the WTRU 102 may include any number of transmit / receive elements 122. For example, the WTRU 102 may employ MIMO technology. Thus, in an 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.

[0038] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit / receive element 122 and to demodulate the signals that are received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11, for example.

[0039] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker / microphone 124. the keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 1 18 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory', such as the non-removable memory 130 and / or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), readonly memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0040] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0041] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment.

[0042] The processor 118 may further be coupled to other elements / peripherals 138, which may include one or more software and / or hardware modules / units that provide additional features, functionality and / or wired or wireless connectivity. For example, the elements / peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (e.g., for photographs and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a virtual reality’ and / or augmented reality (VR / AR) device, an activity tracker, and the like. The elements / peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity’ sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0043] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the uplink (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and / or simultaneous. The full duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the uplink (e.g., for transmission) or the downlink (e.g., for reception)).

[0044] FIG. 1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b. and 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0045] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology7. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU 102a.

[0046] Each of the eNode-Bs 160a, 160b, and 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink (UL) and / or downlink (DL), and the like. As show n in FIG. 1C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0047] The CN 106 shown in FIG. 1C may include a mobility’ management entity (MME) 162, a serving gatew ay (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any one of these elements may be owned and / or operated by an entity' other than the CN operator.

[0048] The MME 162 may be connected to each of the eNode-Bs 160a, 160b, and 160c in the RAN 104 via an SI interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c. and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0049] The SGW 164 may be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN 104 via the S 1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring user planes during inter-eNode-B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0050] 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 1 10, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0051] The CN 106 may facilitate communications with other netw orks. 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 communicatewith, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b. 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers.

[0052] Although the WTRU is described in FIGs. 1A-1D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[0053] In representative embodiments, the other network 112 may be a WLAN.

[0054] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have an access or an interface to a distribution system (DS) or another ty pe of wired / wireless network that carries traffic into and / or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and / or referred to as peer-to-peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802.1 le DLS or an 802.1 Iz tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and the STAs (e.g.. all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an "ad-hoc" mode of communication.

[0055] When using the 802.1 lac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier sense multiple access with collision avoidance (CSMA / CA) may be implemented, for example in in 802.11 systems. For CSMA / CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed / d elected 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.

[0056] High throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary' 20 MHz channel with an adj acent or nonadj acent 20 MHz channel to form a 40 MHz wide channel.

[0057] Very' high throughput (VHT) STAs may support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz, and / or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse fast fourier transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above-described operation for the 80+80 configuration may be reversed, and the combined data may be sent to a medium access control (MAC) layer, entity, etc.

[0058] Sub 1 GHz modes of operation are supported by 802.11af and 802.11 ah. The channel operating bandwidths, and earners, are reduced in 802. 1 laf and 802. 1 lah relative to those used in 802.1 In, and 802.1 lac. 802.1 laf supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV white space (TVWS) spectrum, and 802.1 lah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11 ah may support meter type control / machine-type communications (MTC), such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and / or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battei ' life).

[0059] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.1 In, 802.1 lac, 802.1 laf, and 802.1 lah, include a channel which may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.1 lah, the primary channel may be 1 MHz wide for STAs (e.g., MTC ty pe devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the status of the primary channel. If the primary’ channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP,the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0060] In the United States, the available frequency bands, which may be used by 802. 1 lah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802. 1 lah is 6 MHz to 26 MHz depending on the country code.

[0061] FIG. ID is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0062] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 180b may utilize beamforming to transmit signals to and / or receive signals from the WTRUs 102a, 102b. 102c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0063] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b. 180c using transmissions associated with a scalable numerology. 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 gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., including a varying number of OFDM symbols and / or lasting varying lengths of absolute time).

[0064] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a. 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the standaloneconfiguration, WTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b. 180c using signals in an unlicensed band. In anon-standalone configuration WTRUs 102a, 102b, 102c may communicate with / connect to gNBs 180a, 180b, 180c while also communicating with / connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a. 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In the non-standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for servicing WTRUs 102a, 102b, 102c.

[0065] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards user plane functions (UPFs) 184a, 184b, routing of control plane information towards access and mobility management functions (AMFs) 182a, 182b, and the like. As shown in FIG. ID, the gNBs 180a, 180b. 180c may communicate with one another over an Xn interface.

[0066] The CN 1 15 shown in FIG. ID may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and at least one Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0067] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different protocol data unit (PDU) sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility7management, and the like. Network slicing may be used by the AMF 182a, 182b, e.g., to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a. 102b, 102c. For example, different network slices may be established for different use cases such as sendees relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for MTC access, and / or the like. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radiotechnologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0068] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP address, managing PDU sessions, controlling policy enforcement and QoS. providing downlink data notifications, and the like. A PDU session type may be IP -based, non-IP based. Ethernet-based, and the like.

[0069] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, e.g., 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 multihomed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility' anchoring, and the like.

[0070] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers. In an embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0071] In view of FIGs. 1A-1D, and the corresponding description of FIGs. 1A-1D, one or more, or all, of the functions described herein with regard to any of WTRUs 102a-d, base stations 1 14a- b, eNode-Bs 160a-c, MME 162, SGW 164, PGW 166, gNBs 180a-c, AMFs 182a-b, UPFs 184a- b, SMFs 183a-b, DNs 185a-b, and / or any other element(s) / device(s) described herein, may be performed by one or more emulation elements / devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0072] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and / or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partiallyimplemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and / or may performing testing using over-the-air wireless communications.

[0073] The one or more emulation devices may perform the one or more, including all, functions while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in a testing scenario in a testing laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0074] Introduction

[0075] Radio Frequency (RF) impairments introduce signal distortions that impact the quality of a received signal in different ways. For instance, the local oscillator introduces non-ideal imperfections and time-domain instabilities either through the phase noise (PN) and / or carrier frequency offset (CFO) and / or in-phase (I) and quadrature-phase (Q) imbalance. The power amplifier (PA) is another source that impacts the system performance by introducing non-linear distortions.

[0076] RF impairments cause in-band and out-of-band distortions. Tn-band distortions fall inside the operating bandwidth and degrade the system’s performance, e.g., they disrupt the orthogonality of subcarriers in orthogonal frequency division multiplexing (OFDM) systems and introduce intercarrier interference (ICI). Out-of-band distortions are often caused by non-linearities in power amplifiers, and may impact the neighboring applications outside the operating bandwidth.

[0077] Due to these distortions, the system performance degrades, possibly significantly. This degradation can manifest in different ways: (1) a decrease in the signal-to-noise ratio (SNR) and an increase the bit error rate (BER), (2) an increase of the Error Vector Magnitude (EVM) because of phase and amplitude distortions in the signal constellation, (3) a decrease in achievable rates and increase in outages, and (4) a reduction in the quality of channel estimations. Thus, the impacts of RF impairments on wireless transceivers can be substantial.

[0078] Existing solutions apply a power back-off to mitigate the non-linearity by pushing the PA to operate in the linear region. However, this results in degraded energy efficiency, coverage, and system throughput. On the other hand, pushing the PA to saturation can maximize the receivedSNR at the receiver, but may also result in non-linear distortions that impact the quality of the communication link and make signal detection more challenging, especially if linear detection / equalization methods (e.g., minimum mean square error, MMSE) are used at the receiver. In addition, non-linear amplification produces in-band and out-of-band radiations that degrade user performance and result in adjacent channel interference.

[0079] It will thus be appreciated that solutions are needed to address shortcomings of the existing solutions and mitigate the PA non-linearity effects.

[0080] Very briefly, the present principles provide a framework with a two-sided Artificial Intelligence / Machine Learning (AI / ML) model to detect and mitigate / compensate the PA nonlinearity through adaptively controlling the input peak-to-average-power ratio (PAPR) to the PA.Machine learning

[0081] Machine learning generally refers to a type of algorithms that solve a problem based on learning through experience (‘data’), without explicitly being programmed (‘configuring set of rules’). Machine learning can be considered as a subset of Al. Different machine learning paradigms may be envisioned based on the nature of data or feedback available to the learning algorithm. Supervised learning involves learning a function that maps input to an output based on labeled training examples, wherein each training example may be a pair consisting of input and the corresponding output. Unsupervised learning involves detecting patterns in the data with no pre-existing labels Reinforcement learning involves performing a sequence of actions in an environment to maximize the cumulative reward. It is also possible to apply machine learning algorithms using a combination or interpolation of the different ML variants. For example, semisupervised learning uses a combination of a small amount of labeled data with a large amount of unlabeled data during training. In this regard semi-supervised learning falls between unsupervised learning (with no labeled training data) and supervised learning (with only labeled training data).Deep Learning (DL)

[0082] Deep learning refers to a class of machine learning algorithms that employ artificial neural networks loosely inspired by biological systems. Deep Neural Networks (DNNs) are a special class of deep learning models inspired by human brain wherein the input is linearly transformed and passed through non-linear activation functions multiple times. DNNs typically consist of multiple layers where each layer includes linear transformation and given non-linear activation functions. The DNNs can be trained using training data via back-propagation algorithm. Recently, DNNs have shown state-of-the-art performance in a variety of domains, e.g., speech, vision, natural language etc. and for various machine learning settings: supervised, unsupervised, and semi-supervised. The term AI / ML based methods / processing may refer to realization of behaviors and / or conformance to requirements by learning based on data, without explicit configuration of asequence of actions. Such methods may enable learning of complex behaviors which might be difficult to specify and / or implement using legacy methods.Autoencoder

[0083] Auto-encoders (AE) are a specific class of DNNs that arise in context of unsupervised machine learning wherein the input (e.g., high-dimensional) data is non-linearly transformed to a different space / representation (e.g., lower dimensional latent vector, or a representation with some enforced constraints) using the DNN based encoder. Then, the transformed representation / space (e.g., lower dimensional latent vector) is used to reproduce the original data space / representation (high-dimensional data) using a non-linear decoder. The encoder is represented as E(x; We) where x is the original data (e.g., high-dimensional) and Werepresents the parameters of the encoder. The decoder is represented as D (z; Wd) where z is the transformed / latent representation (e.g., lowdimensional latent representation) and Wdrepresents the parameters of the decoder. Further, using training data { x1(, xN} the auto-encoder can be trained by solving the following optimization problem:N{Wetr, W* } = arg min V | | xL- £)(E(x- VKe); Wd) \\ . We,Wd ' ‘ i = lThis optimization problem can be approximately solved using a backpropagation algorithm. The trained encoder E (%; Wetrcan be used to transform (e.g., compress) the original data space and trained decoder D (z; Wdr) can be used to retransform / retrieve (decompress) the original data space from the transformed one.

[0084] Two main embodiments of the present principles that will now' be summarized will subsequently be described in further detail.UE procedures for constellation mode selection and associated parameter determination

[0085] PA non-linearity results in signal distortions that may impact the system performance. PAPR reduction techniques can mitigate the PA non-linearity impacts via reducing / adapting the input PAPR to the PA. This embodiment provides methods and procedures for generation and / or selection of one or more constellations with controlled PAPR while maintaining a target BER / Block Error Rate (BLER) performance. This can enable efficient PA operation which in turn can result in improvement in system performance.

[0086] AI / ML is used as an enabler for generating a signal with a second constellation when input with a signal using a first constellation, such that the signal with a second constellation satisfies certain properties (e.g., low / controlled PAPR). The adopted two-sided AI / ML model (e.g.. Autoencoder) is trained and used to generate a signal with a constellation that strikes a balance between BER performance (i.e., sufficiently spread-out symbols) and the output PAPR. Thisenables efficient PA operation without introducing a large power back-off that may impact the system performance. Multiple AEs may be trained to handle different PAPR and modulation options or a single generalized model may be trained to generate the output based on a given input PAPR threshold. Model pairing and / or selection procedures may be required for proper operation.

[0087] The UE is configured with one or more parameters associated with one or more PAPR constellation mode(s). The configuration may include one or more of constellation mode, constellation mode selection flag, autoencoder (AE) configuration, conditions / parameters for cascaded mode selection and operation, and reporting configuration.

[0088] Constellation mode (and parameters thereof) can include single mode and cascaded mode. Single mode corresponds to legacy operation and transmission using the first constellation, wherein the first constellation may be associated with a standardized modulation scheme (e.g., QPSK). Cascaded mode corresponds to applying a first constellation followed by a second constellation, wherein the second constellation may be associated with an arbitrary symbol set (e.g., leamt by autoencoder) and may satisfy one or more requirements (e.g., PAPR constraint, max / mean energy, alphabet length).

[0089] AE configuration can include one or more of input to the AE (e.g., PAPR value), output of the AE (e.g., alphabet length), post processing (e.g., energy constraint), and AE selection information (e.g., as a function of first constellation, PAPR threshold, alphabet, energy constraint, etc.)

[0090] Conditions / parameters for cascaded mode selection / operation can include one or more of a PAPR threshold (e.g. to apply cascaded mode operation on condition that the PAPR is above a threshold), one or more (e.g., non-linear) thresholds associated with transmission (e.g., EVM threshold, ACER thresholds), that cascaded mode is to be applied if the EVM associated with the single mode exceeds a certain EVM (and / or ACER) threshold, and waveform (DFT-s-OFDM vs OFDM).

[0091] Reporting configuration (e.g., preconfigured symbols in PUSCH ( / i.e., PUSCH format) includes settings relative to reporting of UE-determined constellation mode and / or parameters thereof.

[0092] The UE receives signaling (e.g., UL grant indicating a PUSCH transmission), wherein the signaling may indicate constellation mode selection and / or configuration thereof, such as implicit indication, explicit indication and alternate methods.

[0093] Implicit indication of constellation mode selection and / or AE configuration can include two Modulation and Coding Scheme (MCS) fields, a first MCS field indicating first constellation and a second MCS field indicating constellation mode selection and / or AE configuration, or preconfigured Cell Radio-Network Temporary Identifier (C-RNTI) specific to cascaded mode -(the UE may be preconfigured to monitor the C-RNTI specific to cascaded model based on a network (NW) command and upon receiving UL grant addressed to the preconfigured C-RNTI, the UE performs constellation mode selection).

[0094] Explicit indication, e.g., in a new Downlink Control Information (DCI) format, including fields specific to carrying constellation mode selection and / or configuration thereof.

[0095] Alternate methods based on Medium Access Control Control Element (MAC-CE), e.g., the UE may be configured to activate ( / deactivate) the cascaded mode operation based on MAC CE.

[0096] The UE determines the constellation mode and / or configuration thereof (e.g., postprocessing information, preferred AI / ML model), based on one or more of received signaling, measured PAPR using the first constellation, measured EVM / ACLR using the first constellation, and waveform.

[0097] Based on the measured PAPR using the first constellation, the UE selects the single mode if the measured PAPR of the first constellation meets the configured PAPR threshold, otherwise, selects the cascaded constellation mode.

[0098] Based on the measured EVM / ACLR using the first constellation, the UE selects the single mode if the measured EVM / ACLR of the first constellation is below the configured threshold, otherwise, selects the cascaded constellation mode.

[0099] Based on waveform, e.g., the UE selects the single mode for a first wave form (e.g., DFT- s-OFDM) and selects one of the two constellation modes for a second waveform (e.g., OFDM)

[0100] The UE applies the determined constellation mode and configuration thereof, on an UL transmission, wherein the configuration may include one or more of post-processing information (e.g., clipping based on energy' constraint), alphabet length if quantization or clipping is applied, measured PAPR associated with the generated constellation and the selected AE model associated with the second constellation (cascaded constellation mode). .

[0101] The UE reports the selected constellation mode (and optionally, its associated parameters), e.g., features associated with the cascaded constellation mode (e.g., max / mean energy7, alphabet length, generation method), an indication of selected AE ( / pairing information) etc.

[0102] The reporting can be PUSCH-based (e.g., preconfigured time-frequency locations (e.g., first / second OFDM symbols for early decoding) for reporting the selected mode and its associated parameters), wherein the UE may apply a preconfigured constellation on these time-frequency locations. Alternately, the UE may implicitly indicate selected constellation mode via DMRS sequence selection.

[0103] The reporting can also be UCI-based, where in one or more fields are reserved for the constellation mode and its associated parameters.

[0104] The UE transmits the UL transmission (e.g., PUSCH) using the determined constellation mode and its associated parameters.UE procedures to detect and mitigate PA non-linearity

[0105] While applying power back-off at the transmitter side forces the PA to operate in the linear region to avoid the non-linear distortions, it results in reduction of the received SNR which in turn impacts the detection performance at the receiver side. Partially or fully compensating the PA non-linearity at the receiver side may allow for operating the PA in the non-linear region which may result in lower power back-off, thereby improving the system performance. This embodiment provides UE procedures to determine and report UE capability for compensating / mitigating nonlinearity.

[0106] The UE is configured with one or more parameters associated with the transmitted constellation. The configuration may include one or more of constellation mode, configuration information, and non-linearity7reference sequence (NL-RS) configuration.

[0107] Constellation mode (and parameters thereof) can include single mode and cascaded mode. Single mode corresponds to legacy operation and transmitting using the first constellation, wherein the first constellation may be associated with a standardized modulation scheme (e.g., QPSK). Cascaded mode corresponds to applying a first constellation followed by a second constellation, wherein the second constellation may be associated with an arbitrary7symbol set (e.g., learnt by autoencoder) and may satisfy one or more requirements (e.g., PAPR constraint, max / mean energy, alphabet length).

[0108] Configuration information for non-linearity7mitigation / compensation can for example include levels (e.g.. N) of non-linearity compensation / mitigation, wherein each level may have an associated PAPR, EVM threshold(s), e.g., level 1 lowest EVM and level N highest EVM.

[0109] Non-linearity reference sequences (NL-RS) configuration is intended for NL detection / mitigation / compensation / tracking at the device. This can enable more efficient operation of the PA that eventually can result in enhanced system performance.

[0110] NL-RS configuration information may be transmitted in a standalone mode without data to determine UE capability of PA compensation and the tolerable PAPR. The NL-RS could be configured at RB granularity7(instead of at RE level). The NL-RS configuration may7have one of more characteristics catered for non-linearity handling (e.g., can be transmitted with high order modulation to enforce high PAPR which is needed to assess UE capability for non-linearity7handling). The UE may be preconfigured with plurality of NL-RS sequences, wherein each sequence may have different characteristics (e.g., each sequence may have different PAPR etc.).The NL-RS configuration information may be transmitted in a multiplexed mode, i.e., associated with data channel (e.g., PUSCH / PDSCH). and can be transmitted with the same constellation as the data. The NL-RS may be configured periodically, or semi-persistently, i.e., based on triggers. The NL-RS configuration information can be present in both downlink and uplink.

[0111] The UE receives a first transmission, wherein the first transmission includes a first NL- RS sequence (e.g., either in standalone mode or multiplexed mode). The first transmission may be associated with one or more EVM threshold(s) and / or first PAPR. The first transmission may also be associated with a first constellation mode (e.g.. single mode).

[0112] The UE determines the non-linearity mitigation / compensation level based on measurements performed on the NL-RS of the first transmission. The UE can select a configured non-linearity level, each associated with NL-RS EVM threshold: e.g., NL mitigation / compensation can be a binary level indicating whether a UE is capable of NL mitigation / compensation for a configured EVM threshold. The UE can also select a configured non-linearity level based on the measured EVM associated with the received NL-RS and compare it against the EVM threshold(s), each threshold mapping to one NL compensation level. The UE can also select a configured non-linearity level based on measured BLER of the first transmission (or of one or more previous transmissions, e.g., number of consecutive NACKs).

[0113] The UE reports the NL compensation / mitigation level. The report can include a binary field indicating if a UE is capable of compensating non-linearity7associated with first transmission, or multi-level reporting based on how much the UE can compensate / mitigate. The report can include PAPR-based assistance information (e.g.. relax / increase / fix PAPR). The report can also include a request for additional NL-RS transmission for NL handling improvement.

[0114] The UE can receive a second transmission based on reported NL compensation level. The second transmission may include a second NL-RS sequence along with its associated EVM and / or PAPR, or in another option the second transmission may not include NL-RS transmission. The second transmission may be associated with a second constellation mode (e.g., cascaded). The second transmission may be associated with a second PAPR.

[0115] As a number of aspects are common to the two main embodiments, these will be described before going into the details of each embodiment.

[0116] AI / ML model refers to an artificial intelligence / machine learning model (e.g., autoencoder) trained to perform a specific task. While the present embodiments assume an autoencoder model, it will be appreciated that other AI / ML models may be also utilized. The terms Al model, ML model, AI / ML model, AE model may be used interchangeably.

[0117] Non-linearity (NL) capability refers to the UE capability in handling, detecting, mitigating and / or compensating the non-linearity (i.e., non-linear distortions) introduced by thepower amplifier. The term PA non-linearity refers to the non-linear distortions introduced in the system by the power amplifier.

[0118] Constellation mode refers to the mode at which the final constellation is formed at the transmitter. The constellation mode may be ‘single,’ wherein only the legacy constellation (i.e., standardized modulation scheme) is used, or 'cascaded,’ wherein the final constellation may be formed using two cascaded steps; first the legacy constellation is formed (e.g., QPSK, 16QAM) followed by application of a second constellation where the output of the second constellation satisfies one or more requirement(s) and / or predefined conditions.

[0119] The present principles provide a way to detect and / or mitigate non-linear distortions introduced by the RF impairments. The embodiments can maximize the power amplifier efficiency, enable reliable signal detection in the presence of non-linear distortions, and provide a seamless way dynamically to adapt the power amplifier point of operation via control of the input peak-to-average-power-ratio (PAPR).

[0120] FIG. 2 illustrates an example two-sided AI / ML model for non-linearity mitigation of the present principles. [S1(represents the symbols associated with the legacy constellation (e.g., QPSK) that are input to an AI / ML encoder 210 that outputs [X1(.... X / ^ that denotes the output of the second constellation. The output [X1;satisfies one or more constraints (e.g., output PAPR is less than a configured PAPR threshold). The output is passed through Inverse Fast Fourier Transform 220 and transmitted over a channel 230 to a decoder that passes the received information through Fast Fourier Transform 240 to, barring transmission errors and the like, retrieve the original data symbols [X ... , X^J that are fed to an AI / ML decoder 250 to retrieve (again, barring errors) the input symbols.

[0121] The two-sided encoder / decoder associated to the AIML model may be placed in different locations with respect to the Tx / Rx chain modules. For example, the encoder may be located before the IFFT block, and the decoder after the FFT block, wherein the input of the AIML encoder are the complex symbols modulated using the first constellation (e.g., standardized modulation scheme), and the input of the AIML decoder are the output of the FFT block, as show n in FIG. 2. The encoder may also be located before the first constellation mapper (modulator), and the decoder after the first constellation demapper (demodulator), wherein the input of the AIML encoder are the binary code blocks and the input of the AIML decoder are the demodulated binary symbols using the first constellation. Optionally, the input of the AIML decoder may be the soft outputs produced by the soft demodulator. The outputs of the AIML decoder are fed to the channel decoder. The UE can be pre-configured with different location configurations of the same AIML model for PA NL detection and mitigation. The UE may receive an indication flag of the locationof the encoder / decoder. In one option, the flag can be a new DCI field of 1 bit, indicating which configuration is selected. In another option, the model location flag can be received in MAC CE.

[0122] The AIML model (AE) for PA NL detection and mitigation relies on the PAPR threshold to output an according constellation. The AIML may be configured following different options. In one option, the Tx and Rx are pre-configured with different AIML models, wherein each model corresponds to a specific PAPR threshold, i.e., the model is pre-trained to handle a specific PAPR threshold value and outputs the convenient constellation. In another option, the Tx and Rx are preconfigured with a single AIML model (AE) trained using a mixed values of the PAPR threshold, wherein the single AE takes the PAPR threshold as an additional input and outputs the constellation accordingly. In a further option, the Tx and Rx are pre-configured with a single AIML model trained on different PAPR thresholds and incorporating the attention mechanism for adaptively supporting different PAPR thresholds and producing different constellations. In this further option, the PAPR threshold is side information introduced in the model. The AIML model may incorporate attention layers that adapt the weights of the main layers accordingly with respect to the PAPR threshold. Alternatively, the attention mechanism may be adopted using a separate parameter adapter neural network (PAN), trained separately for different values of the PAPR threshold. In this further option, the input of the PAN is the output of the AE and the PAPR threshold, and the output is the adapted constellation.

[0123] The AIML model input / output sizes may depend on the supported configuration, for example including on or more of the modulation order, i.e.. the number of bits per symbol in the constellation, the number of Tx / Rx antennas, the FFT size, the cyclic prefix length, the carrier frequency, and the subcarrier spacing, depending on the carrier frequency.

[0124] The Tx / Rx may be configured with one or many two-sided AIML models (AE) that handle different constellations, i.e., bits per symbol, and other parameters. The Rx may indicate / receive how many bits per symbol are configured in a binary DCI field, or by MAC CE. A single AE per configuration may be configured and pre-trained for each combination of constellation order, number of antennas, FFT size, single subcarrier, or a group of subcarriers, etc. In this option, the TX / Rx switches the model accordingly based on the pre-configured or received constellation order flag and other settings. Alternatively, the same AE for all the configurations may be configured. In this option, the number of bits per symbol of the constellation is fed to the encoder and decoder as input, wherein the output is adapted accordingly. Also, the input / output may be adapted accordingly based the number of Tx / Rx antennas, carrier frequency, subcarrier spacing, FFT size, cyclic prefix length, wherein these parameters may be provided as input to the AIML model.

[0125] The two-sided AIML model (AE) may be pre-trained offline according to different configurations provided as input, using a mixed dataset in one option. In another option, different AIML models are pre-trained according to different sets of configurations, wherein the input and outputs are adaptively rescaled.

[0126] The model may be equipped with a pre- / post-processing module for adapting the inputs / outputs, or alternatively may include internal adaptation layers. The model may include procedures for rotating / rescaling the inputs, e.g., transforming a vector / matrix of complex symbols to a matrix / tensor of real symbols. The encoder / decoder may include internal IFFT / FFT layers, wherein these layers are adaptively configured by the FFT size and cyclic prefix length inputs.

[0127] The Tx may report the latent-post processing and / or the input pre-processing type to the Rx explicitly or implicitly. The AE can be trained by incorporating a composed loss function that may include different terms, depending on the technical requirements that may consider reliability maximization (reconstruction accuracy), or alternatively error rates minimization as well as the PAPR minimization, or a metric associated with the power amplifier operation (e.g., adjacent- channel-leakage-ratio (ACLR)), out of band emissions or in-band emissions. The loss function may be expressed as:wherein Aj is an adaptive scaling parameter used to improve / balance performance of the model based on technical requirements, and ft(x) is a specific function of the input x, related to the optimization metric.

[0128] The components of the loss function may be one or more of reliability’ or reconstruction accuracy (e g., BER, BLER, soft bit error rate, Cross Entropy loss function, and NMSE) and Power amplifier related metric for optimized PA operation (e.g., Peak to average power ratio (PAPR), Adjacent channel leakage ratio (ACLR), and in-band emissions or out-of-band emissions).

[0129] The first main embodiment of the present principles provides UE procedures for constellation mode selection and associated parameters determination.

[0130] A UE may be configured or indicated to measure, determine and report the constellation mode for uplink transmissions, for example to mitigate transmitter PA non-linearity. The configuration may include the constellation mode, the constellation mode selection flag, measurement configuration for constellation mode determination, conditions for preferred constellation mode determination, as well as reporting configuration.

[0131] The UE may receive configuration information for a list of constellation modes to be used for uplink transmissions. The constellation modes may include single mode and cascaded mode.

[0132] When operating in the single mode, the UE may use a single constellation. In one solution, the single mode may use a legacy constellation such as QPSK, 16-QAM, 64-QAM or other supported higher order modulations, for example per the MCS indicated in the uplink grant.

[0133] When operating in the cascaded mode, in a first step, the UE may use a first constellation (e.g., a legacy constellation such as QPSK or QAM) and, in a second step, further process the symbols modulated according to the first constellation (e.g., using an AI / ML model, such as the AI / ML encoder part of an AE model) to generate modulated symbols according to a second (e.g., learned) constellation that meets one or more configured conditions (e.g., PAPR, ACER, max EVM and the like).

[0134] A default constellation mode may be the single mode. For example, when the UE is enabled to use the cascaded mode, initial or fallback transmissions may use the configured default (e.g., single) constellation mode.

[0135] The UE may be signaled the constellation mode selection flag, wherein when present or when the flag is set, the constellation mode selection flag may enable the UE to apply the reported preferred constellation mode (for example, the UE may apply the previously reported preferred constellation mode for the data transmission corresponding to the grant) or enable the UE to determine and report the preferred constellation mode (for example, the UE may perform measurements (e.g., PAPR, ACER, EVM) associated with the data transmission corresponding to the grant). The constellation mode selection flag may be included as one bit in the DCI for the grant (e.g., the uplink grant).

[0136] The UE may be configured with measurements to determine the constellation mode. The configuration may include at least one of metric to be measured and timing of the constellation measurements.

[0137] Metrics to be measured may for example include at least one of PAPR, estimated EVL, actual EVM and ACER.

[0138] In one example, the UE may measure the PAPR corresponding to the first constellation, e.g., when the UE operates in single constellation mode. In another example, the UE may (e.g., may only) measure the PAPR corresponding to the output constellation, e.g., when the UE operates in cascaded constellation mode. In yet another example, the UE may measure the PAPR corresponding to the first constellation as well as the PAPR corresponding to the second constellation, e.g., when the UE operates in cascaded constellation mode.

[0139] The UE may be configured to estimate the EVM at the output of the transmitter (e.g., PA), where the estimation of the EVM may be based on the actual measured PAPR and the current configured PA backoff. For example, the UE may use a lookup table (e.g., determined offline during factory calibration) that stores the offline measured EVM as a function of PAPR, PAbackoff, for the specific UE RF front end. The UE may determine the estimated EVM before performing the over-the-air transmission of the current modulated symbols (constellation).

[0140] If supported by the UE, it may be configured to measure the actual EVM at the output of the transmitter.

[0141] The UE may be configured to measure the estimated ACLR, or, if supported, the actual ACLR.

[0142] The timing of the constellation measurements may be periodic or aperiodic.

[0143] Periodic: the UE may be configured to perform constellation measurements with each UE transmission (e.g., UL transmission), or at a configured periodicity.

[0144] Aperiodic: the UE may perform constellation measurements when it detects a change in the channel conditions, or when the UE receives a power control command, or when the grant indicates a new modulation type, or when the UE is configured to use a different waveform. For example, when the grant (e.g., the UL grant) indicates a higher order modulation type, the UE may perform constellation measurements, which may trigger the switch from the single mode to cascaded mode; when the grant indicates a lower order modulation, the UE may perform constellation measurements, which may trigger the switch from the cascaded mode to the single mode. As another example, when the UE is configured to use a different waveform, e.g., when switching from DFT-s-OFDM to OFDM, the UE may perform constellation measurements to determine whether the cascaded mode is needed.

[0145] The UE may be configured with a set of parameters to determine the preferred constellation mode, where the parameters may include one or more of PAPR threshold(s), transmission-associated thresholds (e.g., EVM, ACLR) and configured transmission waveform changes.

[0146] The UE may be configured with a first PAPR threshold, for example for the PAPR corresponding to the first constellation, and a second PAPR threshold, for example corresponding to the second constellation. When the UE operates in the single mode, the UE may determine the cascaded mode as preferred mode, when the measured PAPR for the first constellation exceeds the first threshold. When the UE operates in the cascaded mode, the UE may determine the single mode as preferred mode, for example when the measured PAPR for the second constellation is smaller than a second threshold, and / or the measured PAPR for the first constellation is smaller than the first threshold. The UE may also determine the single mode as preferred mode if the difference between the measured PAPR for the first and second constellation is smaller than a preconfigured (e.g., third) threshold.

[0147] The UE may be configured with a first EVM (ACLR) threshold, for example for the EVM (ACLR) corresponding to the first constellation, and a second EVM (ACLR) threshold, forexample corresponding to the second constellation. The UE may determine the preferred constellation mode when the estimated EVM (or estimated ACLR), or when the measured EVM (or measured ACLR) - if supported - meet the configured thresholds. For example, if the current mode is single mode, the UE may determine the cascaded mode as preferred if the estimated (or measured) EVM (or ACLR) exceeds a first EVM (or ACLR) threshold. As another example, if the current mode is cascaded mode, the UE may determine single mode as preferred, for example when the estimated (or measured) EVM (or ACLR) for the second constellation is smaller than the second EVM (ACLR) threshold, and the estimated (or measured) EVM (or ACLR) for the first constellation is smaller than the first EVM (ACLR) threshold.

[0148] As to the change in the configured transmission waveform (e.g., OFDM vs DFT-s- OFDM), when the UE for example operates in cascaded mode using the OFDM waveform, the UE may determine the single mode as preferred, when the waveform is configured to DFT-s- OFDM.

[0149] The UE may be configured with one or more ML models (e.g., AI / ML encoders) to generate or shape the second constellation (e.g., when operating in the cascaded mode) to meet preconfigured criteria. The UE may be indicated the AE (e.g.. the AI / ML encoder) configuration, where the configuration may include one or more of inputs to the AI / ML encoder (e.g., PAPR corresponding to the first constellation, modulation type for the first constellation, available power headroom), outputs of the encoder (e.g., alphabet length), energy’ constraint and output EVM constraint.

[0150] The UE may receive information relating to configuration of constellation mode reporting. The configuration may for example include timing of the reports and resources for reporting.

[0151] The UE may be configured to report the preferred constellation mode periodically (e.g., with a configured periodicity), or aperiodically (e.g., when the UE is triggered to perform constellation measurements). The UE may also be configured only to report the preferred constellation mode when the newly determined preferred constellation mode is different from the configured (current) one.

[0152] The resources for reporting the preferred constellation mode may be dedicated PUSCH resources for PUSCH-based reporting (for example, an UL grant for the UE to indicate the preferred constellation mode). The UE may also be configured with a set of REs, which may be a small subset of the current UL grant, to indicate the preferred constellation mode. In another configuration, the UE may use the first UCI report to include the indication (e g., flag) for the preferred constellation mode.

[0153] The UE may determine (i.e., select) the constellation mode and associated parameters in different ways.

[0154] The UE may be configured with a set of non-linearity-mitigation modes or a set of parameters for one or more non-linearity-mitigation mode. A constellation mode may be an example of a non-linearity-mitigation mode. Herein, the term constellation mode may be used interchangeably with the term non-linearity -mitigation mode.

[0155] A UE may be indicated to use one of the configured constellation modes or one or more parameters of a constellation mode. The indicated mode or one or more parameters may belong to a set of configured constellation modes or sets of parameters for one or more constellation modes. The indication may be semi-static and may be applicable to a set of transmissions. For example, a UE may receive an indication for a constellation mode or parameters thereof and apply such a mode or parameters thereof for subsequent transmissions until receiving further indication from the receiving node (e.g., gNB or other UE).

[0156] A UE may determine a constellation mode, or a set of parameters associated with a constellation mode, to use for one or more transmissions based on at least one of an indication from a receiving node, an indication in a scheduling message, a determined performance of a power amplifier, measurements, performance of a transmission, a parameter of a transmission, an allocation of the transmission, each of which will be further described.

[0157] Indication from receiving node (e.g., gNB or UE). For example, the UE may be configured via RRC with a constellation mode, or a set of parameters associated with a constellation mode.

[0158] Indication in scheduling message. For example, the UE may determine the constellation mode or parameters associated with a constellation mode, for a transmission from the DCI scheduling the transmission. The indication may be determined from the contents of the DCI (e.g., explicit indication). The DCI may have a field specifically used for the indication of the constellation mode or parameters associated with a constellation mode. The UE may determine the constellation mode or parameters associated with a constellation mode from one or more parameters associated with another field of the DCI. For example, the UE may determine the constellation mode or parameters associated with a constellation mode based on the parameters of an allocation (e.g.. the RBs. or the timing of the transmission, or the BWP. or the transmission power, etc.). The indication may also be determined from a parameter of the DCI (e g., implicit indication). The parameters of the DCI may include at least one of the Radio-Network Temporary Identifier (RNTI) used to decode the DCI, CORESET or search-space of the PDCCH transmission including the DCI, aggregation level of the PDCCH / PSCCH transmission of the DCI, timing ofthe DCI reception, beam or Transmission configuration indication (TCI) state used for the PDCCH / PSCCH transmission of the DCI.

[0159] Determined performance of a power amplifier. The UE may determine to use a constellation mode or parameters associated with a constellation mode based on the expected / measured performance of the power amplifier for a transmission or the measured performance of the power amplifier of an associated transmission. The UE may also determine a constellation mode or parameters associated with a constellation mode based on at least one of PAPR and EVM.

[0160] Measurements. The UE may determine or select a constellation mode or parameters associated with a constellation mode based on at least one of: RSRP, RSRQ, RSSI, SINR, CSI (e.g., RI, PMI, CQI, LI -RSRP, CRI, LI), UE speed, doppler shift, doppler spread, average delay, delay spread, AoA, AoD, channel access procedure (e.g., LBT) measurement, Channel Occupancy, UE position, interference (e.g. CLI measurement).

[0161] Performance of a transmission. The UE may determine or select a constellation mode or parameters associated with a constellation mode based on a performance of a transmission (e.g., measured performance of an associated transmission or estimated performance of a transmission). The performance may be determined from a HARQ-ACK / NACK rate, BLER, etc.

[0162] Parameter of a transmission. The UE may determine or select a constellation mode, or parameters associated with a constellation mode, for a transmission based on one or more parameters of the transmission. The parameters of the transmission may include at least one of whether it is a first transmission or a retransmission, retransmission number, priority of the transmission (e.g., LI priority, LCH priority), channel of the transmission (e.g., PUSCH, PUCCH, PSSCH, PSCCH), whether it includes UCI or not, one or more LCH included in the transmission, whether the transmission includes DRB(s) or SRB(s), identity of the included DRB(s) or SRB(s), the TCI state or beam of the transmission, the transmission waveform (e.g., OFDM. DFT-s- OFDM), Configured Grant or Dynamic Grant.

[0163] Allocation of the transmission. The UE may determine or select a constellation mode, or parameters associated with a constellation mode, for a transmission based on one or more parameters associated with the allocation of the transmission. The parameters may include at least one of: frequency allocation (e.g., RBs), Frequency region (FR) of the allocation, whether it is for UL or SL, whether it is using a normal UL or supplementary UL, the timing of the transmission, the number of symbols of the allocation, whether repetition is used or not, the number of repetitions, the repetition number of a transmission, the repetition ty pe, the number of CodeBlock Groups (CBGs), MCS. transmission power.

[0164] The indication of a constellation mode, or parameters associated with a constellation mode may include at least one of a set of constellations or set of parameters associated with one or more constellation modes, one or more MCS fields, or an MCS field pointing to multiple values (for example, the UE may be configured with an MCS field to use as input to an AI / ML model, and an MCS field to use for the output to an AI / ML model, or the UE may be configured with input-output pairs of MCS values and an MCS field may point to a pair), a constellation mode pointer or set of parameters associated with a constellation mode pointer, a flag (the flag may toggle between using a constellation mode or not, or the flag may toggle between using a first and second constellation mode), and the UE may determine a set of constellation mode parameters as a function of a determined or selected or indicated constellation mode.

[0165] As for the reporting of constellation mode parameters, there are a number of different solutions.

[0166] The UE may be configured to report one or more parameters associated with a cascaded mode of operation. The UE may be preconfigured with max and min range of parameter values to report as part of configuration aspects as already described. The parameters and / or the value of parameters may be a function of UE capability. The UE may determine the constellation mode and / or the parameters thereof based on conditions as already described. The report may be associated with corresponding PUSCH transmission generated based on the determined constellation mode. The report may be applicable to only the PUSCH linked to it or referenced by it. The UE may skip the transmission of report to indicate that single / legacy mode is selected for transmission of PUSCH. The UE may trigger transmission of report when the UL grant indicating PUSCH transmission includes constellation mode selection flag.

[0167] The UE may report the constellation mode associated with PUSCH transmission. The constellation mode may be single or cascaded mode. The single mode may indicate that the UE has applied legacy constellation for PUSCH transmission. The cascaded mode may indicate that the has applied second constellation on top of legacy constellation for PUSCH transmission. The report may include additional aspects / parameters as a function of constellation mode indicated in the report. When the UE indicates cascaded constellation mode, the UE may include one or more properties of second constellation mode, properties of AIML model etc.

[0168] The UE may report one or more properties of second constellation associated with PUSCH transmission. The properties may include, but not limited to max / mean energy, alphabet length, PAPR / EVM / ACLR associated with second constellation etc. The UE may report the postprocessing information associated with second constellation. The post-processing information may include, but is not limited to clipping based on energy constraint, alphabet length if quantization or clipping is applied, measured PAPR associated with generated constellation etc.

[0169] The UE may report the method for generating the second constellation. The second constellation may be generated by a AIML model (e.g., encoder). The UE may choose one model from a plurality of AIML models available for generating second constellation. The UE may report the AIML model selection information. The UE may indicate an identity associated with the AIML model. The identity may be associated with functionality of AIML model. The UE may indicate a pairing information, wherein the pairing information identifies the appropriate decoder associated with the encoder that generates the second constellation. The pairing information may enable the receiver to select appropriate AIML model (e.g., decoder) to process the received PUSCH.

[0170] The UE may be preconfigured with resources to report the constellation mode selection and / or associated parameters thereof. The UE may be configured with reserved symbols on PUSCH for transmission of report. The reserved symbols may be configured on preconfigured time-frequency locations. The time location may correspond to first few OFDM symbols, which allows for early decoding at the receiver. The UE may indicate the constellation mode applied to PUSCH in the reserved symbols associated with the PUSCH. The UE may apply a preconfigured constellation on the symbols reserved for constellation mode selection reporting. The UE may be configured to apply the first constellation for the symbols reserved for reporting. The first constellation may be explicitly signalled on the DCI carrying UL grant associated with PUSCH transmission.

[0171] The UE may be configured to report the constellation mode selection and / or associated parameters in a UCI (Uplink Control Information). The UCI carrying the report may be multiplexed with PUSCH, possibly only when the PUSCH is associated with cascaded constellation mode. The UE may be configured to apply the first constellation for the UCI transmission associated with reporting. The first constellation may be explicitly signalled on the DCI carrying UL grant associated with PUSCH transmission.

[0172] The UE may be configured to report the constellation mode selection and / or associated parameters implicitly via DMRS sequence selection. The UE may be preconfigured with multiple DMRS sequences, possibly each DMRS sequence may be selected / transmitted to indicate constellation mode selection and / or parameters thereof. A first DMRS sequence may be used to indicate single constellation mode and a second DMRS sequence may be used to indicate cascaded constellation mode. A third DMRS sequence may be used to indicate a second constellation. A plurality of DMRS sequences may be used to indicate a parameter (and / or parameter set) associated with second constellation. The UE may transmit afirst PUSCH along with a first DMRS sequence to indicate that legacy constellation is applied to the first PUSCH. The UE may transmit a second PUSCH along with a third DMRS sequence to indicate that a second constellation is applied to the second PUSCH. Similar solutions may be envisioned to indicate parametersassociated with second constellation via transmission of appropriate DMRS sequence. The UE may be configured to transmit t pe-.x DMRS and t pe-y DMRS wherein type-x DMRS may be associated with report transmission and type-y DMRS may be associated with PUSCH transmission. The UE may apply a first constellation for type-x DMRS and the second constellation for type-y DMRS. The type-y DMRS may be associated with the same constellation as the PUSCH transmission. The type-y DMRS may be generated by the output of AIML model when type-x DMRS is applied as input to the AIML model, wherein the same AIML model may be used for generation of second constellation associated with PUSCH transmission.

[0173] The resources for report transmission may be preconfigured for a UE, wherein the resources may generally refer to reserved symbols in PUSCH and / or UCI resources and / or DMRS configuration. The resources may be predefined in the specification, e.g., as a PUSCH format, UCI format, DMRS format etc. The resources may be specified as default configuration. The resources may be configured via RRC configuration (e.g., PUSCH configuration and / or UCI configuration and / or DMRS configuration). These resources may be activated / deactivated by MAC CE.

[0174] FIG. 3 illustrates a flow chart of a method according to the first main embodiment of the present principles. The method is performed by a UE.

[0175] In step S310, the UE is configured with one or more parameters associated with one or more PAPR constellation mode(s).

[0176] The configuration may include one or more of constellation modes, constellation mode selection flag, AE configuration, conditions / parameters for cascaded mode selection / operation, and reporting configuration.

[0177] Constellation modes (and parameters thereof) include single mode and cascaded mode.

[0178] Single mode corresponds to legacy operation and transmitting using the first constellation, wherein the first constellation may be associated with a standardized modulation scheme (e.g., QPSK).

[0179] Cascaded mode corresponds to applying a first constellation followed by a second constellation, wherein the second constellation may be associated with an arbitrary symbol set (e.g., leamt by autoencoder) and may satisfy one or more requirements (e.g., PAPR constraint, max / mean energy, alphabet length).

[0180] Constellation mode selection flag has already been described.

[0181] AE configuration can include input to the AE (e.g., PAPR value), output of the AE (e.g., alphabet length), post-processing (e.g., energy constraint) and AE selection information (e.g., as a function of first constellation, PAPR threshold, alphabet, energy constraint, etc.)

[0182] Conditions / parameters for cascaded mode selection / operation can include PAPR threshold (apply cascaded mode operation in case PAPR is above a threshold), one or more (e.g.,non-linear) thresholds associated with transmission (e.g., EVM threshold, ACLR thresholds), apply cascaded mode in case the EVM associated with the single mode exceeds a certain EVM threshold, similar methods for ACLR etc., and waveform (DFT-s-OFDM vs OFDM).

[0183] Reporting configuration (e.g., preconfigured symbols in PUSCH ( / i.e., PUSCH format) for reporting UE-determined constellation mode and / or parameters thereof.

[0184] In step S320, the UE receives signaling (e.g., UL grant indicating a PUSCH transmission). The signaling may indicate constellation mode selection and / or configuration thereof.

[0185] The indication of constellation mode selection and / or AE configuration may be implicit. The indication may include two MCS fields, a first MCS field indicates first constellation and a second MCS field indicates constellation mode selection and / or AE configuration. The indication may include a preconfigured CRNTI specific to cascaded mode (the UE may be preconfigured to monitor the CRNTI specific to cascaded model based on NW command and upon receiving UL grant addressed to the preconfigured CRNTI, the UE performs constellation mode selection).

[0186] The indication may be explicit, e.g., in a new DCI format including fields specific to carrying constellation mode selection and / or configuration thereof.

[0187] Alternate indication methods may be based on MAC CE. For example, the UE may be configured to activate ( / deactivate) the cascaded mode operation based on MAC CE.

[0188] In step S330, the UE determines the constellation mode and / or configuration thereof. The determination can be based on one or more of received signaling, the measured PAPR using the first constellation (e.g., select the single mode if the measured PAPR of the first constellation meets the configured PAPR threshold, otherwise, select the cascaded constellation mode), the measured EVM / ACLR using the first constellation (e.g., select the single mode if the measured EVM / ACLR of the first constellation is below the configured threshold, otherwise, select the cascaded constellation mode) and waveform (e.g., select single mode for a first wave form (e.g., DFT-s- OFDM) and select one of the two constellation modes for a second waveform (e.g., OFDM)).

[0189] In step S340, the UE applies the determined constellation mode, and configuration thereof, on an UL transmission.

[0190] The application may include post-processing information (e.g., clipping based on energy' constraint), alphabet length if quantization or clipping is applied, measured PAPR associated with the generated / determined constellation mode, and the selected AE associated with the cascaded constellation mode.

[0191] In step S350, the UE reports the selected constellation mode (and optionally, its associated parameters, e.g., features associated with the cascaded constellation mode (e.g., max / mean energy, alphabet length, generation method), indication of selected AE and / or pairing information etc.)

[0192] The reporting may be PUSCH-based (e.g., preconfigured time-frequency locations (e.g., first / second OFDM symbols for early decoding) for reporting the selected mode and its associated parameters), wherein the UE may apply a preconfigured constellation on these time-frequency locations. Alternately, the UE may implicitly indicate selected constellation mode via DMRS sequence selection.

[0193] The reporting may also be UCI-based, wherein one or more fields are reserved for the constellation mode and its associated parameters.

[0194] In step S360, the UE transmits the information of the UL transmission (e.g., PUSCH) using the determined constellation mode and its associated parameters.

[0195] The second main embodiment of the present principles provides UE procedures to detect and mitigate non-linearity.

[0196] While the second main embodiment for reasons of clarity is described for downlink transmissions, it will be understood that the embodiment also can apply to uplink and sidelink transmissions.

[0197] A UE capable of PA non-linearity handling may be configured to detect, mitigate and or compensate non-linearity and report its detection / mitigation / compensation capability through RRC, MAC CE and DCI. The configuration for NL detection and / or mitigation may include one or more of constellation mode, non-linearity level(s), NL monitoring indication and AI / ML model configuration.

[0198] The UE may be configured within a constellation mode. The constellation mode may be configured using a bit indicating either single or cascaded mode. If configured as single mode, the UE can assume that only legacy constellation is used, i.e., the constellation generated is composed of symbols from a standardized modulation scheme (e.g., BPSK, QPSK, 16 QAM, 64 QAM). If configured as cascaded mode, the UE can assume that final transmitted constellation is generated through two cascaded steps, first the legacy / first constellation is formed and then passed through an AI / ML model that may process the first constellation to generate a second constellation that may be associated with a symbol set (e.g., arbitrary) that may satisfy one or more preconfigured condition(s) / requirement(s).

[0199] The UE may be configured with one or more (e.g., N) non-linearity levels, wherein each level may have its associated / defined PAPR and EVM threshold(s). For example, level one may be associated with the minimum EVM while the highest level (e.g., N) may be associated with the maximum EVM, wherein the number of levels, / V. may be configured or indicated to the UE, and each N has its associated, possibly predefined, parameters (e.g., EVM and / or PAPR and / or ACLR).

[0200] Table 1 shows an example of N=4 levels, wherein each level is defined by two features: the corresponding EVM threshold and a PAPR value associated with each level. The gNB may configure the UE with different EVM or PAPR threshold(s) for a given N. The UE may be configured with a plurality of N non-linearity levels, wherein a first N non-linearity levels may be indicated to the UE with only EVM threshold(s) while a second N non-linearity level(s) may be indicated to the UE with PAPR thresholds. The N non-linearity levels may also be indicated to the UE with both EVM and PAPR thresholds as indicated in Table 1.Table 1 Example of N=4 non-linearity levels for detection and mitigation purposes

[0201] NL monitoring indication: the UE may be configured or indicated with a parameter (e.g., one bit) indicating whether the UE can perform and / or report non-linearity compensation capability.

[0202] AI / ML model (e.g., AE model) configuration: if the UE is configured with the cascaded constellation mode, it may also be configured with additional model information. For example, model information may include the encoder model ID for proper AE operation, post-processing information (e.g., max / mean energy, alphabet length) and input / output information (e.g., input PAPR).

[0203] The configuration parameters may be indicated either explicitly or implicitly through DCI, RRC or MAC CE. For explicit indication, the configuration parameters may be transmitted in new DCI formats including fields specific to earn ing constellation mode configuration, NL monitoring indication, and non-linearity levels and configuration thereof. For implicit indication, the UE may be configured with one or more MCS fields that implicitly convey information about the constellation mode and parameters thereof. In another option, UE may be configured with preconfigured CRNTI specific to the cascaded mode operation.

[0204] Non-linearity reference signals (NL-RS) is a set of reference symbols used for the purpose of non-linearity detection / mitigation / compensation, wherein the NL-RS may have specificcharacteristics catered for NL detection / mitigation / compensation. For instance, unlike existing reference signals, NL-RS may be transmitted with any modulation scheme (e.g., higher order modulation) which may be needed to serve the purpose of NL detection / mitigation at the receiver side. NL-RS can be configured for both uplink and downlink transmissions. NL_RS could be configured at RB granularity or sub-band granularity instead of RE granularity. NL-RS can be transmitted periodically or configured or triggered for aperiodic NL-RS transmission.

[0205] The NL-RS configuration may be performed in different ways.

[0206] In a solution, the NL-RS may be configured in either a standalone (data-free) mode or multiplexed mode. Wherein in the standalone (data-free) mode, NL-RS may be transmitted alone, without any data, in uplink or downlink, and may be spanning one or more RBs. Such a configuration may assist the UE to determine its capability for NL mitigation regardless of data transmission. In another option, NL-RS may be configured in a multiplexed mode, e.g., similar to DM-RS, wherein the transmission occurs simultaneously with the data, uplink or downlink. If NL- RS is configured in a multiplexed mode, it may be transmitted with the same constellation as the data. The NL-RS may be transmitted in specific time / frequency resources that assist the UE with early determination of its NL capability prior data decoding / processing. For example, a first NL- RS type may be transmitted early in time, e.g., symbol 1 or 2, while a second NL-RS type may be transmitted in any symbol.

[0207] In another solution, the UE may be configured with a plurality of NL-RS predefined sequences, wherein each sequence may have different characteristics. Each sequence may have a unique logical identity. Each sequence may have different modulation order. Each sequence may be associated with one or more metric(s) or configured threshold(s), e.g., PAPR, EVM, ACLR. Each sequence may have a different RS density. Some of the sequences may be associated with a first waveform (e.g., OFDM) while other sequences may be associated with a second waveform (e g., DFT-s-OFDM).

[0208] NL-RS sequences may be generated in a way that serves the purpose of NL detection and / or mitigation / compensation. For example, NL-RS sequences may need to satisfy one or more requirements that impact the power amplifier operation. For example, different NL-RS sequence may result in different PAPR, thereby enabling accurate detection and or mitigation of UE nonlinearity capability. In a solution, a predefined pseudo-random sequence can be configured for the UE and the sequence may be a function of the non-linearity level, transmitter or cell ID, subcarrier spacing, CRNTI. In a solution, the NL-RS sequence may be a function of the DM-RS associated with the PDSCH.

[0209] In a solution, the NL-RS sequences may be generated using an Al model that transforms a given generated DM-RS sequence to an NL-RS sequence satisfying some requirements (e.g.,PAPR). The AI / ML mode may be trained offline to generate every possible DM-RS sequence to an NL-RS sequence with a predefined PAPR. This way, NL-RS may be generated by re-using the procedures described for DM-RS sequences generation with an additional post-processing step that utilizes an AI / ML model to transform the DM-RS sequence to NL-RS sequence.

[0210] A UE may be configured with one or more NL-RS on which to perform measurements, e.g., to determine the UE's ability to mitigate non-linearities in one or more received transmissions. The measurements may be classified into measurement types defined by at least one of the amount of non -linearity the UE may mitigate for decoding of transmissions using similar transmission parameters as that of at least one NL-RS (for example, a UE may report if it can mitigate more or less non-linearity than that present in one or more NL-RS, or the UE may report how much more or less non-linearity the UE can mitigate than that present in one or more NL-RS), the type (or cause) of non-linearity the UE may mitigate for decoding transmissions using similar transmission parameters as that of at least one NL-RS (for example, the UE may indicate if it can mitigate PAPR, or EVM type non-linearities, and the UE may also indicate the amount of each type on non-linearity it may mitigate) and whether or not it can achieve required decoding performance of a transmission using similar transmission parameters as that of at least one NL-RS (for example, the UE may report a binary indication whether or not the UE can achieve the required decoding performance of a transmission using similar transmission parameters as that of at least one NL- RS).

[0211] Mitigating non-linearities may be defined as a UE being able to achieve a specific or configurable decoding or reception performance. For example, mitigating non-linearities may be defined as achieving a specific BLER operating point or HARQ-ACK rate for a transmission.

[0212] A UE may report one or more measurements for each of the one or more NL-RS it receives. For example, a UE may report a bitmap associated with multiple NL-RS resources, where each bit of the bitmap indicates whether or not the UE may achieve required decoding performance for a transmission using similar transmission parameters as that of an NL-RS.

[0213] A UE may report one or more measurements of one or more measurement types and one or more associated NL-RS ID.

[0214] A UE may report the NL-RS IDs of NL-RS transmissions for which it can or cannot mitigate the non-linearities.

[0215] A UE may be configured with an NL-RS and a set of non-linearity parameters applied to the NL-RS (e.g., PAPR, EVM, etc.). Based on at least one measurement performed on the NL-RS and at least one non-linearity parameter applied to the NL-RS, the UE may determine at least one maximum or minimum or average non-linearity parameter that it may mitigate. The UE may reportthe value of the at least one maximum or minimum or average non-linearity' parameter that it may mitigate.

[0216] A UE may report an AIML model used to determine the non-linearity capability measurements.

[0217] A UE may report the amount of extra non-linearity' it may be able to mitigate (e.g., nonlinearity' headroom).

[0218] A UE may perform and report measurements on a first NL-RS. Based on the measurement reported, or on a configuration, the UE may receive a second NL-RS. A UE may also request for the transmission of a second NL-RS, based on a measurement value determined from the first NL- RS. The request may indicate whether the second NL-RS may have more or less non-linearities. Such a sequential reception of NL-RS may continue until a UE determines the maximum or minimum or average non-linearities it may mitigate. When the UE determines the maximum or minimum or average non-linearities that it may mitigate, the UE may indicate to the transmitter that it doesn’t require a subsequent NL-RS transmission, or the index or identity7or parameter of the NL-RS for which it reached the maximum or minimum or average non-linearities that it may mitigate.

[0219] A UE may be triggered to request NL-RS based or additional NL-RS based on a measurement performed on another RS or on another transmission (e.g., based on RSRP, RSRQ, RSSI, RI, PMI, CQI, SINR, UE speed, UE position, doppler spread, doppler shift, delay spread, average delay, AoA, AoD, CO).

[0220] A UE may be configured to receive an NL-RS transmission with a data transmission. The NL-RS transmission may be indicated in the same control information scheduling the data transmission to the UE.

[0221] The UE may report the HARQ-ACK of the received data transmission and may provide details on the mitigation measurements or capabilities obtained from at least one of the received NL-RS transmission or the received data transmission. The UE may include the mitigation measurement or capabilities based on the HARQ-ACK value (for example, the UE may include the mitigation measurement or capability only if the HARQ is ACK or only if the HARQ is NACK).

[0222] The UE may be configured with resources to report the mitigation measurements or capabilities. Such resources may be UCI resources (e g., in PUCCH or PSCCH) or UCI resources in a data transmission (e.g., UCI on PUSCH, or UCI on PSSCH).

[0223] The UE may be configured to mitigate / compensate non-linearity7, for example based on one or more of received NL-RS and detected NL level.

[0224] There are different possibilities for mitigating the non-linearity based on the received NL- RS. In case the EVM associated with the received NL-RS falls above the highest configured EVM threshold, the UE may recommend a decrease in the transmit PAPR, or switch its equalization method, e.g., using a non-linear equalizer. In case the EVM associated with the transmitted / first NL-RS is high (e.g., greater than some preconfigured threshold), the UE may request additional / second NL-RS transmission to accurately determine the tolerable PAPR level and for improved reporting of its non-linearity mitigation capability. In case the EVM associated with the transmitted / first NL-RS is high (e.g., greater than some preconfigured threshold), the UE may indicate a constellation mode switch, for example, cascaded instead of single. In case the EVM associated with the transmitted / first NL-RS is high (e.g., greater than some preconfigured threshold), the UE may indicate a model update, e.g., switch AI / ML model at the gNB, or request a model update (e.g.. fine-tuning)

[0225] There are different possibilities also for mitigating the non-linearity based on the detected NL level. In case the detected non-linearity level is higher than some preconfigured level threshold, the UE may recommend a change (e.g., decrease or fix) in PAPR. In case the detected non-linearity level is higher than some preconfigured level threshold, the UE may recommend a constellation mode switch. In case the detected non-linearity level is higher than some preconfigured threshold, the UE may indicate to NW AI / ML model update (e.g., model switch or fine-tuning).

[0226] The UE may alternatively mitigate the non-linearity through requesting one or more NL- RS transmissions, each with different conditions / metrics. For example, the different transmission may be associated with different PAPRs and EVM thresholds, and the UE may report its mitigation capability7based on the detection quality associated with each received NL-RS sequence.

[0227] A UE may be configured to detect and / or monitor its capability for NL mitigation based one or more triggers including time and measurements.

[0228] For time triggers, the UE may be configured with time instances or specific slots to determine / update its non-linearity mitigation capability, or be configured to report its non-linearity mitigation capability every N slots, where N is configured.

[0229] The UE may perform measurements to detect / mitigate non-linearity. The measurements may be based on a constellation mode switch (e.g.. if a constellation mode is switched / changes relative to the previous transmission), on a detected change in any of the constellation mode parameters (e.g., AE configuration, model ID, model input, PAPR level, etc.), on a detected change in the configured number of levels associated w ith non-linearity detection, on a detected change in channel conditions (e.g., delay spread, Doppler, SINR, SNR), on AI / ML model training / retraining / fine-tune being triggered, on NL-RS being transmi tted / configured, or when there is a change in the NL-RS transmission mode (for example, if the DCI indicates PDSCH witha DM-RS and NL-RS or PDSCH with NL-RS only, standalone NL-RS without PDSCH), and on measurements (e.g., EVM) achieving certain thresholds or criterion (criteria).

[0230] The UE may be configured to report one or more aspects associated with detection and / or mitigation of non-linear effects in received transmission in different ways.

[0231] The UE may be preconfigured with a range (e.g., min, max) of parameter values to report as part of configuration aspects already described. The parameters and / or the value range of parameters may be a function of UE capability. The UE may report a first capability for NL detection and a second capability NL mitigation. The UE may receive a first configuration for NL detection and a second configuration for NL mitigation.

[0232] The UE may determine one or more the following aspects based on reception of NL-RS: detection of non-linearity and / or parameters thereof, mitigation of non-linearity and / or UE capability thereof based on procedures already described. The UE may be configured to report whether it is able to detect the NL in a received transmission. The UE may be configured to report whether it is able to mitigate / compensate the NL (non-linearity) in the received transmissions; in other words, the UE may be configured to report whether it is able to achieve a specific metric on the received transmission. The metric may be expressed as BER threshold. The UE may report that it is able to mitigate the NL level when the BER on the received transmission is below a preconfigured threshold. The metric may be expressed as achieving a successful decoding / CRC check / HARQ status on the on the received transport block. The UE may report that it is able to mitigate the NL in the received transmission when the transport block can be successfully decoded / CRC passes or HARQ ACK is generated.

[0233] In case more than one level of non-linearity is be defined, possibly based on the magnitude of non-linearity, the UE may determine one or more the following aspects based on reception of NL-RS: detection of NL levels and / or parameters thereof, mitigation of NL levels and / or UE capability thereof based on procedures already described. The UE may be configured to report the detected NL level and / or the NL level that can be mitigated and / or compensated by the UE. Each NL level may be associated with a preconfigured measurement / statistic. The measurement may for example include one or more of BER, BLER, EVM, PAPR, and ACER. The UE may be configured to report one level among multiple preconfigured NL levels. The reported level for mitigation may be a function of the extent of non-linearity in the transmission and the performance metric preconfigured for the UE. For the given non-linearity level, the UE may measure the detection performance in terms of BER and / or based on CRC check (e.g., achieving successful decoding / CRC check on the received PDSCH). The reported level may be the highest NL level that the UE can mitigate. The reported level may be the highest NL level that the UE can mitigate with x% confidence, wherein the value of x may be preconfigured. The reported NL level may behighest level that the UE can mitigate assuming a hypothetical PDSCH transmission, wherein the parameters of hypothetical PDSCH transmission may be preconfigured. The parameters include the size, first constellation, transmit power, number of allocated RBs, number of OFDM symbols, coding rate, etc.

[0234] The UE may be configured with PUCCH resources to report the NL detection and / or mitigation status and / or levels. The UE may be configured with a first PUCCH resource and a second PUCCH resource. The UE may transmit an indication in the first PUCCH resource to indicate that the non-linearity can be mitigated. The UE may transmit an indication in the second PUCCH resource to indicate that the non-linearity cannot be mitigated. The UE may be configured to indicate the mitigation status via a HARQ ACK / NACK. The UE may transmit a HARQ ACK to indicate that the non-linearity' can be mitigated. The UE may transmit a HARQ NACK to indicate that the non-linearity cannot be mitigated.

[0235] The UE may be configured with multiple PUCCH resources to report NL detection and / or mitigation levels, wherein each PUCCH resource may be associated with specific NL detection and NL mitigation level. The UE may be configured to select a PUCCH resource as a function of the determined NL detection and / or motivation level. The UE may be configured to transmit an indication on the selected PUCCH resource. The indication may be a HARQ ACK. For example, the indication may be a Scheduling Request (SR).

[0236] The UE may be configured to transmit the report in a UCI. The UE may be configured with PUCCH resources for UCI transmission. The UCI format may be defined to carry multiple information elements, wherein each information element may indicate the NL detection and / or mitigation information. The information element may include an indication of NL detection and / or mitigation level. The information element may include an indication of non-linearity metric including but not limited to BER, BLER, EVM, PAPR, ACLR etc.

[0237] The UE may be configured to transmit assistance information related to non-linearity adaption at the transmitter. The UE may transmit assistance information associated with PAPR threshold at the transmitter. Based on reception status of transport block, the UE may determine that it can mitigate additional non-linearity effects. The UE may transmit an indication to relax the PAPR threshold at the transmitter, in case the transport block can be successfully decoded and additional non-linearity can be mitigated. The UE may transmit an indication to increase the PAPR threshold at the transmitter, in case the transport block cannot be successfully decoded. The UE may transmit an indication to fix the PAPR threshold at the transmitter, in case the transport block can be successfully decoded and additional non-linearity cannot be mitigated. Here PAPR is used as an example of non-linearity, but the solutions are applicable to other non-linear effects likeEVM and ACLR. The solutions can also apply to any logical abstraction of non-linearity effects. For example, the UE may indicate to increase, decrease, or fix the NL levels.

[0238] The UE may request for transmission of NL-RS on-demand based on preconfigured conditions. The UE may request for additional NL-RS transmission if the previous NL-RS transmissions are not sufficient for NL detection and / or mitigation. The UE may specifically request for increased density of NL-RS transmission in time and / or frequency domain. The UE may request for NL-RS transmission associated with specific NL level. The UE may be configured with multiple PUCCH resources to request for NL-RS transmission, wherein each PUCCH resource may be associated with NL detection and / or mitigation level and / or NL-RS density. The UE may be configured to select a PUCCH resource as a function of the requested NL-RS characteristic. The UE may be configured to transmit an indication (e.g., scheduling request) on the selected PUCCH resource to request for transmission of associated NL-RS. The UE may be configured to transmit request for NL-RS if the NL mitigation level changes from the previous reported NL mitigation level. The UE may be configured to transmit request for NL-RS upon a change in serving cell. The UE may be configured to transmit request for NL-RS upon a preconfigured time elapsed from the previous transmission of NL-RS.

[0239] FIG. 4 illustrates a flow chart of a method according to the second main embodiment of the present principles.

[0240] In step S410, the UE is configured with one or more parameters associated with the transmitted constellation. The configuration may include one or more of constellation modes, configuration information for non-linearity mitigation / compensation. and non-linearity reference sequences (NL-RS) configuration information.

[0241] The constellation mode (& parameters thereof) can be single mode and cascaded mode. Single mode corresponds to legacy operation and transmitting using the first constellation, wherein the first constellation may be associated with a standardized modulation scheme (e.g., QPSK). Cascaded mode corresponds to applying a first constellation followed by a second constellation, wherein the second constellation may be associated with an arbitrary symbol set (e.g., leamt by autoencoder) and may satisfy one or more requirements (e.g., PAPR constraint, max / mean energy, and alphabet length).

[0242] The configuration information for non-linearitv mitigation / compensation can include levels (e.g., N) of non-linearity compensation / mitigation, wherein each level may have an associated PAPR, EVM thresh old(s), e.g., level 1 lowest EVM and level N highest EVM.

[0243] The non-linearity reference sequences (NL-RS) configuration information is intended for NL detection / mitigation / compensation / tracking at the device. This can enable more efficient operation of the PA that can result in enhanced system performance.

[0244] The NL-RS configuration information may be transmitted in a standalone mode without data to determine UE capability of PA compensation and the tolerable PAPR. The NL-RS could be configured at RB granularity (instead of at RE level).

[0245] The NL-RS may have one of more characteristics catered for non-linearity handling (e.g., can be transmitted with high order modulation to enforce high PAPR which is needed to assess UE capability for non-linearity handling). Possibly the UE may be preconfigured with plurality of NL-RS sequences, wherein each sequence may have different characteristics (e.g., each sequence may have different PAPR etc.).

[0246] NL-RS configuration information may be transmitted in a multiplexed mode, i.e., associated with data channel (e.g., PUSCH / PDSCH), and can be transmitted with the same constellation as the data.

[0247] The NL-RS may be configured periodically, or semi-persistently, i.e., based on triggers.

[0248] The NL-RS configuration information can be present in both downlink and uplink.

[0249] In step S420, the UE receives a first transmission, wherein the first transmission includes a first NL-RS sequence (e.g., either in standalone mode or multiplexed mode). The first transmission may be associated with one or more EVM threshold(s) and / or first PAPR. The first transmission may also be associated with a first constellation mode (e.g., single mode).

[0250] In step S430, the UE determines the non-linearity mitigation / compensation level based on measurements performed on the NL-RS of the first transmission.

[0251] The UE may select one of the configured N nonlinearity levels: each associated with NL- RS EVM threshold. The NL mitigation / compensation can be a binary level indicating whether a UE is capable of NL mitigation / compensation for a configured EVM threshold.

[0252] The determination can be based on the measured EVM associated with the received NL- RS compared against the EVM threshold(s), each threshold mapping to one NL compensation level.

[0253] The determination can be based on measured BLER of the first transmission (or of one or more previous transmissions, e.g., nr of consecutive NACKs).

[0254] In step s440, the UE reports the NL compensation / mitigation level to the NW. The report can include a binary field indicating whether a UE is capable of compensating non-linearity’ associated with first transmission, or multi-level reporting based on how much the UE can compensate / mitigate. The report can also include PAPR-based assistance information (e.g., relax / increase / fix PAPR), or a request for additional NL-RS transmission for NL handling improvement.

[0255] In step S450, the UE can receive a second transmission based on reported NL compensation / mitigation level. The second transmission may include a second NL-RS sequencealong with its associated EVM and / or PAPR, or may omit the NL-RS transmission. The second transmission may be associated with a second constellation mode (e.g., cascaded). The second transmission may be associated with a second PAPR.

[0256] In an embodiment, the present principles are directed to a method at a Wireless Transfer / Receive Unit, WTRU, comprising receiving a transmission from the network, determining, based on the received transmission, a constellation mode, the constellation mode being single mode in which a first constellation is used for an uplink signal, or cascaded mode in which the first constellation and a second constellation, obtained from a first constellation, are used for an uplink signal, reporting, to the network, the determined constellation mode, and transmitting, to the network, the uplink signal generated using the determined constellation mode.

[0257] In the cascaded mode, the method can further comprise using an encoder to generate the uplink signal in the second constellation from an input signal in the first constellation. The encoder can be implemented as a deep learning algorithm. The encoder can be an autoencoder.

[0258] The uplink signal in the second constellation can satisfy at least one given transmission property. The transmission property can be a peak-to-average-power ratio.

[0259] The constellation mode can be determined based on constellation mode information in the transmission.

[0260] The constellations can be symbol constellations.

[0261] In an embodiment, the present principles are directed to a Wireless Transfer / Receive Unit, WTRU, comprising at least one processor configured to: receive a transmission from the network, determine, based on the received transmission, a constellation mode, the constellation mode being single mode in which a first constellation is used for an uplink signal, or cascaded mode in which the first constellation and a second constellation, obtained from a first constellation, are used for an uplink signal, report, to the network, the determined constellation mode, and transmit, to the network, the uplink signal generated using the determined constellation mode.

[0262] In an embodiment, the present principles are directed to a method at a Wireless Transfer / Receive Unit, WTRU, comprising determining, based on at least one measurement of a generated signal, a constellation mode, the constellation mode being single mode in which the first constellation is used for an uplink signal, or cascaded mode in which the first constellation and a second constellation, obtained from a first constellation, are used for an uplink signal, reporting, to the network, the determined constellation mode, and transmitting, to the network, the uplink signal generated using the determined constellation mode.

[0263] In the cascaded mode, the method can further comprise using an encoder to generate the uplink signal in the second constellation from an input signal in the first constellation. The encoder can be implemented as a deep learning algorithm. The encoder can be an autoencoder.

[0264] The uplink signal in the second constellation can satisfy at least one given transmission property. The transmission property can be a peak-to-average-power ratio.

[0265] The at least one measurement can be of a peak-to-average-power ratio of the transmitted signal and the cascaded mode can be selected in case the peak-to-average-power ratio is above a given value.

[0266] The at least one measurement can be of at least one of an Error Vector Magnitude and an adjacent channel leakage ratio, and the cascaded mode can be selected in case at least one of the Error Vector Magnitude and an adjacent channel leakage ratio is above a given value.

[0267] The constellations can be symbol constellations.

[0268] In an embodiment, the present principles are directed to a Wireless Transfer / Receive Unit, WTRU, comprising at least one processor configured to determine, based on at least one measurement of a generated signal, a constellation mode, the constellation mode being single mode in which the first constellation is used for an uplink signal, or cascaded mode in which the first constellation and a second constellation, obtained from a first constellation, are used for an uplink signal, report, to the network, the determined constellation mode, and transmit, to the network, the uplink signal generated using the determined constellation mode.

[0269] In an embodiment, the present principles are directed to a method at a Wireless Transfer / Receive Unit, WTRU, comprising determining, based on a configured waveform to use for uplink transmissions, a constellation mode, the constellation mode being, for a first waveform, single mode in which the first constellation is used for an uplink signal, or. for a second waveform, cascaded mode in which the first constellation and a second constellation, obtained from a first constellation, are used for an uplink signal, reporting, to the network, the determined constellation mode, and transmitting, to the network, the uplink signal generated using the determined constellation mode.

[0270] In the cascaded mode, the method can further comprise using an encoder to generate the uplink signal in the second constellation from an input signal in the first constellation. The encoder can be implemented as a deep learning algorithm. The encoder can be an autoencoder.

[0271] The uplink signal in the third constellation can satisfy at least one given transmission property. The transmission property can be a peak-to-average-power ratio.

[0272] The constellations can be symbol constellations.

[0273] In an embodiment, the present principles are directed to a Wireless Transfer / Receive Unit, WTRU, comprising at least one processor configured to determine, based on a configured waveform to use for uplink transmissions, a constellation mode, the constellation mode being, for a first waveform, single mode in which the first constellation is used for an uplink signal, or, for a second waveform, cascaded mode in which the first constellation and a second constellation,obtained from a first constellation, are used for an uplink signal, report, to the network, the determined constellation mode, and transmit, to the network, the uplink signal generated using the determined constellation mode.

[0274] In an embodiment, the present principles are directed to a method at a Wireless Transfer / Receive Unit, WTRU, comprising receiving, from a network, a first transmission including a first non-linear reference sequence, determining, based on measurements of the first non-linear reference sequence, a compensation level, and reporting, to the network, the determined compensation level.

[0275] The first non-linear reference sequence can be transmitted independent of further data.

[0276] The first non-linear reference sequence can be transmitted with data using a constellation that is the same for the first non-linear reference sequence and the data.

[0277] The report can include information indicative of a capability of the WTRU to compensate for non-linearities based on the received first non-linear reference sequence. The capability can include information indicative of how much of the non-linearities the WTRU can compensate for based on the received first non-linear reference sequence.

[0278] The measurements can relate to non-linearity and wherein the report, based on the measurements, can include information indicative of that the network can increase or decrease the peak-to-average-power ratio.

[0279] In an embodiment, the present principles are directed to a Wireless Transfer / Receive Unit, WTRU, comprising at least one processor configured to receive, from a network, a first transmission including a first non-linear reference sequence, determine, based on measurements of the first non-linear reference sequence, a compensation level, and report, to the network, the determined compensation level.

[0280] Conclusion

[0281] Although features and elements are provided above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations may be made without departing from its spirit and scope, as will be apparent to those skilled in the art. No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly provided as such. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure isto be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods or systems.

[0282] The foregoing embodiments are discussed, for simplicity, with regard to the terminology and structure of infrared capable devices, i.e., infrared emitters and receivers. However, the embodiments discussed are not limited to these systems but may be applied to other sy stems that use other forms of electromagnetic waves or non-electromagnetic waves such as acoustic waves.

[0283] It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. As used herein, the term "video" or the term "imagery" may mean any of a snapshot, single image and / or multiple images displayed over a time basis. As another example, when referred to herein, the terms "user equipment" and its abbreviation "UE". the term "remote" and / or the terms "head mounted display" or its abbreviation "HMD" may mean or include (i) a wireless transmit and / or receive unit (WTRU); (ii) any of a number of embodiments of a WTRU; (iii) a wireless-capable and / or wired-capable (e.g., tetherable) device configured with, inter aha, some or all structures and functionality of a WTRU; (iii) a wireless-capable and / or wired-capable device configured with less than all structures and functionality of a WTRU; or (iv) the like. Details of an example WTRU, which may be representative of any WTRU recited herein, are provided herein with respect to FIGs. 1 A-1D. As another example, various disclosed embodiments herein supra and infra are described as utilizing a head mounted display. Those skilled in the art will recognize that a device other than the head mounted display may be utilized and some or all of the disclosure and various disclosed embodiments can be modified accordingly without undue experimentation. Examples of such other device may include a drone or other device configured to stream information for providing the adapted reality experience.

[0284] In addition, the methods provided 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 (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer- readable storage media include, but are not limited to. a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

[0285] Variations of the method, apparatus and system provided above are possible without departing from the scope of the invention. In view of the wide variety of embodiments that can be applied, it should be understood that the illustrated embodiments are examples only, and should not be taken as limiting the scope of the following claims. For instance, the embodiments provided herein include handheld devices, which may include or be utilized with any appropriate voltage source, such as a battery' and the like, providing any appropriate voltage.

[0286] Moreover, in the embodiments provided above, processing platforms, computing systems, controllers, and other devices that include processors are noted. These devices may include at least one Central Processing Unit ("CPU") and memory. In accordance with the practices of persons skilled in the art of computer programming, reference to acts and symbolic representations of operations or instructions may be performed by the various CPUs and memories. Such acts and operations or instructions may be referred to as being "executed," "computer executed" or "CPU executed."

[0287] One of ordinary skill in the art will appreciate that the acts and symbolically represented operations or instructions include the manipulation of electrical signals by the CPU. An electrical system represents data bits that can cause a resulting transformation or reduction of the electrical signals and the maintenance of data bits at memory locations in a memory system to thereby reconfigure or otherwise alter the CPU's operation, as well as other processing of signals. The memory' locations where data bits are maintained are physical locations that have particular electrical, magnetic, optical, or organic properties corresponding to or representative of the data bits. It should be understood that the embodiments are not limited to the above-mentioned platforms or CPUs and that other platforms and CPUs may support the provided methods.

[0288] The data bits may also be maintained on a computer readable medium including magnetic disks, optical disks, and any other volatile (e.g., Random Access Memory (RAM)) or non-volatile (e.g., Read-Only Memory (ROM)) mass storage system readable by the CPU. The computer readable medium may include cooperating or interconnected computer readable medium, which exist exclusively' on the processing system or are distributed among multiple interconnected processing systems that may be local or remote to the processing system. It should be understood that the embodiments are not limited to the above-mentioned memories and that other platforms and memories may support the provided methods.

[0289] In an illustrative embodiment, any of the operations, processes, etc. described herein may be implemented as computer-readable instructions stored on a computer-readable medium. The computer-readable instructions may be executed by a processor of a mobile unit, a network element, and / or any other computing device.

[0290] There is litle distinction left between hardware and software implementations of aspects of systems. The use of hardware or software is generally (but not always, in that in certain contexts the choice between hardware and software may become significant) a design choice representing cost versus efficiency tradeoffs. There may be various vehicles by which processes and / or systems and / or other technologies described herein may be effected (e.g., hardware, software, and / or firmware), and the preferred vehicle may vary with the context in which the processes and / or systems and / or other technologies are deployed. For example, if an implementer determines that speed and accuracy are paramount, the implementer may opt for a mainly hardware and / or firmware vehicle. If flexibility is paramount, the implementer may opt for a mainly software implementation. Alternatively, the implementer may opt for some combination of hardware, software, and / or firmware.

[0291] The foregoing detailed description has set forth various embodiments of the devices and / or processes via the use of block diagrams, flowcharts, and / or examples. Insofar as such block diagrams, flowcharts, and / or examples include one or more functions and / or operations, it will be understood by those within the art that each function and / or operation within such block diagrams, flowcharts, or examples may be implemented, individually and / or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. In an embodiment, several portions of the subject mater described herein may be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), and / or other integrated formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein, in whole or in part, may be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and / or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject mater described herein may be distributed as a program product in a variety of forms, and that an illustrative embodiment of the subject mater described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. Examples of a signal bearing medium include, but are not limited to, the following: a recordable type medium such as a floppy disk, a hard disk drive, a CD, a DVD, a digital tape, a computer memory, etc., and a transmission type medium such as a digital and / or an analog communication medium (e.g., a fiber optic cable, a waveguide, a wired communications link, a wireless communication link, etc.).

[0292] Those skilled in the art will recognize that it is common within the art to describe devices and / or processes in the fashion set forth herein, and thereafter use engineering practices to integrate such described devices and / or processes into data processing systems. That is, at least a portion of the devices and / or processes described herein may be integrated into a data processing system via a reasonable amount of experimentation. Those having skill in the art will recognize that a typical data processing system may generally include one or more of a system unit housing, a video display device, a memory such as volatile and non-volatile memory, processors such as microprocessors and digital signal processors, computational entities such as operating systems, drivers, graphical user interfaces, and applications programs, one or more interaction devices, such as a touch pad or screen, and / or control systems including feedback loops and control motors (e.g., feedback for sensing position and / or velocity, control motors for moving and / or adjusting components and / or quantities). A typical data processing system may be implemented utilizing any suitable commercially available components, such as those typically found in data computing / communication and / or network computing / communi cation systems.

[0293] The herein described subject matter sometimes illustrates different components included within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures may be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality' may be achieved. Hence, any two components herein combined to achieve a particular functionality may be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermedia! components. Likewise, any two components so associated may also be viewed as being "operably connected", or "operably coupled", to each other to achieve the desired functionality, and any two components capable of being so associated may also be viewed as being "operably couplable" to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and / or physically interacting components and / or wirelessly interactable and / or wirelessly interacting components and / or logically interacting and / or logically interactable components.

[0294] With respect to the use of substantially any plural and / or singular terms herein, those having skill in the art can translate from the plural to the singular and / or from the singular to the plural as is appropriate to the context and / or application. The various singular / plural permutations may be expressly set forth herein for sake of clarity.

[0295] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," theterm "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, where only one item is intended, the term "single" or similar language may be used. As an aid to understanding, the following appended claims and / or the descriptions herein may include usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim including such introduced claim recitation to embodiments including only one such recitation, even when the same claim includes the introductory' phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and / or "an" should be interpreted to mean "at least one" or "one or more"). The same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e g., the bare recitation of "two recitations," without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together. B and C together, and / or A, B. and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together. A and C together, B and C together, and / or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and / or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B." Further, the terms "any of followed by a listing of a plurality of items and / or a plurality of categories of items, as used herein, are intended to include "any of," "any combination of," "any multiple of," and / or "any combination of multiples of the items and / or the categories of items, individually or in conjunction with other items and / or other categories of items. Moreover, as used herein, the term "set" is intended to include any number of items, including zero. Additionally, as used herein, the term "number" isintended to include any number, including zero. And the term "multiple", as used herein, is intended to be synonymous with "a plurality".

[0296] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0297] As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As anon-limiting example, each range discussed herein may be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as "up to," "at least," "greater than," "less than," and the like includes the number recited and refers to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1. 2, 3, 4, or 5 cells, and so forth.

[0298] Moreover, the claims should not be read as limited to the provided order or elements unless stated to that effect. In addition, use of the terms "means for" in any claim is intended to invoke 35 U.S.C. § 1 12. ^ 6 or means-plus-function claim format, and any claim without the terms "means for" is not so intended.

Claims

CLAIMSWhat is claimed is:

1. A method at a wireless transmit / receive unit, WTRU, comprising: receiving configuration information from a network; determining, based on the received configuration information, a constellation mode, the constellation mode being a single mode in which a first constellation is used to generate an uplink signal, or a cascaded mode in which the first constellation and then a second constellation, obtained from the first constellation, are used to generate the uplink signal; reporting, to the network, the determined constellation mode; and transmitting, to the network, the uplink signal generated using the determined constellation mode.

2. The method of claim 1, wherein, in the cascaded mode, the method further comprises using an encoder to generate, using the second constellation, the uplink signal, from an input signal output by the first constellation.

3. The method of claim 2, wherein the encoder is implemented as a deep learning algorithm.

4. The method of claim 2 or 3, wherein the encoder is an autoencoder.

5. The method of any of claims 1 to 4, wherein the cascaded mode uplink signal satisfies at least one transmission property.

6. The method of claim 5, wherein the transmission property is a peak-to-average-power ratio, PAPR.

7. The method of any of claims 1 to 6, wherein the constellation mode is determined based on constellation mode information in the configuration information.

8. The method of claim 7, wherein the constellation mode is explicitly indicated in the configuration information.

9. The method of claim 7, wherein the constellation mode is implicitly indicated in the configuration information.

10. The method of claim 1, wherein the constellation mode is determined based on measurements on a transmission received using the first constellation.

11. The method of any of claims 1 to 10, wherein the first and second constellations are symbol constellations.

12. A wireless transfer / receive unit, WTRU. comprising at least one processor configured to: receive configuration information from a network; determine, based on the received configuration information, a constellation mode, the constellation mode being a single mode in which a first constellation is used to generate an uplink signal, or a cascaded mode in which the first constellation and then a second constellation, obtained from the first constellation, are used to generate the uplink signal; report, to the network, the determined constellation mode; and transmit, to the network, the uplink signal generated using the determined constellation mode.

13. The WTRU of claim 12, wherein, in the cascaded mode, the WTRU further comprises an encoder configured to generate, using the second constellation, the uplink signal, from an input signal output by the first constellation.

14. The WTRU of claim 13, wherein the encoder is implemented as a deep learning algorithm.

15. The WTRU of claim 13 or 14, wherein the encoder is an autoencoder.

16. The WTRU of any of claims 12 to 15, wherein the cascaded mode uplink signal satisfies at least one transmission property.

17. The WTRU of claim 16, wherein the transmission property is a peak-to-average-power ratio, PAPR.

18. The WTRU of any of claims 12 to 17, wherein the at least one processor is configured to determine the constellation mode based on constellation mode information in the configuration information.

19. The WTRU of claim 18, wherein the constellation mode is explicitly indicated in the configuration information.

20. The WTRU of claim 18, wherein the constellation mode is implicitly indicated in the configuration information.

21. The WTRU of claim 12, wherein the at least one processor is configured to determine the constellation mode based on measurements on a transmission received using the first constellation.

22. The WTRU of any of claims 12 to 21, wherein the first and second constellations are symbol constellations.

23. A method at a wireless transfer / receive unit, WTRU, comprising: determining, based on at least one measurement of a generated signal, a constellation mode, the constellation mode being a single mode in which a first constellation is used to generate an uplink signal, or a cascaded mode in which the first constellation and then a second constellation, obtained from the first constellation, are used to generate the uplink signal; reporting, to a network, the determined constellation mode; and transmitting, to the network, the uplink signal generated using the determined constellation mode.

24. The method of claim 23, wherein, in the cascaded mode, the method further comprises using an encoder to generate, using the second constellation, the uplink signal, from an input signal output by the first constellation.

25. The method of claim 24, wherein the encoder is implemented as a deep learning algorithm.

26. The method of claim 25, wherein the encoder is an autoencoder.

27. The method of any one of claims 23-26, wherein the cascaded mode uplink signal satisfies at least one transmission property.

28. The method of claim 27, wherein the transmission property is a peak-to-average-power ratio, PARP.

29. The method of any one of claims 23-28, wherein the at least one measurement is of a peak-to- average-power ratio of the transmitted signal and wherein the cascaded mode is selected in case the peak-to-average-power ratio is above a given value.

30. The method of any one of claims 23-28, wherein the at least one measurement is of at least one of an Error Vector Magnitude and an adjacent channel leakage ratio, and wherein the cascaded mode is selected in case at least one of the Error Vector Magnitude and an adjacent channel leakage ratio is above a given value.

31. The method of any one of claims 23-30, wherein the first and second constellations are symbol constellations.

32. A wireless transmit / receive unit, WTRU, comprising at least one processor configured to: determine, based on at least one measurement of a generated signal, a constellation mode, the constellation mode being a single mode in which a first constellation is used to generate an uplink signal, or a cascaded mode in which the first constellation and then a second constellation, obtained from the first constellation, are used to generate the uplink signal; report, to a network, the determined constellation mode; and transmit, to the network, the uplink signal generated using the determined constellation mode.

33. The WTRU of claim 32, wherein, in the cascaded mode, the WTRU further comprises an encoder configured to generate, using the second constellation, the uplink signal, from an input signal output by the first constellation.

34. The WTRU of claim 33, wherein the encoder is implemented as a deep learning algorithm.

35. The WTRU of claim 34, wherein the encoder is an autoencoder.

36. The WTRU of any one of claims 32-35, wherein the cascaded mode uplink signal satisfies at least one transmission property .

37. The WTRU of claim 36, wherein the transmission property is a peak-to-average-power ratio, PARP.

38. The WTRU of any one of claims 32-37, wherein the at least one measurement is of a peak-to- average-power ratio of the transmitted signal and wherein the at least one processor configured to select the cascaded mode in case the peak-to-average-power ratio is above a given value.

39. The WTRU of any one of claims 32-37, wherein the at least one measurement is of at least one of an Error Vector Magnitude and an adjacent channel leakage ratio, and wherein the at least one processor configured to select the cascaded mode in case at least one of the Error Vector Magnitude and an adjacent channel leakage ratio is above a given value.

40. The WTRU of any one of claims 32-39, wherein the first and second constellations are symbol constellations.

41. A method at a wireless transmit / receive unit, WTRU, comprising: determining, based on a configured waveform to use for uplink transmissions, a constellation mode, the constellation mode being, for a first waveform, a single mode in which a first constellation is used to generate an uplink signal, or, for a second waveform, a cascaded mode in which the first constellation and then a second constellation, obtained from a first constellation, are used to generate the uplink signal; reporting, to a network, the determined constellation mode; and transmitting, to the network, the uplink signal generated using the determined constellation mode.

42. The method of claim 41, wherein, in the cascaded mode, the method further comprises using an encoder to generate, using the second constellation, the uplink signal, from an input signal output by the first constellation.

43. The method of claim 42, wherein the encoder is implemented as a deep learning algorithm.

44. The method of claim 42 or 43, wherein the encoder is an autoencoder.

45. The method of any of claims 41-44, wherein the cascaded mode uplink signal satisfies at least one transmission property.

46. The method of claim 45, wherein the transmission property is a peak-to-average-power ratio, PAPR.

47. The method of any of claims 41-46, wherein the first and second constellations are symbol constellations.

48. A wireless transfer / receive unit, WTRU. comprising at least one processor configured to: determine, based on a configured waveform to use for uplink transmissions, a constellation mode, the constellation mode being, for a first waveform, a single mode in which a first constellation is used to generate an uplink signal, or. for a second waveform, a cascaded mode in which the first constellation and then a second constellation, obtained from a first constellation, are used to generate the uplink signal; report, to a network, the determined constellation mode; and transmit, to the network, the uplink signal generated using the determined constellation mode.

49. The WTRU of claim 48, wherein, in the cascaded mode, the WTRU further comprises an encoder configured to generate, using the second constellation, the uplink signal, from an input signal output by the first constellation.

50. The WTRU of claim 49, wherein the encoder is implemented as a deep learning algorithm.

51. The WTRU of claim 49 or 50, wherein the encoder is an autoencoder.

52. The WTRU of any of claims 48-51, wherein the cascaded mode uplink signal satisfies at least one transmission property.

53. The WTRU of claim 52, wherein the transmission property is a peak-to-av erage-power ratio, PAPR.

54. The WTRU of any of claims 48-53, wherein the first and second constellations are symbol constellations.

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