CN117256103A - Signaling of information for a non-linearity model - Google Patents

Abstract

Aspects relate to signaling related to a non-linearity model for power amplifier circuitry of a transmitting device. The power amplifier circuitry may apply Digital Predistortion (DPD) to the signal prior to amplification and transmission of the signal. The receiving device may apply digital post-distortion (DPoD) to the signal received from the transmitting device, wherein the DPoD is based on the non-linearity model. The transmitting device may send the non-linearity parameters for the non-linearity model to the receiving device.

Description

Signaling of information for a non-linearity model

Cross Reference to Related Applications

The present patent application claims priority from pending non-provisional application S/n.17/738,983 filed by the U.S. patent and trademark office at 5/month 6 of 2022, and provisional application S/n.63/186,795 filed by the U.S. patent and trademark office at 5/month 10 of 2021, both of which are assigned to the assignee of the present application and are hereby expressly incorporated by reference as if fully set forth below and for all applicable purposes.

Technical Field

The techniques discussed below relate generally to wireless communications and, more particularly, relate to techniques for signaling information related to a non-linearity model of power amplifier circuitry.

Introduction to the invention

A next generation wireless communication system (e.g., 5 GS) may include a 5G core network and a 5G Radio Access Network (RAN), such as a New Radio (NR) -RAN. The NR-RAN supports communication via one or more cells. For example, a wireless communication device, such as a User Equipment (UE), may access a first cell of another wireless communication device, such as a first base station (e.g., a gNB), and/or access a second cell of a second base station.

A base station may schedule access to a cell to support access for multiple UEs. For example, a base station may allocate different resources (e.g., time domain and frequency domain resources) for different UEs operating within the cell of the base station. The UE may thus transmit data to the base station via one or more of these allocated resources. In addition, the UE may receive data transmitted by the base station via one or more of these allocated resources.

Brief summary of some examples

The following presents a simplified summary of one or more aspects of the disclosure in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated features of the disclosure, and is intended to neither identify key or critical elements of all aspects of the disclosure nor delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in a form as a prelude to the more detailed description that is presented later.

In some examples, a first wireless communication device may include a transceiver, a memory, and a processor coupled to the transceiver and the memory. The processor may be configured to determine a change in a non-linearity model for a power amplifier circuit including a digital predistorter. The processor may be further configured to transmit, via the transceiver, an indication of a change in the non-linearity model to the second wireless communication device.

In some examples, a method for wireless communication at a first wireless communication device is disclosed. The method may include determining a change in a non-linearity model for a power amplifier circuit including a digital predistorter. The method may further include transmitting an indication of a change in the non-linearity model to the second wireless communication device.

In some examples, a first wireless communication device may include means for determining a change in a non-linearity model for a power amplifier circuit including a digital predistorter. The first wireless communication device may further include means for transmitting an indication of a change in the non-linearity model to the second wireless communication device.

In some examples, a non-transitory computer readable medium has stored therein instructions executable by a processing system of a first wireless communication device to determine a change in a non-linearity model for a power amplifier circuit including a digital predistorter. The computer readable medium may also have stored therein instructions executable by a processing system of the first wireless communication device to communicate an indication of a change in the non-linearity model to the second wireless communication device.

In some examples, a first wireless communication device may include a transceiver, a memory, and a processor coupled to the transceiver and the memory. The processor may be configured to receive, via the transceiver, an indication of a change in a non-linearity model of a power amplifier circuit for a second wireless communication device from the second wireless communication device. The processor may be further configured to update the nonlinearity information of the digital post-distorter for the first wireless communication device after receiving the indication. The processor may be further configured to receive a signal from a second wireless communication device via the transceiver. The processor may additionally be configured to compensate for nonlinear distortion in the signal using a digital post-distorter.

In some examples, a method for wireless communication at a first wireless communication device is disclosed. The method may include receiving, from a second wireless communication device, an indication of a change in a non-linearity model of a power amplifier circuit including a digital predistorter for the second wireless communication device. The method may further include updating the nonlinearity information of the digital post-distorter for the first wireless communication device after receiving the indication. The method may further include receiving a signal from a second wireless communication device. The method may additionally include compensating for nonlinear distortion in the signal using digital post-distortion.

In some examples, a first wireless communication device may include means for receiving, from a second wireless communication device, an indication of a change in a non-linearity model of a power amplifier circuit including a digital predistorter for the second wireless communication device. The first wireless communication device may further include means for updating the nonlinearity information of the digital post-distorter for the first wireless communication device after receiving the indication. The first wireless communication device may further comprise means for receiving a signal from the second wireless communication device. The first wireless communication device may additionally include means for compensating for nonlinear distortion in the signal using digital post-distortion.

In some examples, a non-transitory computer readable medium has stored therein instructions executable by a processing system of a first wireless communication device to receive, from a second wireless communication device, an indication of a change in a non-linearity model of a power amplifier circuit for the second wireless communication device. The computer readable medium may also have stored therein instructions executable by a processing system of the first wireless communication device to update the nonlinearity information of the digital post-distorter for the first wireless communication device after receiving the indication. The computer readable medium may have further stored therein instructions executable by a processing system of the first wireless communication device to receive a signal from the second wireless communication device. The computer readable medium may additionally have stored therein instructions executable by a processing system of the first wireless communication device to compensate for nonlinear distortion in the signal using a digital post-distorter.

These and other aspects of the present disclosure will be more fully understood upon review of the following detailed description. Other aspects, features and examples of the present disclosure will become apparent to those of ordinary skill in the art upon review of the following description of specific exemplary aspects of the disclosure in conjunction with the accompanying drawings. Although features of the present disclosure may be discussed below with respect to certain examples and figures, all examples of the present disclosure may include one or more of the advantageous features discussed herein. In other words, while one or more examples may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with various examples of the disclosure discussed herein. In a similar manner, although example aspects may be discussed below as device, system, or method examples, it should be understood that such example aspects may be implemented in a variety of devices, systems, and methods.

Brief Description of Drawings

Fig. 1 is a schematic illustration of a wireless communication system in accordance with some aspects.

Fig. 2 is a conceptual illustration of an example of a radio access network according to some aspects.

Fig. 3 is a diagram providing a high-level illustration of one example of a configuration of an decomposed base station, according to some aspects.

Fig. 4 is a schematic diagram illustrating an organization of radio resources in an air interface utilizing Orthogonal Frequency Division Multiplexing (OFDM), according to some aspects.

Fig. 5 is a conceptual illustration of examples of power amplifier nonlinearities and different backoff according to some aspects.

Fig. 6 is a conceptual illustration of an example use of Digital Predistortion (DPD) according to some aspects.

Fig. 7 is a conceptual illustration of an example of a wireless communication system in which digital post-distortion (DPoD) is applied to a non-linearly distorted signal, according to some aspects.

Fig. 8 is a conceptual illustration of another example of a wireless communication system in which digital post-distortion (DPoD) is applied to a non-linearly distorted signal, according to some aspects.

Fig. 9 is a conceptual illustration of an example of a wireless communication device signaling non-linearity information, according to some aspects.

Fig. 10 is a conceptual illustration of an example of a tuned DPD configuration according to some aspects.

Fig. 11 is a schematic illustration of an example of a tuned DPD configuration according to some aspects.

Fig. 12 is a conceptual illustration of an example of applying digital post-distortion (DPoD) to a non-linearly distorted received signal, according to some aspects.

Fig. 13 is a schematic illustration of an example of a receive chain including DPoD functionality, according to some aspects.

Fig. 14 is a graphical illustration of an example of DPoD related gains according to some aspects.

Fig. 15 is a conceptual illustration of an example of a wireless communication device signaling effective power amplifier parameters in accordance with some aspects.

Fig. 16 is a signaling diagram illustrating an example of signaling to indicate a change in a non-linearity model, according to some aspects.

Fig. 17 is a signaling diagram illustrating an example of calculating DPD information at a recipient device according to some aspects.

Fig. 18 is a signaling diagram illustrating an example of signaling for joint DPD and DPoD calculations in accordance with some aspects.

Fig. 19 is a signaling diagram illustrating an example of a multiple Crest Factor Reduction (CFR) based signal in accordance with some aspects.

Fig. 20 is a block diagram illustrating an example of a hardware implementation of a wireless communication device (e.g., user equipment or base station) employing a processing system in accordance with some aspects.

Fig. 21 is a flow diagram illustrating an example process for indicating a change in a non-linearity model, according to some aspects.

Fig. 22 is a flowchart illustrating an example process involving use of received DPD information according to some aspects.

Fig. 23 is a flow diagram illustrating an example process involving transmitting signals based on multiple CFRs, according to some aspects.

Fig. 24 is a block diagram illustrating an example of a hardware implementation of a wireless communication device (e.g., a user equipment or base station) employing a processing system in accordance with some aspects.

Fig. 25 is a flow diagram illustrating an example process for updating non-linearity information in response to changes in a non-linearity model, according to some aspects.

Fig. 26 is a flowchart illustrating an example process involving calculating DPD information according to some aspects.

Fig. 27 is a flow diagram illustrating an example process involving receiving signals based on multiple CFRs, according to some aspects.

Detailed Description

The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. It will be apparent, however, to one skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

While aspects and examples are described in this application by way of illustration of some examples, those skilled in the art will appreciate that additional implementations and use cases may be produced in many different arrangements and scenarios. The innovations described herein may be implemented across many different platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, aspects and/or uses may be generated via integrated chip examples and other non-module component based devices (e.g., end user devices, vehicles, communication devices, computing devices, industrial equipment, retail/shopping devices, medical devices, artificial intelligence (AI-enabled) devices, etc.). While some examples may or may not be specific to each use case or application, the broad applicability of the described innovations may occur. Implementations may range from chip-level or module components to non-module, non-chip-level implementations, and further to aggregated, distributed or Original Equipment Manufacturer (OEM) devices or systems incorporating one or more aspects of the described innovations. In some practical environments, devices incorporating the described aspects and features may also necessarily include additional components and features to implement and practice the claimed and described examples. For example, the transmission and reception of wireless signals must include several components (e.g., hardware components including antennas, radio Frequency (RF) chains, power amplifiers, modulators, buffers, processor(s), interleavers, adders/summers, etc.) for analog and digital purposes. The innovations described herein are intended to be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, decomposed arrangements (e.g., base stations and/or UEs), end user devices, and the like, of various sizes, shapes, and configurations.

Aspects of the present disclosure relate to signaling information about a non-linearity model (equivalently, a non-linearity model) of power amplifier circuitry at a transmitting device. The power amplifier circuitry applies Digital Predistortion (DPD) to the signal prior to nonlinear amplification and transmission of the signal. The nonlinearity model represents the nonlinearity of power amplifier circuitry (such as a power amplifier, digital predistorter, and optionally other components).

The receiving device may apply digital post-distortion (DPoD) to the signal received from the transmitting device. In some aspects, DPoD may be based on a non-linearity model of the power amplifier circuitry of the transmitting device.

The non-linearity model may change over time due to one or more factors (e.g., changes in properties related to the power amplifier of the power amplifier circuitry, changes in DPD configuration, etc.). In this case, the transmitting device may send an indication of the change in the non-linearity model to the receiving device. In this way, the recipient device may be triggered to update its locally maintained non-linearity model of the power amplifier circuitry. Alternatively or additionally, the transmitting device may send the non-linearity parameters for the non-linearity model to the receiving device after the non-linearity model has changed.

In some examples, the receiving device may calculate non-linearity information (e.g., DPD coefficients) for a non-linearity model of the power amplifier circuitry and transmit this information to the transmitting device. For example, the transmitting device may request the receiving device to calculate DPD coefficients to offload this task from the transmitting device. Upon receiving the DPD coefficients, the transmitting device may update its locally maintained non-linearity model for the power amplifier circuitry. In some examples, the recipient device may jointly calculate DPD information and DPoD information.

In some examples, the transmitting device applies a first Crest Factor Reduction (CFR) function, a DPD function, and a second CFR function to the signal prior to power amplification and transmission of the signal. In this case, the transmitting device may send parameters to the receiving device indicating an effective model of the power amplifier, including parameters associated with the first CFR function, the DPD function, and the second CFR function. The receiving device may thereby take these parameters into account to determine a non-linearity model of the power amplifier circuitry and use the non-linearity model for the DPoD function at the receiving device.

The various concepts presented throughout this disclosure may be implemented across a wide variety of telecommunication systems, network architectures, and communication standards. Referring now to fig. 1, various aspects of the present disclosure are illustrated with reference to a wireless communication system 100 by way of illustrative example and not limitation. The wireless communication system 100 includes three interaction domains: a core network 102, a Radio Access Network (RAN) 104, and a User Equipment (UE) 106. By way of the wireless communication system 100, the UE 106 may be enabled to perform data communications with an external data network 110, such as, but not limited to, the internet.

RAN 104 may implement any suitable one or more wireless communication technologies to provide radio access to UEs 106. As one example, RAN 104 may operate in accordance with the third generation partnership project (3 GPP) New Radio (NR) specification (commonly referred to as 5G). As another example, the RAN 104 may operate under a mix of 5G NR and evolved universal terrestrial radio access network (eUTRAN) standards, commonly referred to as Long Term Evolution (LTE). The 3GPP refers to this hybrid RAN as the next generation RAN, or NG-RAN. In another example, RAN 104 may operate in accordance with both LTE and 5G NR standards. Of course, many other examples may be utilized within the scope of the present disclosure.

As illustrated, the RAN 104 includes a plurality of base stations 108. Broadly, a base station is a network element in a radio access network responsible for radio transmission and reception to or from a UE in one or more cells. In different technologies, standards, or contexts, a base station may be variously referred to by those skilled in the art as a Base Transceiver Station (BTS), a radio base station, a radio transceiver, a transceiver function, a Basic Service Set (BSS), an Extended Service Set (ESS), an Access Point (AP), a Node B (NB), an evolved node B (eNB), a next generation node B (gNB), a Transmission Reception Point (TRP), or some other suitable terminology. In some examples, a base station may include two or more TRPs that may be co-located or non-co-located. Each TRP may communicate on the same or different carrier frequencies within the same or different frequency bands. In an example where RAN 104 operates in accordance with both LTE and 5G NR standards, one of base stations 108 may be an LTE base station and the other base station may be a 5G NR base station.

The radio access network 104 is further illustrated as supporting wireless communications for a plurality of mobile devices. A mobile device may be referred to in the 3GPP standards as a User Equipment (UE) 106, but may also be referred to by those skilled in the art as a Mobile Station (MS), a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless communication device, a remote device, a mobile subscriber station, an Access Terminal (AT), a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, or some other suitable terminology. The UE 106 may be a device that provides a user with access to network services. In examples where RAN 104 operates in accordance with both LTE and 5G NR standards, UE 106 may be an evolved universal terrestrial radio access network-new radio dual connectivity (EN-DC) UE capable of simultaneously connecting to an LTE base station and a NR base station to receive data packets from both the LTE base station and the NR base station.

Within this document, a mobile device need not necessarily have mobility capabilities, and may be stationary. The term mobile device or mobile equipment refers broadly to a wide variety of devices and technologies. The UE may include several hardware structural components sized, shaped, and arranged to facilitate communication; such components may include antennas, antenna arrays, RF chains, amplifiers, one or more processors, and so forth, electrically coupled to each other. For example, some non-limiting examples of mobile devices include mobile equipment, cellular (cell) phones, smart phones, session Initiation Protocol (SIP) phones, laptops, personal Computers (PCs), notebooks, netbooks, smartbooks, tablet devices, personal Digital Assistants (PDAs), and a wide variety of embedded systems, e.g., corresponding to the internet of things (IoT).

Additionally, the mobile apparatus may be an automobile or other transportation vehicle, a remote sensor or actuator, a robot or robotic device, a satellite radio, a Global Positioning System (GPS) device, an object tracking device, an unmanned aerial vehicle, a multi-axis aircraft, a four-axis aircraft, a remote control device, a consumer and/or wearable device (such as eyeglasses), a wearable camera, a virtual reality device, a smart watch, a health or fitness tracker, a digital audio player (e.g., MP3 player), a camera, a game console, and the like. The mobile device may additionally be a digital home or smart home appliance such as a home audio, video and/or multimedia appliance, vending machine, smart lighting device, home security system, smart meter, etc. Additionally, the mobile device may be a smart energy device, a security device, a solar panel or solar array, a municipal infrastructure device (e.g., smart grid) controlling electricity, lighting, water, etc., industrial automation and enterprise devices, logistics controllers, agricultural equipment, and the like. Still further, the mobile device may provide networked medical or telemedicine support, i.e., remote health care. The remote healthcare device may include a remote healthcare monitoring device and a remote healthcare supervising device, whose communications may be given priority or prioritized access over other types of information, for example, in the form of prioritized access to critical service data transmissions and/or associated QoS to critical service data transmissions.

Wireless communication between RAN 104 and UE 106 may be described as utilizing an air interface. Transmissions from a base station (e.g., base station 108) to one or more UEs (e.g., UE 106) over an air interface may be referred to as Downlink (DL) transmissions. In some examples, the term downlink may refer to a point-to-multipoint transmission originating at a base station (e.g., base station 108). Another way to describe this point-to-multipoint transmission scheme may be to use the term broadcast channel multiplexing. The transmission from a UE (e.g., UE 106) to a base station (e.g., base station 108) may be referred to as an Uplink (UL) transmission. In some examples, the term uplink may refer to point-to-point transmissions originating at a UE (e.g., UE 106).

In some examples, access to the air interface may be scheduled, with a scheduling entity (e.g., base station 108) of some other type of network entity allocating resources for communication among some or all devices and equipment within its service area or cell. Within this disclosure, a scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more scheduled entities (e.g., UEs), as discussed further below. That is, for scheduled communications, multiple UEs 106 (which may be scheduled entities) may utilize resources allocated by a scheduling entity (e.g., base station 108).

The base station 108 is not the only entity that can be used as a scheduling entity. That is, in some examples, a UE may act as a scheduling entity, scheduling resources for one or more scheduled entities (e.g., one or more other UEs). For example, a UE may communicate with other UEs in a peer-to-peer or device-to-device manner and/or in a relay configuration.

As illustrated in fig. 1, a scheduling entity (e.g., base station 108) may broadcast downlink traffic 112 to one or more scheduled entities (e.g., UEs 106). Broadly, a scheduling entity is a node or device responsible for scheduling traffic (including downlink traffic 112 and, in some examples, uplink traffic 116 and/or uplink control information 118 from one or more scheduled entities to the scheduling entity) in a wireless communication network. In another aspect, the scheduled entity is a node or device that receives downlink control information 114 (including but not limited to scheduling information (e.g., grants), synchronization or timing information), or other control information, from another entity in the wireless communication network, such as a scheduling entity.

In addition, uplink control information 118, downlink control information 114, downlink traffic 112, and/or uplink traffic 116 may be divided in time into frames, subframes, slots, and/or symbols. As used herein, a symbol may refer to a unit of time that carries one Resource Element (RE) per subcarrier in an Orthogonal Frequency Division Multiplexing (OFDM) waveform. In some examples, a slot may carry 7 or 14 OFDM symbols. A subframe may refer to a duration of 1 millisecond (ms). Multiple subframes or slots may be grouped together to form a single frame or radio frame. Within this disclosure, frames may refer to a predetermined duration (e.g., 10 ms) for wireless transmission, where each frame includes 10 subframes of 1ms each, for example. Of course, these definitions are not required, and the waveforms may be organized using any suitable scheme, and the various time divisions of the waveforms may have any suitable duration.

In general, the base station 108 may include a backhaul interface for communicating with a backhaul 120 of a wireless communication system. Backhaul 120 may provide a link between base station 108 and core network 102. Further, in some examples, the backhaul network may provide interconnection between respective base stations 108. Various types of backhaul interfaces may be employed, such as direct physical connections using any suitable transport network, virtual networks, and so forth.

The core network 102 may be part of the wireless communication system 100 and may be independent of the radio access technology used in the RAN 104. In some examples, the core network 102 may be configured according to a 5G standard (e.g., 5 GC). In other examples, core network 102 may be configured according to a 4G Evolved Packet Core (EPC) or any other suitable standard or configuration.

Referring now to fig. 2, a schematic illustration of a Radio Access Network (RAN) 200 is provided by way of example and not limitation. In some examples, RAN 200 may be the same as RAN 104 described above and illustrated in fig. 1.

The geographic area covered by the RAN 200 may be divided into cellular areas (cells) that may be uniquely identified by a User Equipment (UE) based on an identification broadcast from one access point or base station. Fig. 2 illustrates cells 202, 204, 206, and 208, each of which may include one or more sectors (not shown). A sector is a sub-region of a cell. All sectors within a cell are served by the same base station. The radio links within a sector may be identified by a single logical identification belonging to the sector. In a sectorized cell, multiple sectors within the cell may be formed by groups of antennas, with each antenna being responsible for communication with UEs in a portion of the cell.

Various base station arrangements may be utilized. For example, in fig. 2, two base stations 210 and 212 are shown in cells 202 and 204; and base station 214 is shown controlling a Remote Radio Head (RRH) 216 in cell 206. That is, the base station may have an integrated antenna, or may be connected to an antenna or RRH by a feeder cable. In the illustrated example, the cells 202, 204, and 206 may be referred to as macro cells because the base stations 210, 212, and 214 support cells having a large size. Further, base station 218 is shown in cell 208, where cell 208 may overlap with one or more macro cells. In this example, the cell 208 may be referred to as a small cell (e.g., a micro cell, pico cell, femto cell, home base station, home node B, home evolved node B, etc.) because the base station 218 supports cells having a relatively small size. Cell sizing may be done according to system design and component constraints.

It will be appreciated that the RAN 200 may include any number of radio base stations and cells. Furthermore, relay nodes may be deployed to extend the size or coverage area of a given cell. The base stations 210, 212, 214, 218 provide wireless access points to the core network for any number of mobile devices. In some examples, base stations 210, 212, 214, and/or 218 may be the same as the base station/scheduling entities described above and illustrated in fig. 1.

Fig. 2 further includes an Unmanned Aerial Vehicle (UAV) 220, which may be an unmanned aerial vehicle or a four-axis aerial vehicle. UAV 220 may be configured to function as a base station, or more specifically as a mobile base station. That is, in some examples, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile base station (such as UAV 220).

Within RAN 200, cells may include UEs that may be in communication with one or more sectors of each cell. Further, each base station 210, 212, 214, and 218 may be configured to provide an access point to the core network 102 (see fig. 1) for all UEs in the respective cell. For example, UEs 222 and 224 may be in communication with base station 210; UEs 226 and 228 may be in communication with base station 212; UEs 230 and 232 may be in communication with base station 214 via RRH 216; and UE 234 may be in communication with base station 218. In some examples, UEs 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, and/or 242 may be the same as the UEs/scheduled entities described above and illustrated in fig. 1. In some examples, UAV 220 (e.g., a four-axis vehicle) may be a mobile network node and may be configured to function as a UE. For example, UAV 220 may operate within cell 202 by communicating with base station 210.

In a further aspect of the RAN 200, side-chain signals may be used between UEs without having to rely on scheduling or control information from the base station. The side link communication may be used in, for example, a device-to-device (D2D) network, a peer-to-peer (P2P) network, a vehicle-to-vehicle (V2V) network, a vehicle networking (V2X) network, and/or other suitable side link network. For example, two or more UEs (e.g., UEs 238, 240, and 242) may communicate with each other using side link signals 237 without relaying the communication through a base station. In some examples, UEs 238, 240, and 242 may each act as a scheduling entity or transmitting side link device and/or a scheduled entity or receiver side link device to schedule resources and communicate side link signals 237 therebetween without relying on scheduling or control information from a base station. In other examples, two or more UEs (e.g., UEs 226 and 228) within the coverage area of a base station (e.g., base station 212) may also communicate side link signal 227 over a direct link (side link) without communicating the communication through base station 212. In this example, base station 212 may allocate resources to UEs 226 and 228 for side link communication.

In the RAN 200, the ability of a UE to communicate independent of its location while moving is referred to as mobility. The various physical channels between the UE and the radio access network are typically set up, maintained and released under control of access and mobility management functions (AMFs, not illustrated, part of the core network 102 in fig. 1), which may include Security Context Management Functions (SCMFs) that manage security contexts for both control plane and user plane functionalities, and security anchor functions (SEAFs) that perform authentication.

RAN 200 may utilize DL-based mobility or UL-based mobility to implement mobility and handover (i.e., the connection of the UE is transferred from one radio channel to another). In a network configured for DL-based mobility, the UE may monitor various parameters of signals from its serving cell and various parameters of neighboring cells during a call with a scheduling entity, or at any other time. Depending on the quality of these parameters, the UE may maintain communication with one or more neighboring cells. During this time, the UE may make a handover or handoff from the serving cell to the neighboring (target) cell if the UE moves from one cell to another cell, or if the signal quality from the neighboring cell exceeds the signal quality from the serving cell for a given amount of time. For example, UE 224 (illustrated as a vehicle, but any suitable form of UE may be used) may move from a geographic region corresponding to its serving cell (e.g., cell 202) to a geographic region corresponding to a neighbor cell (e.g., cell 206). When the signal strength or quality from a neighbor cell exceeds the signal strength or quality of a serving cell for a given amount of time, UE 224 may transmit a report message to its serving base station (e.g., base station 210) indicating the condition. In response, UE 224 may receive the handover command and the UE may experience a handover to cell 206.

In a network configured for UL-based mobility, UL reference signals from each UE may be used by the network to select a serving cell for each UE. In some examples, base stations 210, 212, and 214/216 may broadcast unified synchronization signals (e.g., unified Primary Synchronization Signal (PSS), unified Secondary Synchronization Signal (SSS), and unified Physical Broadcast Channel (PBCH)). UEs 222, 224, 226, 228, 230, and 232 may receive the unified synchronization signals, derive carrier frequencies and slot timings from these synchronization signals, and transmit uplink pilot or reference signals in response to the derived timings. Uplink pilot signals transmitted by UEs (e.g., UE 224) may be received concurrently by two or more cells (e.g., base stations 210 and 214/216) within RAN 200. Each of these cells may measure the strength of the pilot signal and the radio access network (e.g., one or more of base stations 210 and 214/216 and/or a central node within the core network) may determine a serving cell for UE 224. As UE 224 moves in RAN 200, the network may continue to monitor uplink pilot signals transmitted by UE 224. When the signal strength or quality of the pilot signal measured by a neighbor cell exceeds the signal strength or quality measured by the serving cell, the RAN 200 may switch the UE 224 from the serving cell to the neighbor cell with or without informing the UE 224.

Although the synchronization signals transmitted by the base stations 210, 212, and 214/216 may be uniform, the synchronization signals may not identify a particular cell, but may identify a partition that includes multiple cells operating on the same frequency and/or having the same timing. The use of zones in a 5G network or other next generation communication network enables an uplink-based mobility framework and improves the efficiency of both the UE and the network, as the number of mobility messages that need to be exchanged between the UE and the network can be reduced.

In various implementations, the air interface in the RAN 200 may utilize licensed spectrum, unlicensed spectrum, or shared spectrum. Licensed spectrum typically provides proprietary use of a portion of the spectrum by a mobile network operator purchasing a license from a government regulatory agency. Unlicensed spectrum provides shared use of a portion of spectrum without the need for government granted licenses. While it is still generally desirable to follow some technical rules to access the unlicensed spectrum, any operator or device may gain access. The shared spectrum may fall between licensed and unlicensed spectrum, where technical rules or restrictions may be needed to access the spectrum, but the spectrum may still be shared by multiple operators and/or multiple Radio Access Technologies (RATs). For example, a licensee of a portion of licensed spectrum may provide Licensed Shared Access (LSA) to share the spectrum with other parties, e.g., to gain access using conditions determined by the appropriate licensee.

The air interface in RAN 200 may utilize one or more multiplexing and multiple access algorithms to enable simultaneous communication of the various devices. For example, the 5G NR specification utilizes Orthogonal Frequency Division Multiplexing (OFDM) with a Cyclic Prefix (CP) to provide multiple access for UL transmissions from UEs 222 and 224 to base station 210 and multiplexing for DL transmissions from base station 210 to one or more UEs 222 and 224. In addition, for UL transmissions, the 5G NR specification provides support for discrete fourier transform spread OFDM (DFT-s-OFDM) with CP, also known as single carrier FDMA (SC-FDMA). However, it is within the scope of the present disclosure that multiplexing and multiple access are not limited to the above-described schemes, and may be provided using Time Division Multiple Access (TDMA), code Division Multiple Access (CDMA), frequency Division Multiple Access (FDMA), sparse Code Multiple Access (SCMA), resource Spread Multiple Access (RSMA), or other suitable multiple access schemes. Further, multiplexing DL transmissions from base station 210 to UEs 222 and 224 may be provided using Time Division Multiplexing (TDM), code Division Multiplexing (CDM), frequency Division Multiplexing (FDM), orthogonal Frequency Division Multiplexing (OFDM), sparse Code Multiplexing (SCM), or other suitable multiplexing scheme.

The air interface in RAN 200 may further utilize one or more duplexing algorithms. Duplex refers to a point-to-point communication link in which two endpoints can communicate with each other in two directions. Full duplex means that two endpoints can communicate with each other at the same time. Half duplex means that only one endpoint can send information to the other endpoint at a time. Half-duplex emulation is typically implemented for wireless links using Time Division Duplexing (TDD). In TDD, transmissions in different directions on a given channel are separated from each other using time division multiplexing. That is, at some times, the channel is dedicated to transmissions in one direction, and at other times, the channel is dedicated to transmissions in the other direction, where the direction may change very rapidly, e.g., several times per slot. In wireless links, full duplex channels typically rely on physical isolation of the transmitter and receiver, as well as suitable interference cancellation techniques. Full duplex emulation is typically achieved for wireless links by utilizing Frequency Division Duplexing (FDD) or Space Division Duplexing (SDD). In FDD, transmissions in different directions operate at different carrier frequencies. In SDD, transmissions in different directions on a given channel are separated from each other using Space Division Multiplexing (SDM). In other examples, full duplex communications may be implemented within unpaired spectrum (e.g., within a single carrier bandwidth), where transmissions in different directions occur within different sub-bands of the carrier bandwidth. This type of full duplex communication may be referred to as sub-band full duplex (SBFD), cross-division duplex (xDD), or flexible duplex.

Fig. 3 shows a diagram illustrating an example split base station 300 architecture. The split base station 300 architecture may include one or more Central Units (CUs) 310 that may communicate directly with the core network 320 via a backhaul link, or indirectly with the core network 320 through one or more split base station units, such as Near real-time (Near-RT) RAN Intelligent Controllers (RIC) 325 via E2 links, or Non-real-time (Non-RT) RIC 315 associated with a Service Management and Orchestration (SMO) framework 305, or both. CU 310 may communicate with one or more Distributed Units (DUs) 330 via a corresponding mid-range link, such as an F1 interface. DU 330 may communicate with one or more Radio Units (RUs) 340 via respective outbound links. RU 340 can communicate with respective UEs 350 via one or more Radio Frequency (RF) access links. In some implementations, the UE 350 may be served by multiple RUs 340 simultaneously.

Each of the units (i.e., CU 310, DU 330, RU 340, and near RT RIC 325, non-RT RIC 315, and SMO framework 305) may include or be coupled to one or more interfaces configured to receive or transmit signals, data, or information (collectively referred to as signals) via wired or wireless transmission media. Each of the units, or an associated processor or controller that provides instructions to a communication interface of the units, may be configured to communicate with one or more of the other units via a transmission medium. For example, the units may include a wired interface configured to receive or transmit signals to one or more of the other units over a wired transmission medium. Additionally, the units may include a wireless interface that may include a receiver, transmitter, or transceiver (such as a Radio Frequency (RF) transceiver) configured to receive or transmit signals to one or more of the other units, or both, over a wireless transmission medium.

In some aspects, CU 310 may host one or more higher layer control functions. Such control functions may include Radio Resource Control (RRC), packet Data Convergence Protocol (PDCP), service Data Adaptation Protocol (SDAP), etc. Each control function may be implemented with an interface configured to communicate signals with other control functions hosted by CU 310. CU 310 may be configured to handle user plane functionality (i.e., central unit-user plane (CU-UP)), control plane functionality (i.e., central unit-control plane (CU-CP)), or a combination thereof. In some implementations, CU 310 may be logically split into one or more CU-UP units and one or more CU-CP units. When implemented in an O-RAN configuration, the CU-UP unit may communicate bi-directionally with the CU-CP unit via an interface, such as an E1 interface. CU 310 may be implemented to communicate with Distributed Units (DUs) 330 for network control and signaling, as desired.

DU 330 may correspond to a logic unit that includes one or more base station functions to control the operation of one or more RUs 340. In some aspects, the DUs 330 may host one or more of a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, and one or more high Physical (PHY) layers, such as modules for Forward Error Correction (FEC) encoding and decoding, scrambling, modulation, and demodulation, etc., depending at least in part on a functional partitioning, such as that defined by the third generation partnership project (3 GPP). In some aspects, DU 330 may further host one or more lower PHY layers. Each layer (or module) may be implemented with an interface configured to communicate signals with other layers (and modules) hosted by DU 330 or with control functions hosted by CU 310.

The lower layer functionality may be implemented by one or more RUs 340. In some deployments, RU 340 controlled by DU 330 may correspond to a logical node hosting RF processing functions or low PHY layer functions, such as performing Fast Fourier Transforms (FFTs), inverse FFTs (iffts), digital beamforming, physical Random Access Channel (PRACH) extraction and filtering, etc., or both, based at least in part on functional partitioning, such as lower layer functional partitioning. In such an architecture, RU(s) 340 may be implemented to handle over-the-air (OTA) communications with one or more UEs 350. In some implementations, the real-time and non-real-time aspects of control and user plane communications with RU(s) 340 may be controlled by corresponding DUs 330. In some scenarios, this configuration may enable DU(s) 330 and CU 310 to be implemented in a cloud-based RAN architecture, such as a vRAN architecture.

SMO framework 305 may be configured to support RAN deployment and provisioning of non-virtualized and virtualized network elements. For non-virtualized network elements, SMO framework 305 may be configured to support deployment of dedicated physical resources for RAN coverage requirements that may be managed via an operation and maintenance interface (such as an O1 interface). For virtualized network elements, SMO framework 305 may be configured to interact with a Cloud computing platform, such as open Cloud (O-Cloud) 390, to perform network element lifecycle management (such as instantiating virtualized network elements) via a Cloud computing platform interface, such as an O2 interface. Such virtualized network elements may include, but are not limited to, CU 310, DU 330, RU 340, and near RT RIC 325. In some implementations, SMO framework 305 may communicate with hardware aspects of the 4G RAN, such as open eNB (O-eNB) 311, via an O1 interface. Additionally, in some implementations, SMO framework 305 may communicate directly with one or more RUs 340 via an O1 interface. SMO framework 305 may also include a non-RT RIC 315 configured to support the functionality of SMO framework 305.

The non-RT RIC 315 may be configured to include logic functions that enable non-real-time control and optimization of RAN elements and resources, artificial intelligence/machine learning (AI/ML) workflows including model training and updating, or policy-based guidance of applications/features in the near RT RIC 325. non-RT RIC 315 may be coupled to or in communication with near RT RIC 325 (such as via an A1 interface). Near RT RIC 325 may be configured to include logic functions that enable near real-time control and optimization of RAN elements and resources via data collection and actions through an interface (such as via an E2 interface) that connects one or more CUs 310, one or more DUs 330, or both, and an O-eNB with near RT RIC 325.

In some implementations, to generate the AI/ML model to be deployed in the near RT RIC 325, the non-RT RIC 315 may receive parameters or external rich information from an external server. Such information may be utilized by near RT RIC 325 and may be received at SMO framework 305 or non-RT RIC 315 from a non-network data source or from a network function. In some examples, the non-RT RIC 315 or near-RT RIC 325 may be configured to tune RAN behavior or performance. For example, the non-RT RIC 315 may monitor long-term trends and patterns of performance and employ AI/ML models to perform corrective actions through SMO framework 305 (such as via reconfiguration of O1) or via creation of RAN management policies (such as A1 policies).

Various aspects of the disclosure will be described with reference to OFDM waveforms, examples of which are schematically illustrated in fig. 4. Those of ordinary skill in the art will appreciate that the various aspects of the present disclosure may be applied to SC-FDMA waveforms in substantially the same manner as described below. That is, while some examples of the present disclosure may focus on OFDM links for clarity, it should be understood that the same principles may also be applied to SC-FDMA waveforms.

Referring now to fig. 4, an expanded view of an example frame 402 is illustrated, showing an OFDM resource grid. However, as those skilled in the art will readily appreciate, the Physical (PHY) layer transmission structure for any particular application may vary from the examples described herein depending on any number of factors. Here, the time is in a horizontal direction in units of OFDM symbols; and the frequency is in the vertical direction in units of subcarriers of the carrier.

The resource grid 404 may be used to schematically represent time-frequency resources for a given antenna port. In some examples, an antenna port is a logical entity for mapping data streams to one or more antennas. Each antenna port may be associated with a reference signal (e.g., this may allow the receiver to distinguish data streams associated with different antenna ports in the received transmission). An antenna port may be defined such that a channel over which a symbol is communicated upon the antenna port may be inferred from a channel over which another symbol is communicated upon the same antenna port. Thus, a given antenna port may represent a particular channel model associated with a particular reference signal. In some examples, a given antenna port and subcarrier spacing (SCS) may be associated with a corresponding resource grid (including REs as discussed above). Here, modulated data symbols from a multiple-input multiple-output (MIMO) layer may be combined and redistributed to each antenna port, then precoding is applied, and the precoded data symbols are applied to the corresponding REs for OFDM signal generation and transmission via one or more physical antenna elements. In some examples, the mapping of antenna ports to physical antennas may be based on beamforming (e.g., signals may be transmitted on certain antenna ports to form a desired beam). Thus, a given antenna port may correspond to a particular set of beamforming parameters (e.g., signal phase and/or amplitude).

In a MIMO implementation where multiple antenna ports are available, a corresponding number of resource grids 404 may be available for communication. The resource grid 404 is partitioned into a plurality of Resource Elements (REs) 406. REs (which are 1 subcarrier x 1 symbol) are the smallest discrete part of the time-frequency grid and contain a single complex value representing data from a physical channel or signal. Each RE may represent one or more information bits, depending on the modulation utilized in a particular implementation. In some examples, the RE blocks may be referred to as Physical Resource Blocks (PRBs) or, more simply, resource Blocks (RBs) 408, which contain any suitable number of consecutive subcarriers in the frequency domain. In one example, an RB may include 12 subcarriers, the number being designed independent of the parameters used. In some examples, an RB may include any suitable number of consecutive OFDM symbols in the time domain, depending on the parameter design. Within this disclosure, it is assumed that a single RB (such as RB 408) corresponds entirely to a single communication direction (transmission or reception for a given device).

The contiguous or non-contiguous set of resource blocks may be referred to herein as a Resource Block Group (RBG), subband, or bandwidth part (BWP). The set of subbands or BWP may span the entire bandwidth. Scheduling of a scheduled entity (e.g., UE) for downlink, uplink, or side-link transmissions generally involves scheduling one or more resource elements 406 within one or more subbands or bandwidth portions (BWP). Thus, the UE typically utilizes only a subset of the resource grid 404. In some examples, an RB may be the smallest resource unit that can be allocated to a UE. Thus, the more RBs scheduled for a UE and the higher the modulation scheme selected for the air interface, the higher the data rate of that UE. RBs may be scheduled by a scheduling entity, such as a base station (e.g., a gNB, eNB, etc.), or may be self-scheduled by a UE implementing D2D side-link communication.

In this illustration, RB 408 is shown to occupy less than the entire bandwidth of subframe 402, with some subcarriers above and below RB 408 being illustrated. In a given implementation, the subframe 402 may have a bandwidth corresponding to any number of one or more RBs 408. Further, in this illustration, RB 408 is shown to occupy less than the entire duration of subframe 402, but this is merely one possible example.

Each 1ms subframe 402 may include one or more contiguous slots. As an illustrative example, in the example shown in fig. 4, one subframe 402 includes four slots 410. In some examples, a slot may be defined according to a specified number of OFDM symbols having a given Cyclic Prefix (CP) length. For example, a slot may include 7 or 14 OFDM symbols with a nominal CP. Additional examples may include mini-slots with shorter durations (e.g., one to three OFDM symbols), sometimes referred to as shortened Transmission Time Intervals (TTIs). In some cases, these mini-slots or shortened Transmission Time Intervals (TTIs) may be transmitted occupying resources scheduled for ongoing slot transmissions for the same or different UEs. Any number of resource blocks may be utilized within a subframe or slot.

An expanded view of one of the slots 410 illustrates that the slot 410 includes a control region 412 and a data region 414. In general, control region 412 may carry control channels and data region 414 may carry data channels. Of course, a slot may contain full DL, full UL, or at least one DL portion and at least one UL portion. The structure illustrated in fig. 4 is merely an example, and a different time slot structure may be utilized, and one or more may be included for each of the control region and the data region.

Although not illustrated in fig. 4, individual REs 406 within RBs 408 may be scheduled to carry one or more physical channels, including control channels, shared channels, data channels, and the like. Other REs 406 within an RB 408 may also carry pilot or reference signals. These pilot or reference signals may be provided to the recipient device to perform channel estimation for the corresponding channel, which may enable coherent demodulation/detection of control and/or data channels within the RB 408.

In some examples, the time slot 410 may be used for broadcast, multicast, or unicast communications. For example, broadcast, multicast, or multicast communication may refer to a point-to-multipoint transmission by one device (e.g., a base station, UE, or other similar device) to another device. Here, broadcast communications are delivered to all devices, while multicast or multicast communications are delivered to multiple target recipient devices. Unicast communication may refer to a point-to-point transmission by one device to a single other device.

In an example of cellular communication over a cellular carrier via a Uu interface, a scheduling entity (e.g., a base station) may allocate one or more REs 406 (e.g., within a control region 412) for DL transmissions to carry DL control information including one or more DL control channels, such as a Physical Downlink Control Channel (PDCCH), to one or more scheduled entities (e.g., UEs). The PDCCH carries Downlink Control Information (DCI), including, but not limited to, power control commands (e.g., one or more open-loop power control parameters and/or one or more closed-loop power control parameters), scheduling information, grants, and/or RE assignments for DL and UL transmissions. The PDCCH may further carry a hybrid automatic repeat request (HARQ) feedback transmission, such as an Acknowledgement (ACK) or a Negative Acknowledgement (NACK). HARQ is a well-known technique to those of ordinary skill in the art, wherein for accuracy, the integrity of a packet transmission may be checked on the receiving side, for example, using any suitable integrity check mechanism, such as a checksum (checksum) or Cyclic Redundancy Check (CRC). If the integrity of the transmission is acknowledged, an ACK may be transmitted, and if not acknowledged, a NACK may be transmitted. In response to the NACK, the transmitting device may send HARQ retransmissions, which may enable chase combining, incremental redundancy, and so on.

The base station may further allocate one or more REs 406 (e.g., in a control region 412 or a data region 414) to carry other DL signals, such as demodulation reference signals (DMRS); phase tracking reference signal (PT-RS); channel State Information (CSI) reference signals (CSI-RS); and a Synchronization Signal Block (SSB). SSBs may be broadcast at regular intervals based on periodicity (e.g., 5, 10, 20, 30, 80, or 130 milliseconds). SSBs include a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a physical broadcast control channel (PBCH). The UE may utilize PSS and SSS to achieve radio frame, subframe, slot, and symbol synchronization in the time domain, identify the center of channel (system) bandwidth in the frequency domain, and identify the Physical Cell Identity (PCI) of the cell.

The PBCH in SSB may further include: a Master Information Block (MIB) that includes various system information and parameters for decoding a System Information Block (SIB). The SIB may be, for example, system information type1 (SIB 1), which may include various additional (remaining) system information. The MIB and SIB1 together provide minimum System Information (SI) for initial access. Examples of system information transmitted in the MIB may include, but are not limited to: subcarrier spacing (e.g., default downlink parameter design), system frame number, configuration of PDCCH control resource set (CORESET) (e.g., PDCCH CORESET 0), cell prohibit indicator, cell reselection indicator, raster offset, and search space for SIB 1. Examples of Remaining Minimum System Information (RMSI) transmitted in SIB1 may include, but are not limited to, random access search space, paging search space, downlink configuration information, and uplink configuration information. The base station may also communicate Other System Information (OSI).

In UL transmission, the UE may utilize one or more REs 406 to carry UL Control Information (UCI) to the scheduling entity, including one or more UL control channels, such as a Physical Uplink Control Channel (PUCCH). UCI may include various packet types and categories including pilot, reference signals, and information configured to enable or assist in decoding uplink data transmissions. Examples of uplink reference signals may include Sounding Reference Signals (SRS) and uplink DMRS. In some examples, UCI may include a Scheduling Request (SR), i.e., a request for a scheduling entity to schedule uplink transmissions. Here, in response to the SR transmitted on the UCI, the scheduling entity may transmit Downlink Control Information (DCI) which may schedule resources for uplink packet transmission. UCI may also include HARQ feedback, channel State Feedback (CSF) (such as CSI reporting), or any other suitable UCI.

In addition to control information, one or more REs 406 (e.g., within data region 414) may also be allocated for data traffic. Such data traffic may be carried on one or more traffic channels, such as on a Physical Downlink Shared Channel (PDSCH) for DL transmissions; or may be carried on a Physical Uplink Shared Channel (PUSCH) for UL transmissions. In some examples, one or more REs 406 within the data region 414 may be configured to carry other signals, such as one or more SIBs and DMRSs.

In an example of side link communication over a side link carrier via a proximity services (ProSe) PC5 interface, the control region 412 of the slot 410 may include a physical side link control channel (PSCCH) that includes side link control information (SCI) transmitted by an initiator (transmitter) side link device (e.g., a transmitter (Tx) V2X device or other Tx UE) to a set of one or more other receiver side link devices (e.g., a receiver (Rx) V2X device or some other Rx UE). The data region 414 of the slot 410 may include a physical side link shared channel (PSSCH) that includes side link data traffic transmitted by an initiator (transmitting) side link device within resources reserved by the transmitting side link device via the SCI on side link carriers. Other information may be further transmitted on each RE 406 within the slot 410. For example, HARQ feedback information may be transmitted from a receiver-side link device to a transmitter side link device in a physical side link feedback channel (PSFCH) within the time slot 410. Further, one or more reference signals, such as side link SSB, side link CSI-RS, side link SRS, and/or side link Positioning Reference Signals (PRS), may be transmitted within the slot 410.

These physical channels are typically multiplexed and mapped to transport channels for handling by the Medium Access Control (MAC) layer. The transport channel carries blocks of information, which are called Transport Blocks (TBs). The Transport Block Size (TBS), which may correspond to the number of information bits, may be a controlled parameter based on the Modulation and Coding Scheme (MCS) and the number of RBs in a given transmission.

The channels or carriers described above with reference to fig. 1-4 are not necessarily all channels or carriers available between the scheduling entity and the scheduled entity, and one of ordinary skill in the art will recognize that other channels or carriers may be utilized in addition to those illustrated, such as other traffic, control, and feedback channels.

Power amplifiers, such as those used in wireless communication devices (e.g., UEs and base stations), typically exhibit non-linear behavior at higher input power levels. Graph 502 of fig. 5 illustrates the power output (P _OUT ) And power input (P) _IN ) Examples of characteristics. Here, it can be seen that the amplification of the power amplifier is at a lower level P _IN Where is linear. However, with P _IN The amplification becomes nonlinear and the power amplifier eventually reaches saturation corresponding to maximum output power Level 504.

Such amplifier-induced nonlinearity may result in-band and out-of-band distortion of the amplified signal and degraded (i.e., larger) Error Vector Magnitude (EVM). In general, EVM is a measure of the quality of the transmitting party, i.e. the distance of the transmitted constellation point from the ideal. Since each constellation point represents a different phase and amplitude combination, to ensure a low EVM at the transmitting side, the transmitting side's power amplifier should have a sufficiently large operating range to represent the amplitude range of the signal to be transmitted.

To avoid non-linearities, the power amplifier may operate at an operating point 506, which operating point 506 is several decibels (dB) below the saturation level, as represented by a back-off (BO) 508. The appropriate power level may be determined by selecting the input power at which the signal is maintained below a certain level. For example, the BO 508 may be selected to be proportional to the peak-to-average power ratio (PAPR). As another example, if the signal has a PAPR of x dB, BO 508 of x dB may be used to avoid non-linearity regions, even at the peak of the input signal. In practice, various tradeoffs may be made in selecting a desired operating point for the power amplifier.

As discussed above, the use of Orthogonal Frequency Division Multiplexing (OFDM) may enable more efficient channel estimation at the receiver and provide greater flexibility in utilizing available time and frequency resources. However, the use of OFDM may result in a higher PAPR compared to single carrier technology.

In addition, some applications may use relatively higher order modulation schemes, such as 256 Quadrature Amplitude Modulation (QAM), 1024QAM, or even 16K QAM, for signal transmission. However, using a higher order modulation scheme (e.g., in a single carrier scheme) may result in a higher PAPR than that observed when using lower order modulation.

In order to make the power efficiency of the power amplifier mu=p _OUT /P _IN Maximization, the operating point for the power amplifier can be made as close as possible to P _OUT And P _IN Nonlinear portions of the curve. In a scenario in which the PAPR is relatively high (e.g., an OFDM scenario), a relatively large backoff (e.g., as in chart 502) may be used to ensure a highThe EVM required for the level modulation scheme is satisfied. However, a large backoff results in an inefficient use of the power amplifier, as the highest output power achieved may be lower than the power level the power amplifier can provide in its linear range. Thus, lower power may be transmitted to the channel than in the scenario where a lower back-off is used. Reducing the PAPR would enable the use of smaller BO and achieve an operating point with higher power efficiency without sacrificing EVM.

The chart 510 of fig. 5 illustrates an example in which a smaller BO 512 is used (e.g., in a low PAPR scenario). This results in a more efficient use of the power amplifier because the highest output power achieved is closer to the power output that the power amplifier is capable of providing, while still operating in the linear operating range of the power amplifier.

To address these competing issues, the signal to be transmitted may be subjected to crest factor reduction (e.g., clipping and filtering), thereby reducing the PAPR while still using an operating point with a desired level of power efficiency. However, crest factor reduction may introduce nonlinear distortion into the signal, which may make it more difficult for the receiving device to successfully decode the received signal.

In view of the above, in a high PAPR scenario, a power amplifier (e.g., a high power amplifier) with a limited linear dynamic range may generate a Nonlinear (NL) component and thus distort the transmitted signal. This nonlinear distortion may be classified as in-band distortion (such as EVM) and/or out-of-band (OOB) emissions (such as Adjacent Channel Leakage Ratio (ACLR). ACLR may be defined as the ratio of the amount of transmitted power that leaks into one or more adjacent channels relative to the amount of transmitted power in the user-allocated channel (e.g., adjacent channel power +.main channel power). In some examples, ACLR limits may be specified (e.g., by the network) to prevent the transmitting device from unduly interfering with channels used by other wireless communication devices.

Some transmit/receive architectures may use a digital predistorter or a digital post-distorter to maintain the amount of distortion in the signal at a target level. Here, the power amplifier at the transmitting device is allowed to operate in its nonlinear region. In addition, the transmission power BO is kept as low as possible, thereby realizing a power amplifier operating point with relatively high power efficiency. Advantageously, a greater power gain can be achieved without sacrificing EVM when using Digital Predistortion (DPD) as discussed below.

Digital Predistortion (DPD) involves predistortion of a signal input into a Power Amplifier (PA) such that the overall response of the DPD and PA is linearized. For example, DPD may apply a frequency response to the signal that is the inverse of the frequency response of the power amplifier. DPD may help reduce in-band distortion (e.g., EVM) and out-of-band emissions (e.g., ACLR) at least to some extent because DPD may be used to control the amount of distortion present in the transmitted signal (e.g., where characteristics of the DPD may be tuned based on feedback from the recipient device). The above description of DPD is only one example of DPD. In other DPD implementations, DPD may be implemented in other ways.

The graph 600 of fig. 6 illustrates a power output (P) of a power amplifier similar to that of fig. 5 _OUT ) And power input (P) _IN ) Examples of characteristics. As in fig. 5, the power amplifier response 602 is at a lower level P _IN Is linear and then follows P _IN Increases to become nonlinear, eventually reaches a saturation level (P _SAT ). Using the conventional power BO scheme, the operating point for the power amplifier may be set at point P, which corresponds to the power amplifier operating region represented by region 604. However, if DPD is used, the power amplifier response 606 may be substantially linear up to a saturation level (P _SAT ). In this case, the operating point for the power amplifier may be at point P _DPD Where it corresponds to a wider power amplifier operating region represented by both region 604 and region 608.

Digital post-distortion (DPoD) may be used at the receiver device to remove non-linearity components in the received signal. Thus, DPoD can be characterized as a post-PA equalizer. In contrast to DPD, DPoD involves no feedback. In some examples, using DPoD may enable the PA to operate in a non-linear range (e.g., with lower backoff). Since the backoff can be reduced, higher power efficiency can be achieved without sacrificing EVM after DPoD. As used herein, post-DPoD EVM (or post-DPoD EVM) refers in some way to compensation of EVM distortion in the recipient. In this case, the DPoD process may handle not only the transmitting EVM but also noise added to the signal. In some aspects, DPoD may provide better EVM performance than DPD. However, DPoD does not mitigate out-of-band emissions because DPoD is performed at the recipient device. Thus, the benefits of DPoD are therefore limited by the allowed out-of-band emissions.

Fig. 7 illustrates an example of a wireless communication system 700 that includes a transmitting device 702 and a receiving device 704, where the receiving device 704 employs DPoD. Here, the DPoD employed at the receiver device 704 may be used to remove the non-linearity components in the received signal.

Fig. 7 illustrates several components of a transmit chain of a transmitting device 702. The transmit chain includes a transmit baseband component 706, a power amplifier 708, and at least one antenna 710 for transmitting a signal 714 to the recipient device 704.

In some examples, the power amplifier 708 may exhibit relatively higher gain compression (e.g., under higher levels of amplification, the gain may effectively decrease as the input power increases). This gain compression (and/or other characteristics of the transmit chain) may impart non-linearities on the amplified signal. In some examples, the output of the power amplifier 708 may be characterized by a function G (x), as represented by block 712 of fig. 7.

In G (x) of block 712, the second, third, and subsequent components represent nonlinear distortion components of the amplified signal. In some examples, the function G (x) may be characterized by a kernel and a set of associated coefficients.

Fig. 7 also illustrates several components of the receive chain of the receiver device 704. The receive chain includes at least one antenna 716, a summer (or subtractor) 718, a DPoD component 720 (e.g., a digital post-distorter), and a receive baseband component 722. In some examples, DPoD component 720 includes a slicer 724 that slices input signal 726 and an estimator 728 that generates an estimate of nonlinear distortion d 730 present in received signal y. In some examples, DPoD component 720 performs an iterative process with adder 718, whereby an estimate of nonlinear distortion d 730 is subtracted from received signal y, thereby removing nonlinear signal components from received signal y. The DPoD component 720 (including the slicer 724 and the estimator 728) shown in fig. 7 is only one example of a DPoD architecture. In other DPoD implementations, other DPoD structures may be used. For example, the DPoD structure may be any type of module that provides post-PA equalization functionality, which may be implemented in a variety of ways.

As discussed above, operating the PA in the nonlinear region may improve the power efficiency and received signal power of the PA, which thereby increases the signal-to-noise ratio (SNR). However, reducing backoff results in instantaneous high input power peaks, especially for high PAPR waveforms (such as OFDM), which can adversely affect PA reliability and lifetime.

To limit the peak power of the PA input and avoid affecting PA reliability and lifetime, a Crest Factor Reduction (CFR) block may be used at the PA input. Thus, the transmitting device may add CFR to the input signal to the PA to keep the instantaneous peak power at a permissible level in terms of PA reliability.

Fig. 8 illustrates an example of a wireless communication system 800 that includes a transmitting device 802 and a receiving device 804, where the transmitting device 802 employs CFR. As in the example of fig. 7, DPoD is employed at the receiver device 804 to remove non-linearity components in the received signal.

Fig. 8 illustrates several components of a transmit chain of a transmitting device 802. The transmit chain includes a transmit baseband component 806, a Crest Factor Reduction (CFR) component 808 (e.g., a crest factor reducer), a power amplifier 810, and at least one antenna 812 for transmitting a signal 814 to the receiving device 804. In some examples, CFR component 808 may apply clipping and filtering.

Fig. 8 also illustrates several components of the receive chain of the receiver device 804. The receive chain includes at least one antenna 816, an adder (or subtractor) 818, a DPoD component 820 (e.g., a digital post-distorter), and a receive baseband component 822. Similar to DPoD component 720 of fig. 7, DPoD component 820 can include a slicer 824 that slices input signal 826 and an estimator 828 that generates an estimate of nonlinear distortion d 830 present in received signal y. In some examples, DPoD component 820 performs an iterative process with adder 818, whereby an estimate of nonlinear distortion d 830 is subtracted from received signal y, thereby removing nonlinear signal components from received signal y.

In some aspects, the present disclosure relates to using both DPD and DPoD to reduce in-band distortion and out-of-band emissions. At the transmitting device, DPD is used to reduce out-of-band emissions (e.g., ACLR). For example, DPD functionality may be tuned to emphasize the reduction of out-of-band emissions (in contrast to in-band distortion). For example, different weights may be applied to different frequency bands (e.g., heavier weights may be applied to out-of-band regions) to tune DPD functionality in a desired manner. At the recipient device, DPoD is used to reduce in-band distortion (e.g., EVM). In some aspects, use of DPD may enable use of relatively high transmit power levels (e.g., at or near saturation), while use of DPoD may allow in-band distortion requirements to be met without violating out-of-band emission requirements (due to use of DPD).

In some aspects, the present disclosure relates to different types of signaling that may be used in conjunction with the joint use of DPD and DPoD. Fig. 9 illustrates an example of a wireless communication system 900 in which a transmitting device 902 and a receiving device 904 exchange signaling related to joint use of DPD and DPoD. Here, the reverse power amplifier employed at the transmitting device 902 pre-equalizes (e.g., DPD) to focus on (e.g., is tuned for) ACLR reduction. In addition, post-amplifier equalization (e.g., DPoD) employed at the receiver device 904 is used to reduce in-band distortion.

Fig. 9 illustrates several components of a transmit chain of a transmitting device 902. The transmit chain includes a transmit baseband component 906, a Crest Factor Reduction (CFR) component 908 (e.g., crest factor reducer), a DPD component 910 (e.g., digital predistorter), a power amplifier 912, and at least one antenna 914. As mentioned above, in some examples, CFR component 908 can apply clipping and filtering.

In some examples, the power amplifier 912 may exhibit relatively higher gain compression (e.g., under higher levels of amplification, the gain may effectively decrease as the input power increases). This gain compression (and/or other characteristics of the transmit chain) may impart non-linearities on the amplified signal. In some examples, the output of the power amplifier 912 may be characterized as set forth in equation 1.

y＝G(x)＝x+c ₁ x|x| ² +c ₂ x|x| ⁴ ...

Equation 1

In equation 1, the second, third and subsequent components represent nonlinear distortion components of the amplified signal. In some examples, the function G (x) may be characterized by a kernel and a set of associated coefficients.

In some examples, a DPD component (e.g., a set of kernels) may be characterized based on a specified combination of input signals x as set forth in equation 2. As mentioned above, in some aspects, equation 2 may be formulated to provide an inverse response relative to the response of the power amplifier 912.

Equation 1 is just one example of a PA model. In a typical example, the PA model may be more complex (e.g., the PA model may include memory terms, unlike equation 1). In some examples, the more generic PA model has a form similar to equation 2. In some examples, an equation in the form of equation 2 may be used to describe both the PA model and the DPD model, where different models will have different coefficient values. Some kernels may not appear in the PA model or DPD model. This may be manifested in the fact that its corresponding coefficient is set to zero in this case. Further, equation 2 is only one example of a kernel model. For example, a typical model may have more kernels than the example of equation 2.

In some examples, the CFR component 908, DPD component 910, and power amplifier 912 (e.g., the combined response of these components) may be referred to as an effective power amplifier 916 (e.g., an effective nonlinearity model). The components of the active power amplifier 916 may be collectively referred to herein as power amplifier circuitry. In addition, the function G (x) of equation 1, etc., may be referred to as a non-linearity model of the active power amplifier (e.g., a non-linearity model of the power amplifier circuitry).

Fig. 9 also illustrates several components of the receive chain of the receiver device 904. The receive chain includes at least one antenna 918, a DPoD component 920 (e.g., a digital post-distorter), and a receive baseband component 922. In some examples, the DPoD process provided by DPoD component 920 is based on a non-linearity model of active power amplifier 916. For example, the DPoD process may be based on the parameter G (x) of equation 1, etc. Accordingly, the recipient device 904 can maintain a local copy of the non-linearity model (e.g., an estimate of the effective power amplifier model) for use by the DPoD component 920.

A DPoD procedure (e.g., a Bussgang procedure as discussed below, or some other DPoD procedure) may be applied as long as the receiver device 904 receives a data signal comprising a nonlinear distortion component d (e.g., the PA output may be decomposed into y (x) =alpha x+d or more generally y (x) =f (x) +d based on a Bussgang decomposition, where f is any function selected to optimize Bussgang iterations, reduce complexity, or a combination of both). In some examples, the DPoD process iteratively removes an estimate of the nonlinear distortion component d by using a correction step, a slicing step, and a nonlinear distortion estimation step as discussed below to recover the original data signal x. In this process, knowledge of the non-linearity model G (x) is used to estimate the non-linear distortion term d.

This non-linearity model may change over time. For example, one or more properties (e.g., temperature, etc.) associated with the power amplifier 912 may change over time. Such changes in properties may affect the power amplifier state, thereby resulting in a change in the nonlinearity that the power amplifier 912 applies to the signal.

As another example, the transmitting device 902 may choose to change the configuration of the CFR component 908 and/or DPD component 910. Such a change in configuration may result in a transient change in the nonlinearity imparted to the signal by the CFR component 908 and/or DPD component 910. In some examples, the transmitting device 902 may choose to change the configuration of the CFR component 908 and/or DPD component 910 as a result of a change in an in-band distortion parameter (e.g., EVM limit), a change in an out-of-band emission parameter (e.g., ACLR limit), a change in a maximum power reduction parameter, a change in modulation to be used in transmitting a signal via the power amplifier circuit, some other factor, or a combination of these factors. In some examples, one or more of the above changes may occur as a result of the scheduling of the transmitting device 902. For example, ACLR requirements may become more stringent if a base station (which may be, for example, the transmitting device 902) allocates a new user relatively close to the transmitting device 902. This may thus cause the transmitting device 902 to change DPD/CFR mode to meet the new ACLR requirements.

In some aspects, the present disclosure relates to the transmitting device 902 transmitting the non-linearity change indication 924 to the receiving device 904 as long as there is a change (e.g., some degree of change) in the non-linearity model. In some examples, the transmitting device 902 transmits the indication 924 whenever the transmitting device 902 detects a change in conditions that result in a change in the non-linearity model (e.g., a change affecting the operating state of the power amplifier 912). In some examples, the transmitting device 902 transmits the indication 924 whenever the transmitting device 902 modifies a parameter (e.g., configuration of the CFR component 908 and/or the DPD component 910) that causes a change in the non-linearity model.

The manner in which the non-linearity model changes (and thus the manner in which the recipient device 904 learns of the changes) may depend on the cause of the changes. For example, when transmitting device 902 changes DPD configuration, relatively abrupt changes (e.g., large and rapid changes) may occur in the non-linearity model. Thus, for DPD changes, the recipient device 904 may need to immediately receive the change indication to enable the recipient device 904 to quickly calculate a new non-linearity model. In contrast, temperature variations of the power amplifier 912 may cause relatively slow changes in the non-linearity model. In some examples, these slow changes may be tracked and handled by periodic recalculation of the non-linearity model in the recipient device 904 (e.g., the indication 924 may not be used to indicate slow changes in the non-linearity model in some examples).

Upon receiving the indication 924, the recipient device 904 may update its locally stored non-linearity model. For example, the recipient device 904 can update its estimate of the effective power amplifier model used by the DPoD component 920 to apply DPoD to the received signal.

In some examples, as a result of receiving the indication 924, the recipient device 904 may autonomously re-estimate the non-linearity model (e.g., new DPoD functionality). For example, the receiver device 904 can determine the new non-linearity model by selecting a new set of kernels based on dedicated pilots received from the transmitter device 902. After selecting the new set of kernels, the recipient device 904 uses these kernels to calculate new coefficients. The new kernel and set of coefficients build a new G (x) that will be used later in the DPoD process.

The following is a more detailed example of an estimation of the non-linearity model G (x). The recipient device 904 will have a list of kernels corresponding to the current nonlinearity model (e.g., the transmitting device 902 may have sent the initial list to the recipient device 904). The receiver device then estimates kernel coefficients in each signal reception based on the received dedicated pilots (using a given set of kernels, the receiver device may apply a least squares estimation). The resulting new kernel and set of coefficients provide an updated G (x) that the DPoD component 920 will use in the nonlinear distortion estimation stage.

In some examples, the receiver device 904 may send a request for the nonlinearity information to the transmitter device 902 to assist the receiver device 904 in the calculation of the new nonlinearity model. In response to the request, the transmitting device 902 may transmit the nonlinearity parameter 926 to the receiving device 904. For example, the transmitting device 902 may send a new set of nonlinearity kernels for the nonlinearity model. As another example, the transmitting device 902 may send the complete non-linearity model (effective PA model). For example, the transmitting device may send the kernel and coefficients of the new non-linearity model.

In different examples, the transmitting device 902 may transmit the nonlinearity parameter 926 in different ways. In some examples, the transmitting device 902 may transmit the nonlinearity parameter 926 whenever there is a change (e.g., a degree of change) in the nonlinearity model. In some examples, the transmitting device 902 may transmit the indication 924 and the nonlinearity parameter 926 in separate transmissions. In some examples, the transmitting device 902 may transmit the indication 924 and the nonlinearity parameter 926 in the same transmission (e.g., in a single message). In some examples, the transmission of the nonlinearity parameter 926 may be used as an indication that there is a change (e.g., a change to some extent) in the nonlinearity model (e.g., the indication 924 may not be sent in this case).

In some aspects, the present disclosure relates to the receiver device 904 assisting the transmitter device 902 in calculating DPD information for the DPD component 910. For example, when the non-linearity model is changed, the receiver device 904 may calculate DPD information 928 (e.g., DPD coefficients such as α of equation 4 below) and transmit the DPD information 928 to the transmitter device 902. The DPD component 910 may then use the DPD information 928 for DPD of the signal provided to the power amplifier 912. In different implementations, the computation of DPD may be complete or partial. In the case of partial calculations, the remaining calculations are done in the transmitting device.

In some examples (e.g., where the receiver device 904 indicates that it can calculate DPD information), the transmitter device 902 sends a request to the receiver device to jointly calculate DPD information and DPoD information and send the DPD information to the transmitter device 902. In some aspects, such joint calculation may enable optimization of the balance between in-band compensation and out-of-band compensation for DPD component 910 (e.g., because a single device may select weights for different frequency bands and/or frequency band windows to achieve optimal results).

The transmitting device 902 may send one or more constraints to the receiving device 904 for DPD calculation. For example, such a constraint may be an ACLR requirement defining an upper limit that should not be exceeded. The transmitting device 902 may send weights to the receiving device 904 for DPD calculation optimization. For example, different weights may be defined for different frequency bands (e.g., to assign higher weights to out-of-band frequencies and lower weights to in-band frequencies).

In some examples, DPD component 910 may be tuned to mitigate out-of-band emissions. Fig. 10 illustrates a high-level example of DPD training circuit 1000. Here, a power amplifier 1002 (e.g., power amplifier 912 of fig. 9) amplifies a signal y to provide a signal x. DPD component 1004 (e.g., DPD component 910 of fig. 9) generates an output signal that is provided to training component 1006, which training component 1006 tunes the DPD configuration to minimize Least Squares Error (LSE). In the example of fig. 10, DPD component 1004 is depicted after power amplifier 1002 (in reverse order of these components in fig. 9) to illustrate the (typical) calculation procedure of DPD. The model for the power amplifier 1002 may take the form of y≡xα, where y is the PA input, X is the PA output, and X is the kernel matrix of X, as set forth, for example, in equation 3. The kernel matrix (e.g., comprising nonlinear kernels) may be selected based on characteristics of the power amplifier 1002 (e.g., using known kernel matrix techniques).

X＝[f ₀ (x) f ₁ (x) …]Kernel matrix of x

Equation 3

f _i (x) Is the ith NL kernel applied to x

The training component 1006 can train (e.g., tune) the DPD by solving a Least Squares (LS) problem, as set forth, for example, in equation 4.

α＝argmin||y-Xα|| ² ＝(X ^H X) ^-1 X ^H y

Equation 4

Thus, the goal is to calculate the coefficient α such that the combination of the power amplifier 1002 and DPD component 1004 is linear. In other words, multiplying the output x of PA by α should result in PA input y.

In some examples, training may be based on weights applied under certain conditions. For example, different weights may be applied for different frequency bands, as mentioned above. Equation 5 illustrates an example of equation 4 that has been modified to accommodate weights, where W is a weight vector and F is a linear transformation (e.g., a Fast Fourier Transform (FFT) matrix).

α＝argmin||WF(y-Xα)|| ²

Equation 5

Fig. 11 illustrates a more detailed example 1100 of DPD training circuit 1000 in which a receive chain of a receiver device (e.g., receiver device 904 of fig. 9) feeds information back to a transmit chain of a transmitter device (e.g., transmitter device 902 of fig. 9).

The transmit chain includes a DPD component 1102 (e.g., DPD component 910 of fig. 9), a digital-to-analog converter (DAC) 1104, a filter 1106, a mixer 1108, and a power amplifier 1110 (e.g., power amplifier 912 of fig. 9). The transmit chain processes the signal x and amplifies the signal y for transmission to the receive chain.

The receive chain includes a Low Noise Amplifier (LNA) 1112, a mixer 1114, a filter 1116, an analog-to-digital converter (ADC) 1118, and a nonlinear forward model coefficient estimation component 1120. The estimation component 1120 calculates information (e.g., X, coefficients, etc.) based on the received signal and communicates the information to the transmit chain.

In the transmit chain, digital PA model 1122 in conjunction with DPD parameter estimation component 1124 generate DPD parameters for DPD component 1102 based on information received from the receive chain. In the example of fig. 11, it is shown that the receiver side calculates the forward NL model, which is then sent to the transmitter side (which calculates DPD (reverse model)). In other examples, DPD may be calculated in other ways. For example, the transmitting side may also calculate DPD (reverse model) itself. As used herein, the term forward model refers to the PA model and the term reverse model refers to the DPD model. The DPD model is referred to as the inverse model because it is intended to reverse PA operation. The receiver side may calculate either model and send the calculated model to the transmitter side. If the receiver side calculates the DPD model, the transmitter side calculates DPD coefficients from the received DPD model and then uses those coefficients for DPD operations (DPD based corrections).

Charts 1126, 1128, 1130, and 1132 of fig. 11 illustrate input-to-output responses of the different components of fig. 11. For example, chart 1126 illustrates that the response of DPD component 1102 corresponds to the inverse of the response of power amplifier 1110 (as represented by chart 1128). Graph 1130 illustrates that DPD component 1102 compensates for the nonlinearity of power amplifier 1110 such that the transmitted signal corresponds to response 606 of fig. 6. Diagram 1132 illustrates the estimation component 1120 generating information corresponding to the response of the power amplifier 1110.

Referring now to the DPoD procedure of the receiver device, as mentioned above, the receiver device may receive a data signal y comprising a nonlinear distortion component d. In some examples, the DPoD process is based on modeling nonlinear distortion as an additive signal. For example, as shown in fig. 12, the output of a Power Amplifier (PA) 1202 of a transmitting device may be represented by y=g (x) =ax+d.

In some examples, the DPoD process may be an iterative process based on Bussgang decomposition discussed below. As shown in fig. 12, the receiver device essentially provides a nonlinear equalizer (S) 1204 in which the response H of the Power Amplifier (PA) 1206 is inverted after use (H ^-1 _p ) 1208.

Fig. 13 illustrates a receive chain 1300 of a receiver device that includes a DPoD component 1302 with an input-to-output response 1304. The receive chain 1300 may include an LNA 1306, a Surface Acoustic Wave (SAW) component 1308, a mixer 1310, a filter 1312, and an ADC 1314, similar to the receive chain of fig. 11. As indicated by response 1316, response 1304 of DPoD component 1302 can be the inverse of the response of the transmitted signal.

An example of a DPoD procedure implemented using an iterative Bussgang decomposition procedure is illustrated in table 1.

TABLE 1

Here, y (x) is the received signal at the receiver device after channel equalization. The signal y (x) (i.e., y) is based on the original data signal x at the transmitting device. As discussed above, the original data signal x is subject to nonlinear distortion (e.g., at CFR 908, DPD 910, and PA 912 of fig. 9). The term G (x) represents this nonlinear distortion model.

The distorted signal may be considered as x (e.g., ax) with a scaled version of the nonlinear distortion component d. In some examples, the scaling factor α may be a Bussgang coefficient. In Table 1, bussgang coefficient α=argmin E [ |y-ax| ² ]. In BussgangIn the solution y=αx+d, the linear term x and the nonlinear distortion component d are orthogonal to each other. The way alpha is calculated (i.e., alpha = argmin E [ |y-ax| ² ]) This orthogonality is ensured. This can be shown by taking the derivative of the expression and comparing it to zero (0).

Parameters in Table 1Nonlinear distortion occurring at the transmitting device may be represented. The DPoD reconstruction procedure involves estimating nonlinear distortion in the received signal>With each iteration of the loop, x and +.>Is a more accurate estimate of (a).

Initially the first time the second time the,is set to 0. The iterative process then starts with a correction phase, in which +.>Is subtracted from the received signal y. In the decision (e.g., slicing) stage, the resulting y _corrected The values are scaled by 1/α, converted to the frequency domain (e.g., to obtain a constellation representation of OFDM symbols), and then sliced (e.g., to estimate signal values) using knowledge of the modulation used by the transmitting device (e.g., 64QAM, 256QAM, etc.). This result is converted back into the time domain to obtain an estimated signal +. >In different examples, the slicing operations of the decision stage may take different forms. In some examples, the slicing operation is a hard slicing operation. In some examples, the slicing operation is a soft slicing operation. In some examples, the slicing operation is a transparent slicing operation. In some aspects, transparent slicing means that the output of the slicing function is equal toAnd (5) inputting.

In the estimation phase, the reconstruction process applies the same nonlinear distortion G (x) applied by the transmitting device to the original data signal x toHere, by removing the scaled version +_from the nonlinear distortion signal>Obtain->Is a new estimate of (a). In the next iteration of the loop, this +.>The value is removed from y during the correction phase to get y _corrected Is a better estimate of (c).

The iterative loop may be performed one or more times (e.g., depending on the desired performance level). In some examples, the iterative loop is performed a defined number of times (e.g., once, twice, etc.).

In some examples, an iterative loop is performed until a defined criterion (e.g., convergence) is met. For example, if the Mean Square Error (MSE) as measured at the slicer output is less than or equal to the error threshold, the iteration may be stopped. It should be appreciated that for purposes of illustration, the DPoD process has been described without accounting for multipath channels. DPoD may be modified to take multipath channels into account by, for example, adding: 1) For y _corrected To remove the channel; and 2) subtracting from y to obtain y _corrected Previously convolved with the channel of d.

In different examples, the non-linearity model G (x) used in the above estimation stage may be obtained in different ways. As mentioned above, in some examples, the receiver device receives from the sender device the nonlinearity parameters for the nonlinearity model, and calculates the nonlinearity model based on those parameters. In some examples, the transmitting device sends the entire nonlinearity model to the receiving device. In some examples, the recipient device autonomously estimates the non-linearity model.

Fig. 14 illustrates that using DPD and DPoD as disclosed herein can increase power efficiency while still meeting out-of-band emissions requirements (e.g., ACLR constraints). The use of DPoD itself may provide significant gains in performance if ACLR limitations are ignored. When ACLR constraints are considered, DPoD gain may be relatively limited. One way to alleviate this problem is to use a combination of dpd+dpod as described herein. Another way to partially alleviate this problem is to have dynamic out-of-band requirements so that these requirements can be relaxed where possible, allowing more gain of the DPoD.

For example, chart 1402 of fig. 14 illustrates an example of EVM at a receiver device for different modulation schemes (QPSK, 16QAM, 64QAM, and 256 QAM). Generally, at higher gain states of the power amplifier, nonlinear distortion increases, thereby deteriorating ACLR. Line 1404 represents the EVM when DPD and DPoD are not enabled. Line 1406 represents the EVM when DPD is not enabled but DPoD is enabled. Line 1408 illustrates the DPoD gain for 64 QAM. Line 1410 illustrates the DPoD gain for 128 QAM. In this example, an ACLR limit of-28 dB is employed, and is exceeded if a gain state greater than 10 is used. This is a significant constraint on power efficiency.

In contrast, the chart 1412 of fig. 14 illustrates an example of EVM at a recipient device when using a combination of DPD and DPoD to achieve DPoD with out-of-band emissions compliance as taught herein. As discussed above, the DPD component compensates for out-of-band emissions, while the DPoD component compensates for EVM. Line 1414 represents the EVM when DPD and DPoD are not enabled (as in graph 1402). Line 1416 represents the minimum EVM with ACLR still met, with CFR, DPD and DPoD configurations selected appropriately. Line 1418 illustrates the DPoD gain for 64 QAM. Line 1420 illustrates the DPoD gain for 128 QAM. Thus, it can be seen that the combination of DPD and DPoD can provide a significant increase in power efficiency (e.g., up to gain state 14). Furthermore, as discussed above, the combination of DPD and DPoD may also enable out-of-band combination compliance.

In the combined DPD-DPoD scheme discussed above, the PAPR of the signal may be increased (e.g., compared to other schemes). As discussed above, a higher PAPR may adversely affect PA reliability. In some aspects, the present disclosure relates to mitigating such reliability issues by limiting the instantaneous input power of the PA.

For the combined scheme of dpd+dpod, an additional CFR module may be introduced between the DPD and the PA to limit the instantaneous input power to the PA. In some aspects, the effective PA model may be modified using this additional CFR module. Thus, the characteristics of this additional CFR module may be communicated to the recipient device so that the DPoD algorithm may be modified accordingly.

Fig. 15 illustrates an example of a wireless communication system 1500 that includes a transmitting device 1502 and a receiving device 1504, wherein the transmitting device 1502 employs two CFR functions. As in the example of fig. 9, DPD is employed at the transmitting device 902 and DPoD is employed at the receiving device 1504.

Fig. 15 illustrates several components of a transmit chain of a transmitting device 1502. The transmit chain includes a transmit baseband component 1506, a first CFR component 1508, a DPD component 1510, a second CFR component 1512, a power amplifier 1514, and at least one antenna 1516. As mentioned above, in some examples, each CFR component 1508 or 1512 may apply clipping and filtering.

Fig. 15 also illustrates several components of the receive chain of the receiver device 1504. The receive chain includes at least one antenna 1518, a DPoD component 1520 (e.g., a digital post-distorter), and a receive baseband component 1522. In some examples, the DPoD function performed by the DPoD component 1520 is based on a non-linearity model of the active power amplifier (e.g., active power amplifier model 1524). Accordingly, the recipient device 1504 may maintain a local copy of the non-linearity model (e.g., an estimate of the effective power amplifier model 1524) for use by the DPoD component 1520.

In the example of fig. 15, the effective power amplifier model 1524 for the transmitting device 1502 is based on the first CFR component 1508, the DPD component 1510, the second CFR component 1512, and the power amplifier 1514. To enable the receiver device to determine the non-linearity model, the transmitter device 1502 transmits the valid PA parameters 1526 to the receiver device 1504. In some examples, the effective PA parameters 1526 may include a first parameter (e.g., clipping level) for the first CFR component 1508, a second parameter (e.g., kernel and associated parameters) for the DPD component 1510, a third parameter (e.g., clipping level) for the second CFR component 1512, and a fourth parameter (e.g., kernel and associated parameters) for the power amplifier 1514. In some examples, the first CFR component 1508 may clip the signal to an absolute voltage level. In some examples, the second CFR component 1512 may clip the signal to meet a target PAPR of a transmission using the power amplifier 1514.

Table 2 illustrates an example of signal processing operations that may be performed by the first CFR component 1508, the DPD component 1510, and the second CFR component 1512 of the transmitting device 1502. Signal s [ n ]]Is the original OFDM time domain waveform input to the first CFR component 1508. The output x [ n ] of the first CFR component 1508]Is an input to DPD component 1510. Output of DPD assembly 1510Is an input to the second CFR component 1512. The output y n of the second CFR component 1512]Is the input to the power amplifier 1514. />

TABLE 2

Table 3 illustrates an example of signal processing operations that may be performed by the DPoD component 1520 of the recipient device 1504. As discussed above, the DPoD function involves iterative operations. In this example, the operation is based in part on parameters of both the first CFR component 1508 and the second CFR component 1512.

/>

TABLE 3 Table 3

Fig. 16 is a signaling diagram 1600 illustrating an example of signaling related to a non-linearity model in a wireless communication system including a sender device 1602 and a receiver device 1604. In some examples, the transmitting device 1602 may correspond to any of the transmitting devices shown in any of fig. 7-9, 15, and 17-19. In some examples, the transmitting device 1602 may correspond to any of the network entities, base stations, CUs, DUs, RUs, or scheduling entities shown in any of fig. 1-3, 20, and 24. In some examples, the transmitting device 1602 may correspond to any of the UEs or scheduled entities shown in any of fig. 1-3, 20, and 24. In some examples, the recipient device 1604 may correspond to any of the recipient devices shown in any of figures 7-9, 15, and 17-19. In some examples, the receiver device 1604 may correspond to any of the network entities, base stations, CUs, DUs, RUs, scheduling entities shown in any of fig. 1-3, 20, and 24. In some examples, the recipient device 1604 may correspond to any of the UEs or scheduled entities shown in any of fig. 1-3, 20, and 24.

At #1606 of fig. 16, a change in the non-linearity (NL) model occurs at the transmitting device 1602. For example, the transmitting device 1602 may detect or cause a change in the DL model, as discussed above.

At #1608, the sender device 1602 sends an indication of the change to the NL model to the receiver device 1604.

At optional #1610, the sender device 1602 may send NL parameters to the receiver device 1604. For example, the sender device 1602 may send a set of kernels corresponding to the new NL model or the entire new NL model to the receiver device 1604.

At #1612, the recipient device 1604 determines a new NL model for its DPoD procedure. As discussed above, the recipient device may calculate the NL model itself (e.g., based on the received pilot signal), the recipient device may calculate the NL model based on the NL parameters received at #1610, the recipient device may obtain the entire NL model from the NL parameters received at #1610, or the recipient device 1604 may determine the new NL model in some other way.

At #1614, the transmitting device 1602 may calculate parameters (e.g., DPD coefficients) for its DPD procedure where applicable (e.g., due to changes in the NL model).

At #1616, the transmitting device 1602 applies DPD to the signal to be transmitted to the receiving device 1604 at # 1618.

At #1620, the receiver device 1604 applies DPoD (based on the new NL model) to the signal received at # 1618.

Fig. 17 is a signaling diagram 1700 illustrating an example of signaling related to a non-linearity model in a wireless communication system including a sender device 1702 and a receiver device 1704. In some examples, the transmitter device 1702 may correspond to any of the transmitter devices shown in any of fig. 7-9, 15, 16, and 18-19. In some examples, the transmitting device 1702 may correspond to any of the network entities, base stations, CUs, DUs, RUs, or scheduling entities shown in any of fig. 1-3, 20, and 24. In some examples, the transmitting device 1702 may correspond to any of the UEs or scheduled entities shown in any of fig. 1-3, 20, and 24. In some examples, the recipient device 1704 may correspond to any of the recipient devices shown in any of figures 7-9, 15, 16, and 18-19. In some examples, the recipient device 1704 may correspond to any of the network entities, base stations, CUs, DUs, RUs, scheduling entities shown in any of fig. 1-3, 20, and 24. In some examples, the recipient device 1704 may correspond to any of the UEs or scheduled entities shown in any of fig. 1-3, 20, and 24.

At #1706 of fig. 17, the receiver device 1704 notifies the transmitter device that the receiver device 1704 is able to calculate DPD information. For example, the recipient device 1704 may transmit a capability message including a DPD capability bit.

At #1708, the transmitting device 1702 transmits a request to the receiving device 1704 for the receiving device 1704 to calculate DPD information. In some examples, the transmitting device 1702 instructs the receiving device 1704 to perform joint DPD and DPoD operations.

At optional #1710, the transmitting device 1702 may send DPD parameters to the receiving device 1704. For example, the transmitting device 1702 may send information (e.g., kernel type, DPD parameters, etc.) that the receiving device 1704 may use to calculate DPD information. As another example, the transmitting device 1702 may send at least one constraint (e.g., ACLR limit, weight, etc.) for calculating DPD information.

At #1712, the transmitting device 1702 transmits a signal to the receiving device 1704.

At #1714, the receiver device 1704 calculates DPD information (e.g., DPD coefficients) for the DPD procedure at the transmitter device 1702. For example, the recipient device may calculate the new DPD coefficients as a result of receiving an indication of a change to the NL model (e.g., as discussed above in connection with fig. 16).

In some examples, the recipient device 1704 jointly calculates DPD and DPoD information. For example, the receiver device 1704 may jointly calculate DPD parameters (e.g., DPD coefficients) for the DPD procedure of the transmitter device 1702 and DPoD parameters for the receiver device 1704 (e.g., joint calculation based on ACLR constraints).

At #1716, the receiver device 1704 sends DPD information to the transmitter device 1702.

At #1718, the transmitting device 1702 applies DPD (based on the DPD information received at # 1716) to another signal to be transmitted to the receiving device 1704.

Fig. 18 is a signaling diagram 1800 illustrating an example of signaling related to a non-linearity model in a wireless communication system including a transmitting device 1802 and a receiving device 1804. In some examples, the transmitting device 1802 may correspond to any of the transmitting devices shown in any of fig. 7-9, 15-17, and 19. In some examples, the transmitting device 1802 may correspond to any of the network entities, base stations, CUs, DUs, RUs, or scheduling entities shown in any of fig. 1-3, 20, and 24. In some examples, the transmitting device 1802 may correspond to any of the UEs or scheduled entities shown in any of fig. 1-3, 20, and 24. In some examples, the recipient device 1804 may correspond to any of the recipient devices shown in any of fig. 7-9, 15-17, 19. In some examples, the recipient device 1804 may correspond to any of the network entities, base stations, CUs, DUs, RUs, scheduling entities shown in any of fig. 1-3, 20, and 24. In some examples, the recipient device 1804 may correspond to any of the UEs or scheduled entities shown in any of fig. 1-3, 20, and 24.

At #1806 of fig. 18, a change in the non-linearity (NL) model occurs at the transmitting device 1802. For example, the transmitting device 1802 may detect or cause a change in the NL model, as discussed above.

At #1808, the transmitting device 1802 sends an indication of a change to the NL model to the receiving device 1804.

At optional #1810, the transmitting device 1802 may send NL parameters to the receiving device 1804. For example, the transmitting device 1802 may send a set of kernels corresponding to the new NL model or the entire new NL model to the receiving device 1804.

At #1812, the recipient device 1804 determines a new NL model for its DPoD procedure. As discussed above, the recipient device may calculate the NL model itself (e.g., based on the received pilot signal), the recipient device may calculate the NL model based on the NL parameters received at #1810, the recipient device may obtain the entire NL model from the NL parameters received at #1810, or the recipient device 1804 may determine the new NL model in some other way.

At #1814, the transmitting device 1802 transmits a signal to the receiving device 1804.

At #1816, the recipient device 1804 jointly calculates DPD and DPoD information. For example, the receiver device 1804 may jointly calculate DPD parameters (e.g., DPD coefficients) for the DPD procedure of the transmitter device 1802 and DPoD parameters for the receiver device 1804 (e.g., joint calculations based on ACLR constraints).

At #1818, the receiver device 1804 transmits the calculated DPD information to the transmitter device 1802.

Fig. 19 is a signaling diagram 1900 illustrating an example of signaling related to a non-linearity model in a wireless communication system including a sender device 1902 and a receiver device 1904. In some examples, the sender device 1902 may correspond to any of the sender devices shown in any of fig. 7-9 and 15-18. In some examples, the transmitting device 1902 may correspond to any of the network entities, base stations, CUs, DUs, RUs, or scheduling entities shown in any of fig. 1-3, 20, and 24. In some examples, the transmitting device 1902 may correspond to any of the UEs or scheduled entities shown in any of fig. 1-3, 20, and 24. In some examples, the recipient device 1904 may correspond to any of the recipient devices shown in any of figures 7-9 and 15-18. In some examples, the recipient device 1904 may correspond to any of the network entities, base stations, CUs, DUs, RUs, scheduling entities shown in any of fig. 1-3, 20, and 24. In some examples, the recipient device 1904 may correspond to any of the UEs or scheduled entities shown in any of fig. 1-3, 20, and 24.

At #1906 of fig. 19, the transmitting device 1902 sends an indication of its effective power amplifier parameters to the receiving device 1904. As discussed herein, these parameters may include parameters for the first CFR function, parameters for the DPD function, parameters for the second CFR function, and parameters for the power amplifier model.

At #1908, the recipient device 1904 determines an effective power amplifier model for its DPoD procedure based on the parameters received at # 1906.

At #1910, the transmitting device 1902 applies a first CFR function, a DPD function, a second CFR function, and a power amplification to signals to be transmitted to the receiving device 1904 at # 1912.

At #1914, the receiving device 1904 applies DPoD (based on the active power amplifier model determined at # 1908) to the signal received at # 1912.

Fig. 20 is a block diagram illustrating an example of a hardware implementation of a wireless communication device 2000 employing a processing system 2014. In some examples, the wireless communication device 2000 may be a UE or a scheduled entity configured to wirelessly communicate with a base station or a scheduling entity, as discussed in any one or more of fig. 1-19. In this case, the wireless communication device 2000 may correspond to any of the UEs or scheduled entities shown in any of fig. 1-3 and 24. In some examples, the wireless communication device 2000 may be a base station or scheduling entity configured to wirelessly communicate with a UE or scheduled entity, as discussed in any one or more of fig. 1-19. In this case, the wireless communication apparatus 2000 may correspond to any of the base stations or scheduling entities shown in any of fig. 1-3 and 24. In some examples, the wireless communication device 2000 may correspond to any of the transmitting devices shown in any of fig. 7-9 and 15-19. In some examples, the wireless communication device 2000 may correspond to any of the recipient devices shown in any of fig. 7-9 and 15-19.

According to various aspects of the disclosure, an element, or any portion of an element, or any combination of elements, may be implemented using the processing system 2014. The processing system 2014 may include one or more processors 2004. Examples of processor 2004 include microprocessors, microcontrollers, digital Signal Processors (DSPs), field Programmable Gate Arrays (FPGAs), programmable Logic Devices (PLDs), state machines, gate logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionalities described throughout this disclosure. In various examples, the wireless communication device 2000 may be configured to perform any one or more of the functions described herein. That is, as utilized in the wireless communication device 2000, the processor 2004 may be utilized to implement any one or more of the processes and procedures described herein.

In some examples, the processor 2004 may be implemented via a baseband or modem chip, while in other implementations, the processor 2004 may include several devices that are distinct and different from the baseband or modem chip (e.g., may work cooperatively in such scenarios to arrive at the examples discussed herein). And as mentioned above, various hardware arrangements and components outside of the baseband modem processor may be used in implementations, including RF chains, power amplifiers, modulators, buffers, interleavers, adders/summers, and the like.

In this example, the processing system 2014 may be implemented with a bus architecture, represented generally by the bus 2002. The bus 2002 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 2014 and the overall design constraints. The bus 2002 communicatively couples various circuitry including one or more processors (represented generally by the processor 2004), memory 2005, and computer-readable media (represented generally by the computer-readable media 2006). The bus 2002 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. Bus interface 2008 provides an interface between bus 2002 and transceiver 2010 and antenna array 2020, and between bus 2002 and interface 2030. The transceiver 2010 provides a communication interface or means for communicating with various other apparatus over a wireless transmission medium. Interface 2030 provides a communication interface or means for communicating with various other apparatus and devices over an internal bus or external transmission medium, such as an ethernet cable, for example, other devices housed within the same apparatus or other external device as wireless communication device 2000. Depending on the nature of the equipment, interface 2030 may include a user interface (e.g., keypad, display, speaker, microphone, joystick). Of course, such user interfaces are optional and may be omitted in some examples (such as base stations).

The processor 2004 is responsible for managing the bus 2002 and general processing, including the execution of software stored on the computer-readable medium 2006. The software, when executed by the processor 2004, causes the processing system 2014 to perform the various functions described infra for any particular apparatus. The computer-readable medium 2006 and the memory 2005 can also be used for storing data that is manipulated by the processor 2004 when executing software. For example, the memory 2005 may store NL model information 2015 (e.g., kernels, coefficients, etc.) that is used by the processor 2004 in conjunction with the transceiver 2010 for NL model-related operations described herein.

One or more processors 2004 in a processing system may execute software. Software should be construed broadly to mean instructions, instruction sets, code segments, program code, programs, subroutines, software modules, applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether described in software, firmware, middleware, microcode, hardware description language, or other terminology. The software may reside on the computer readable medium 2006.

The computer readable medium 2006 may be a non-transitory computer readable medium. By way of example, non-transitory computer-readable media include magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips), optical disks (e.g., compact Disk (CD) or Digital Versatile Disk (DVD)), smart cards, flash memory devices (e.g., card, stick, or key drive), random Access Memory (RAM), read Only Memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically Erasable PROM (EEPROM), registers, removable disk, and any other suitable medium for storing software and/or instructions that can be accessed and read by a computer. The computer readable medium 2006 may reside within the processing system 2014, external to the processing system 2014, or distributed across multiple entities including the processing system 2014. The computer readable medium 2006 may be embodied in a computer program product. By way of example, a computer program product may include a computer readable medium in an encapsulating material. Those skilled in the art will recognize how to best implement the described functionality presented throughout this disclosure depending on the particular application and overall design constraints imposed on the overall system.

The wireless communication device 2000 may be configured to perform any one or more operations as described herein (e.g., as described above in connection with fig. 1-19 and as described below in connection with fig. 21-23). In some aspects of the disclosure, the processor 2004 as utilized in the wireless communication device 2000 may include circuitry configured for various functions.

The processor 2004 may include communication and processing circuitry 2041. In examples where the wireless communication device 2000 is a scheduled entity (e.g., a UE), the communication and processing circuitry 2041 may be configured to communicate with a scheduling entity, such as a base station. In examples where the wireless communication device 2000 is a scheduling entity (e.g., a base station), the communication and processing circuitry 2041 may be configured to communicate with a scheduled entity (such as a UE). The communication and processing circuitry 2041 may include one or more hardware components that provide physical structure to perform various processes related to wireless communication (e.g., signal reception and/or signal transmission) as described herein. The communication and processing circuitry 2041 may further include one or more hardware components that provide physical structure to perform various processes related to signal processing (e.g., processing received signals and/or processing signals for transmission) as described herein. In some examples, the communication and processing circuitry 2041 may include two or more transmit/receive chains, each configured to process signals of a different RAT (or RAN) type. The communication and processing circuitry 2041 may be further configured to execute the communication and processing software 2051 included on the computer readable medium 2006 to implement one or more of the functions described herein.

In some implementations in which communication involves receiving information, the communication and processing circuitry 2041 may obtain information from components of the wireless communication device 2000 (e.g., from the transceiver 2010 that receives information via radio frequency signaling or some other type of signaling suitable for the applicable communication medium), process (e.g., decode) the information, and output the processed information. For example, communication and processing circuitry 2041 may output information to another component of processor 2004, to memory 2005, or to bus interface 2008. In some examples, the communication and processing circuitry 2041 may receive one or more of signals, messages, other information, or any combination thereof. In some examples, communication and processing circuitry 2041 may receive information via one or more channels. In some examples, the communication and processing circuitry 2041 may include functionality for a receiving device. In some examples, the communication and processing circuitry 2041 may include functionality of means for decoding.

In some implementations in which communication involves sending (e.g., transmitting) information, communication and processing circuitry 2041 may obtain the information (e.g., from another component of processor 2004, memory 2005, or bus interface 2008), process (e.g., encode) the information, and output the processed information. For example, the communication and processing circuitry 2041 may output information to the transceiver 2010 (e.g., which communicates the information via radio frequency signaling or some other type of signaling suitable for the applicable communication medium). In some examples, the communication and processing circuitry 2041 may send one or more of signals, messages, other information, or any combination thereof. In some examples, communication and processing circuitry 2041 may send information via one or more channels. In some examples, the communication and processing circuitry 2041 may include functionality for transmitting (e.g., means for transmitting). In some examples, the communication and processing circuitry 2041 may include functionality of means for encoding.

The processor 2004 may include non-linearity (NL) processing circuitry 2042 configured to perform NL processing-related operations as discussed herein (e.g., one or more of the NL processing-related operations described in connection with fig. 6-19). The NL processing circuitry 2042 can be configured to execute NL processing software 2052 included on the computer readable medium 2006 to implement one or more functions described herein.

In some examples, NL processing circuitry 2042 can include functionality for pre-distorting signals. For example, NL processing circuitry 2042 can be configured to apply DPD functionality to signals to be amplified and transmitted. In some examples, the DPD function may be based on equation 2.

In some examples, the NL processing circuitry 2042 may include functionality for transmitting signals to a wireless communication device. For example, NL processing circuitry 2042 can be configured to apply a first CFR function, a DPD function, and a second CFR function to signals to be amplified and transmitted (e.g., as described in #1910 of fig. 19).

The processor 2004 may include model processing circuitry 2043 configured to perform operations related to model processing as discussed herein (e.g., one or more of the operations related to model processing described in connection with fig. 6-19). The model processing circuitry 2043 may be configured to execute model processing software 2053 included on the computer readable medium 2006 to implement one or more functions described herein.

In some examples, the model processing circuitry 2043 may include functionality of means for determining a change in the non-linearity model. For example, the model processing circuitry 2043 may be configured to determine new parameters for the model based on the received signals (e.g., as described in #1606 of fig. 16).

In some examples, the model processing circuitry 2043 may include functionality for transmitting an indication of a change in the non-linearity model. For example, the model processing circuitry 2043 may be configured to send an indication of the change (e.g., as described in #1608 and/or #1610 of fig. 16) to the transmitting device via the designated wireless communication channel.

In some examples, the model processing circuitry 2043 may include functionality for transmitting an indication associated with a non-linearity model for the power amplifier circuit. For example, the model processing circuitry 2043 may be configured to send an indication (e.g., as depicted in #1906 of fig. 19) to the wireless communication device via the designated wireless communication channel including the first parameter for the first CFR function, the second parameter for the DPD function, and the third parameter for the second CFR function.

The processor 2004 may include Digital Predistortion (DPD) control circuitry 2044 configured to perform operations related to DPD control as discussed herein (e.g., one or more DPD control processing operations described in connection with fig. 6-19). The DPD control circuitry 2044 may be further configured to execute DPD control software 2054 included on the computer readable medium 2006 to implement one or more of the functions described herein.

In some examples, DPD control circuitry 2044 may include functionality for means for receiving DPD information. For example, DPD control circuitry 2044 may be configured to receive DPD information from the recipient device via the designated channel (e.g., as described in #1716 of fig. 17 and/or #1818 of fig. 18).

The transceiver 2010 may include amplifier circuitry (e.g., a power amplifier) configured to amplify the predistorted signal to provide an amplified signal. The transceiver 2010 may include a circuit system configured to transmit an amplified signal.

Fig. 21 is a flow chart illustrating an example method 2100 for wireless communication in accordance with some aspects of the present disclosure. As described below, some or all of the illustrated features may be omitted from a particular implementation within the scope of the present disclosure, and some of the illustrated features may not be required to implement all examples. In some examples, the method 2100 may be performed by the wireless communication device 2000 illustrated in fig. 20. In some examples, method 2100 may be performed by any suitable apparatus or device for implementing the functions or algorithms described below.

At block 2102, the first wireless communication device may determine a change in a non-linearity model for a power amplifier circuit including a digital predistorter. For example, model processing circuitry 2043, shown and described above in connection with fig. 20, along with communication and processing circuitry 2041 and transceiver 2010, may provide means for determining changes in a non-linearity model for a power amplifier circuit including a digital predistorter.

In some examples, determining the change in the non-linearity model may include detecting a change associated with a power amplifier of the power amplifier circuit. In some examples, determining the change in the non-linearity model may include changing a configuration of the digital predistorter. In some examples, determining the change in the non-linearity model may include changing a configuration of a crest factor reducer of the power amplifier circuit. In some examples, determining the change in the non-linearity model may include determining at least one of: a change in an in-band distortion parameter, a change in an out-of-band emission parameter, a change in a maximum power reduction parameter, a change in a modulation to be used when transmitting a signal via a power amplifier circuit, or a combination thereof. In some examples, the change in demodulation triggers a change in backoff, which results in a change in the non-linearity model.

At block 2014, the first wireless communication device may transmit an indication of a change in the non-linearity model to the second wireless communication device. In some examples, the indication of the change in the non-linearity model may include at least one non-linearity parameter of the non-linearity model. For example, model processing circuitry 2043, shown and described above in connection with fig. 20, together with communication and processing circuitry 2041 and transceiver 2010, may provide means for transmitting an indication of a change in the non-linearity model to a second wireless communication device.

In some examples, the indication of the change in the non-linearity model is for a digital post-distorter of the second wireless communication device. In some examples, the digital post-distorter is associated with mitigating out-of-band emissions. In some examples, a digital predistorter is associated with mitigating in-band emissions.

In some examples, the method may further include transmitting at least one nonlinearity parameter of the nonlinearity model to the second wireless communication device. In some examples, the at least one nonlinearity parameter may comprise at least one nonlinearity kernel of the digital predistorter. In some examples, the at least one non-linearity parameter may include a non-linearity model. In some examples, the at least one nonlinearity parameter is transmitted after determining the change in the nonlinearity model. In some examples, the at least one non-linearity parameter is transmitted after receiving a request for the at least one non-linearity parameter from the second wireless communication device.

In some examples, the method may further include receiving digital predistortion information from the second wireless communication device. In some examples, the method may further include adjusting the non-linearity model based on the digital predistortion information. In some examples, the first wireless communication device may receive digital predistortion information from the second wireless communication device, the digital predistortion information comprising at least a portion of a set of digital predistortion parameters for the digital predistorter. In some examples, the first wireless communication device may adjust parameters of the digital predistorter based on the digital predistortion information.

In some examples, a first wireless communication device may receive a first message from a second wireless communication device. In some examples, the first message indicates that the second wireless communication device has the capability to calculate digital predistortion information. In some examples, the first wireless communication device may transmit the second message to the second wireless communication device after receiving the first message. In some examples, the second message requests the second wireless communication device to calculate digital predistortion information and transmit the digital predistortion information to the first wireless communication device. In some examples, the digital predistortion information is received from the second wireless communication device after transmitting the second message. In some examples, the second message further requests the second wireless communication device to calculate digital post-distortion information in combination with the digital pre-distortion information.

In some examples, the method may further comprise: receiving a first message from a second wireless communication device, wherein the first message indicates that the second wireless communication device has the capability to calculate digital predistortion information; transmitting a second message to the second wireless communication device after receiving the first message, wherein the second message requests the second wireless communication device to calculate digital predistortion information and transmit the digital predistortion information to the first wireless communication device. In some examples, the digital predistortion information is received from the second wireless communication device after transmitting the second message. In some examples, the second message requests the second wireless communication device to jointly calculate the digital predistortion information and the digital post-distortion information.

In some examples, the method may further include transmitting first information for calculating the digital predistortion information to the second wireless communication device. In some examples, the first information may include at least one of a kernel type, a digital predistortion parameter, or a combination thereof, and the digital predistortion information may include digital predistortion kernel coefficients.

In some examples, the method may further include transmitting at least one constraint for calculating the digital predistortion information to the second wireless communication device. In some examples, the at least one constraint may include at least one of an Adjacent Channel Leakage Ratio (ACLR) limit, a weight for at least one frequency band, or a combination thereof.

In some examples, the method may further comprise: receiving digital predistortion coefficients for the digital predistorter from the second wireless communication device; pre-distorting the signal based on the pre-distortion coefficients to provide a pre-distorted signal; amplifying the predistorted signal at a power amplifier of a power amplifier circuit to provide an amplified signal; and transmitting the amplified signal.

In some examples, the method may further comprise: calculating digital predistortion coefficients for the digital predistorter after determining the change in the non-linearity model (after its determination); pre-distorting the signal based on the pre-distortion coefficients to provide a pre-distorted signal; amplifying the predistorted signal at a power amplifier of a power amplifier circuit to provide an amplified signal; and transmitting the amplified signal to the second wireless communication device.

Fig. 22 is a flowchart illustrating an example method 2200 for wireless communication in accordance with some aspects of the present disclosure. As described below, some or all of the illustrated features may be omitted from a particular implementation within the scope of the present disclosure, and some of the illustrated features may not be required to implement all examples. In some examples, the method 2200 may be performed by the wireless communication device 2000 illustrated in fig. 20. In some examples, method 2200 may be performed by any suitable apparatus or device for implementing the functions or algorithms described below.

At block 2202, the first wireless communication device may receive digital predistortion information from the second wireless communication device. In some examples, the digital predistortion information may include digital predistortion coefficients. For example, DPD control circuitry 2044 shown and described above in connection with fig. 20, along with communication and processing circuitry 2041 and transceiver 2010, may provide means for receiving digital predistortion information from a second wireless communication device.

At block 2204, the first wireless communication device may predistort the signal based on the predistortion information to provide a predistorted signal. For example, NL processing circuitry 2042 shown and described above in connection with fig. 20 can provide, along with communication and processing circuitry 2041 and transceiver 2010, means for predistorting a signal based on predistortion information to provide a predistorted signal.

At block 2206, the first wireless communication device may amplify the predistorted signal to provide an amplified signal. For example, the communication and processing circuitry 2041 and transceiver 2010 shown and described above in connection with fig. 20 may provide means for amplifying a predistorted signal to provide an amplified signal.

At block 2208, the first wireless communication device may transmit the amplified signal to the second wireless communication device. For example, the communication and processing circuitry 2041 and transceiver 2010 shown and described above in connection with fig. 20 may provide means for transmitting an amplified signal to a second wireless communication device.

In some examples, the method may further comprise: receiving a first message from a second wireless communication device, wherein the first message indicates that the second wireless communication device has the capability to calculate digital predistortion information; and transmitting the second message to the second wireless communication device after receiving the first message. In some examples, the second message requests the second wireless communication device to calculate digital predistortion information and transmit the digital predistortion information to the first wireless communication device. In some examples, the digital predistortion information is received from the second wireless communication device after transmitting the second message. In some examples, the second message requests the second wireless communication device to jointly calculate the digital predistortion information and the digital post-distortion information.

In some examples, the method may further include transmitting first information for calculating the digital predistortion information to the second wireless communication device. In some examples, the first information may include at least one of a kernel type, a digital predistortion parameter, or a combination thereof, and the digital predistortion information may include digital predistortion kernel coefficients.

In some examples, the method may further include transmitting at least one constraint for calculating the digital predistortion information to the second wireless communication device. In some examples, the at least one constraint may include an Adjacent Channel Leakage Ratio (ACLR) limit. In some examples, the at least one constraint may include at least one weight for the at least one frequency band.

Fig. 23 is a flow chart illustrating an example method 2300 for wireless communication, according to some aspects of the disclosure. As described below, some or all of the illustrated features may be omitted from a particular implementation within the scope of the present disclosure, and some of the illustrated features may not be required to implement all examples. In some examples, method 2300 may be performed by wireless communication device 2000 illustrated in fig. 20. In some examples, method 2300 may be performed by any suitable apparatus or device for implementing the functions or algorithms described below.

At block 2302, the first wireless communication device may transmit an indication associated with a non-linearity model for the power amplifier circuit to the second wireless communication device, the indication including a first parameter for a first crest factor reduction function, a second parameter for a digital predistortion function, and a third parameter for a second crest factor reduction function. For example, model processing circuitry 2043, shown and described above in connection with fig. 20, together with communication and processing circuitry 2041 and transceiver 2010, may provide means for transmitting an indication associated with a non-linearity model for the power amplifier circuit to the second wireless communication device.

At block 2304, the first wireless communication device may transmit a first signal to the second wireless communication device, the first signal based on the first crest factor reduction function, the digital predistortion function, and the second crest factor reduction function. In some examples, the indication of the change in the non-linearity model may include at least one non-linearity parameter of the non-linearity model. For example, NL processing circuitry 2042 shown and described above in connection with fig. 20, along with communication and processing circuitry 2041 and transceiver 2010, can provide means for transmitting a first signal to a second wireless communication device.

In some examples, the first parameter may include a first clipping level associated with a first crest factor reduction function. In some examples, the first clipping level is an absolute clipping level.

In some examples, the third parameter may include a second clipping level associated with a second crest factor reduction function. In some examples, the second clipping level is defined relative to a signal power associated with a transmission using the power amplifier circuit. In some examples, the second clipping level is associated with a target peak-to-average power ratio associated with transmissions using the power amplifier circuit.

In some examples, the second parameter may include at least one non-linearity kernel associated with the digital predistortion function. In some examples, the second parameter may include at least one nonlinearity parameter for at least one nonlinearity kernel associated with the digital predistortion function.

In some examples, the indication further includes a non-linearity model of the power amplifier circuit. In some examples, the non-linearity model of the power amplifier circuit may include at least one non-linearity kernel.

In some examples, the first wireless communication device may provide the second signal to a first crest factor reduction function to obtain a third signal. In some examples, the first wireless communication device may provide the third signal to a digital predistortion function to obtain the fourth signal. In some examples, the first wireless communication device may provide the fourth signal to a second crest factor reduction function to provide a fifth signal. In some examples, the first wireless communication device may provide the fifth signal to the power amplifier circuit to obtain the first signal.

In some examples, the first wireless communication device may transmit the indication based on a change in the non-linearity model.

In some examples, the first wireless communication device may receive a request for the indication from the second wireless communication device. In some examples, the first wireless communication device may transmit the indication after receiving the request.

In some examples, the first wireless communication device may receive digital predistortion information for a digital predistortion function from the second wireless communication device. In some examples, the first wireless communication device may adjust the non-linearity model based on the digital predistortion information.

In some examples, a first wireless communication device may receive a first message from a second wireless communication device. In some examples, the first message indicates that the second wireless communication device has the capability to calculate digital predistortion information for the digital predistortion function. In some examples, the first wireless communication device may transmit the second message to the second wireless communication device after receiving the first message. In some examples, the second message may include a request to the second wireless communication device to calculate digital predistortion information and transmit the digital predistortion information to the first wireless communication device. In some examples, the digital predistortion information is received from the second wireless communication device after transmitting the second message.

In some examples, the first wireless communication device may transmit a message requesting the second wireless communication device to calculate digital predistortion information for the digital predistortion function. In some examples, the message includes at least one parameter for calculating digital predistortion information to meet a target crest factor reduction clipping level associated with the digital predistortion function. In some examples, the at least one parameter includes: a first limit on instantaneous signal peaks at an input to the power amplifier, a second limit on peak-to-average power ratio associated with the power amplifier, or a combination thereof.

Referring again to fig. 20, in one configuration, the wireless communication device 2000 includes: means for determining a change in a non-linearity model for a power amplifier circuit including a digital predistorter; and means for transmitting an indication of the change in the non-linearity model to the second wireless communication device. In one configuration, the wireless communication device 2000 includes: means for receiving digital predistortion information from a second wireless communication device; means for predistorting the signal based on the predistortion information to provide a predistorted signal; means for amplifying the predistorted signal to provide an amplified signal; and means for transmitting the amplified signal to a second wireless communication device. In one configuration, the wireless communication device 2000 includes: means for transmitting an indication associated with a non-linearity model for the power amplifier circuit to the second wireless communication device, the indication comprising a first parameter for a first crest factor reduction function, a second parameter for a digital predistortion function, and a third parameter for a second crest factor reduction function; and means for transmitting a signal to the second wireless communication device, the signal generated based on the first crest factor reduction function, the digital predistortion function, and the second crest factor reduction function. In one aspect, the foregoing apparatus may be a processor 2004 shown in fig. 20 configured to perform the functions recited by the foregoing apparatus (e.g., as discussed above). In another aspect, the foregoing apparatus may be circuitry or any equipment configured to perform the functions recited by the foregoing apparatus.

Of course, in the above examples, the circuitry included in the processor 2004 is provided by way of example only, and other means for performing the described functions may be included within aspects of the present disclosure, including but not limited to instructions stored in the computer-readable medium 2006, or any other suitable device or means described in one or more of fig. 1-3, 7-13, and 15-20 and utilizing, for example, the methods and/or algorithms described herein with respect to fig. 21-23.

Fig. 24 is a block diagram illustrating an example of a hardware implementation of the wireless communication device 2400 employing the processing system 2414. In some examples, the wireless communication device 2400 may be a UE or a scheduled entity configured to wirelessly communicate with a base station or a scheduling entity, as discussed in any one or more of fig. 1-19. In this case, the wireless communication apparatus 2400 may correspond to any of the UEs or scheduled entities shown in any of fig. 1-3 and 20. In some examples, the wireless communication device 2400 may be a base station or scheduling entity configured to wirelessly communicate with a UE or scheduled entity, as discussed in any one or more of fig. 1-19. In this case, the wireless communication apparatus 2400 may correspond to any of the base stations or scheduling entities shown in any of fig. 1-3 and 20. In some examples, the wireless communication device 2000 may correspond to any of the transmitting devices shown in any of fig. 7-9 and 15-19. In some examples, the wireless communication device 2000 may correspond to any of the recipient devices shown in any of fig. 7-9 and 15-19.

According to various aspects of the disclosure, an element, or any portion of an element, or any combination of elements, may be implemented using the processing system 2414. The processing system may include one or more processors 2404. The processing system 2414 may be substantially the same as the processing system 2014 illustrated in fig. 20, including a bus interface 2408, a bus 2402, a memory 2405, a processor 2404, a computer readable medium 2406, a transceiver 2410, and an antenna array 2420. The memory 2405 may store NL model information 2415 (e.g., kernels, coefficients, etc.) that is used by the processor 2404 in cooperation with the transceiver 2410 for NL model-related operations described herein. Furthermore, the wireless communication device 2400 may include an interface 2430 providing means for communicating with at least one other device within the core network and with at least one radio access network.

The wireless communication device 2400 may be configured to perform any one or more of the operations as described herein (e.g., as described above in connection with fig. 1-19 and as described below in connection with fig. 25-27). In some aspects of the disclosure, the processor 2404 as utilized in the wireless communication device 2400 may include circuitry configured for various functions.

In some aspects of the disclosure, processor 2404 may include communication and processing circuitry 2441. Communication and processing circuitry 2444 may be configured to communicate with a UE. Communication and processing circuitry 2441 may include one or more hardware components that provide physical structure to perform various processes related to communication (e.g., signal reception and/or signal transmission) as described herein. Communication and processing circuitry 2441 may further include one or more hardware components that provide physical structure to perform various processes related to signal processing (e.g., processing received signals and/or processing signals for transmission) as described herein. Communication and processing circuitry 2441 may be further configured to execute communication and processing software 2451 included on computer-readable medium 2406 to implement one or more functions described herein.

In some implementations in which communication involves receiving information, the communication and processing circuitry 2441 may obtain information from a component of the wireless communication device 2400 (e.g., from the transceiver 2410 that receives information via radio frequency signaling or some other type of signaling suitable for the applicable communication medium), process (e.g., decode) the information, and output the processed information. For example, communication and processing circuitry 2441 may output information to another component of processor 2404, to memory 2405, or to bus interface 2408. In some examples, communication and processing circuitry 2441 may receive one or more of signals, messages, other information, or any combination thereof. In some examples, communication and processing circuitry 2441 may receive information via one or more channels. In some examples, communication and processing circuitry 2441 may include functionality for a receiving device. In some examples, communication and processing circuitry 2441 may include functionality for the means for decoding.

In some implementations in which communication involves sending (e.g., transmitting) information, communication and processing circuitry 2441 may obtain information (e.g., from another component of processor 2404, memory 2405, or bus interface 2408), process (e.g., encode) the information, and output the processed information. For example, communication and processing circuitry 2441 may output information to transceiver 2410 (e.g., which communicates the information via radio frequency signaling or some other type of signaling suitable for the applicable communication medium). In some examples, communication and processing circuitry 2441 may send one or more of signals, messages, other information, or any combination thereof. In some examples, communication and processing circuitry 2441 may transmit information via one or more channels. In some examples, communication and processing circuitry 2441 may include functionality for transmitting (e.g., means for transmitting). In some examples, communication and processing circuitry 2441 may include functionality for the encoded means.

The processor 2404 may include digital post-distortion (DPoD) processing circuitry 2442 configured to perform operations related to DPoD processing as discussed herein (e.g., one or more of the operations related to DPoD processing described in connection with fig. 6-19). The DPoD processing circuitry 2442 may be configured to execute DPoD processing software 2452 included on the computer-readable medium 2406 to implement one or more functions described herein.

In some examples, DPoD processing circuitry 2442 may include functionality for a device to receive a signal. For example, DPoD processing circuitry 2442 may be configured to cooperate with communication and processing circuitry 2441 and transceiver 2410 to receive signals having non-linearity components from a wireless communication device via a designated channel (e.g., as described at #1618 of fig. 16 and/or 1912 of fig. 19).

In some examples, DPoD processing circuitry 2442 may include functionality for using digital post-distortion to compensate for nonlinear distortion in a signal. For example, the DPoD processing circuitry 2442 may be configured to apply DPoD functionality to a received signal (e.g., as described at #1620 of fig. 16 and/or 1914 of fig. 19).

Processor 2404 may include model processing circuitry 2443 configured to perform operations related to model processing as discussed herein (e.g., one or more of the operations related to model processing described in connection with fig. 6-19). Model processing circuitry 2443 can be configured to execute model processing software 2453 included on computer-readable medium 2406 to implement one or more functions described herein.

In some examples, model processing circuitry 2443 may include functionality to receive an indication of a change in the non-linearity model. For example, model processing circuitry 2443 may receive an indication (e.g., including a new kernel and associated parameters) from the wireless communication device via the designated channel (e.g., as described in #1608 of fig. 16).

In some examples, model processing circuitry 2443 may include functionality for means for updating non-linearity information for a digital post-distorter. For example, the model processing circuitry 2443 may regenerate the active power amplifier model based on the received parameters or based on processing of the received signal (e.g., as described at #1612 of 16).

In some examples, model processing circuitry 2443 may include functionality for receiving an indication associated with a non-linearity model. For example, model processing circuitry 2443 may receive an indication (e.g., as described in #1906 of fig. 19) from the wireless communication device via the designated channel that includes a first parameter for the first CFR function, a second parameter for the DPD function, and a third parameter for the second CFR function.

In some examples, model processing circuitry 2443 may include functionality to derive a non-linearity model based on the indication. For example, the model processing circuitry 2443 may generate or regenerate the effective power amplifier model based on the first parameter for the first CFR function, the second parameter for the DPD function, and the third parameter for the second CFR function from the wireless communication device via the designated channel (e.g., as described in #1908 of fig. 19).

Processor 2404 may include Digital Predistortion (DPD) processing circuitry 2444 configured to perform operations related to DPD processing as discussed herein (e.g., one or more of the DPD processing operations described in connection with fig. 6-19). The DPD processing circuitry 2444 may be further configured to execute DPD processing software 2454 included on the computer-readable medium 2406 to implement one or more functions described herein.

In some examples, DPD processing circuitry 2444 may include functionality for means for calculating DPD information. For example, DPD processing circuitry 2444 may generate DPD parameters based on processing the received signal (e.g., as described in #1714 of fig. 17).

In some examples, DPD processing circuitry 2444 may include functionality for means for transmitting DPD information. For example, DPD processing circuitry 2444 may transmit DPD parameters to the wireless communication device via the designated channel (e.g., as described in #1716 of fig. 17).

Fig. 25 is a flow chart illustrating an example method 2500 for wireless communication in accordance with some aspects of the present disclosure. As described below, some or all of the illustrated features may be omitted from a particular implementation within the scope of the present disclosure, and some of the illustrated features may not be required to implement all examples. In some examples, the method 2500 may be performed by the wireless communication device 2400 illustrated in fig. 24. In some examples, method 2500 may be performed by any suitable apparatus or device for implementing the functions or algorithms described below.

At block 2502, the first wireless communication device may receive, from a second wireless communication device, an indication of a change in a non-linearity model of a power amplifier circuit for the second wireless communication device. For example, the model processing circuitry 2443 shown and described above in connection with fig. 24, along with the communication and processing circuitry 2441 and the transceiver 2410, may provide means for receiving an indication of a change in a non-linearity model of a power amplifier circuit for a second wireless communication device from the second wireless communication device.

In some examples, the indication of the change in the non-linearity model is used to indicate a change associated with a power amplifier of the power amplifier circuit. In some examples, the indication of the change in the non-linearity model is used to indicate a change in a configuration of a digital predistorter of the power amplifier circuit. In some examples, the indication of the change in the non-linearity model is used to indicate a change in a configuration of a crest factor reducer of the power amplifier circuit. In some examples, the indication of the change in the non-linearity model is used to indicate at least one of: a change in an in-band distortion parameter, a change in an out-of-band emission parameter, a change in a maximum power reduction parameter, a change in a modulation to be used when transmitting a signal via a power amplifier circuit, or a combination thereof. In some examples, the indication of the change in the non-linearity model may include at least one non-linearity parameter of the non-linearity model.

At block 2504, the first wireless communication device may update non-linearity information of a digital post-distorter (e.g., for a digital post-distortion process) of the first wireless communication device after receiving the indication. For example, the model processing circuitry 2443 shown and described above in connection with fig. 24 may provide means for updating the nonlinearity information of the digital post-distorter (e.g., for the digital post-distortion process) of the first wireless communication device after receiving the indication.

In some examples, updating the nonlinearity information of the digital post-distorter may include determining a nonlinearity model. In some examples, determining the nonlinearity model may include receiving the nonlinearity model from the second wireless communication device.

In some examples, determining the nonlinearity model may include selecting a set of kernels for the nonlinearity model after receiving an indication of a change in the nonlinearity model, and calculating coefficients for the nonlinearity model based on the set of kernels. In some examples, selecting the set of kernels for the non-linearity model may include selecting the set of kernels based on at least one received signal.

In some examples, determining the non-linearity model may include receiving at least one non-linearity parameter of the non-linearity model from the second wireless communication device, and generating an estimate of the non-linearity model based on the at least one non-linearity parameter. In some examples, the at least one nonlinearity parameter may include at least one nonlinearity core of a digital predistorter of the power amplifier circuit. In some examples, the method may further include transmitting a request for at least one non-linearity parameter, wherein the at least one non-linearity parameter is received after transmitting the request.

At block 2506, a first wireless communication device may receive a signal from a second wireless communication device. For example, the DPoD processing circuitry 2442 shown and described above in connection with fig. 24, along with the communication and processing circuitry 2441 and transceiver 2410, may provide means for receiving signals from a second wireless communication device.

At block 2508, the first wireless communication device may use a digital post-distorter to compensate for nonlinear distortion in the signal. For example, the DPoD processing circuitry 2442 shown and described above in connection with fig. 24, along with communication and processing circuitry 2441 and transceiver 2410, may provide a means for compensating for nonlinear distortion in a signal using a digital post-distorter.

In some examples, the method may further include calculating digital predistortion information for a digital predistorter of the second wireless communication device. In some examples, the method may further include transmitting digital predistortion information to the second wireless communication device.

In some examples, the method may further comprise: transmitting a first message to a second wireless communication device, wherein the first message indicates the ability to calculate digital predistortion information; and receiving a second message from the second wireless communication device after transmitting the first message, wherein the second message requests the first wireless communication device to calculate digital predistortion information and transmit the digital predistortion information to the second wireless communication device, wherein the digital predistortion information is transmitted to the second wireless communication device after receiving the second message. In some examples, the second message requests the first wireless communication device to jointly calculate the digital predistortion information and the digital post-distortion information.

In some examples, the method may further include receiving first information from the second wireless communication device for calculating digital predistortion information, wherein calculating the digital predistortion information may include calculating the digital predistortion information from the first information. In some examples, the first information may include at least one of a kernel type, a digital predistortion parameter, or a combination thereof, and the digital predistortion information may include digital predistortion kernel coefficients.

In some examples, the method may further include receiving at least one constraint for calculating the digital predistortion information from the second wireless communication device. In some examples, calculating the digital predistortion information may include calculating the digital predistortion information in accordance with at least one constraint.

Fig. 26 is a flowchart illustrating an example method 2600 for wireless communication according to some aspects of the present disclosure. As described below, some or all of the illustrated features may be omitted from a particular implementation within the scope of the present disclosure, and some of the illustrated features may not be required to implement all examples. In some examples, the method 2600 may be performed by the wireless communication device 2400 illustrated in fig. 24. In some examples, method 2600 may be performed by any suitable apparatus or device for implementing the functions or algorithms described below.

At block 2602, the first wireless communication device may calculate digital predistortion information for a digital predistorter of the second wireless communication device. In some examples, the digital predistortion information may include digital predistortion coefficients. For example, DPD processing circuitry 2444 shown and described above in connection with fig. 24 may provide means for calculating digital predistortion information for a digital predistorter of a second wireless communication device.

At block 2604, the first wireless communication device may transmit digital predistortion information to the second wireless communication device. For example, DPD processing circuitry 2444 shown and described above in connection with fig. 24, along with communication and processing circuitry 2441 and transceiver 2410, may provide means for transmitting digital predistortion information to a second wireless communication device.

In some examples, the method may further comprise: transmitting a first message to a second wireless communication device, wherein the first message indicates the ability to calculate digital predistortion information; and receiving a second message from the second wireless communication device after transmitting the first message, wherein the second message requests the first wireless communication device to calculate digital predistortion information and transmit the digital predistortion information to the second wireless communication device, wherein the digital predistortion information is transmitted to the second wireless communication device after receiving the second message. In some examples, the second message requests the first wireless communication device to jointly calculate the digital predistortion information and the digital post-distortion information.

In some examples, the method may further include receiving first information from the second wireless communication device for calculating digital predistortion information, wherein calculating the digital predistortion information may include calculating the digital predistortion information from the first information. In some examples, the first information may include at least one of a kernel type, a digital predistortion parameter, or a combination thereof, and the digital predistortion information may include digital predistortion kernel coefficients.

In some examples, the method may further include receiving at least one constraint for calculating the digital predistortion information from the second wireless communication device, wherein calculating the digital predistortion information may include calculating the digital predistortion information in accordance with the at least one constraint. In some examples, the at least one constraint may include an Adjacent Channel Leakage Ratio (ACLR) limit. In some examples, the at least one constraint may include at least one weight for the at least one frequency band.

Fig. 27 is a flowchart illustrating an example method 2700 for wireless communication in accordance with some aspects of the present disclosure. As described below, some or all of the illustrated features may be omitted from a particular implementation within the scope of the present disclosure, and some of the illustrated features may not be required to implement all examples. In some examples, the method 2700 may be performed by the wireless communication device 2400 illustrated in fig. 24. In some examples, method 2700 may be performed by any suitable apparatus or device for implementing the functions or algorithms described below.

At block 2702, the first wireless communication device may receive, from the second wireless communication device, an indication associated with a non-linearity model for a power amplifier circuit of the second wireless communication device, the indication including a first parameter for a first crest factor reduction function, a second parameter for a digital predistortion function, and a third parameter for the second crest factor reduction function. For example, the model processing circuitry 2443 shown and described above in connection with fig. 24, along with the communication and processing circuitry 2441 and the transceiver 2410, may provide means for receiving an indication from the second wireless communication device associated with a non-linearity model of a power amplifier circuit for the second wireless communication device.

At block 2704, the first wireless communication device may derive a non-linearity model based on the indication. For example, model processing circuitry 2443 shown and described above in connection with fig. 24 may provide means for deriving a non-linearity model based on the indication.

At block 2706, the first wireless communication device may receive a first signal from a second wireless communication device. For example, the DPoD processing circuitry 2442 shown and described above in connection with fig. 24, along with the communication and processing circuitry 2441 and the transceiver 2410, may provide means for receiving a first signal from a second wireless communication device.

At block 2708, the first wireless communication device can use a non-linearity model to compensate for non-linear distortion in the first signal. For example, the DPoD processing circuitry 2442 shown and described above in connection with fig. 24, along with the communication and processing circuitry 2441 and transceiver 2410, may provide a means for compensating for nonlinear distortion in the first signal using a nonlinearity model.

In some examples, the first parameter may include a first clipping level associated with a first crest factor reduction function. In some examples, the first clipping level is an absolute clipping level.

In some examples, the third parameter may include a second clipping level associated with a second crest factor reduction function. In some examples, the second clipping level is defined relative to a signal power associated with a transmission using the power amplifier circuit. In some examples, the second clipping level is associated with a target peak-to-average power ratio associated with transmissions using the power amplifier circuit.

In some examples, the second parameter may include at least one non-linearity kernel associated with the digital predistortion function. In some examples, the second parameter may include at least one nonlinearity parameter for at least one nonlinearity kernel associated with the digital predistortion function.

In some examples, the indication further includes a non-linearity model of the power amplifier circuit. In some examples, the non-linearity model of the power amplifier circuit may include at least one non-linearity kernel.

In some examples, the first wireless communication device may select a set of kernels for the non-linearity model after receiving the indication. In some examples, the first wireless communication device may calculate coefficients for the non-linearity model based on the set of kernels. In some examples, the first wireless communication device may select the set of kernels based on the first signal.

In some examples, the first wireless communication device may transmit a request for the indication. In some examples, the indication is received after the request is transmitted.

In some examples, the first wireless communication device may receive a message requesting the first wireless communication device to calculate digital predistortion information for the digital predistortion function. In some examples, the message includes at least one parameter for calculating digital predistortion information to meet a target crest factor reduction clipping level associated with the digital predistortion function. In some examples, the at least one parameter includes: a first limit on instantaneous signal peaks at an input to the power amplifier, a second limit on peak-to-average power ratio associated with the power amplifier, or a combination thereof. In some examples, the first wireless communication device may calculate the digital predistortion information such that: the first limit on the instantaneous signal peak value of the input to the power amplifier is not exceeded, the second limit on the peak-to-average power ratio associated with the power amplifier is not exceeded, or a combination thereof.

Referring again to fig. 24, in one configuration, the wireless communication device 2400 includes: means for receiving, from a second wireless communication device, an indication of a change in a non-linearity model of a power amplifier circuit including a digital predistorter for the second wireless communication device; means for updating the non-linearity information of the digital post-distorter for the first wireless communication device after receiving the indication; means for receiving a signal from a second wireless communication device; and means for compensating for nonlinear distortion in the signal using the digital post-distortion. In one configuration, the wireless communication device 2400 includes: means for calculating digital predistortion information for a digital predistorter of a second wireless communication device; and means for transmitting the digital predistortion information to the second wireless communication device. In one configuration, the wireless communication device 2400 includes: means for receiving, from the second wireless communication device, an indication associated with a non-linearity model of a power amplifier circuit for the second wireless communication device, the indication comprising a first parameter for a first crest factor reduction function, a second parameter for a digital predistortion function, and a third parameter for a second crest factor reduction function; means for deriving a non-linearity model based on the indication; means for receiving a first signal from a second wireless communication device; and means for compensating for nonlinear distortion in the first signal using the nonlinearity model. In one aspect, the foregoing means may be the processor 2404 shown in fig. 24 configured to perform the functions recited by the foregoing means (e.g., as discussed above). In another aspect, the foregoing apparatus may be circuitry or any equipment configured to perform the functions recited by the foregoing apparatus.

Of course, in the above examples, the circuitry included in processor 2404 is provided by way of example only, and other means for performing the described functions may be included within aspects of the disclosure, including but not limited to instructions stored in computer-readable medium 2406, or any other suitable device or means described in one or more of fig. 1-3, 7-13, 15-19, and 24 and utilizing, for example, the methods and/or algorithms described herein with respect to fig. 25-27.

The methods shown in fig. 20-23 and 25-27 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in conjunction with one or more other processes described elsewhere herein. The following provides an overview of several aspects of the disclosure:

aspect 1: a method for wireless communication at a first wireless communication device, the method comprising: determining a change in a non-linearity model for a power amplifier circuit including a digital predistorter; and transmitting an indication of the change in the non-linearity model to the second wireless communication device.

Aspect 2: the method of aspect 1, wherein determining the change in the non-linearity model comprises: a change associated with a power amplifier of the power amplifier circuit is detected.

Aspect 3: the method of aspect 1 or 2, wherein determining the change in the non-linearity model comprises: the configuration of the digital predistorter is changed.

Aspect 4: the method of any of aspects 1-3, wherein determining a change in the non-linearity model comprises: the configuration of the crest factor reducer of the power amplifier circuit is changed.

Aspect 5: the method of any of aspects 1-4, wherein determining a change in the non-linearity model comprises determining at least one of: a change in an in-band distortion parameter, a change in an out-of-band emission parameter, a change in a maximum power reduction parameter, a change in a modulation to be used when transmitting a signal via a power amplifier circuit, or a combination thereof.

Aspect 6: the method of any of aspects 1-5, wherein the indication comprises at least one nonlinearity parameter of a nonlinearity model.

Aspect 7: the method of aspect 6, wherein the at least one non-linearity parameter comprises at least one of: a non-linearity kernel of the digital predistorter, a non-linearity model, or a combination thereof.

Aspect 8: the method of aspect 6, further comprising: the at least one non-linearity parameter is transmitted after receiving a request for the at least one non-linearity parameter from the second wireless communication device.

Aspect 9: the method of any one of aspects 1 to 8, further comprising: receiving digital predistortion information from a second wireless communication device, the digital predistortion information comprising at least a portion of a set of digital predistortion parameters for a digital predistorter; and adjusting parameters of the digital predistorter based on the digital predistortion information.

Aspect 10: the method of aspect 9, further comprising: receiving a first message from a second wireless communication device, wherein the first message indicates that the second wireless communication device has the capability to calculate digital predistortion information; transmitting a second message to the second wireless communication device after receiving the first message, wherein the second message requests the second wireless communication device to calculate digital predistortion information and transmit the digital predistortion information to the first wireless communication device, and wherein the digital predistortion information is received from the second wireless communication device after transmitting the second message.

Aspect 11: the method of aspect 10, wherein the second message further requests the second wireless communication device to calculate digital post-distortion information in combination with the digital pre-distortion information.

Aspect 12: the method of aspect 9, further comprising: first information for calculating digital predistortion information is transmitted to a second wireless communication device.

Aspect 13: the method of aspect 12, wherein: the first information includes at least one of: kernel type, digital predistortion parameters, or a combination thereof; and the digital predistortion information includes digital predistortion kernel coefficients.

Aspect 14: the method of aspects 9-12, further comprising: transmitting at least one constraint for calculating digital predistortion information to the second wireless communication device, wherein the at least one constraint comprises at least one of: adjacent Channel Leakage Ratio (ACLR) limits, weights for at least one frequency band, or a combination thereof.

Aspect 15: the method of any one of aspects 1 to 14, further comprising: receiving digital predistortion coefficients for the digital predistorter from the second wireless communication device; pre-distorting the signal based on the pre-distortion coefficients to provide a pre-distorted signal; amplifying the predistorted signal at a power amplifier of a power amplifier circuit to provide an amplified signal; and transmitting the amplified signal to the second wireless communication device.

Aspect 16: the method of any one of aspects 1 to 15, further comprising: calculating digital predistortion coefficients for the digital predistorter after determining the change in the non-linearity model; pre-distorting the signal based on the pre-distortion coefficients to provide a pre-distorted signal; amplifying the predistorted signal at a power amplifier of a power amplifier circuit to provide an amplified signal; and transmitting the amplified signal to the second wireless communication device.

Aspect 21: a method for wireless communication at a first wireless communication device, the method comprising: receiving, from the second wireless communication device, an indication of a change in a non-linearity model of a power amplifier circuit including a digital predistorter for the second wireless communication device; updating the nonlinearity information of the digital post-distorter for the first wireless communication device after receiving the indication; receiving a signal from a second wireless communication device; and compensating for nonlinear distortion in the signal using a digital post-distorter.

Aspect 22: the method of aspect 21, wherein the indication of the change in the non-linearity model is used to indicate at least one of: a change associated with a power amplifier of the power amplifier circuit, a change in a configuration of a digital predistorter of the power amplifier circuit, a change in a configuration of a crest factor reducer of the power amplifier circuit, or a combination thereof.

Aspect 23: the method of any of aspects 21-22, wherein the indication of a change in the non-linearity model is used to indicate at least one of: a change in an in-band distortion parameter, a change in an out-of-band emission parameter, a change in a maximum power reduction parameter, a change in a modulation to be used when transmitting a signal via a power amplifier circuit, or a combination thereof.

Aspect 24: the method of any of aspects 21-23, wherein updating the nonlinearity information for the digital post-distorter comprises: a non-linearity model is determined.

Aspect 25: the method of aspect 24, wherein determining the non-linearity model comprises: selecting a set of kernels for the non-linearity model after receiving an indication of a change in the non-linearity model; and calculating coefficients for the non-linearity model based on the kernel set.

Aspect 26: the method of aspect 25, wherein selecting the set of kernels for the non-linearity model comprises: a set of kernels is selected based on at least one received signal.

Aspect 27: the method of aspect 24, wherein determining the non-linearity model comprises: receiving at least one nonlinearity parameter of a nonlinearity model from a second wireless communication device; and generating an estimate of the non-linearity model based on the at least one non-linearity parameter.

Aspect 28: the method of aspect 27, further comprising: a request for at least one non-linearity parameter is transmitted, wherein the at least one non-linearity parameter is received after the request is transmitted.

Aspect 29: the method of any of aspects 21 to 28, wherein determining the non-linearity model comprises: a non-linearity model is received from a second wireless communication device.

Aspect 30: the method of any one of aspects 21 to 29, further comprising: calculating digital predistortion information for a digital predistorter of the second wireless communication device; and transmitting the digital predistortion information to the second wireless communication device.

Aspect 31: the method of aspect 30, further comprising: transmitting a first message to a second wireless communication device, wherein the first message indicates the ability to calculate digital predistortion information; and receiving a second message from the second wireless communication device after transmitting the first message, wherein the second message requests the first wireless communication device to calculate digital predistortion information and transmit the digital predistortion information to the second wireless communication device, wherein the digital predistortion information is transmitted to the second wireless communication device after receiving the second message.

Aspect 32: the method of aspect 30, further comprising: first information is received from the second wireless communication device for calculating digital predistortion information, wherein calculating the digital predistortion information comprises calculating digital predistortion information from the first information.

Aspect 41: a method for wireless communication at a first wireless communication device, the method comprising: transmitting, to a second wireless communication device, an indication associated with a non-linearity model for a power amplifier circuit, the indication comprising a first parameter for a first crest factor reduction function, a second parameter for a digital predistortion function, and a third parameter for a second crest factor reduction function; and transmitting a first signal to the second wireless communication device, the first signal generated based on the first crest factor reduction function, the digital predistortion function, and the second crest factor reduction function.

Aspect 42: the method of aspect 41, wherein the first parameter includes a first clipping level associated with a first crest factor reduction function.

Aspect 43: the method of aspect 42, wherein the first clipping level is an absolute clipping level.

Aspect 44: the method of any of aspects 41-43, wherein the third parameter includes a second clipping level associated with a second crest factor reduction function.

Aspect 45: the method of aspect 44, wherein the second clipping level is defined relative to a signal power associated with a transmission using the power amplifier circuit.

Aspect 46: the method of aspect 44, wherein the second clipping level is associated with a target peak-to-average power ratio associated with a transmission using the power amplifier circuit.

Aspect 47: the method of any of aspects 41-46, wherein the second parameter comprises at least one non-linearity kernel associated with a digital predistortion function.

Aspect 48: the method of aspect 47, wherein the second parameters further comprise at least one nonlinearity parameter for at least one nonlinearity kernel associated with the digital predistortion function.

Aspect 49: the method of any one of aspects 41 to 48, wherein: the indication further includes a non-linearity model of the power amplifier circuit; and the non-linearity model of the power amplifier circuit includes at least one non-linearity kernel.

Aspect 50: the method of any one of aspects 41-49, further comprising: providing the second signal to a first crest factor reduction function to obtain a third signal; providing the third signal to a digital predistortion function to obtain a fourth signal; providing a fourth signal to a second crest factor reduction function to provide a fifth signal; and providing the fifth signal to the power amplifier circuit to obtain the first signal.

Aspect 51: the method of any one of aspects 41 to 50, further comprising: the indication is transmitted based on a change in the non-linearity model.

Aspect 52: the method of any one of aspects 41 to 50, further comprising: receiving a request for an indication from a second wireless communication device; and transmitting an indication after receiving the request.

Aspect 53: the method of any one of aspects 41-52, further comprising: receiving digital predistortion information for a digital predistortion function from a second wireless communication device; and adjusting the non-linearity model based on the digital predistortion information.

Aspect 54: the method of any one of aspects 41 to 53, wherein: the method further includes transmitting a message requesting the second wireless communication device to calculate digital predistortion information for the digital predistortion function; the message includes at least one parameter for calculating digital predistortion information to meet a target crest factor reduction clipping level associated with the digital predistortion function; and the at least one parameter comprises: a first limit on instantaneous signal peaks at an input to the power amplifier, a second limit on peak-to-average power ratio associated with the power amplifier, or a combination thereof.

Aspect 55: the method of any one of aspects 41 to 53, wherein: the method further includes receiving a first message from a second wireless communication device; the first message indicates that the second wireless communication device has the capability to calculate digital predistortion information for the digital predistortion function; the method further includes transmitting a second message to the second wireless communication device after receiving the first message; the second message includes a request to the second wireless communication device to calculate digital predistortion information and transmit the digital predistortion information to the first wireless communication device; and the digital predistortion information is received from the second wireless communication device after transmitting the second message.

Aspect 57: a method for wireless communication at a first wireless communication device, the method comprising: receiving, from the second wireless communication device, an indication associated with a non-linearity model for a power amplifier circuit of the second wireless communication device, the indication comprising a first parameter for a first crest factor reduction function, a second parameter for a digital predistortion function, and a third parameter for a second crest factor reduction function; deriving a non-linearity model based on the indication; receiving a first signal from a second wireless communication device; and compensating for nonlinear distortion in the first signal using a nonlinear model.

Aspect 58: the method of aspect 57, wherein the first parameter includes a first clipping level associated with a first crest factor reduction function.

Aspect 59: the method of aspect 58, wherein the first clipping level is an absolute clipping level.

Aspect 60: the method of any of aspects 57-58, wherein the third parameter includes a second clipping level associated with a second crest factor reduction function.

Aspect 61: the method of aspect 60, wherein the second clipping level is defined relative to a signal power associated with a transmission using the power amplifier circuit.

Aspect 62: the method of aspect 60, wherein the second clipping level is associated with a target peak-to-average power ratio associated with a transmission using the power amplifier circuit.

Aspect 63: the method of any of aspects 57-62, wherein the second parameter includes at least one non-linearity kernel associated with a digital predistortion function.

Aspect 64: the method of aspect 63, wherein the second parameters further comprise at least one nonlinearity parameter for at least one nonlinearity kernel associated with the digital predistortion function.

Aspect 65: the method of any one of aspects 57-64, wherein: the indication further includes a non-linearity model of the power amplifier circuit; and the non-linearity model of the power amplifier circuit includes at least one non-linearity kernel.

Aspect 66: the method of any one of aspects 57-65, further comprising: selecting a set of kernels for the non-linearity model after receiving the indication; and calculating coefficients for the non-linearity model based on the kernel set.

Aspect 67: the method of aspect 66, further comprising: a set of kernels is selected based on the first signal.

Aspect 68: the method of any one of aspects 57 to 67, wherein: the method further includes transmitting a request for an indication; and the indication is received after the request is transmitted.

Aspect 69: the method of any one of aspects 57 to 67, wherein: the method further includes receiving a message requesting the first wireless communication device to calculate digital predistortion information for the digital predistortion function; the message includes at least one parameter for calculating digital predistortion information to meet a target crest factor reduction clipping level associated with the digital predistortion function; the at least one parameter includes: a first limit on instantaneous signal peaks of an input to the power amplifier, a second limit on peak-to-average power ratio associated with the power amplifier, or a combination thereof; and the method further comprises calculating the digital predistortion information such that: the first limit on the instantaneous signal peak value of the input to the power amplifier is not exceeded, the second limit on the peak-to-average power ratio associated with the power amplifier is not exceeded, or a combination thereof.

Aspect 81: a method for wireless communication at a first wireless communication device, the method comprising: receiving digital predistortion information from a second wireless communication device; pre-distorting the signal based on the pre-distortion information to provide a pre-distorted signal; amplifying the predistorted signal to provide an amplified signal; and transmitting the amplified signal to the second wireless communication device.

Aspect 82: the method of aspect 81, wherein the digital predistortion information comprises digital predistortion coefficients.

Aspect 83: the method of aspect 81 or 82, further comprising: receiving a first message from a second wireless communication device, wherein the first message indicates that the second wireless communication device has the capability to calculate digital predistortion information; and transmitting a second message to the second wireless communication device after receiving the first message, wherein the second message requests the second wireless communication device to calculate digital predistortion information and transmit the digital predistortion information to the first wireless communication device, wherein the digital predistortion information is received from the second wireless communication device after transmitting the second message.

Aspect 84: the method of aspect 83, wherein the second message requests the second wireless communication device to jointly calculate digital predistortion information and digital post distortion information.

Aspect 85: the method of any one of aspects 81 to 84, further comprising: first information for calculating digital predistortion information is transmitted to a second wireless communication device.

Aspect 86: the method of aspect 85, wherein: the first information includes at least one of: kernel type, digital predistortion parameters, or a combination thereof; and the digital predistortion information includes digital predistortion kernel coefficients.

Aspect 87: the method of any one of aspects 81 to 86, further comprising: at least one constraint for calculating digital predistortion information is transmitted to the second wireless communication device.

Aspect 88: the method of aspect 87, wherein the at least one constraint comprises an Adjacent Channel Leakage Ratio (ACLR) limit.

Aspect 89: the method of aspect 87, wherein the at least one constraint includes at least one weight for at least one frequency band.

Aspect 101: a method for wireless communication at a first wireless communication device, the method comprising: calculating digital predistortion information for a digital predistorter of the second wireless communication device; and transmitting the digital predistortion information to the second wireless communication device.

Aspect 102: the method of aspect 101, wherein the digital predistortion information comprises digital predistortion coefficients.

Aspect 103: the method of aspect 101 or 102, further comprising: transmitting a first message to a second wireless communication device, wherein the first message indicates the ability to calculate digital predistortion information; and receiving a second message from the second wireless communication device after transmitting the first message, wherein the second message requests the first wireless communication device to calculate digital predistortion information and transmit the digital predistortion information to the second wireless communication device, wherein the digital predistortion information is transmitted to the second wireless communication device after receiving the second message.

Aspect 104: the method of aspect 103, wherein the second message requests the first wireless communication device to jointly calculate digital predistortion information and digital post distortion information, wherein the calculation of the digital predistortion information is constrained by Adjacent Channel Leakage Ratio (ACLR) limitations.

Aspect 105: the method of any one of aspects 101 to 104, further comprising: first information is received from the second wireless communication device for calculating digital predistortion information, wherein calculating the digital predistortion information comprises calculating digital predistortion information from the first information.

Aspect 106: the method of aspect 105, wherein: the first information includes at least one of: kernel type, digital predistortion parameters, or a combination thereof; and the digital predistortion information includes digital predistortion kernel coefficients.

Aspect 107: the method of any one of aspects 101 to 106, further comprising: at least one constraint for calculating digital predistortion information is received from the second wireless communication device, wherein calculating the digital predistortion information comprises calculating the digital predistortion information in accordance with the at least one constraint.

Aspect 108: the method of aspect 107, wherein the at least one constraint includes Adjacent Channel Leakage Ratio (ACLR) limitations.

Aspect 109: the method of any of aspects 107-108, wherein the at least one constraint comprises at least one weight for at least one frequency band.

Aspect 110: a wireless communication device, comprising: a transceiver; a memory; and a processor communicatively coupled to the transceiver and the memory, wherein the processor is configured to perform any of aspects 1 to 19.

Aspect 111: an apparatus configured for wireless communication, comprising at least one means for performing any of aspects 1-19.

Aspect 112: a non-transitory computer-readable medium storing computer-executable code comprising code for causing a device to perform any one of aspects 1 to 19.

Aspect 113: a wireless communication device, comprising: a transceiver; a memory; and a processor communicatively coupled to the transceiver and the memory, wherein the processor is configured to perform any of aspects 21 to 39.

Aspect 114: an apparatus configured for wireless communication, comprising at least one means for performing any of aspects 21 to 39.

Aspect 115: a non-transitory computer-readable medium storing computer-executable code comprising code for causing a device to perform any one of aspects 21 to 39.

Aspect 116: a wireless communication device, comprising: a transceiver; a memory; and a processor communicatively coupled to the transceiver and the memory, wherein the processor is configured to perform any of aspects 81 to 89.

Aspect 117: an apparatus configured for wireless communication, comprising at least one means for performing any of aspects 81-89.

Aspect 118: a non-transitory computer-readable medium storing computer-executable code comprising code for causing a device to perform any one of aspects 81 to 89.

Aspect 119: a wireless communication device, comprising: a transceiver; a memory; and a processor communicatively coupled to the transceiver and the memory, wherein the processor is configured to perform any of aspects 101 through 109.

Aspect 120: an apparatus configured for wireless communication, comprising at least one means for performing any of aspects 101-109.

Aspect 121: a non-transitory computer-readable medium storing computer-executable code comprising code for causing a device to perform any one of aspects 101 to 109.

Aspect 122: a wireless communication device, comprising: a transceiver; a memory; and a processor communicatively coupled to the transceiver and the memory, wherein the processor is configured to perform any of aspects 41 through 55.

Aspect 123: an apparatus configured for wireless communication, comprising at least one means for performing any of aspects 41-55.

Aspect 124: a non-transitory computer-readable medium storing computer-executable code comprising code for causing a device to perform any one of aspects 41 to 55.

Aspect 125: a wireless communication device, comprising: a transceiver; a memory; and a processor communicatively coupled to the transceiver and the memory, wherein the processor is configured to perform any of aspects 56 to 69.

Aspect 126: an apparatus configured for wireless communication, comprising at least one means for performing any of aspects 56-69.

Aspect 127: a non-transitory computer-readable medium storing computer-executable code comprising code for causing a device to execute any one of aspects 56 to 69.

Several aspects of a wireless communication network have been presented with reference to example implementations. As will be readily appreciated by those skilled in the art, the various aspects described throughout this disclosure may be extended to other telecommunication systems, network architectures, and communication standards.

As an example, various aspects may be implemented within other systems defined by 3GPP, such as Long Term Evolution (LTE), evolved Packet System (EPS), universal Mobile Telecommunications System (UMTS), and/or Global System for Mobile (GSM). The various aspects may also be extended to systems defined by third generation partnership project 2 (3 GPP 2), such as CDMA2000 and/or evolution data optimized (EV-DO). Other examples may be implemented within systems employing Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, ultra Wideband (UWB), bluetooth, and/or other suitable systems. The actual telecommunications standards, network architectures, and/or communication standards employed will depend on the particular application and the overall design constraints imposed on the system.

Within this disclosure, the phrase "exemplary" is used to mean "serving as an example, instance, or illustration. Any implementation or aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects of the disclosure. Likewise, the term "aspect" does not require that all aspects of the disclosure include the discussed feature, advantage or mode of operation. The term "coupled" is used herein to refer to a direct or indirect coupling between two objects. For example, if object a physically contacts object B and object B contacts object C, then objects a and C may still be considered coupled to each other even though they are not in direct physical contact with each other. For example, a first object may be coupled to a second object even though the first object is never in direct physical contact with the second object. The terms "circuitry" and "circuitry" are used broadly and are intended to encompass both hardware implementations of electronic devices and conductors, which, when connected and configured, enable performance of the functions described in this disclosure, without limitation as to the type of electronic circuitry, as well as software implementations of information and instructions, which, when executed by a processor, enable performance of the functions described in this disclosure.

One or more of the components, steps, features, and/or functions illustrated in fig. 1-27 may be rearranged and/or combined into a single component, step, feature, or function, or implemented in several components, steps, or functions. Additional elements, components, steps, and/or functions may also be added without departing from the novel features disclosed herein. The apparatus, devices, and/or components illustrated in fig. 1-3, 7-13, 15-20, and 24 may be configured to perform one or more of the methods, features, or steps described herein. The novel algorithms described herein may also be efficiently implemented in software and/or embedded in hardware.

It is to be understood that the specific order or hierarchy of steps in the methods disclosed are illustrations of example processes. Based on design preferences, it is understood that the specific order or hierarchy of steps in the methods may be rearranged. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented, unless specifically recited herein.

As used herein, the term "determining" encompasses a wide variety of actions. For example, "determining" may include calculating, computing, processing, deriving, researching, looking up (e.g., looking up in a table, database, or another data structure), ascertaining, and the like. Also, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in memory), and the like. Likewise, "determining" may also include parsing, selecting, choosing, establishing, and the like.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more". The term "some" means one or more unless specifically stated otherwise. The phrase referring to a list of items "at least one of" refers to any combination of these items, including individual members. As an example, "at least one of a, b, or c" is intended to encompass: a, a; b; c, performing operation; a and b; a and c; b and c; and a, b and c. The elements of the various aspects described throughout this disclosure are all structural and functional equivalents that are presently or later to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Furthermore, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No element of a claim should be construed under the specification of 35u.s.c. ≡112 (f) unless the element is explicitly recited using the phrase "means for … …" or in the case of method claims the element is recited using the phrase "step for … …".

Claims (30)

1. A first wireless communication device, comprising:

a transceiver;

a memory; and

a processor coupled to the transceiver and the memory, wherein the processor is configured to:

determining a change in a non-linearity model for a power amplifier circuit including a digital predistorter; and

an indication of the change in the non-linearity model is transmitted via the transceiver to a second wireless communication device.

2. The first wireless communication device of claim 1, wherein the processor is configured to determine the change in the non-linearity model by being further configured to:

a change associated with a power amplifier of the power amplifier circuit is detected.

3. The first wireless communication device of claim 1, wherein the processor is configured to determine the change in the non-linearity model by being further configured to:

changing the configuration of the digital predistorter.

4. The first wireless communication device of claim 1, wherein the processor is configured to determine the change in the non-linearity model by being further configured to:

Changing the configuration of the crest factor reducer of the power amplifier circuit.

5. The first wireless communications device of claim 1, wherein the processor is configured to determine the change in the non-linearity model by being further configured to determine at least one of:

a change in an in-band distortion parameter, a change in an out-of-band emission parameter, a change in a maximum power reduction parameter, a change in a modulation to be used when transmitting a signal via the power amplifier circuit, or a combination thereof.

6. The first wireless communication device of claim 1, wherein the indication comprises at least one nonlinearity parameter of the nonlinearity model.

7. The first wireless communications apparatus of claim 6, wherein the at least one nonlinearity parameter comprises at least one of: the digital predistorter's nonlinearity kernel, the nonlinearity model, or a combination thereof.

8. The first wireless communication device of claim 6, wherein the processor is further configured to transmit the at least one nonlinearity parameter after receiving a request for the at least one nonlinearity parameter from the second wireless communication device.

9. The first wireless communication device of claim 1, wherein the processor is further configured to:

receiving digital predistortion information from the second wireless communication device, the digital predistortion information comprising at least a portion of a set of digital predistortion parameters for the digital predistorter; and

parameters of the digital predistorter are adjusted based on the digital predistortion information.

10. The first wireless communication device of claim 9, wherein:

the processor is further configured to receive a first message from the second wireless communication device;

the first message indicating that the second wireless communication device has the capability to calculate the digital predistortion information;

the processor is further configured to transmit a second message to the second wireless communication device after receiving the first message;

the second message requesting the second wireless communication device to calculate the digital predistortion information and transmit the digital predistortion information to the first wireless communication device; and is also provided with

The digital predistortion information is received from the second wireless communication device after transmitting the second message.

11. The first wireless communication device of claim 10, wherein the second message further requests the second wireless communication device to calculate digital post-distortion information in combination with the digital pre-distortion information.

12. The first wireless communication device of claim 9, wherein the processor is further configured to:

first information for calculating the digital predistortion information is transmitted to the second wireless communication device.

13. The first wireless communication device of claim 12, wherein:

the first information includes at least one of: kernel type, digital predistortion parameters, or a combination thereof; and is also provided with

The digital predistortion information includes digital predistortion kernel coefficients.

14. The first wireless communication device of claim 9, wherein:

the processor is further configured to transmit at least one constraint for calculating the digital predistortion information to the second wireless communication device; and is also provided with

The at least one constraint includes at least one of: adjacent Channel Leakage Ratio (ACLR) limits, weights for at least one frequency band, or a combination thereof.

15. The first wireless communication device of claim 1, wherein the processor is further configured to:

receiving digital predistortion coefficients for the digital predistorter from the second wireless communication device;

pre-distorting a signal based on the digital pre-distortion coefficients to provide a pre-distorted signal;

Amplifying the predistorted signal at a power amplifier of the power amplifier circuit to provide an amplified signal; and

the amplified signal is transmitted to the second wireless communication device.

16. The first wireless communication device of claim 1, wherein the processor is further configured to:

calculating digital predistortion coefficients for the digital predistorter after determining the change in the nonlinearity model;

pre-distorting a signal based on the digital pre-distortion coefficients to provide a pre-distorted signal;

amplifying the predistorted signal at a power amplifier of the power amplifier circuit to provide an amplified signal; and

the amplified signal is transmitted to the second wireless communication device.

17. A method for wireless communication at a first wireless communication device, the method comprising:

determining a change in a non-linearity model for a power amplifier circuit including a digital predistorter; and

an indication of the change in the non-linearity model is transmitted to a second wireless communication device.

18. A first wireless communication device, comprising:

a transceiver;

a memory; and

A processor coupled to the transceiver and the memory, wherein the processor is configured to:

receiving, via the transceiver, from a second wireless communication device, an indication of a change in a non-linearity model of a power amplifier circuit for the second wireless communication device;

updating non-linearity information of a digital post-distorter for the first wireless communication device after receiving the indication;

receiving a signal from the second wireless communication device via the transceiver; and

the digital post-distorter is used to compensate for nonlinear distortion in the signal.

19. The first wireless communications apparatus of claim 18, wherein the indication of the change in the non-linearity model is used to indicate at least one of: a change associated with a power amplifier of the power amplifier circuit, a change in a configuration of a digital predistorter of the power amplifier circuit, a change in a configuration of a crest factor reducer of the power amplifier circuit, or a combination thereof.

20. The first wireless communications apparatus of claim 18, wherein the indication of the change in the non-linearity model is used to indicate at least one of: a change in an in-band distortion parameter, a change in an out-of-band emission parameter, a change in a maximum power reduction parameter, a change in a modulation to be used when transmitting a signal via the power amplifier circuit, or a combination thereof.

21. The first wireless communication device of claim 18, wherein the processor is further configured to:

and determining the nonlinearity model.

22. The first wireless communication device of claim 21, wherein the processor is further configured to:

selecting a set of kernels for the non-linearity model after receiving the indication of the change in the non-linearity model; and

coefficients for the non-linearity model are calculated based on the set of kernels.

23. The first wireless communication device of claim 22, wherein the processor is further configured to:

the set of kernels is selected based on at least one received signal.

24. The first wireless communication device of claim 21, wherein the processor is further configured to:

receiving at least one nonlinearity parameter of the nonlinearity model from the second wireless communication device; and

an estimate of the non-linearity model is generated based on the at least one non-linearity parameter.

25. The first wireless communications device of claim 24, wherein:

the processor is further configured to transmit a request for the at least one non-linearity parameter; and is also provided with

The at least one non-linearity parameter is received after transmitting the request.

26. The first wireless communication device of claim 18, wherein the processor is further configured to:

the non-linearity model is received from the second wireless communication device.

27. The first wireless communication device of claim 18, wherein the processor is further configured to:

calculating digital predistortion information for a digital predistorter of the second wireless communication device; and

transmitting the digital predistortion information to the second wireless communication device.

28. The first wireless communications device of claim 27, wherein:

the processor is further configured to transmit a first message to the second wireless communication device;

the first message indicating the ability to calculate the digital predistortion information; and is also provided with

The processor is further configured to receive a second message from the second wireless communication device after transmitting the first message;

the second message requesting the first wireless communication device to calculate the digital predistortion information and transmitting the digital predistortion information to the second wireless communication device; and is also provided with

The digital predistortion information is transmitted to the second wireless communication device after receiving the second message.

29. The first wireless communication device of claim 27, wherein the processor is further configured to:

receiving first information for calculating the digital predistortion information from the second wireless communication device; and

the digital predistortion information is calculated from the first information.

30. A method for wireless communication at a first wireless communication device, the method comprising:

receiving, from a second wireless communication device, an indication of a change in a non-linearity model of a power amplifier circuit including a digital predistorter for the second wireless communication device;

updating non-linearity information of a digital post-distorter for the first wireless communication device after receiving the indication;

receiving a signal from the second wireless communication device; and

the digital post-distorter is used to compensate for nonlinear distortion in the signal.