Dpd with reference signal feedback

Abstract

Example embodiments of the present disclosure relate to digital post-distortion (DPoD) for reference signal feedback. A method includes receiving, from a second apparatus, a channel state information, CSI, configuration, the CSI configuration indicating whether digital post-distortion, DPoD, is to be performed for a channel state information reference signal, CSI-RS, performing, based on the CSI configuration, channel estimation on a received channel state information reference signal, CSI-RS, and transmitting, to the second apparatus, a CSI-RS report, the CSI-RS report including a result of the channel estimation.

Description

Cross-references to related applications

[0001] This application claims priority and benefit to EP patent application No. 25168246.4, filed on April 3, 2025, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0002] The various exemplary embodiments of this disclosure generally relate to the telecommunications field, and more specifically to digital post-distortion (DPoD) for reference signal feedback. Background Technology

[0003] In the field of communications, improving the efficiency and quality of signal transmission is a continuous pursuit. In communication systems, the characteristics of the power amplifier in the transmitter have a significant impact on the quality of signal transmission. Some transmitters employ strategies that allow the power amplifier to operate in the saturation region. In this region, although the power amplifier enhances power utilization efficiency, its nonlinear characteristics can lead to signal distortion. This signal distortion can affect not only in-band signals but also out-of-band signals, severely impacting the spectral efficiency and signal quality of the communication system. Furthermore, stringent transmission requirements have been introduced for receivers (e.g., user equipment).

[0004] Therefore, in at least some cases, it may be necessary to control the nonlinearity in the power amplifiers used in the user equipment radio transmitter in a manner that also takes into account the transmission requirements. Summary of the Invention

[0005] In a first aspect of this disclosure, a first apparatus is provided. The first apparatus includes: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to at least: receive a Channel State Information (CSI) configuration from a second apparatus, the CSI configuration indicating whether Digital Post-distortion (DPoD) should be performed against a Channel State Information Reference Signal (CSI-RS); perform channel estimation on the received CSI-RS based on the CSI configuration; and transmit a CSI-RS report to the second apparatus, the CSI-RS report including the results of the channel estimation.

[0006] In a second aspect of this disclosure, a second apparatus is provided. The second apparatus includes: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to at least: transmit a Channel State Information (CSI) configuration to the first apparatus, the CSI configuration indicating whether Digital Post-distortion (DPoD) is to be executed against a Channel State Information Reference Signal (CSI-RS); and receive a CSI-RS report from the first apparatus, the CSI-RS report including results of a channel estimation determined based on the CSI configuration.

[0007] In a third aspect of this disclosure, a method is provided. The method includes: receiving channel state information (CSI) configuration from a second device, the CSI configuration indicating whether digital post-distortion (DPoD) is to be performed on a channel state information reference signal (CSI-RS); performing channel estimation on the received CSI-RS based on the CSI configuration; and transmitting a CSI-RS report to the second device, the CSI-RS report including the results of the channel estimation.

[0008] In a fourth aspect of this disclosure, a method is provided. The method includes: transmitting Channel State Information (CSI) configuration to a first device, the CSI configuration indicating whether Digital Post-distortion (DPoD) is to be performed against a Channel State Information Reference Signal (CSI-RS); and receiving a CSI-RS report from the first device, the CSI-RS report including the result of a channel estimation determined based on the CSI configuration.

[0009] In a fifth aspect of this disclosure, a first apparatus is provided. The first apparatus includes: components for receiving channel state information (CSI) configuration from a second apparatus, the CSI configuration indicating whether digital post-distortion (DPoD) is to be performed on a channel state information reference signal (CSI-RS); components for performing channel estimation on the received CSI-RS based on the CSI configuration; and components for transmitting a CSI-RS report to the second apparatus, the CSI-RS report including the results of the channel estimation.

[0010] In a sixth aspect of this disclosure, a second apparatus is provided. The second apparatus includes: components for transmitting Channel State Information (CSI) configuration to a first apparatus, the CSI configuration indicating whether Digital Post-distortion (DPoD) is to be performed for a Channel State Information Reference Signal (CSI-RS); and components for receiving a CSI-RS report from the first apparatus, the CSI-RS report including the result of a channel estimation determined based on the CSI configuration.

[0011] In a seventh aspect of this disclosure, a computer-readable medium is provided. The computer-readable medium includes instructions stored thereon for causing a device to perform at least the method according to a third aspect.

[0012] In an eighth aspect of this disclosure, a computer-readable medium is provided. The computer-readable medium includes instructions stored thereon for causing a device to execute at least the instructions according to the method of the fourth aspect.

[0013] It should be understood that the summary portion is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0014] Some exemplary embodiments will now be described with reference to the accompanying drawings, in which: Figure 1 An example communication environment in which example embodiments of this disclosure may be implemented is shown; Figure 2 The signaling flow for a measurement report of a reference signal according to some example embodiments of this disclosure is shown; Figure 3 The signaling flow for measurement reports of the Channel State Information Reference Signal (CSI-RS) according to some example embodiments of the present disclosure is shown; Figure 4 The process of measurement reporting implemented at a first device according to some example embodiments of the present disclosure is illustrated; Figure 5 Example signaling flows for CSI-RS measurement reporting using DPoD according to some example embodiments of this disclosure are shown; Figure 6 Example signaling flows for CSI-RS measurement reporting without DPoD application are shown according to some other example embodiments of this disclosure; Figure 7 A flowchart is shown illustrating a method implemented at a first device according to some exemplary embodiments of the present disclosure; Figure 8 A flowchart is shown illustrating a method implemented at a second device according to some example embodiments of the present disclosure; Figure 9 A flowchart is shown of a method implemented at a first device according to some other exemplary embodiments of the present disclosure; Figure 10 A flowchart is shown of a method implemented at a second device according to some other exemplary embodiments of the present disclosure; Figure 11 A flowchart is shown illustrating a method implemented at a first device according to some other exemplary embodiments of the present disclosure; Figure 12 A simplified block diagram of a device suitable for implementing example embodiments of the present disclosure is shown; and Figure 13 A block diagram of an example computer-readable medium according to some example embodiments of the present disclosure is shown.

[0015] In all the accompanying drawings, the same or similar reference numerals denote the same or similar elements. Detailed Implementation

[0016] The principles of this disclosure will now be described with reference to some exemplary embodiments. It should be understood that these embodiments are described for illustrative purposes only and to help those skilled in the art to understand and implement this disclosure, without implying any limitation on the scope of this disclosure. The embodiments described herein can be implemented in various ways other than those described below.

[0017] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0018] References to "an embodiment," "embodiment," "example embodiment," etc., in this disclosure indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment includes that particular feature, structure, or characteristic. Furthermore, these phrases do not necessarily refer to the same embodiment. In addition, when a particular feature, structure, or characteristic is described in conjunction with an example embodiment, it is to be noted that those skilled in the art will recognize, whether explicitly described or not, that such features, structures, or characteristics apply in conjunction with other embodiments.

[0019] It should be understood that although terms such as "first," "second," etc., preceding (multiple) nouns may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another, and they do not restrict the order of (multiple) nouns. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the scope of the exemplary embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0020] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, wherein a list of two or more elements combined with “and” or “or” means at least one of these elements, or any two or more of these elements, or at least all of these elements.

[0021] As used herein, unless explicitly stated otherwise, the execution step “in response to A” does not indicate that the step is executed immediately after “A” occurs, and may include one or more intermediate steps.

[0022] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” “having,” “possessing,” “containing,” and / or “covering,” as used herein, specify the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0023] The term "circuit system" as used in this application may refer to one or more of the following: (a) Hardware circuit implementation only (such as implementation in analog and / or digital circuits only) and (b) A combination of hardware circuitry and software, such as (if applicable): (i) A combination of (multiple) analog and / or digital hardware circuits and software / firmware, and (ii) Any part of the (multiple) hardware processors (including (multiple) digital signal processors), software, and (multiple) memories, which work together to enable a device (such as a mobile phone or server) to perform various functions and (c) (Multiple) hardware circuits and / or (multiple) processors, such as (multiple) microprocessors or a portion thereof, which require software (e.g. firmware) to operate, but may not exist when the software is not required to operate.

[0024] The definition of "circuit system" applies to all uses of the term in this application, including any claim. As yet another example, as used in this application, the term "circuit system" also covers implementations of hardware circuitry or processors (or processors) or a portion thereof, including but not limited to hardware circuitry or processors and their accompanying software and / or firmware. The term "circuit system" also covers, for example (and if applicable to a particular claim element), baseband integrated circuits or processor integrated circuits for mobile devices or similar integrated circuits in servers, cellular network devices, or other computing or networking devices.

[0025] As used herein, the term "communication network" refers to a network that conforms to any suitable communication standard, such as New Radio (NR) systems, Long Term Evolution (LTE), LTE-A Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), etc. Furthermore, communication between terminal devices and network devices in a communication network can be performed according to any suitable generation of communication protocol, including but not limited to first-generation (1G), second-generation (2G), 2.5G, 2.75G, third-generation (3G), fourth-generation (4G), 4.5G, fifth-generation (5G), 5.5G, sixth-generation (6G) communication protocols, and / or any other currently known or under development protocols. Embodiments of this disclosure can be applied to a variety of communication systems. Given the rapid development of communications, future types of communication technologies and systems that can implement this disclosure will inevitably emerge. The scope of this disclosure should not be considered limited to the systems described above.

[0026] As used herein, the term "network device" refers to a node in a communications network through which terminal devices access the network and receive services. Depending on the terminology and technology applied, a network device can refer to a base station (BS) or access point (AP), such as a Node B (NodeB or NB), an evolved Node B (eNodeB or eNB), an NR NB (also known as a gNB), a Remote Radio Unit (RRU), a Radio Header (RH), a Remote Radio Header End (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low-power node (such as a femtosecond or picosecond), a non-terrestrial network (NTN) or non-terrestrial network device (such as a satellite network device), a low Earth orbit (LEO) satellite and a geostationary Earth orbit (GEO) satellite, a spacecraft network device, etc. In some example embodiments, the Radio Access Network (RAN) split architecture includes a centralized unit (CU) and a distributed unit (DU) at the IAB donor node. An IAB node includes a mobile terminal (IAB-MT) portion that behaves like a UE toward the parent node, and a DU portion that behaves like a base station toward the next-hop IAB node.

[0027] The term "terminal device" refers to any end device with wireless communication capabilities. As an example and not a limitation, a terminal device can refer to communication equipment, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), or access terminal (AT). Terminal devices can include, but are not limited to, mobile phones, cellular phones, smartphones, Voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image acquisition terminal devices (such as digital cameras), gaming terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded devices (LEE), laptop mounted devices (LME), USB dongles, smart devices, wireless client devices (CPE), Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated processing chains), consumer electronic devices, devices operating on commercial and / or industrial wireless networks, etc. Terminal equipment may also correspond to the mobile terminal (MT) portion of an IAB node (also known as a relay node) or a WAB node. In the following description, the terms "terminal equipment," "communication equipment," "terminal," "user equipment," and "UE" are used interchangeably.

[0028] As used herein, the terms “resource,” “transmission resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” can refer to any resource used to perform communication, such as communication between a terminal device and a network device, including time-domain resources, frequency-domain resources, spatial-domain resources, code-domain resources, or any other combination of time-domain, frequency-domain, spatial-domain, and / or code-domain resources capable of communication. In the following, unless explicitly stated otherwise, resources in both the frequency and time domains will be used as examples of transmission resources used to describe some exemplary embodiments of this disclosure. Note that the exemplary embodiments of this disclosure are equally applicable to other resources in other domains.

[0029] Figure 1 A schematic diagram of an example communication environment 100 in which exemplary embodiments of the present disclosure may be implemented is shown. In the communication environment 100, multiple communication devices, including terminal device 110 and network device 120, can communicate with each other.

[0030] exist Figure 1 In the example, terminal device 110 may be a UE, and network device 120 may be a base station serving the UE. Network device 120 operates in a radio access network (RAN) and is therefore also referred to as a RAN network device.

[0031] It should be understood that Figure 1 The number of devices and their connections shown are for illustrative purposes only and do not imply any limitation. Communication environment 100 may include any suitable number of devices configured to implement the exemplary embodiments of this disclosure. Note that although shown as a network device, network device 120 may be another device besides a network device. Although illustrated as a terminal device, terminal device 110 may be another device besides a terminal device.

[0032] In the following description, for illustrative purposes, some example embodiments are described in which terminal device 110 operates as a UE and network device 120 operates as a base station (e.g., gNB). However, in some example embodiments, the operations described in connection with the terminal device can be implemented at the network device or other devices, and the operations described in connection with the network device can be implemented at the terminal device or other devices.

[0033] In some example embodiments, the communication direction from network device 120 to terminal device 110 is referred to as the downlink (DL), and the communication direction from terminal device 110 to network device 120 is referred to as the uplink (UL). In the DL, network device 120 is a transmission (TX) device (or transmitter), and terminal device 110 is a reception (RX) device (or receiver). In the UL, terminal device 110 is a TX device (or transmitter), and network device 120 is an RX device (or receiver).

[0034] Communication in communication environment 100 can be implemented according to any suitable communication protocol, including but not limited to cellular communication protocols such as first-generation (1G), second-generation (2G), third-generation (3G), fourth-generation (4G), fifth-generation (5G), and sixth-generation (6G), wireless local network communication protocols such as IEEE 802.11, and / or any other currently known or future-developed protocols. Furthermore, communication can utilize any suitable wireless communication technology, including but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiplexing (OFDM), Discrete Fourier Transform Extended OFDM (DFT-s-OFDM), and / or any other currently known or future-developed technologies.

[0035] In a communications environment, it may be necessary to control the nonlinearity of the power amplifiers used in the user equipment radio transmitter in a manner that also takes into account transmission requirements.

[0036] Currently, the Digital Post-distortion (DPoD) method is used to eliminate nonlinear distortion in power amplifiers. Unlike traditional methods, the DPoD method allows the transmitter to transmit a signal in the nonlinear region of the power amplifier, causing signal distortion. The receiver then needs to process the received signal to eliminate the nonlinearity of the power amplifier and restore the signal. When applying the DPoD method, the transmitter does not need to operate the power amplifier in the linear region, nor does it require the use of complex Digital Predistortion (DPD) methods to eliminate distortion.

[0037] Early DPoD techniques relied on iterative algorithms to estimate nonlinear distortion caused by the transmitter. These methods were known as Power Amplifier Nonlinear Compensation (PANC). More recently, artificial intelligence (AI) and machine learning (ML) based DPoD methods have been used to assist DPoD in addressing nonlinear distortion problems. In these methods, the receiver uses a neural network-based DPoD model to, for example, process signals with power amplifier distortion. Furthermore, an end-to-end power amplifier cancellation system distributed between the transmitter and receiver has been proposed to address this issue. In this system, a Direct Power Detection (DPD) for eliminating Adjacent Channel Leakage Ratio (ACLR) and a DPoD for correcting Error Vector Magnitude (EVM) are jointly trained. This method requires coordination between the DPD and DPoD modules in both the transmitter and receiver.

[0038] In some implementations, the ACLR in NR is defined as the ratio between the average filtered power centered on the assigned NR channel frequency and the average filtered power centered on the adjacent NR channel frequencies at the nominal channel interval. The assigned NR channel power and the adjacent NR channel power are measured using a rectangular filter with a measurement bandwidth as specified in Table 1.

[0039] Table 1

[0040] If the measured adjacent channel power is greater than -50dBm, then the NR ACLR should be higher than the value specified in Table 2.

[0041] Table 2

[0042] In some implementations, out-of-band emissions refer to unwanted emissions immediately outside the allocated channel bandwidth. These unwanted emissions are caused by nonlinearities in the modulation process and transmitter, but do not include spurious emissions. This out-of-band emission limitation is specified based on spectral emission masks and ACLR. To improve measurement accuracy, sensitivity, and efficiency, the resolution bandwidth can be smaller than the measurement bandwidth. When the resolution bandwidth is smaller than the measurement bandwidth, the result should be integrated over the measurement bandwidth to obtain the equivalent noise bandwidth of the measurement bandwidth.

[0043] EVM is a measure of the difference between a reference waveform and a measured waveform. This difference is called the error vector. Before calculating the EVM, the measured waveform is corrected for sampling timing offset and RF frequency offset. Then, carrier leakage is removed from the measured waveform before calculating the EVM.

[0044] The measured waveforms are further equalized using channel estimation, which satisfies the spectral flatness requirements of the EVM equalizer. For Discrete Fourier Transform Extended Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) waveforms, the EVM result, after the front-end Fast Fourier Transform (FFT) and Inverse Discrete Fourier Transform (IDFT), is defined as the square root of the ratio of the average error vector power to the average reference power, expressed as a percentage. For Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) waveforms, the EVM result, after the front-end FFT, is defined as the square root of the ratio of the average error vector power to the average reference power, expressed as a percentage.

[0045] The basic EVM measurement interval in the time domain is a preamble sequence for the Physical Random Access Channel (PRACH) and a time slot for the Physical Uplink Control Channel (PUCCH) and Physical Uplink Shared Channel (PUSCH) in the time domain. The EVM measurement interval is reduced by removing any symbols that contain allowed power transients within the measurement interval.

[0046] For the average EVM value, the root mean square (RMS) average of the basic EVM measurements over 10 subframes, and for the reference signal EVM value, the root mean square (RMS) average of the basic EVM measurements over 60 subframes, should not exceed the values ​​specified in Table 3 for the parameters defined in Table 4, depending on the modulation scheme. For EVM evaluation purposes, all 13 PRACH preamble formats and all 5 PUCCH formats are considered to have the same EVM requirements as Quadrature Phase Shift Keying (QPSK) modulation.

[0047] Table 3

[0048] Table 4

[0049] The presence of nonlinear distortion introduced by the power amplifier may necessitate determining the impact of power amplifier nonlinearity on reference signals transmitted from the transmitter to the receiver, including the Channel State Information Reference Signal (CSI-RS) used for beamforming. The transmission and reception of the reference signal play a crucial role in various communications. For example, the CSI-RS signal can be used to estimate the channel, and the channel estimation results can then be applied to beamforming and precoder selection. To ensure high-quality beamforming operation, CSI feedback calculated based on the CSI-RS is required.

[0050] The availability of DPoD at the receiver will allow the PA to operate in the nonlinear region. Therefore, if the RS has high power, it may fall into the nonlinear region of the PA and become distorted. This distortion can lead to suboptimal beamforming designs.

[0051] On the other hand, since some types of RS (such as CSI-RS pilots) can have different power levels compared to data symbols (CSI-RS pilot power can be boosted for high-quality channel estimation in low SNR scenarios), the combined effect of channel and PA on CSI feedback will lead to beamforming scenarios where the beamforming vector is designed to include the PA response, which differs from the PA response to data. This will degrade the performance of beamforming vectors for data symbols because the data symbols will face different levels of PA nonlinearity.

[0052] Therefore, it is important to ensure that the RS measurements provided by the receiver can indicate how RS reception was completed. In the case of CSI-RS, the channel information collected by the receiver on the CSI-RS can well represent the overall channel response (the overall channel response that the data signal will experience in subsequent downlink transmissions from the transmitter to the receiver), or the receiver has the ability to compensate for mismatches.

[0053] In other words, in one way, the receiver of the RS might be able to compensate for nonlinearities not captured by the RS. In this case, the precoding mechanism in the RS transmitter would be responsible for pre-compensating for some distortion (distortion visible in the CSI feedback), while the RS receiver would be responsible for post-compensating for the remaining distortion. Alternatively, the transmitter could determine from the feedback of the measurement results that the RS (e.g., CS-RS) experiences some degree of distortion (caused by PA, wireless propagation channel, and other RF nonlinearities), just like a data signal. In this case, the precoding mechanism in the RS transmitter could be responsible for pre-compensating for the overall channel response, not just the propagation channel response.

[0054] Whether the system operates in one of the two modes requires agreement between the RS receiver and transmitter.

[0055] According to an example embodiment of this disclosure, a solution for a measurement report for a reference signal is proposed. A first device (which may be a receiver of the reference signal (e.g., a terminal device)) is configured by a second device (which may be a transmitter of the reference signal) to perform DPoD on the reference signal. The first device determines the measurement result of the reference signal based on the reference signal configuration and transmits a reference signal report including the measurement result to the second device. In this way, the second device can know whether the DPoD measurement result for the reference signal provided by the first device has been performed or has not been performed. The second device can apply the received measurement result based on the knowledge of whether the DPoD has been performed to determine or adjust other communication parameters for the first device.

[0056] Now, some example procedures will be described. Figure 2 Signaling flow 200 for measurement reports of a reference signal according to some example embodiments of this disclosure is shown. For example... Figure 2 As shown, signaling flow 200 involves a first device 201 and a second device 202. In an example embodiment of this disclosure, the first device 201 may act as a receiver, and the second device 202 may act as a transmitter.

[0057] In some example embodiments, the first device 201 may be or be included in terminal device 110. The second device 202 may be or be included in network device 120. It should be understood that, in the opposite direction, the first device 201 may be or be included in terminal device 110. The second device 202 may be or be included in network device 120. However, it should be understood that the first device 201 may be included in any other suitable device as a receiver of a particular signal, and the second device 202 may be included in any other suitable device as a transmitter of a particular signal.

[0058] In the following description, although operations are depicted in a specific order, this should not be construed as requiring that such operations be performed in the specific order shown or sequentially, or that all shown operations be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, while several specific embodiment details are included in the above discussion, these details should not be construed as limiting the scope of the invention, but rather as descriptions of features that may be specific to particular embodiments. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0059] In signaling stream 200, the second device 202 transmits (227) a reference signal configuration to the first device 201, and the first device 201 receives (230) a reference signal configuration accordingly. The reference signal configuration indicates whether DPoD should be performed for a reference signal to be transmitted from the second device 202 to the first device 201.

[0060] Since the second device 202 may want to receive a measurement report about the reference signal from the first device 201, it can request the first device 201 to apply or not apply DPoD to the reference signal when reporting the measurement results. Various types of reference signals may exist to be transmitted from the second device 202 to the first device 201, and these reference signals are transmitted for different purposes. The second device 202 can be configured to apply or not apply DPoD to a particular reference signal. The second device 202 can also configure the validity of the reference signal configuration, for example, in a time-based manner or by transmitting updated reference signal configurations.

[0061] In a scenario where the first device 201 is a terminal device and the second device 202 is a network device, the reference signal may include a DL reference signal. For example, a CSI-RS may be transmitted from the second device 202 to the first device 201 to estimate the channel response for the communication channel between the second device 202 and the first device 201. Information about the channel response may be reported to the second device 202 to determine communication configuration parameters to be applied to the communication between the first and second devices. In addition to CSI-RS, other DL reference signals may also be applicable to the example embodiments of this disclosure, such as demodulation reference signals (DM-RS), cell-specific reference signals (CRS), etc.

[0062] In some example embodiments, the reference signal configuration may be transmitted via RRC signaling. For example, if the reference signal is CSI-RS, the reference signal configuration may be included in a CSI configuration message. In some examples, a New Information Element (IE) may be defined in the reference signal configuration to indicate whether the DPoD should be applied by the first device 201 before measuring the reference signal.

[0063] In some example embodiments, before transmitting the reference signal configuration, the second device 202 may transmit (210) a request to the first device 201 for whether the reporting capability for DPoD to the reference signal is supported or not.

[0064] In response to receiving (215) a request for information regarding the capability of DPoD, the first device 201 may transmit (220) capability information indicating the capability to support DPoD for a reference signal. The capability information may include a DPoD capability indicator to indicate whether the first device 201 has the capability to perform DPoD and transmit PA-free feedback for the reference signal.

[0065] The second device 202 can receive (225) capability information and determine a reference signal configuration for the first device 201 based on the capability information. For example, based on the capability information indicating that the first device 201 supports performing DPoD, the second device 202 can transmit to the first device 201 a reference signal configuration indicating that DPoD should be performed on the reference signal. Otherwise, if the first device 201 indicates to the second device 202 that it does not support DPoD, the second device 202 can transmit a reference signal configuration indicating that DPoD should not be performed on the reference signal.

[0066] In some example embodiments, the first device 201 may not be configured to perform DPoD on the reference signal. In this case, the second device 202 may not need to transmit a request to confirm the DPoD capability for the reference signal. Instead, the second device 202 may directly transmit to the first device 201 a reference signal configuration indicating that DPoD is not performed on the reference signal.

[0067] Then, the second device 202 can transmit a reference signal (235) to the first device 201 using transmission power. In some examples, the second device 202 can transmit the reference signal using a transmission power different from the transmission power of one or more data symbols. In some examples, the transmission power of the reference signal is higher than the transmission power of one or more data symbols. In some example embodiments, the second device 202 can configure the transmission of the reference signal based on the reference signal.

[0068] If a reference signal configuration has been transmitted to configure the first device 201 to apply DPoD, the second device 202 can transmit the reference signal with transmission power that includes nonlinear distortion from the PA. In this case, the second device 202 transmits the reference signal, and the receiver (i.e., the first device 201) is expected to perform DPoD upon receiving the reference signal. In some examples, if a reference signal configuration has been transmitted to configure the first device 201 not to apply DPoD, the second device 202 can transmit the reference signal with high transmission power to keep the PA in the nonlinear region. If the transmission power of the reference signal is low, it can be boosted to allow it to operate in the nonlinear region.

[0069] The first device 201 can receive (240) a reference signal and determine a measurement result based on the reference signal configuration. After obtaining the measurement result of the reference signal, the first device 201 transmits (245) a reference signal report to the second device 202. The reference signal report may include the measurement result of the reference signal obtained based on the reference signal configuration.

[0070] The details of the measurement results can depend on the type of reference signal. In some examples, the measurement results may include Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), SNR, etc. In some examples, if the reference signal includes CSI-RS, the measurement results may include channel state information estimated from the received CSI-RS, including, for example, Channel Quality Indicator (CQI), Rank Indicator (RI), precoding information such as the Precoding Matrix Indicator (PMI), beam and phase information, etc.

[0071] In some example embodiments, the reference signal configuration may instruct the first device 201 to perform DPoD on the reference signal. Since the first device 201 is configured to perform DPoD on the reference signal, it can determine or be configured to select a DPoD mode for the measurement results of the reference signal. The first device 201 can select any DPoD mode to remove distortion from the received reference signal.

[0072] As used herein, a DPoD mode refers to a specific method or technique applied to perform PA compensation on received signals. In some example embodiments, a DPoD mode may be based on a DPoD algorithm, such as the PANC algorithm, a multinomial model, etc. Different DPoD modes can be determined by applying different parameter values ​​in the DPoD algorithm. Alternatively or additionally, in some example embodiments, a DPoD mode may be based on an AI / ML model, referred to as an AI / ML-based DPoD model. Different DPoD models can be trained with different model parameter values ​​to process received signals for PA compensation purposes.

[0073] In the case of performing DPoD, in response to receiving a reference signal, the first device 201 can perform DPoD on the reference signal, and then remove PA distortion from the measurement result of the reference signal. The level of distortion removal will depend on the amount of distortion.

[0074] In some example embodiments, the reference signal configuration may indicate that the first device 201 does not need to perform DPoD against the reference signal. In this case, the first device 201 can determine the measurement result without applying any DPoD mode.

[0075] In some example embodiments, in addition to the measurement results, the reference signal report may also include an indication of whether the DPoD has been performed for the measurement results of the reference signal. In some examples, the reference signal report may include a new IE, wherein the first device 201 notifies whether the DPoD has been activated for the measurement results of the reference signal. For example, the indication may be a flag indicating whether the DPoD has been performed.

[0076] In some examples, if the reference signal configuration instructs the first device 201 to perform DPoD and the first device 201 has already performed DPoD, the reference signal report may include an indication that DPoD has been performed for the measurement results. In this case, the measurement results in the reference signal report may not include PA distortion. Additionally, the reference signal report may also include information about the DPoD process, such as the DPoD mode applied, the level of distortion removal, the number of iterations if a well-known algorithm (such as Power Amplifier Nonlinear Compensation (PANC)) is used, etc.

[0077] In some other example embodiments, if the reference signal configuration indicates that the first device 201 does not perform DPoD, the reference signal report may include, in addition to the measurement result, an indication that DPoD has not yet been performed for the measurement result. Depending on the transmission power of the reference signal, the measurement result may or may not include PA distortion.

[0078] The second device 202 receives (250) a measurement report from the first device 201 and can apply the measurement results and (optionally) an indication of whether the DPoD has been executed in response to the measurement results to enable further communication processes, which are not limited in this respect.

[0079] Figure 3 Signaling stream 300 for CSI-RS measurement reporting according to some example embodiments of this disclosure is shown. Signaling stream 300 can be considered as an example of signaling stream 200, and CSI-RS (also referred to as CSI-RS pilot) is an example of a reference signal in signaling stream 200.

[0080] In signaling stream 200, the second device 202 transmits (330) CSI configuration to the first device 201, and the first device 201 receives (330) CSI configuration accordingly. CSI configuration indicates whether DPoD is performed for CSI-RS to be transmitted from the second device 202 to the first device 201.

[0081] In some example embodiments, the CSI configuration may be transmitted via RRC signaling. For example, if the reference signal is CSI-RS, the CSI configuration may be included in the CSI configuration message. In some examples, a New Information Element (IE) may be defined in the CSI configuration to indicate whether DPoD should be applied by the first device 201 prior to CSI feedback.

[0082] In some example embodiments, before transmitting the reference signal configuration, the second device 202 may transmit (310) a request to the first device 201 for a report on whether the capability for DPoD to CSI-RS is supported. In response to receiving (315) the request regarding the capability for DPoD, the first device 201 may transmit (320) capability information indicating support for DPoD to CSI-RS. The capability information may include a DPoD capability indicator to indicate whether the first device 201 has the capability to perform DPoD and send PA-distortion-free feedback to CSI-RS.

[0083] Based on the DPoD capability received from the first device 201 (325), the second device 202 can transmit a CSI-RS configuration to the first device 201 to indicate whether DPoD should be performed on the reference signal. For example, based on the first device 201's indication of its ability to perform DPoD, the second device 202 can transmit a CSI-RS configuration to the first device 201 indicating that DPoD should be performed on the reference signal. Otherwise, if the first device 201 indicates to the second device 202 that it does not support DPoD, the second device 202 can transmit a CSI-RS configuration indicating that DPoD should not be performed on the reference signal.

[0084] In some example embodiments, if the second device 202 is intended to utilize a power boost from the CSI-RS, the second device 202 may configure the first device 201 to apply DPoD. This power boost may be, for example, at least 3 dB with a 3 dB increment. In some example embodiments, the second device 202 may configure the first device 201 to apply DPoD even if the CSI-RS transmission power is not boosted but falls within the nonlinear region of the PA.

[0085] Then, the second device 202 can transmit (340) CSI-RS to the first device 201 using a transmission power different from that of one or more data symbols. Furthermore, the transmission power of the CSI-RS can be higher than that of one or more data symbols. For example, the transmission power of the CSI-RS will fall into the nonlinear region of the PA.

[0086] In some example embodiments, the second device 202 may transmit CSI-RS to the first device 201 using a transmission power different from the transmission power of one or more data symbols. In some example embodiments, the transmission power of the CSI-RS is higher than the transmission power of one or more symbols for data transmission. For example, the second device 202 may transmit CSI-RS with a transmission power that includes nonlinear distortion from the PA. If the transmission power of the CSI-RS is low, the second device 202 may increase the transmission power to operate in the nonlinear region.

[0087] When the first device 201 is configured to perform DPoD for CSI-RS, the second device 202 can transmit CSI-RS, thus anticipating that the first device 201 will perform DPoD. If the first device 201 is configured not to perform DPoD for CSI-RS, the second device 202 can anticipate receiving CSI feedback with distorted channel state information.

[0088] The first device 201 receives (345) CSI-RS and performs (350) channel estimation on the received CSI-RS based on the CSI configuration. The channel estimation may include channel state information estimated from the received CSI-RS.

[0089] Depending on whether the DPoD is configured in the received CSI configuration, the first device 201 may or may not apply the DPoD to the received CSI-RS. The following will refer to... Figure 4 Explain the detailed behavior of the first device 201.

[0090] The first device 201 transmits (355) a CSI-RS report, including the results of channel estimation, to the second device 202. The second device 202 receives (360) the CSI-RS report accordingly. The CSI-RS report may also be referred to as CSI feedback.

[0091] In some example embodiments, the CSI-RS report may also include an indication of whether DPoD has been performed for channel estimation.

[0092] In some example embodiments, if DPoD is applied, signaling flow 300 provides a mechanism for CSI feedback, wherein the DPoD algorithm is used to calculate the effect of PA and remove it from the CSI-RS signal before the CSI feedback is sent. DPoD can be applied before the compression and quantization of the channel state matrix. In these cases, the CSI-RS report may optionally or additionally include information about the DPoD process.

[0093] In some example embodiments, if DPoD is not applied, the CSI-RS report may also include an indication that DPoD has not yet been performed for the channel estimation, as well as the result of the channel estimation. Signaling flow 300 provides a mechanism to ensure that if the CSI feedback contains both channel estimation information and PA distortion response, the second device 202 can ensure that the PA response of the data transmission is the same as that of the CSI-RS pilot. This will require the second device 202 to maintain the transmission power of the data symbols at the same level as the CSI-RS transmission power.

[0094] In some example embodiments, based on the channel estimation results indicated in the CSI-RS report, the second device 202 can perform (365) beamforming on the first device 201. Since DPoD has already been applied to the channel estimation by the first device 201, the second device 202 can perform beamforming, where the channel estimation only characterizes the propagation channel (without RA response). The second device 202 can transmit data symbols to the first device 201 based on the beamforming.

[0095] In some example embodiments, if the CSI-RS report includes an indication that DPoD has not yet been performed for channel estimation, or if the second device 202 determines, based on the CSI configuration sent to the first device 201, that DPoD has not yet been performed, then the second device 202 may perform (365) beamforming on the first device 201 based on the result of channel estimation with PA distortion. In some example embodiments, if the CSI-RS report includes an indication that DPoD has not yet been performed for channel estimation, or if the second device 202 determines, based on the CSI configuration sent to the first device 201, that DPoD has not yet been performed, then the transmission of data symbols toward the second device 201 may involve subprocess 368. Specifically, the second device 202 may perform (370) power control on one or more data symbols to control the transmission power of one or more additional data symbols to be equal to the transmission power of the CSI-RS, for example, the transmission power applied when transmitting the CSI-RS at 340. The second device 202 transmits (375) the one or more data symbols to the first device 201 using the determined transmission power.

[0096] The first device 201 receives (380) one or more data symbols from the second device 202. In some examples, the first device 201 may optionally apply (385) DPoD to any residual distortion level of the received data symbols(s).

[0097] Figure 4A measurement reporting process 400 implemented at a first device 201 according to some example embodiments of this disclosure is illustrated. Process 400 includes behaviors implemented by the first device 201 to support CSI feedback with and without DPoD.

[0098] In block 410, the first device 201 receives a CSI configuration from the second device 202, which may include at least an indication for DPoD (referred to as the DPoD flag). The DPoD flag indicates whether DPoD is to be performed against CSI-RS. The DPoD flag may be set to a first value to indicate that DPoD is to be performed against CSI-RS, or it may be set to a second value to indicate that DPoD is not to be performed against CSI-RS.

[0099] In box 420, the first device 201 can check the DPoD flag in the CSI configuration to determine whether to apply DPoD for receiving CSI-RS from the second device 202.

[0100] If the DPoD flag indicates that DPoD should be performed on the CSI-RS, then in block 422, the first device 201 receives the CSI-RS from the second device 202. Based on the configuration indicating that DPoD should be performed, the first device 201 can determine channel state information by performing DPoD on the received CSI-RS before determining the CSI feedback. Specifically, in block 424, the first device 201 performs DPoD on samples of the received CSI-RS to compensate for PA distortion in the received signal samples and remove or eliminate PA distortion. The first device 201 can choose any appropriate DPoD method (e.g., a classical DPoD algorithm or an AI / ML-based DPoD model) to remove or eliminate PA distortion from the samples of the received CSI-RS. The level of distortion removal will depend on the amount of PA distortion. The first device 201 can perform DPoD before compressing and quantizing the channel response based on the CSI-RS. In some examples, the first device 201 can determine precoding information based on the CSI-RS after DPoD has been performed on the CSI-RS. For example, if the first device 201 is also selecting PMI, then PMI selection can be performed after CSI-RS distortion removal.

[0101] After DPoD has been performed, the first device 201 can extract CSI information as CSI feedback to be reported based on the CSI-RS after DPoD processing. The CSI information may include channel response, channel quality information (such as CQI), and precoding information (such as PMI). At block 428, the first device 201 can prepare the CSI feedback. Optionally, the first device 201 can also include a DPoD acknowledgment in the CSI-RS report that includes the CSI feedback. The DPoD acknowledgment is used to indicate to the second device 202 that DPoD has been performed for channel state information. Alternatively or additionally, the first device 201 can include information about the DPoD process in the CSI-RS report.

[0102] At box 440, the first device 201 transmits a CSI-RS report, including channel state information as CS feedback, to the second device 202.

[0103] In some other scenarios, if the CSI configuration indication DPoD received from the second device 202 is not executed for CSI-RS, as indicated in block 430, the first device 201 can perform CSI measurements in a conventional manner. Specifically, at block 432, the first device 201 receives CSI-RS from the second device 202. As described above, the second device 202 can transmit the CSI-RS using high transmission power, causing the PA to be in the non-linear region. On the receiver side, the first device 201 can follow the CSI configuration and will not apply DPoD to samples of the received CSI-RS. At block 434, the first device 201 extracts CSI information, such as PMI, CQI, etc. At block 436, the first device 201 can prepare CSI feedback. Optionally, the first device 201 may also include an indication in the CSI-RS report that DPoD was not applied to CSI information.

[0104] In cases where the CSI-RS report includes CSI information for which DPoD has not been applied, and in response to receiving one or more data symbols from the second device 202 thereafter, the first device 201 may perform DPoD on the one or more data symbols. DPoD can be performed for any level of residual distortion.

[0105] Figure 5 Example signaling flow 500 for measurement reporting of CSI-RS with DPoD applied, according to some example embodiments of this disclosure, is shown. Signaling flow 500 can be considered as an example of signaling flow 300.

[0106] In Signaling Stream 500, suppose the transmitter wants to have channel state information that includes only the effects of the propagation channel. For this, receiver assistance is required, and the receiver must use a DPoD algorithm (classical or AI receiver, such as Hybrid Depth RX) to remove PA nonlinearity from the received CSI-RS.

[0107] The second device 202 may request (510) from the first device 201 regarding the DPoD capability for the CSI-RS. In some examples, the second device 202 may initiate the process if it intends to utilize a power boost from the CSI-RS. This power boost is at least 3 dB, with a 3 dB increment. In some examples, the second device 202 may also initiate the process even if the CSI-RS transmission power is not boosted but will fall into the nonlinear region of the PA.

[0108] The first device 201 receives (515) a request for DPoD capability and transmits (520) an indicator regarding DPoD capability for CSI-RS to the second device 202. Figure 5 In the example, the first device 201 can confirm its ability to perform DPoD and send CSI feedback without PA distortion.

[0109] The second device 202 receives confirmation of the DPoD capability of the first device 201 and can configure (530) the first device 201 for CSI feedback with DPoD. This is achieved by indicating in a CSI configuration message that the CSI-RS requires DPoD. The CSI configuration message may include a new IE "DPoD" = "Yes" to indicate a DPoD request. The first device 201 receives (535) such CSI configuration from the second device 202 and can determine the DPoD method for CSI-RS reception.

[0110] The second device 202 transmits (540) CSI-RS to the first device 201 with transmission power including nonlinear distortion from the PA. The second device 202 may transmit CSI-RS pilots, and the first device 201 is expected to perform DPoD.

[0111] The first device 201 receives (545) CSI-RS and, when configured, performs (550) DPoD on the received CSI-RS pilot. The level of distortion removal can depend on the amount of distortion. The first device 201 can select any DPoD method to remove distortion from the CSI-RS.

[0112] In some example embodiments, DPoD can be performed before the compression and quantization of the channel response. If the first device 201 is also selecting a precoding matrix indicator (PMI), then DPoD can be performed after CSI-RS distortion removal by DPoD.

[0113] The first device 201 obtains channel state information based on CSI-RS, and after DPoD has been performed, transmits the channel state information (555) to the second device 202 as CSI feedback. The CSI feedback may include a flag or indication that DPoD has been applied. Alternatively or additionally, the first device 201 may include information about the DPoD process, such as the number of iterations in the case of using a DPoD algorithm (such as PANC).

[0114] The second device 202 receives (560) CSI feedback and confirmation that DPoD has been applied to the CSI feedback, and optionally information about DPoD. The second device 202 can perform (560) beamforming using channel state information that only characterizes the propagation channel, since the first device 201 has removed PA distortion before reporting the channel state information.

[0115] Figure 6 Example signaling flow 600 for measurement reporting of CSI-RS without DPoD application is shown according to some other example embodiments of this disclosure. Signaling flow 600 can be considered as an example of signaling flow 300.

[0116] In this scenario, it is assumed that the CSI-RS signal is distorted by the PA, and the second device 202 requires that the CSI feedback should include the effects of both the channel and the PA. This means that the beamformer at the second device 202 will be designed to handle both the PA and channel effects. This will require the second device 202 to use methods and algorithms that maintain the PA output power at the level of the CSI-RS transmission power.

[0117] In signaling flow 600, the second device 202 configures (610) the first device 201 for CSI feedback without DPoD. This is achieved by indicating in the CSI configuration message that DPoD is not required. The DPoD request can be a new IE "DPoD" = No. The first device 201 receives (615) a configuration for CSI feedback from the second device 202. In this case, the first device 201 may choose to use a simpler DPoD algorithm to remove PA distortion, or it may choose not to apply the DPoD algorithm.

[0118] In some examples, if the second device 202 determines that the first device 201 is not configured to apply DPoD for CSI-RS, the second device 202 may or may not need to request the DPoD capability of the first device 201.

[0119] The second device 202 transmits (620) CSI-RS to the first device 201 using high transmission power, so that PA is in the nonlinear region.

[0120] Then, the second device 202 can transmit a reference signal using high transmission power. In response to receiving this configuration, the first device 201 can perform conventional measurements without performing DPoD against the reference signal. The first device 201 can then transmit a reference signal report to the second device 202. In this case, the reference signal report may include an indication that DPoD has not yet been performed against the measurement results, as well as measurement results with PA distortion. For example, measurement results with PA distortion may indicate both the channel and PA responses, such that a portion of the PA nonlinearity will be compensated by subsequent but incomplete beamforming, leading to further requirements for DPoD against one or more data symbols.

[0121] If the CSI-RS transmission power is low, the second device 202 can increase the CSI-RS transmission power to enable it to operate in the nonlinear region.

[0122] First device 201 receives (625) CSI-RS and calculates channel state information without applying DPoD. First device 202 provides (630) a CSI report including CSI feedback to second device 202. In some examples, first device 201 may also indicate in the CSI report that the CSI feedback was obtained without DPoD post-compensation.

[0123] The second device 202 receives (635) beamforming with distorted CSI-RS. This means that the effects of both the channel and the PA are compensated through beamforming.

[0124] The second device 202 can perform (640) beamforming using the distorted channel state information received from the first device 201 in the CSI report.

[0125] The second device 202 can perform (645) power control for one or more data symbols in such a way that the power of the data symbols(s) is equal to or approximately the transmission power of CSI-RS. Then, the second device 202 can perform (650) data transmission toward the first device 201 using a transmission power equal to or approximately the transmission power of CSI-RS.

[0126] First device 201 receives (655) multiple data symbols transmitted from second device 202. In some examples, first device 201 may optionally perform (660) DPoD on the received multiple data symbols for any residual level of PA distortion.

[0127] Figure 7 A flowchart of an example method 700 implemented at a first device according to some exemplary embodiments of the present disclosure is shown. For the purposes of discussion, the method 700 will be described from the perspective of a first device, which may include... Figure 1 Terminal equipment 110 In block 710, the first device receives a reference signal configuration from the second device, the reference signal configuration indicating whether digital post-distortion DPoD should be performed for the reference signal.

[0128] At frame 720, the first device transmits a reference signal report to the second device, the reference signal report including measurement results of the reference signal based on the reference signal configuration.

[0129] In some example embodiments, the reference signal report also includes an indication of whether the DPoD has been executed in response to the measurement result.

[0130] In some example embodiments, the first device transmits capability information to the second device, the capability information indicating the capability to support DPoD for a reference signal; and the first device receives a reference signal configuration from the second device, the reference signal configuration indicating that DPoD is to be performed for a reference signal.

[0131] In some example embodiments, the first device receives from the second device a request for reporting capability to support DPoD for a reference signal; and in response to the request, the first device transmits capability information to the second device.

[0132] In some example embodiments, the reference signal report includes: an indication that the DPoD has performed an action in response to the measurement result, and the measurement result itself.

[0133] In some example embodiments, the reference signal report also includes information about the DPoD process.

[0134] In some example embodiments, the DPoD is configured not to be executed for the reference signal, and the reference signal report includes: an indication that the DPoD has not yet been executed for the measurement result, and the measurement result with PA distortion.

[0135] In some example embodiments, the reference signal includes at least one of the channel state information reference signals (CSI-RS).

[0136] In some example embodiments, the first device is a terminal device or is included in a terminal device, and the second device is a network device or is included in a network device.

[0137] Figure 8 A flowchart of an example method 800 implemented at a second device according to some example embodiments of the present disclosure is shown. For the purposes of discussion, method 800 will be described from the perspective of a second device, which may include... Figure 1 Network device 120.

[0138] In block 810, the second device transmits a reference signal configuration to the first device, the reference signal configuration indicating whether digital post-distortion DPoD should be performed against the reference signal.

[0139] At frame 820, the second device receives a reference signal report from the first device, the reference signal report including measurement results determined based on the reference signal configuration.

[0140] In some example embodiments, the reference signal report also includes an indication of whether the DPoD has been executed in response to the measurement result.

[0141] In some example embodiments, the second device transmits a reference signal to the first device using a transmission power different from that of one or more data symbols.

[0142] In some example embodiments, the transmission power of the reference signal is higher than the transmission power of one or more data symbols.

[0143] In some example embodiments, the second device receives capability information from the first device, the capability information indicating the capability of a DPoD to support a reference signal; and based on the capability to support a DPoD for a reference signal, the second device transmits a reference signal configuration to the first device, the reference signal configuration indicating that the DPoD is to be performed for a reference signal.

[0144] In some example embodiments, the second device transmits a request to the first device for reporting the capability to support DPoD for a reference signal; and the second device receives capability information from the first device.

[0145] In some example embodiments, the reference signal report includes: an indication that the DPoD has been executed for the measurement results, and a measurement result without power amplifier (PA) distortion.

[0146] In some example embodiments, the reference signal report also includes information about the DPoD process.

[0147] In some example embodiments, the DPoD is configured not to be executed for the reference signal, and the reference signal report includes: an indication that the DPoD has not yet been executed for the measurement result, and the measurement result with PA distortion.

[0148] In some example embodiments, a first means capable of performing any of the methods in method 700 (e.g., Figure 1 The terminal device 110 in the second device may include components for performing corresponding operations of method 700. The first device includes: components for receiving a reference signal configuration from the second device, the reference signal configuration indicating whether digital post-distortion DPoD is to be performed for a reference signal; and components for transmitting a reference signal report to the second device, the reference signal report including measurement results of the reference signal based on the reference signal configuration. This component can be implemented in any suitable form. For example, the component can be implemented in a circuit system or a software module. The first device can be implemented as or included in... Figure 1 In terminal device 110.

[0149] In some example embodiments, a second means capable of performing any of the methods in any method 800 (e.g., Figure 1 The network device 120 in the first device may include components for performing corresponding operations of method 800. The second device includes: components for transmitting a reference signal configuration to the first device, the reference signal configuration indicating whether digital post-distortion DPoD is to be performed against a reference signal; and components for receiving a reference signal report from the first device, the reference signal report including measurement results determined based on the reference signal configuration. This component can be implemented in any suitable form. For example, the component can be implemented in a circuit system or a software module. The second device can be implemented as or included in... Figure 1 Among the network devices in 120.

[0150] Figure 9 A flowchart of an example method 900 implemented at a first device according to some exemplary embodiments of the present disclosure is shown. For the purposes of discussion, the method 900 will be described from the perspective of a first device, which may include... Figure 1 Terminal equipment 110 In block 910, the first device receives Channel State Information (CSI) configuration from the second device. The CSI configuration indicates whether Digital Post-distortion DPoD should be performed against the Channel State Information Reference Signal (CSI-RS).

[0151] In block 920, the first device performs channel estimation on the received Channel State Information Reference Signal (CSI-RS) based on the CSI configuration.

[0152] In box 930, the first device transmits a CSI-RS report to the second device, the CSI-RS report including the results of channel estimation.

[0153] In some example embodiments, the CSI-RS report also includes an indication of whether DPoD has been performed for channel estimation.

[0154] In some example embodiments, the first device transmits capability information to the second device, the capability information indicating the capability to support DPoD for CSI-RS; and the first device receives CSI configuration from the second device, the CSI configuration indicating that DPoD should be performed for the received CSI-RS.

[0155] In some example embodiments, the first device receives a request from the second device for reporting capabilities supporting DPoD for CSI-RS; and in response to the request, the first device transmits capability information to the second device.

[0156] In some example embodiments, the CSI-RS report includes: an indication that DPoD has been performed for channel estimation, and the results of the channel estimation without power amplifier (PA) distortion.

[0157] In some example embodiments, the CSI-RS report also includes information about the DPoD process.

[0158] In some example embodiments, the CSI configuration indicates that the DPoD is not executed for the CSI-RS, and the CSI-RS report includes: an indication that the DPoD has not yet executed for the channel estimation, and the results of the channel estimation with PA distortion.

[0159] In some example embodiments, in response to receiving one or more data symbols from a second device, the first device performs DPoD on one or more data symbols.

[0160] In some example embodiments, the first device is a terminal device or is included in a terminal device, and the second device is a network device or is included in a network device.

[0161] Figure 10 A flowchart of an example method 1000 implemented at a second device according to some exemplary embodiments of the present disclosure is shown. For the purposes of discussion, the method 1000 will be described from the perspective of a second device, which may include... Figure 1 Network device 120.

[0162] In box 1010, the second device transmits Channel State Information (CSI) configuration to the first device. The CSI configuration indicates whether Digital Post-distortion DPoD should be performed against the Channel State Information Reference Signal (CSI-RS).

[0163] In block 1020, the second device receives a CSI-RS report from the first device, the CSI-RS report including the results of channel estimation determined based on the CSI configuration.

[0164] In some example embodiments, the CSI-RS report also includes an indication of whether DPoD has been performed for channel estimation.

[0165] In some example embodiments, the second device transmits CSI-RS to the first device using a transmission power different from the transmission power of one or more data symbols.

[0166] In some example embodiments, the transmission power of CSI-RS is higher than the transmission power of one or more symbols used for data transmission.

[0167] In some example embodiments, the second device receives capability information from the first device, the capability information indicating the capability of the DPoD to support CSI-RS; and based on the capability to support the DPoD for CSI-RS, the second device transmits CSI configuration to the first device, the CSI configuration indicating that the DPoD should be executed for the received CSI-RS.

[0168] In some example embodiments, the second device transmits a request to the first device for reporting the capability to support DPoD for CSI-RS; and the second device receives capability information from the first device.

[0169] In some example embodiments, the CSI-RS report includes: an indication that DPoD has been performed for channel estimation, and the results of the channel estimation without power amplifier (PA) distortion.

[0170] In some example embodiments, the CSI-RS report also includes information about the DPoD process.

[0171] In some example embodiments, the CSI configuration indicates that the DPoD is not executed for the CSI-RS, and the CSI-RS report includes: an indication that the DPoD has not yet executed for the channel estimation, and the results of the channel estimation with PA distortion.

[0172] In some example embodiments, in response to a CSI-RS report including an indication that DPoD has not yet performed channel estimation, the second device performs beamforming using both the results of the channel estimation and PA distortion; the second device performs power control on one or more additional data symbols to control the transmission power of the one or more additional data symbols to be equal to the transmission power of the CSI-RS; and the second device transmits one or more data symbols to the first device using the transmission power.

[0173] In some example embodiments, a first means capable of performing any of the methods in method 900 (e.g., Figure 1 The terminal device 110 may include components for performing corresponding operations of method 900. The first device includes: components for receiving Channel State Information (CSI) configuration from the second device, the CSI configuration indicating whether Digital Post-distortion (DPoD) is to be performed against a Channel State Information Reference Signal (CSI-RS); components for performing channel estimation on the received CSI-RS based on the CSI configuration; and components for transmitting a CSI-RS report to the second device, the CSI-RS report including the results of the channel estimation. These components can be implemented in any suitable form. For example, the components can be implemented in a circuit system or a software module. The first device can be implemented as or included in... Figure 1 In terminal device 110.

[0174] In some example embodiments, a second means capable of performing any of the methods in method 1000 (e.g., Figure 1 The network device 120 in the first device may include components for performing corresponding operations of method 1000. The second device includes: components for transmitting Channel State Information (CSI) configuration to the first device, the CSI configuration indicating whether Digital Post-distortion (DPoD) is to be performed against the Channel State Information Reference Signal (CSI-RS); and components for receiving a CSI-RS report from the first device, the CSI-RS report including the result of a channel estimation determined based on the CSI configuration. This component can be implemented in any suitable form. For example, the component can be implemented in a circuit system or a software module. The second device can be implemented as or included in... Figure 1 Among the network devices in 120.

[0175] Figure 11 A flowchart of an example method 1100 implemented at a first device according to some exemplary embodiments of the present disclosure is shown. For the purposes of discussion, method 1100 will be described from the perspective of a first device, which may include Figure 1 Terminal equipment 110 In block 1110, the first device receives configuration from the second device, the configuration indicating at least whether digitally distorted DPoD should be performed against the Channel State Information Reference Signal (CSI-RS).

[0176] In box 1120, the first device receives CSI-RS from the second device.

[0177] In box 1130, based on the configuration indicating that DPoD is to be performed, the first device determines the channel state information by performing DPoD on the CSI-RS.

[0178] At frame 1140, the first device transmits a report including channel state information to the second device.

[0179] In some example embodiments, the report also includes at least one of the following: an indication that DPoD has been performed for channel state information, or information about the process of DPoD.

[0180] In some example embodiments, the first device performs DPoD before compressing and quantizing the channel response based on CSI-RS.

[0181] In some example embodiments, after DPoD has been performed against CSI-RS, the first device determines precoding information based on CSI-RS.

[0182] In some example embodiments, the first device performs DPoD on the CSI-RS by removing power amplifier PA distortion from the CSI-RS based on a selected DPoD mode.

[0183] In some example embodiments, if the CSI configuration indicates that DPoD is not performed on the CSI-RS, the first device determines channel state information based on the CSI-RS, wherein the channel state information includes PA distortion.

[0184] In some example embodiments, the report also includes an indication that DPoD has not yet been executed for channel state information.

[0185] In some example embodiments, in response to receiving one or more data symbols from a second device, a first device performs DPoD on the one or more data symbols, wherein at least a portion of the PA distortion of the one or more data symbols has been compensated by beamforming utilizing channel state information.

[0186] In some example embodiments, the first device is a terminal device or is included in a terminal device, and the second device is a network device or is included in a network device.

[0187] In some example embodiments, a first means capable of performing any of the methods in method 1100 (e.g., Figure 1The terminal device 110 may include components for performing corresponding operations of method 1100. The first device includes: components for receiving configuration from the second device, the configuration indicating at least whether Digital Post-Distortion Diode (DPoD) is to be performed against a Channel State Information Reference Signal (CSI-RS); components for receiving the CSI-RS from the second device; components for indicating that DPoD is to be performed based on the configuration, and for determining channel state information by performing DPoD against the CSI-RS; and components for transmitting a report including the channel state information to the second device. These components can be implemented in any suitable form. For example, the components can be implemented in a circuit system or a software module. The first device can be implemented as or included in... Figure 1 In terminal device 110.

[0188] Figure 12 This is a simplified block diagram of a device 1200 suitable for implementing exemplary embodiments of the present disclosure. Device 1200 may be provided to implement a communication device, such as... Figure 1 The terminal device 110 or network device 120 shown. As shown, device 1200 includes one or more processors 1210, one or more memories 1220 coupled to processor 1210, and one or more communication modules 1240 coupled to processor 1210.

[0189] Communication module 1240 is used for bidirectional communication. Communication module 1240 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interface can represent any interface necessary for communication with other network elements. In some example embodiments, communication module 1240 may include at least one antenna.

[0190] As a non-limiting example, processor 1210 can be any type suitable for a local technology network and can include one or more of the following as non-limiting examples: general-purpose computer, special-purpose computer, microprocessor, digital signal processor (DSP), and processor based on a multi-core processor architecture. Device 1200 can have multiple processors, such as application-specific integrated circuit chips that are time-dependent on a clock synchronized with the main processor.

[0191] Memory 1220 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 1224, electrically programmable read-only memory (EPROM), flash memory, hard disk, miniature optical disc (CD), digital video disc (DVD), optical disc, laser disc, and other magnetic and / or optical storage. Examples of volatile memories include, but are not limited to, random access memory (RAM) 1222 and other volatile memories that will not be maintained during power outages.

[0192] Computer program 1230 includes computer-executable instructions that are executed by an associated processor 1210. The instructions of program 1230 may include instructions for performing operations / actions of some example embodiments of this disclosure. Program 1230 may be stored in memory, such as ROM 1224. Processor 1210 can perform any suitable actions and processes by loading program 1230 into RAM 1222.

[0193] Example embodiments of this disclosure can be implemented by means of program 1230, so that device 1200 can perform as described in the reference. Figures 2 to 11 Any process discussed in this disclosure. Exemplary embodiments of this disclosure may also be implemented by hardware or by a combination of software and hardware.

[0194] In some example embodiments, program 1230 may be tangibly included in a computer-readable medium, which may be included in device 1200 (such as in memory 1220) or other storage device accessible to device 1200. Device 1200 may load program 1230 from the computer-readable medium into RAM 1222 for execution. In some example embodiments, the computer-readable medium may include any type of non-transitory storage medium, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. As used herein, the term "non-transitory" refers to a limitation on the medium itself (i.e., tangible, not tactile) rather than a limitation on data storage persistence (e.g., RAM vs. ROM).

[0195] Figure 13 An example of a computer-readable medium 1300 is shown, which may be in the form of a CD, DVD, or other optical storage disc. The computer-readable medium 1300 stores a program 1230 thereon.

[0196] In general, the various embodiments of this disclosure can be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some aspects can be implemented in hardware, while others can be implemented in firmware or software executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of this disclosure are illustrated and described as block diagrams, flowcharts, or using some other graphical representation, it should be understood that the blocks, apparatuses, systems, techniques, or methods described herein can be implemented in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof, as examples of non-limiting examples.

[0197] Some exemplary embodiments of this disclosure also provide at least one computer program product tangibly stored on a computer-readable medium (such as a non-transitory computer-readable medium). The computer program product includes computer-executable instructions, such as those included in a program module, which are executed in a device on a target physical or virtual processor to perform any of the methods described above. Typically, a program module includes routines, programs, libraries, objects, classes, components, data structures, etc., that perform a particular task or implement a particular abstract data type. The functionality of the program module can be combined or split as needed among program modules in various embodiments. The machine-executable instructions for the program module can execute in a local device or a distributed device. In a distributed device, the program module can reside in both local storage media and remote storage media.

[0198] Program code for implementing the methods of this disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that, when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0199] In the context of this disclosure, computer program code or related data may be carried on any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations described above. Examples of carriers include signals, computer-readable media, etc.

[0200] Computer-readable media can be computer-readable signal media or computer-readable storage media. Computer-readable media can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any suitable combination thereof. More specific examples of computer-readable storage media include electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable optical disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0201] Furthermore, although the operations are described in a specific order, this should not be construed as requiring that they be performed in the specific order shown or sequentially, or that all the operations shown be performed in order to achieve the desired result. In some cases, multitasking and parallel processes can be advantageous. Similarly, while several specific implementation details are included in the foregoing discussion, they should not be considered as limiting the scope of this disclosure, but rather as a description of features that may be specific to certain embodiments. Unless explicitly stated otherwise, certain features described in the context of a single embodiment may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated otherwise, the various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0202] Although this disclosure has been described in language specific to structural features and / or methodological actions, it should be understood that the disclosure as defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are disclosed as exemplary forms of implementing the claims.

[0203] Furthermore, various implementations of this disclosure can be described with reference to the following entries, and their features can be combined in any reasonable manner.

[0204] Item 1. A first means for communication, comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first means to at least: receive channel state information (CSI) configuration from a second means, the CSI configuration indicating whether digital post-distortion (DPoD) is to be performed against a channel state information reference signal (CSI-RS); perform channel estimation on the received channel state information reference signal (CSI-RS) based on the CSI configuration; and transmit a CSI-RS report to the second means, the CSI-RS report including the results of the channel estimation.

[0205] Item 2. According to the first device of Item 1, wherein the CSI-RS report further includes: an indication of whether DPoD has been performed for channel estimation.

[0206] Item 3. The first means according to Item 1, wherein the first means is configured to: transmit capability information to the second means, the capability information indicating the capability to support DPoD for CSI-RS; and receive CSI configuration from the second means, the CSI configuration indicating that DPoD is to be performed for the received CSI-RS.

[0207] Item 4. The first means according to Item 3, wherein the first means is configured to: receive from the second means a request for reporting capability to support DPoD for CSI-RS; and in response to the request, transmit capability information to the second means.

[0208] Item 5. The first device according to Item 3 or 4, wherein the CSI-RS report includes: an indication that DPoD has been performed for channel estimation, and the result of the channel estimation.

[0209] Item 6. According to the first device of Item 5, wherein the CSI-RS report also includes information about the process of DPoD.

[0210] Item 7. The first apparatus according to Item 1 or 2, wherein the CSI configuration indicates that the DPoD is not performed for the CSI-RS, and the CSI-RS report includes: an indication that the DPoD has not yet performed for the channel estimation, and the result of the channel estimation.

[0211] Item 8. The first means according to Item 7, wherein the first means is further configured to: perform DPoD on one or more data symbols in response to receiving one or more data symbols from the second means.

[0212] Item 9. A second means for communication, comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second means to at least: transmit a Channel State Information (CSI) configuration to a first means, the CSI configuration indicating whether Digital Post-distortion (DPoD) is to be executed against a Channel State Information Reference Signal (CSI-RS); and receive a CSI-RS report from the first means, the CSI-RS report including the result of a channel estimation determined based on the CSI configuration.

[0213] Item 10. The second device according to Item 9, wherein the CSI-RS report further includes: an indication of whether DPoD has been performed for channel estimation.

[0214] Item 11. The second means according to Item 9 or 10, wherein the second means is configured to: receive capability information from the first means, the capability information indicating the capability of the DPoD to support CSI-RS; and, based on the capability to support the DPoD for CSI-RS, transmit a CSI configuration to the first means, the CSI configuration indicating that the DPoD is to be performed for the received CSI-RS.

[0215] Item 12. The second device according to Item 9 or 10, wherein the CSI configuration indicates that the DPoD is not performed for the CSI-RS, and the CSI-RS report includes: an indication that the DPoD has not yet performed for the channel estimation, and the result of the channel estimation.

[0216] Item 13. A method for communication, comprising: receiving channel state information (CSI) configuration from a second device, the CSI configuration indicating whether digital post-distortion (DPoD) is to be performed on a channel state information reference signal (CSI-RS); performing channel estimation on the received channel state information reference signal (CSI-RS) based on the CSI configuration; and transmitting a CSI-RS report to the second device, the CSI-RS report including the results of the channel estimation.

[0217] Item 14. A method for communication, comprising: transmitting channel state information (CSI) configuration to a first device, the CSI configuration indicating whether digital post-distortion (DPoD) is to be performed against a channel state information reference signal (CSI-RS); and receiving a CSI-RS report from the first device, the CSI-RS report including the result of a channel estimation determined based on the CSI configuration.

Claims

1. A first device for communication, comprising: At least one processor; as well as At least one memory stores instructions that, when executed by the at least one processor, cause the first device to at least: The second device receives Channel State Information (CSI) configuration, which indicates whether Digital Post-Distortion (DPoD) should be performed against the Channel State Information Reference Signal (CSI-RS). Based on the CSI configuration, channel estimation is performed on the received Channel State Information Reference Signal (CSI-RS). as well as A CSI-RS report is transmitted to the second device, the CSI-RS report including the results of the channel estimation.

2. The first apparatus according to claim 1, wherein the CSI-RS report further comprises: An indication of whether the DPoD has been performed for the channel estimation.

3. The first device according to claim 1, wherein the first device is configured to: Transmit capability information to the second device, the capability information indicating support for the DPoD for the CSI-RS; and The CSI configuration is received from the second device, which instructs the DPoD to be executed in response to the received CSI-RS.

4. The first device according to claim 3, wherein the first device is configured to: Receive from the second device a request for reporting support of the capability of the DPoD for the CSI-RS; and In response to the request, the capability information is transmitted to the second device.

5. The first apparatus according to claim 3 or 4, wherein the CSI-RS report comprises: Instructions indicating that the DPoD has been performed for the channel estimation, and the result of the channel estimation.

6. The first apparatus of claim 5, wherein the CSI-RS report further includes information about the DPoD process.

7. The first apparatus according to claim 1 or 2, wherein the DPoD is instructed not to be performed for the CSI-RS based on the CSI configuration, and the CSI-RS report includes: Indicates that the DPoD has not yet been executed for the channel estimation, and the result of the channel estimation.

8. The first device according to claim 7, wherein the first device is further configured to: In response to receiving one or more data symbols from the second device, the DPoD is performed on the one or more data symbols.

9. A second means for communication, comprising: At least one processor; as well as At least one memory stores instructions that, when executed by the at least one processor, cause the second device to at least: The first device transmits Channel State Information (CSI) configuration, which indicates whether Digital Post-distortion (DPoD) should be performed against the Channel State Information Reference Signal (CSI-RS). as well as The first device receives a CSI-RS report, which includes the results of channel estimation determined based on the CSI configuration.

10. The second apparatus of claim 9, wherein the CSI-RS report further comprises: An indication of whether the DPoD has been performed for the channel estimation.

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