Configuration of digital pre-distortion function

Abstract

Embodiments of the present application relate to configuration of digital pre-distortion function. A method comprises: sending, by a user equipment, information of a digital pre-distortion (DPD) function associated with each layer of at least one multiple-input multiple-output (MIMO) layer to a network node; receiving configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates to deactivate the DPD function for one or more MIMO layers; receiving at least one parameter associated with transmission of a reference signal for calibration of the at least one MIMO layer, the at least one parameter comprising: information of resources associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to the at least one MIMO layer; deactivating the DPD function for the one or more layers; and transmitting the reference signal based on the at least one parameter.

Description

Technical Field

[0001] This manual relates to wireless communication. Background Technology

[0002] A communication system can be a facility that enables communication between two or more nodes or devices (such as fixed or mobile communication devices). Signals can be carried on wired or wireless carrier waves.

[0003] An example of a cellular communication system is the architecture standardized by the 3rd Generation Partnership Project (3GPP). Recent developments in this field are often referred to as Long Term Evolution (LTE) of Universal Mobile Telecommunications System (UMTS) radio access technology. EUTRA (Evolved UMTS Terrestrial Radio Access) is the air interface for the 3GPP LTE upgrade path for mobile networks. In LTE, base stations or access points (APs), referred to as enhanced node APs (eNBs), provide radio access within a coverage area or cell. In LTE, mobile devices or mobile stations are referred to as user equipment (UEs). LTE has incorporated numerous improvements and developments. All aspects of LTE continue to improve.

[0004] The development of 5G New Radio (NR) is part of an ongoing evolution of mobile broadband to meet 5G requirements, similar to the early evolution of 3G and 4G wireless networks. Furthermore, in addition to mobile broadband, 5G also targets emerging use cases. The goal of 5G is to deliver significant improvements in wireless performance, which can include new levels of data rates, latency, reliability, and security. 5G NR can also be extended to efficiently connect massive Internet of Things (IoT) networks and can provide new types of mission-critical services. For example, ultra-reliable and low-latency communication (URLLC) devices may require high reliability and very low latency. 6G and other networks are also under development. Summary of the Invention

[0005] In some aspects, the technology described herein relates to an apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: transmit to a network node information about digital predistortion (DPD) functions associated with each of at least one multiple-input multiple-output (MIMO) layers; receive from the network node configuration information corresponding to at least one uplink transmission of at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; receive from the network node at least one parameter associated with a transmission of a reference signal for calibration of at least one MIMO layer, wherein the at least one parameter includes at least one of: information about resources associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to at least one MIMO layer; deactivate the DPD function for one or more layers; and transmit the reference signal to the network node at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0006] In some aspects, the technology described herein relates to an apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: receive from a user equipment information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; transmit to the user equipment configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; transmit to the user equipment at least one parameter associated with a transmission of a reference signal for calibration of the at least one MIMO layer, wherein the at least one parameter includes at least one of: information of resources associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to the at least one MIMO layer; and receive the reference signal from the user equipment at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0007] In some aspects, the technology described herein relates to a method comprising: transmitting from a user equipment to a network node information about a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; receiving from the network node configuration information corresponding to at least one uplink transmission of at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; receiving from the network node at least one parameter associated with a transmission of a reference signal for calibration of at least one MIMO layer, wherein the at least one parameter includes at least one of: information about resources associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to at least one MIMO layer; deactivating the DPD function for one or more layers; and transmitting the reference signal to the network node at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0008] In some aspects, the technology described herein relates to a method comprising: receiving from a user equipment (UE) by a network node information about digital predistortion (DPD) functions associated with each of at least one multiple-input multiple-output (MIMO) layers; sending to the UE configuration information corresponding to at least one uplink transmission of at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; sending to the UE at least one parameter associated with a transmission of a reference signal for calibration of at least one MIMO layer, wherein the at least one parameter includes at least one of the following: information about resources associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to at least one MIMO layer; and receiving the reference signal from the UE based at least in part on the at least one parameter associated with the transmission of the reference signal.

[0009] In some aspects, the technology described herein relates to an apparatus comprising components for causing the apparatus to perform at least the following: transmitting to a network node information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; receiving from the network node configuration information corresponding to at least one uplink transmission of at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; receiving from the network node at least one parameter associated with a transmission of a reference signal for calibration of at least one MIMO layer, wherein the at least one parameter includes at least one of the following: information of resources associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to at least one MIMO layer; deactivating the DPD function for one or more layers; and transmitting the reference signal to the network node at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0010] In some aspects, the technology described herein relates to an apparatus comprising components for causing the apparatus to perform at least the following: receiving from a user equipment information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; transmitting to the user equipment configuration information corresponding to at least one uplink transmission of at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; transmitting to the user equipment at least one parameter associated with a transmission of a reference signal for calibration of at least one MIMO layer, wherein the at least one parameter includes at least one of the following: information of resources associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to at least one MIMO layer; and receiving the reference signal from the user equipment at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0011] Other example embodiments are provided or described for each example method, including: components for performing any example method; a non-transitory computer-readable storage medium including instructions stored thereon, which, when executed by at least one processor, are configured to cause a computing system to perform any example method; and means including at least one processor and at least one memory including computer program code, which, together with the at least one processor, causes the means to at least perform any example method.

[0012] Details of one or more examples of embodiments are set forth in the accompanying drawings and the following description. Other features will be apparent from the specification, the drawings, and the claims. Attached Figure Description

[0013] Figure 1 This is a block diagram of a wireless network.

[0014] Figure 2 It is a flowchart illustrating the operation of a device (e.g., it may be a UE, user equipment, or other device).

[0015] Figure 3 It is a flowchart illustrating the operation of a device (e.g., a network node, gNB, eNB, or other device).

[0016] Figure 4 It is a flowchart illustrating the operation of a device (e.g., it may be a UE, user equipment, or other device).

[0017] Figure 5 It is a flowchart illustrating the operation of a device (e.g., a network node, gNB, eNB, or other device).

[0018] Figure 6It is a flowchart illustrating the operation of a device (e.g., it may be a UE, user equipment, or other device).

[0019] Figure 7 It is a flowchart illustrating the operation of a device (e.g., a network node, gNB, eNB, or other device).

[0020] Figure 8 It is a flowchart illustrating the operation of a device (e.g., it may be a UE, user equipment, or other device).

[0021] Figure 9 It is a flowchart illustrating the operation of a device (e.g., a network node, gNB, eNB, or other device).

[0022] Figure 10 This is a diagram illustrating aspects of an example embodiment.

[0023] Figure 11 This is a diagram illustrating aspects of an example embodiment.

[0024] Figure 12A This is a diagram illustrating aspects of an example embodiment.

[0025] Figure 12B This is a diagram illustrating aspects of an example embodiment.

[0026] Figure 13 This is a diagram illustrating aspects of an example embodiment.

[0027] Figure 14 This is a diagram illustrating aspects of an example embodiment.

[0028] Figure 15 This is a block diagram illustrating an example transmitter architecture.

[0029] Figure 16 This is a block diagram of a wireless station or node (e.g., UE, user equipment, AP, BS, eNB, gNB, RAN node, network node, TRP or other node) according to an example embodiment. Detailed Implementation

[0030] It should be understood that although terms such as "first," "second," etc., preceding 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 the nouns. For example, without departing from the scope of the exemplary embodiments, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0031] As used herein, unless explicitly stated otherwise, the “response to A” execution step does not indicate that the step is performed immediately after “A” occurs, and one or more intermediate steps may be included.

[0032] Figure 1 This is a block diagram of wireless network 130. Figure 1 In the wireless network 130, user equipment 131, 132, 133, and 135 (which may also be referred to as mobile stations (MS) or user equipment (UE)) can connect to (and communicate with) a base station (BS) 134 (which may also be referred to as an access point (AP), enhanced node B (eNB), gNB, or RAN (radio access network) node). The BS (or AP) 134 provides radio coverage within the cell 136, including providing radio coverage to user equipment (or UE) 131, 132, 133, and 135. The BS 134 is also connected to the core network 150 via an N2 or NG interface 151. Although only four user equipment (or UE) are shown connected to or attached to one BS 134, any number of user equipment and / or BSs can be provided.

[0033] At least some of the functions of a BS (e.g., NG-RAN, gNB, Access Point (AP), Base Station (BS), or (e)Node B (eNB), RAN node) can also be performed by any node, server, or host operatively coupled to a transceiver (such as a remote wireless head). For example, some functions of a BS can be performed at least partially in a central / centralized unit (CU) and / or distributed unit (DU). Therefore, a 5G network architecture can be based on a so-called CU-DU split. A gNB-CU (central node) can control multiple spatially separated gNB-DUs, at least acting as a transmit / receive (Tx / Rx) node. However, in some embodiments, a gNB-DU (also referred to as a DU) may include, for example, a Radio Link Control (RLC), Medium Access Control (MAC) layer, and a Physical (PHY) layer, while a gNB-CU (also referred to as a CU) may include layers above the RLC layer, such as the Packet Data Convergence Protocol (PDCP) layer, Radio Resource Control (RRC), and Internet Protocol (IP) layer. Other functional splits are also possible.

[0034] According to the illustrative example, a radio access network (RAN) can be part of a mobile telecommunications system. The RAN can include one or more BSs or RAN nodes implementing radio access technologies, for example, to allow one or more UEs to access the network or core network (CN). Thus, for example, the RAN (RAN nodes, such as BSs or gNBs) can reside between one or more user equipments or UEs and the core network. According to the example embodiment, each RAN node (e.g., BS, eNB, gNB, CU / DU, ...) or BS can provide one or more wireless communication services for one or more UEs or user equipments, for example, to allow the UE to wirelessly access the network via the RAN node. Each RAN node or BS can perform or provide wireless communication services, such as allowing the UE or user equipment to establish a wireless connection to the RAN node, and sending and / or receiving data from one or more UEs. For example, after establishing a connection to the UE, the RAN node or network node (e.g., BS, eNB, gNB, CU / DU, ...) can forward data received from the network or core network to the UE, and / or forward data received from the UE to the network or core network. RAN nodes or network nodes (e.g., BS, eNB, gNB, CU / DU, ...) can perform a wide variety of other radio functions or services, such as broadcasting control information to UEs (e.g., system information or on-demand system information), paging UEs when data to be delivered to them is available, assisting UEs in handover between cells, scheduling resources for uplink data transmission from UEs and downlink data transmission to UEs, sending configuration information to configure one or more UEs, etc. These are just a few examples of one or more functions that a RAN node or BS can perform.

[0035] User equipment or user node (user terminal, user equipment (UE), mobile terminal, handheld wireless device, etc.) can refer to portable computing devices that operate with or without a subscriber identification module (SIM), including but not limited to the following types of devices: mobile station (MS), mobile phone, cellular phone, smartphone, personal digital assistant (PDA), cell phone, device using a wireless modem (alarm or measuring device, etc.), laptop and / or touchscreen computer, tablet computer, tablet phone, game console, laptop, vehicle, drone, sensor and multimedia device, as an example, or any other wireless device. It should be understood that user equipment can also be (or may include) a virtually exclusive uplink-only device, an example of which is a camera or camcorder that loads image or video clips onto the network. Furthermore, user node can include user equipment (UE), user device, user terminal, mobile terminal, mobile station, mobile node, subscriber device, subscriber node, subscriber terminal, or other user node. For example, a user node can be used to wirelessly communicate with one or more network nodes (e.g., gNB, eNB, BS, AP, CU, DU, CU / DU) and / or with one or more other user nodes, regardless of the technology or radio access technology (RAT).

[0036] In 5G (which may be referred to as New Radio (NR)) (as an illustrative example), the core network 150 may be referred to as the 5G core network (5GC), which may include Access and Mobility Management Functions (AMF). For example, an AMF may include the following functions (e.g., some AMF functions may be supported in a single instance of an AMF): termination of the RAN Control Plane (CP) interface (N2), termination of the Non-Access Stratum (NAS) (or N1), NAS encryption and integrity protection, registration management, connection management, reachability management, mobility management, lawful interception, etc. The 5GC may also include Session Management Functions (SMF), which may include one or more of the following functions (one or more SMF functions may be supported in a single instance of an SMF): session management (e.g., session establishment, modification, and release, including tunnel maintenance between User Plane Functions (UPF) and BS 134), IP address allocation & management (including optional authorization), selection and control of UPF, configuration of service orientation at the UPF to route services to appropriate destinations, etc. In LTE (as an illustrative example), the core network 150 may be referred to as the evolved packet core (EPC), which may include a mobility management entity (MME) that can handle or assist user equipment mobility / handover between BSs, one or more gateways that can forward data and control signals between the BS and the packet data network or the Internet, and other control functions or blocks.

[0037] Furthermore, the technologies described in this paper can be applied to various types of user equipment or data service types, or to user equipment that can have multiple applications running on it, which can be different data service types. New 5G (NR) development can support a variety of different applications or data service types, such as: Machine-Type Communication (MTC), Enhanced Machine-Type Communication (eMTC), Internet of Things (IoT) and / or Narrowband IoT user equipment, Enhanced Mobile Broadband (eMBB), and Ultra-Reliable and Low-Latency Communication (URLLC). Many of these new 5G (NR) related applications often require higher performance than previous wireless networks.

[0038] The Internet of Things (IoT) can refer to a growing group of objects that possess internet or network connectivity, enabling them to send and receive information from other network devices. For example, many sensor-type applications or devices can monitor physical conditions or states and, for instance, send reports to servers or other network devices when events occur. Machine-type communication (MTC or machine-to-machine communication) is characterized by the fully automated generation, exchange, processing, and actuation of data between intelligent machines, with or without human intervention. Enhanced Mobile Broadband (eMBB) can support data rates significantly higher than those currently available in LTE.

[0039] Ultra-Reliable and Low-Latency Communication (URLLC) is a new type of data service or a new use case that can be supported for new radio (5G) systems. This enables emerging new applications and services such as industrial automation, autonomous driving, vehicle safety, and eHealth services. As an illustrative example, 3GPP aims to provide connections with reliability corresponding to a block error rate (BLER) of 10 to 5 and a U-plane (user / data plane) latency of at most 1 ms. Therefore, for example, URLLC user equipment / UEs may require significantly lower block error rates and low latency (with or without the need for high reliability) than other types of user equipment / UEs. Thus, for example, a URLLC UE (or URLLC applications on a UE) may require much shorter latency compared to an eMBB UE (or an eMBB application running on a UE).

[0040] The techniques described herein can be applied to a wide variety of wireless technologies or wireless networks, such as 5G (New Radio (NR)), centimeter wave (cmWave) and / or millimeter wave (mmWave) band networks, IoT, MTC, eMTC, eMBB, URLLC, 6G, etc.) or any other wireless network or wireless technology. These example networks, technologies, or data service types are provided as illustrative examples only.

[0041] In wireless communication systems, higher-order modulation and transmission bandwidth configurations allow UEs to reduce their maximum output power to meet transmission requirements such as out-of-band transmission (e.g., adjacent channel leakage ratio (ACLR)) or in-band transmission (e.g., error vector magnitude (EVM)). In-band distortion (EVM) can increase when the UE enhances its modulation scheme to a higher order. EVM can also increase with lower-order modulation schemes (e.g., QPSK) if the UE attempts to operate the power amplifier (PA) in saturation to achieve higher power efficiency and lower supply current. To mitigate EVM, UEs are forced to employ sophisticated linearization techniques such as digital predistortion (DPD) or envelope tracking. These linearization techniques can improve both EVM and ACLR at the cost of additional power and higher power consumption in the UE.

[0042] The implementation of DPD or complex linearization techniques leads to inefficient operation of the UE and communication system. Therefore, power consumption may increase and UE battery performance may decrease when DPD is activated. Digital post-distortion (DPoD) can be employed to mitigate in-band transmit (EVM). ACLR control in FR1 may not be the target of using DPoD, as ACLR violations may have already occurred during UE transmission. Therefore, DPoD cannot be used efficiently without implementing a mechanism to prevent UE transmitter ACLR violations. Furthermore, the gNB is unaware of ACLR violations by the UE when the UE is relaxing maximum power reduction (MPR) or operating the PA with high compression to gain the benefits of DPoD. High EVM issues may arise when the MCS order is high (e.g., 256 QAM). Therefore, ACLR cannot be well controlled by relaxing MPR (or increasing transmit power). Additionally, the post-insertion loss (IL) of the PA may differ for different branches (or transmission chains) of the UE in uplink (UL) multiple-input multiple-output (MIMO). Therefore, the PA will reach the nonlinear region faster for branches with higher IL than for other branches. Therefore, it is advantageous to use intelligent DPoD activation procedures to improve the performance of MIMO transmission in order to improve the performance of UEs with different PA insertion losses.

[0043] The example embodiments relate to enhancing signaling between the UE and network nodes (e.g., base stations, gNBs, eNBs, gNB-CUs, gNB-DUs, Transmit and Receive Points (TRPs), etc.) to address the aforementioned issues, thereby improving the UE's operational efficiency. The example embodiments aim to enhance the communication system to ensure optimized and efficient communication in terms of EVM and ACLR. The example embodiments address challenges arising from PA nonlinearity. The example embodiments utilize novel signaling procedures between the UE and gNB in ​​the lower range of frequency ranges 1 (FR1) and FR3 to enable DPoD for UL MIMO. When DPoD is enabled at the gNB, the UE dynamically activates or deactivates the DPD function based on an algorithm (e.g., which may employ a machine learning (ML) based algorithm) or instructions from the network node (or gNB). Therefore, when implementing the example embodiments, the UE is able to transmit at a higher EVM while maintaining ACLR within output spectrum transmission requirements.

[0044] In the example, the UE can send information to the network node regarding the digital predistortion (DPD) function associated with each of at least one Multiple-Input Multiple-Output (MIMO) layers. The UE can receive configuration information from the network node corresponding to at least one uplink transmission of at least one MIMO layer. For example, the configuration information may indicate at least one of the following: selecting a bandwidth portion (BWP) of at least one uplink transmission of at least one MIMO layer, selecting a frequency within the middle portion of the operating bandwidth of at least one uplink transmission of at least one MIMO layer, etc. The configuration information may also instruct the UE to deactivate the DPD function for one or more MIMO layers. For example, the network node may instruct the UE, as part of the configuration information, to deactivate the DPD function for one or more MIMO layers or for any layer where the DPD function is activated. The UE can send an acknowledgment to the network node that may include an indication of configuring at least one uplink transmission, wherein the configuration is based on the configuration information. For example, when the UE performs configuration according to at least one element of the configuration information, the UE may then send an acknowledgment indicating that the configuration is performed according to the configuration information. The UE can perform at least one uplink transmission of at least one MIMO layer at least partially based on the configuration information.

[0045] Figure 2This is a flowchart illustrating the operation of an apparatus (e.g., which may be a UE, user equipment, or other apparatus). Operation 210 includes the user equipment sending information to the network node about the digital predistortion (DPD) function associated with each of at least one of the at least one multiple-input multiple-output (MIMO) layers. Operation 220 includes receiving configuration information from the network node corresponding to at least one uplink transmission of at least one MIMO layer, wherein the configuration information indicates at least one of the following: selecting a bandwidth portion (BWP) of at least one uplink transmission of at least one MIMO layer; selecting a frequency within the middle portion of the operating bandwidth of at least one uplink transmission of at least one MIMO layer; or deactivating the DPD function for one or more MIMO layers. Operation 230 includes sending an acknowledgment to the network node that includes an indication of configuring the execution of at least one uplink transmission, wherein the configuration is based on the configuration information. Operation 240 includes executing at least one uplink transmission of at least one MIMO layer, at least in part, based on the configuration information.

[0046] Figure 3 This is a flowchart illustrating the operation of an apparatus (e.g., a network node, gNB, eNB, or other apparatus). Operation 310 includes the network node receiving information from the user equipment regarding digital predistortion (DPD) functions associated with each of at least one multiple-input multiple-output (MIMO) layers. Operation 320 includes sending configuration information to the user equipment corresponding to at least one uplink transmission of at least one MIMO layer, wherein the configuration information indicates at least one of the following: selecting a bandwidth portion (BWP) of at least one uplink transmission of at least one MIMO layer; selecting a frequency within the middle portion of the operating bandwidth of at least one uplink transmission of at least one MIMO layer; or deactivating the DPD function for one or more MIMO layers. Operation 330 includes receiving an acknowledgment from the user equipment including an indication of configuring at least one uplink transmission, wherein the configuration is based on the configuration information. Operation 340 includes receiving at least one uplink transmission of at least one MIMO layer from the user equipment, at least in part based on the configuration information.

[0047] about Figure 2 and Figure 3 The method described herein allows information about the DPD function to include the state of the DPD function, where the state indicates whether the DPD function is activated or deactivated.

[0048] about Figure 2 and Figure 3 The method described herein allows configuration information to instruct at least one of the following: to activate the DPD function for a first at least one MIMO layer; or to deactivate the DPD function for a second at least one MIMO layer.

[0049] about Figure 2 and Figure 3 The method described herein may include selecting the narrowest BWP for all MIMO layers. Deactivating the DPD function for one or more MIMO layers may include at least one of the following: deactivating the DPD function for all MIMO layers; or deactivating the DPD function for a first at least one MIMO layer, for which the DPD function is active.

[0050] about Figure 2 and Figure 3 The method described herein may include at least one of the following: at least one parameter of at least one PA of the UE (transceiver); information of a reference signal, etc. For example, the information of the reference signal may include at least one of the following: information of one or more codes used for the transmission of the reference signal; information indicating the period or repetition rate of the reference signal; information indicating the frequency mode of the reference signal; or information indicating the mapping of one or more codes to frequency resources of the BWP, etc. For example, the reference signal may include at least one of the following: a sounding reference signal (SRS); or an uplink SRS used for MIMO calibration, etc.

[0051] about Figure 2 and Figure 3 The method described herein allows the UE to receive configuration information from a network node as part of at least one of the following: Radio Resource Control (RRC) signaling / messages, Media Access Control (MAC-CE) elements, etc.

[0052] about Figure 2 and Figure 3 The method described herein allows the UE to perform configuration of at least one uplink transmission, wherein the configuration is based on at least one element of configuration information.

[0053] about Figure 2 and Figure 3 The method described herein, wherein sending information of DPD functions associated with each of at least one MIMO layer may include at least one of the following: sending information of DPD functions associated with each DPD activation layer of at least one MIMO layer; sending information of DPD functions associated with each DPD deactivation layer of at least one MIMO layer; sending information of DPD functions associated with each DPD activation layer and each DPD deactivation layer of at least one MIMO layer, etc.

[0054] about Figure 2 and Figure 3 The method described herein allows configuration information that may include Adjacent Channel Leakage Rate (ACLR) information. The UE can use the ACLR information to determine whether to activate or deactivate the DPD function for one or more MIMO layers.

[0055] about Figure 2 and Figure 3 The method described herein allows the UE to send updates to network nodes with information about the DPD function associated with each of at least one MIMO layer.

[0056] about Figure 2 and Figure 3 The method described herein may include at least one uplink transmission comprising the transmission of at least one of the following: a reference signal; a sounding reference signal (SRS); or an uplink SRS for MIMO calibration.

[0057] Additionally or alternatively, the example embodiments enhance system performance by enabling the UE to receive configuration information of reference signals (such as uplink SRS for MIMO calibration) and adjust the parameters of the PA.

[0058] In one example, the UE can send information about the DPD function associated with each layer of at least one MIMO layer to a network node (e.g., a gNB). For example, the UE can send an RRC message that may include information about the DPD function. The UE can receive configuration information from the network node corresponding to at least one uplink transmission of at least one MIMO layer. For example, the UE can receive an RRC message, MAC-CE, etc., that may include configuration information from the gNB. For example, the configuration information may indicate deactivation of the DPD function for one or more MIMO layers. The UE can receive from the network node at least one parameter associated with the transmission of a reference signal (e.g., SRS, uplink SRS for MIMO calibration, etc.) for calibration of at least one MIMO layer. For example, at least one parameter may include at least one of the following: information about resources associated with the transmission of the reference signal, at least one parameter of at least one PA corresponding to at least one MIMO layer, etc. The UE can deactivate the DPD function for one or more layers. The UE can send the reference signal to the network node based at least in part on at least one parameter associated with the transmission of the reference signal.

[0059] Figure 4This is a flowchart illustrating the operation of an apparatus (e.g., which may be a UE, user equipment, or other apparatus). Operation 410 includes the user equipment sending information to the network node about digital predistortion (DPD) functions associated with each of at least one MIMO layer. Operation 420 includes receiving configuration information from the network node corresponding to at least one uplink transmission of at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers. Operation 430 includes receiving from the network node at least one parameter associated with the transmission of a reference signal for calibration of at least one MIMO layer, wherein the at least one parameter includes at least one of the following: information about resources associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to at least one MIMO layer. Operation 440 includes deactivation of the DPD function for one or more layers. Operation 450 includes sending a reference signal to the network node, at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0060] Figure 5 This is a flowchart illustrating the operation of a device (e.g., a network node, gNB, eNB, or other device). Operation 510 includes the network node receiving information from the user equipment regarding digital predistortion (DPD) functions associated with each of at least one multiple-input multiple-output (MIMO) layers. Operation 520 includes sending configuration information to the user equipment corresponding to at least one uplink transmission of at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers. Operation 530 includes sending to the user equipment at least one parameter associated with the transmission of a reference signal for calibration of at least one MIMO layer, wherein the at least one parameter includes at least one of the following: information about resources associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to at least one MIMO layer. Operation 540 includes receiving a reference signal from the user equipment, at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0061] about Figure 4 and Figure 5 The method described herein may include at least one parameter (as associated with the transmission of a reference signal for calibration of at least one MIMO layer) that may include: information about one or more codes for the transmission of the reference signal; information indicating the period or repetition rate of the reference signal; information indicating the frequency pattern of the reference signal; information indicating the frequency resources that map one or more codes to a bandwidth portion (BWP), etc. For example, the one or more codes for the transmission of the reference signal may include at least one of the following: Gold code; Zadoff-Chu code; or a sequence of modulation symbols, etc.

[0062] about Figure 4and Figure 5 The method described herein allows the UE to amplify a reference signal based on at least one parameter of at least one PA. For example, the PA can amplify the reference signal, and transmitting the reference signal can be based on the output power of at least one PA. One or more configuration parameters of the at least one PA can be determined based on at least one parameter of the at least one PA.

[0063] about Figure 4 and Figure 5 The method described herein allows configuration information to instruct at least one of the following: to select the narrowest BWP for all MIMO layers in at least one uplink transmission of at least one MIMO layer; or to select a frequency within the middle portion of the operating bandwidth of at least one uplink transmission of at least one MIMO layer.

[0064] about Figure 4 and Figure 5 The method described herein allows uplink transmission to be based on Orthogonal Frequency Division Multiplexing (OFDM). For example, the UE can adjust the uplink transmission to a selected frequency within the middle portion of the operating bandwidth of at least one uplink transmission in at least one MIMO layer.

[0065] about Figure 4 and Figure 5 The method described herein may include at least one of the following: an uplink reference signal, an SRS, or an uplink SRS for MIMO calibration.

[0066] about Figure 4 and Figure 5 The method described herein allows information about the DPD function, including its state. For example, the state of the DPD function can indicate whether it is activated or deactivated.

[0067] about Figure 4 and Figure 5 The configuration information described herein may be received by the UE from the network node as part of at least one of the following: RRC signaling / signaling; or MAC-CE.

[0068] about Figure 4 and Figure 5 The method described herein, wherein sending information of DPD functions associated with each of at least one MIMO layer may include at least one of the following: sending information of DPD functions associated with each DPD activation layer of at least one MIMO layer; sending information of DPD functions associated with each DPD deactivation layer of at least one MIMO layer; or sending information of DPD functions associated with each DPD activation layer and each DPD deactivation layer of at least one MIMO layer.

[0069] Additionally or alternatively, the example embodiments enhance system performance by enabling the UE to receive ACLR information from the gNB. The UE can compare the ACLR information with configured (or pre-configured) thresholds to determine whether to activate or deactivate the DPD function.

[0070] In one example, the UE can send information to the network node regarding the DPD function associated with each of at least one MIMO layer. The UE can receive configuration information from the network node corresponding to at least one uplink transmission of at least one MIMO layer. For example, the UE can send an RRC message to the gNB that may include configuration information. For example, the configuration information may indicate at least one of the following: one or more conditions for activating or deactivating the DPD function based on the ACLR value; selection of the BWP for at least one uplink transmission of at least one MIMO layer; or selection of a frequency within the middle portion of the operating bandwidth of at least one uplink transmission of at least one MIMO layer. The UE can receive the ACLR value from the network node. For example, the UE can receive MAC-CE, RRC, or control information that may include the ACLR value from the gNB. The UE can determine whether to activate or deactivate the DPD function for at least one MIMO layer based at least on the ACLR value and the configuration information. The UE can then perform at least one uplink transmission of at least one MIMO layer based at least in part on this determination (e.g., activating or deactivating the DPD).

[0071] Figure 6 This is a flowchart illustrating the operation of an apparatus (e.g., which may be a UE, user equipment, or other apparatus). Operation 610 includes the user equipment sending information to a network node regarding the digital predistortion (DPD) function associated with each layer in at least one multiple-input multiple-output (MIMO) layer. Operation 620 includes receiving configuration information from the network node corresponding to at least one uplink transmission of at least one MIMO layer, wherein the configuration information indicates at least one of the following: one or more conditions for activating or deactivating the DPD function based on a value of the adjacent channel leakage ratio (ACLR); selecting a bandwidth portion (BWP) of at least one uplink transmission of at least one MIMO layer; or selecting a frequency within an intermediate portion of the operating bandwidth of at least one uplink transmission of at least one MIMO layer. Operation 630 includes receiving an ACLR value from the network node. Operation 640 includes determining, based at least on the ACLR value and the configuration information, whether to activate or deactivate the DPD function for at least one MIMO layer. Operation 650 includes performing at least one uplink transmission of at least one MIMO layer, at least in part based on the determination.

[0072] Figure 7This is a flowchart illustrating the operation of an apparatus (e.g., a network node, gNB, eNB, or other apparatus). Operation 710 includes the network node receiving information from the user equipment regarding digital predistortion (DPD) functions associated with each layer in at least one multiple-input multiple-output (MIMO) layer. Operation 720 includes sending configuration information to the user equipment corresponding to at least one uplink transmission of at least one MIMO layer, wherein the configuration information indicates at least one of the following: one or more conditions for activating or deactivating the DPD function based on the adjacent channel leakage ratio (ACLR) value; selecting a bandwidth portion (BWP) of at least one uplink transmission of at least one MIMO layer; or selecting a frequency within an intermediate portion of the operating bandwidth of at least one uplink transmission of at least one MIMO layer. Operation 730 includes sending the ACLR value to the user equipment. Operation 740 includes receiving at least one uplink transmission of at least one MIMO layer from the user equipment, at least in part based on the ACLR value.

[0073] about Figure 6 and Figure 7 The method described herein allows information about the DPD function, including its state. For example, the state of the DPD function can indicate whether it is activated or deactivated. For instance, the state indicates whether the DPD is activated or deactivated.

[0074] about Figure 6 and Figure 7 The method described herein allows the UE to send a status indicating the activation of a DPD function if determining whether to activate or deactivate the DPD function includes determining whether to activate the DPD function. Alternatively, if determining whether to activate or deactivate the DPD function includes determining whether to deactivate the DPD function, the UE can send a status indicating the deactivation of the DPD function.

[0075] about Figure 6 and Figure 7 The method described herein may include selecting the narrowest BWP for all MIMO layers.

[0076] about Figure 6 and Figure 7 The configuration information described herein may be received by the UE from a network node or gNB as part of at least one of the following: RRC signaling / signaling; or MAC-CE.

[0077] about Figure 6 and Figure 7The method described herein, wherein sending information of DPD functions associated with each of at least one MIMO layer may include at least one of the following: sending information of DPD functions associated with each DPD activation layer of at least one MIMO layer; sending information of DPD functions associated with each DPD deactivation layer of at least one MIMO layer; or sending information of DPD functions associated with each DPD activation layer and each DPD deactivation layer of at least one MIMO layer.

[0078] about Figure 6 and Figure 7 The method described herein may include at least one uplink transmission, which may include the transmission of at least one of the following: a reference signal, an uplink reference signal, an SRS, or an uplink SRS for MIMO calibration.

[0079] Additionally or alternatively, the example embodiments enhance system performance by enabling the UE to receive configuration information indicating the activation or deactivation of the selected layer and to determine the PA parameters for the corresponding MIMO layer. Therefore, when implementing the example embodiments, transceiver branches without DPDs can transmit higher power to the PA input to achieve the advantage of transmitting at higher output power at the antenna to enhance coverage.

[0080] In one example, the UE may send information to the network node regarding the DPD function associated with each of at least one MIMO layer. The UE may receive configuration information from the network node corresponding to at least one uplink transmission of at least one MIMO layer. For example, the configuration information may indicate at least one of the following: selecting a bandwidth portion (BWP) of at least one uplink transmission of at least one MIMO layer; selecting a frequency within the middle portion of the operating bandwidth of at least one uplink transmission of at least one MIMO layer; deactivating the DPD function for a first at least one MIMO layer; or activating the DPD function for a second at least one MIMO layer. The UE may determine at least one parameter of at least one PA corresponding to the first at least one MIMO layer or the second at least one MIMO layer (at least in part based on the state of the DPD function corresponding to the first at least one MIMO layer or the second at least one MIMO layer). The UE may perform at least one uplink transmission of at least one MIMO layer based at least in part on at least one parameter of at least one PA. As another example, the configuration information may indicate deactivation or activation of the DPD function for one or more layers. The UE may then determine at least one parameter of at least one PA corresponding to one or more MIMO layers (at least in part based on the state of the DPD function corresponding to one or more MIMO layers).

[0081] In the example implementation, when UE operation causes the same conducted output power at the antenna ports, the output power of each variable amplifier at the output stage of each power control unit and transceiver can be adjusted in the same way. The UE calibration (performed by the calibration block) ensures that the relationship between the power control and the measured conducted output power level at each antenna element is known, characterized, and equal. When the equal conducted output power of each branch reaches a threshold level (compression point level), the UE can activate DPD on that branch. Because the calibration block ensures that the conducted output power level measured at each antenna is characterized and equal, when implementing the example embodiment, the calibration block is enhanced to allow transceiver branches without DPD to transmit higher power to the PA input to gain the advantage of transmitting at higher output power at the antenna to enhance coverage.

[0082] Figure 8 This is a flowchart illustrating the operation of an apparatus (e.g., which may be a UE, user equipment, or other apparatus). Operation 810 includes the user equipment sending information to the network node about the digital predistortion (DPD) function associated with each of at least one of the at least one multiple-input multiple-output (MIMO) layers. Operation 820 includes receiving configuration information from the network node corresponding to at least one uplink transmission of at least one MIMO layer, wherein the configuration information indicates at least one of the following: selecting a bandwidth portion (BWP) of at least one uplink transmission of at least one MIMO layer; selecting a frequency within the middle portion of the operating bandwidth of at least one uplink transmission of at least one MIMO layer; deactivating the DPD function for a first at least one MIMO layer; or activating the DPD function for a second at least one MIMO layer. Operation 830 includes sending an acknowledgment to the network node that includes an indication of configuring the execution of at least one uplink transmission, wherein the configuration is based on the configuration information; Operation 840 includes determining at least one parameter of at least one power amplifier (PA) corresponding to at least one MIMO layer or the second at least one MIMO layer, at least in part based on the state of the DPD function corresponding to the first at least one MIMO layer or the second at least one MIMO layer. Operation 850 includes performing at least one uplink transmission of at least one MIMO layer based at least in part on at least one parameter of at least one PA.

[0083] Figure 9This is a flowchart illustrating the operation of an apparatus (e.g., a network node, gNB, eNB, or other apparatus). Operation 910 includes the network node receiving information from the user equipment regarding digital predistortion (DPD) functions associated with each of at least one of the at least one multiple-input multiple-output (MIMO) layers. Operation 920 includes sending configuration information to the user equipment corresponding to at least one uplink transmission of at least one MIMO layer, wherein the configuration information indicates at least one of the following: selecting a bandwidth portion (BWP) of at least one uplink transmission of at least one MIMO layer; selecting a frequency within the middle portion of the operating bandwidth of at least one uplink transmission of at least one MIMO layer; deactivating the DPD function for a first at least one MIMO layer; or activating the DPD function for a second at least one MIMO layer. Operation 930 includes receiving an acknowledgment from the user equipment including an indication of configuring the execution of at least one uplink transmission, wherein the configuration is based on the configuration information. Operation 940 includes receiving at least one uplink transmission of at least one MIMO layer from the user equipment based at least in part on at least one parameter determined for at least one power amplifier (PA) corresponding to the first at least one MIMO layer or the second at least one MIMO layer.

[0084] about Figure 8 and Figure 9 The method described herein allows the UE to configure at least one PA based on at least one parameter of at least one PA. For example, the UE can configure the power control block of the transceiver's transmission chain. As another example, the UE can configure the calibration unit of the transceiver's transmission chain, or configure the gain of a PA in at least one PA of the transceiver.

[0085] about Figure 8 and Figure 9 The method described herein allows information about the DPD function to include the state of the DPD function, which may indicate whether the DPD function is activated or deactivated. In the example, this configuration information may indicate at least one of the following: activating the DPD function for a first at least one MIMO layer, or deactivating the DPD function for a second at least one MIMO layer.

[0086] about Figure 8 and Figure 9 The method described herein allows configuration information to indicate at least one of the following: selecting the narrowest BWP for all MIMO layers, or selecting a frequency within the middle portion of the operating bandwidth of at least one uplink transmission in at least one MIMO layer.

[0087] about Figure 8 and Figure 9The method described herein may include at least one of the following: at least one parameter of at least one PA, or information about a reference signal. For example, the information about the reference signal may include: information about one or more codes used for the transmission of the reference signal, information indicating the period or repetition rate of the reference signal, information indicating the frequency mode of the reference signal, information indicating the mapping of one or more codes to frequency resources of the BWP, etc. For example, the reference signal may include at least one of the following: an SRS, or an uplink SRS used for MIMO calibration.

[0088] about Figure 8 and Figure 9 The method described herein allows configuration information to be received (by the user equipment from a network node or gNB) as part of at least one of the following: RRC signaling, MAC-CE, etc.

[0089] about Figure 8 and Figure 9 The method described herein allows the UE to perform configuration of at least one uplink transmission, wherein the configuration is based on at least one element of configuration information.

[0090] about Figure 8 and Figure 9 The method described herein, wherein sending information of DPD functions associated with each of at least one MIMO layer may include at least one of the following: sending information of DPD functions associated with each DPD activation layer of at least one MIMO layer; sending information of DPD functions associated with each DPD deactivation layer of at least one MIMO layer; or sending information of DPD functions associated with each DPD activation layer and each DPD deactivation layer of at least one MIMO layer.

[0091] about Figure 8 and Figure 9 The method described herein allows the configuration information to include ACLR information. The UE can then determine (based on ACLR information) whether to activate or deactivate the DPD function for one or more MIMO layers.

[0092] about Figure 8 and Figure 9 The method described herein allows the UE to send updates of information related to the DPD function associated with each of at least one MIMO layer.

[0093] about Figure 8 and Figure 9 The method described herein may include at least one uplink transmission, which may include the transmission of at least one of the following: a reference signal, an SRS, or an uplink SRS for MIMO calibration.

[0094] Figure 10This is a diagram illustrating aspects of an example embodiment. At step 1, UE 110 may be in an RRC connected state. UE 110 may be in closed-loop UL MIMO power control. gNB 120 may schedule UE 110 to use a modulation and coding scheme (MCS) in Physical Uplink Shared Channel (PUSCH) transmissions matched to the lowest signal-to-interference ratio. UE 110 may establish a connection with gNB 120 and may be in closed-loop UL MIMO power control. gNB 120 schedules the MCS and total output power of UE 110 based on the detected SNR level. At step 2a, gNB 120 may request the DPD capability status of UE 110 at each UL MIMO layer. For example, gNB 120 may send a request to UE 110 indicating a request for information on the DPD functionality associated with each of at least one MIMO layer. At step 2b, UE 110 may report its DPD capability status (activated or deactivated) for each layer. For example, UE 110 can send information to the gNB about the DPD function associated with each layer in at least one MIMO layer. At step 3, gNB 120 can send RRC configuration for SRS to UE 110. At step 4, UE 110 can configure SRS transmission according to its capabilities. At step 5, UE 110 can send an SRS signal to the gNB. At step 6, gNB 120 can establish a relationship or mapping between SRS and the UE's antenna ports. At step 7, gNB 120 can activate its own DPoD. At step 8, gNB 120 can send a message to UE 110 indicating that the DPoD is activated. At step 9, gNB 120 can trigger an SRS-based ACLR detection procedure for UE 110. At step 10, gNB 120 may send a request to UE 110 in the next UL time slot instructing the following actions: adjust the UL of all MIMO layers to the narrowest BWP, place the UL bandwidth of the MIMO layers in the middle portion of the available bandwidth of the network, and / or deactivate the DPD deactivated for the active layer. For example, UE 110 may receive configuration information from gNB corresponding to at least one uplink transmission of at least one MIMO layer, wherein the configuration information instructs at least one of the following: select the BWP of at least one uplink transmission of at least one MIMO layer, select a frequency within the middle portion of the working bandwidth of at least one uplink transmission of at least one MIMO layer, or deactivate the DPD function for one or more MIMO layers. At step 11, UE 110 may send the following confirmation to gNB, which may include an instruction to perform the configuration of at least one uplink transmission, wherein the configuration is based on the configuration information.UE 110 can send confirmation to gNB 120 on a dedicated UL time slot for the following changes: the UL for all MIMO layers is adjusted to the narrowest BWP, the UL for all layers is placed in the middle part of the network available bandwidth, and the DPD is deactivated for all layers.

[0095] Figure 11 This is a diagram illustrating aspects of an example embodiment. Figure 10 The process in Figure 11Continuing from step 12, gNB 120 can run / execute the ACLR procedure for measuring the transmitter spectrum of the UE for all MIMO layers. gNB 120 can select the carrier and bandwidth combination (fc, BW) and can determine the minimum BWP bwp_min that can be allocated to the UE. In bwp_min, gNB 120 sets the transmit power P_tx_bwp_min and determines that the UE 110 should transmit according to the reference signal (SRS) indicated for each layer. At step 13, gNB 120 can send a request to the UE 110 to select the minimum BWP and place it in the middle part of the working channel for each ULMIMO layer. This configuration message can be carried as part of MAC-CE or RRC signaling in a new information element (IE) and can include at least the following parameters: Fc, BW, bwp_min, P_tx_bwp_min. For example, UE 110 can receive from gNB at least one parameter associated with the transmission of a reference signal for calibration of at least one MIMO layer, wherein the at least one parameter may include at least one of the following: information about resources associated with the transmission of the reference signal, at least one parameter of at least one PA corresponding to at least one MIMO layer, etc. The reference signal may be a new reference signal, such as a UL SRS for MIMO calibration. For example, the at least one parameter may include information on the generation of a UL SRS code (e.g., Gold code or Zadoff-Chu) or any modulation symbol sequence for MIMO calibration, the repetition rate and period of the UL SRS for MIMO calibration, the frequency pattern (also called comb), and the mapping of the UL SRS code for MIMO calibration to frequency resources in bwp_min. At step 14, UE 110 may transmit a UL SRS for MIMO calibration as configured on each UL MIMO layer. In other words, UE 110 may trigger OFDM transmission of the reference signal and may generate a signal UL SRS for MIMO calibration based on at least one parameter. For example, UE 110 can select the narrowest BWP (e.g., among multiple available BWPs) for all MIMO layers of at least one uplink transmission of at least one MIMO layer, and / or select a frequency within the middle portion of the operating bandwidth of at least one uplink transmission of at least one MIMO layer. The uplink transmission can then be OFDM-based, and UE 110 can adjust (or upconvert) the uplink transmission to the selected frequency within the middle portion of the operating bandwidth of at least one uplink transmission of at least one MIMO layer. At step 16, UE 110 can receive a request message from the gNB indicating whether to activate or deactivate the DPD.The request message can be carried by a new IE as part of MAC-CE or RRC signaling and can include a DPD activation flag, where a flag set to 1 indicates that DPD is needed and should be activated. At step 17, UE 110 can take action based on the request and determine whether to activate or deactivate the DPD at each layer. At step 18, UE 110 can report its updated DPD status at each layer. At step 19, gNB 120 can evaluate or determine whether to increase the UE's output power.

[0096] about Figure 10 and Figure 11 The method described above allows the gNB 120 to construct a transmission spectrum and measure the ACLR of the UE for each layer. In other words, the gNB 120 measures the power over the entire bandwidth centered on carrier fc and performs an assessment of power leakage outside the effective transmission bandwidth bwp_min. The ratio between the power within the effective transmission bandwidth and the power leakage outside the effective transmission bandwidth bwp_min is used to calculate the ACLR according to the standard definition. If the cumulative ACLR of all layers < 3GPP_limit, the gNB 120 can request the UE 110 to deactivate the DPD of all layers in the next time slot. Otherwise, assuming the worst-case antenna meets the 3GPP requirement, the gNB 120 can recalculate the cumulative ACLR. If the recalculated level meets the 3GPP requirement, the gNB 120 can request the UE 110 to activate the DPD on that antenna port. If the cumulative ACLR >= 3GPP_limit, the UE 110 can activate the DPD. In other words, the UE 110 can enable a transport block that performs digital predistortion for the transmit (TX) signal. The DPD block receives the TX signal as input and applies predistortion to generate an output signal, which is then amplified by the PA. Depending on the DPD implementation, the DPD can be configured with additional parameters for the target ACLR, such as 3gpp_limit. The gNB 120 can indicate to the UE 110 the measured ACLR or the percentage between the measured ACLR and 3gpp_limit, the ratio / difference between the measured ACLR and 3gpp_limit, etc.

[0097] Figure 12A This is a diagram illustrating aspects of an example embodiment. As shown and regarding... Figures 2 to 11 The method described above, under constant channel power, expands the bandwidth while maintaining the relative level of the channel power with adjacent channels, such as... Figure 12A As shown. Therefore, detecting the spectrum in a gNB based on the narrowest bandwidth can provide information indicating whether ACLR is violated.

[0098] Figure 12BThis is a diagram illustrating aspects of an example embodiment. As shown and regarding Figures 2 to 11 In the method described above, during spectrum detection in the gNB, UE1 (as depicted in the figure) can be specified (or configured) to have the narrowest BWP and be placed approximately in the middle of the gNB's channel bandwidth, such as... Figure 12B As shown. Therefore, during spectrum detection, the contribution of UE1 to the out-of-band (OOB) transmit template is negligible.

[0099] Figure 13 This is a diagram illustrating aspects of an example embodiment. As shown and regarding... Figures 2 to 11 The method described above allows the gNB to adjust the UE's layer based on the minimum bandwidth and within the middle portion of the gNB's channel bandwidth, and to request the UE to increase its power level. While the deactivated DPD remains deactivated, the gNB can request the UE to configure SRS transmissions and report them to the gNB. The gNB can use the received SRS transmission information to identify the UE's antenna port mapping and perform ACLR detection on each antenna port. As an example, antenna 3 has a poor ACLR, but the cumulative ACLR is within 3GPP limits. Since this cumulative ACLR still meets 3GPP requirements, the UE does not need to activate its own DPD on any MIMO branch. The UE can continue to transmit with any BW and keep its DPD deactivated on all MIMO branches.

[0100] Figure 14 This is a diagram illustrating aspects of an example embodiment. As shown and relative to... Figures 2 to 11 The method described above allows the gNB to recalculate the cumulative ACLR if it violates 3GPP restrictions. If the cumulative ACLR violates 3GPP restrictions, the gNB can recalculate the cumulative ACLR by assuming antenna 3 (which has the worst ACLR) meets the 3GPP requirements. (For example, if the 3GPP cumulative ACLR level for a particular RAT is x dBc, then for a single antenna in a 4-antenna configuration, it would be x-6 dBc.) If the cumulative ACLR meets the 3GPP restrictions, the gNB can request that DPD be activated only on antenna 3 in the next transmission slot. If the cumulative ACLR still violates the 3GPP requirements, the gNB performs another recalculation, where antenna 1 meets the 3GPP requirements, and if the cumulative ACLR meets the 3GPP requirements, the gNB can request that DPD be activated also on antenna 1 in the next transmission slot. If it is necessary to activate DPD on the remaining antennas, the process can continue.

[0101] Figure 15 This is a block diagram illustrating an example transmitter architecture. As shown and regarding... Figures 2 to 11The method described herein can be implemented using a transmitter architecture based on a four-uplink front-end system connected to the antennas. The low-noise amplifiers (LNAs) of the front-end system are not shown connected to the RF transceiver, but can be connected to four down-converter receivers, as illustrated. The UE's uplink power control is determined based on the input received signal strength converted to the corresponding transmitted output power, or based on system information from the network managing the UE's output power levels. This means that the UE itself or from network information determines what adjustments to make to the configured output power. In the example, when UE operation results in the same conducted output power at the antenna ports, the same adjustments to each power control unit and the output power of each variable amplifier at the transceiver's output stage can be equal. UE calibration ensures that the relationship between the power control at each antenna element and the measured conducted output power level is known, characterized, and equal (as shown in the calibration block at each power control unit). It will contain data on how to compensate for offsets in hardware components and printed circuit board (PCB) track losses specific to each transmit chain. Since the calibration block can ensure that the conducted output power level measured at each antenna is characterized and equal, the UE can be enhanced to allow transceiver branches without DPD to transmit higher power to the PA input, thereby gaining the advantage of transmitting at higher output power at the antenna and enhancing coverage.

[0102] Figure 16 This is a block diagram of a wireless station or node (e.g., UE, user equipment, AP, BS, eNB, gNB, RAN node, network node, TRP, or another node) 1300 according to an example embodiment. The wireless station 1300 may include, for example, one or more (e.g., such as...) Figure 16 The two RF (radio frequency) or wireless transceivers 1302A and 1302B shown include a transmitter for transmitting signals and a receiver for receiving signals. The wireless station also includes a processor 1304 or control unit / entity (controller 1308) for executing instructions or software and controlling the transmission and reception of signals; and a memory 1306 for storing data and / or instructions.

[0103] Processor 1304 may also make decisions or determinations, generate frames, packets, or messages for transmission, decode received frames or messages for further processing, and perform other tasks or functions described herein. For example, processor 1304, which may be a baseband processor, may generate messages, packets, frames, or other signals for transmission via wireless transceiver 1302 (1302A or 1302B). Processor 1304 may control the transmission of signals or messages through a wireless network and may control the reception of signals or messages via a wireless network (e.g., after down-conversion by wireless transceiver 1302). Processor 1304 may be programmable and capable of executing software or other instructions stored in memory or other computer media to perform the various tasks and functions described above, such as one or more of the tasks or methods described above. Processor 1304 may be (or may include) hardware, programmable logic, a programmable processor executing software or firmware, and / or any combination of these. Using other terms, processor 1304 and transceiver 1302 together may be considered, for example, a wireless transmitter / receiver system.

[0104] Additionally, refer to Figure 16 The controller 1308 (or processor 1304) can execute software and instructions, and can provide overall control of station 1300, and can provide control over... Figure 16 Control of other systems not shown, such as control of input / output devices (e.g., display, keypad), and / or software that can execute one or more applications available on the wireless station 1300, such as, for example, email programs, audio / video applications, word processors, VoIP applications, or other applications or software.

[0105] Additionally, a storage medium may be provided that includes stored instructions, which, when executed by a controller or processor, may cause processor 1304 or other controllers or processors to perform one or more of the functions or tasks described above.

[0106] According to another example embodiment, the RF or wireless transceiver 1302A / 1302B can receive signals or data and / or transmit or send signals or data. The processor 1304 (and possibly the transceiver 1302A / 1302B) can control the RF or wireless transceiver 1302A or 1302B to receive, transmit, broadcast, or transmit signals or data.

[0107] Example embodiments are provided or described for each example method, including: apparatus (e.g., Figure 16 (of 1300), including components for performing any method (e.g., Figure 16 The processor 1304, RF transceiver 1302A and / or 1302B and / or memory 1306; non-transitory computer-readable storage medium (e.g., Figure 16 The memory 1306 includes instructions stored thereon, which are processed by at least one processor. Figure 16 The processor 1304 is configured to enable the computing system (e.g., Figure 16 (1300) executes any example method; and the device (e.g., Figure 16 The 1300), including at least one processor (e.g., Figure 16 The processor 1304) and at least one memory including computer program code (e.g., Figure 16 The at least one memory (1306) and computer program code are configured together with at least one processor (1304) to enable the device (e.g., 1300) to perform at least any of the example methods.

[0108] Embodiments of the various technologies described herein can be implemented in digital electronic circuit systems, or in computer hardware, firmware, software, or combinations thereof. Embodiments can be implemented as computer program products, i.e., computer programs tangibly embodied in an information carrier (e.g., in a machine-readable storage device or in a propagating signal) for execution by or control of a data processing apparatus (e.g., a programmable processor, a computer, or multiple computers). Embodiments can also be provided on computer-readable media or computer-readable storage media (which may be non-transitory media). Embodiments of the various technologies may also include embodiments provided via transient signals or media, and / or program and / or software embodiments downloadable via the Internet or other networks (wired and / or wireless networks). Additionally, embodiments can be provided via machine-type communication (MTC) and also via the Internet of Things (IoT).

[0109] As used herein, the term “circuit system” or “circuit” means all of the following: (a) a hardware circuit implementation only, such as an implementation only in analog and / or digital circuit systems; and (b) a combination of circuitry and software (and / or firmware), such as (if applicable): (i) a combination of processors or (ii) a processor / software portion, including a digital signal processor, software, and memory, which work together to enable a device to perform various functions; and (c) circuitry, such as a microprocessor or a portion of a microprocessor, which requires software or firmware to operate, even if the software or firmware is not physically present. This definition of “circuit system” applies to all uses of the term in this application. As another example, as used herein, the term “circuit system” will also cover an implementation only of a processor (or multiple processors) or a portion of a processor and its accompanying software and / or firmware. The term “circuit system” will also cover, for example and if applicable, a baseband integrated circuit or application processor integrated circuit for a mobile phone or a similar integrated circuit in a server, cellular network device, or other network device.

[0110] Computer programs can be in the form of source code, object code, or some intermediate form, and they can be stored on some carrier, distribution medium, or computer-readable medium, which can be any entity or device capable of carrying the program. Such carriers include, for example, recording media, computer memory, read-only memory, photoelectric and / or electrical carrier signals, telecommunication signals, and software distribution packages. Depending on the required processing power, a computer program can be executed in a single electronic digital computer, or it can be distributed across multiple computers.

[0111] Furthermore, embodiments of the various technologies described herein can utilize cyber-physical systems (CPS) (systems that control collaborative computing elements of physical entities). CPS enables embodiments and utilizations of a large number of interconnected ICT devices (sensors, actuators, processors, microcontrollers, etc.) embedded in physical objects at different locations. Mobile cyber-physical systems, which are inherently mobile physical systems, are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robots and electronic devices transported by humans or animals. The increasing prevalence of smartphones has increased interest in the field of mobile cyber-physical systems. Therefore, various embodiments of the technologies described herein can be provided via one or more of these technologies.

[0112] Computer programs such as those described above can be written in any programming language (including compiled or interpreted languages) and can be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit or part thereof suitable for use in a computing environment. Computer programs can be deployed to execute on a single computer, at a single site, or on multiple computers distributed across multiple sites and interconnected via a communication network.

[0113] The method steps can be executed by one or more programmable processors that execute a computer program or a portion thereof to perform a function by manipulating input data and generating output. The method steps can also be executed by a dedicated logic circuit system, and the apparatus can be implemented as a dedicated logic circuit, such as an FPGA (Field-Programmable Gate Array) or an ASIC (Application-Specific Integrated Circuit).

[0114] Processors suitable for executing computer programs include, for example, general-purpose and special-purpose microprocessors, and any one or more processors of any kind of digital computer, chip, or chipset. Typically, a processor receives instructions and data from read-only memory or random access memory, or both. The elements of a computer may include at least one processor for executing instructions and one or more memory devices for storing instructions and data. Typically, a computer may also include one or more mass storage devices (e.g., magnetic disks, magneto-optical disks, or optical disks) for storing data, or operatively coupled thereto to receive data or transfer data to or to them, or both. Suitable information carriers for embodying computer program instructions and data include all forms of non-volatile memory, including, for example, semiconductor memory devices such as EPROM, EEPROM, and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and memory may be supplemented by or incorporated into special-purpose logic circuitry.

[0115] To provide interaction with the user, embodiments can be implemented on a computer having a display device (e.g., a cathode ray tube (CRT) or liquid crystal display (LCD) monitor) for displaying information to the user and a user interface (such as a keyboard and pointing device, such as a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback, such as visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including sound, speech, or tactile input.

[0116] The embodiments can be implemented in a computing system that includes backend components, such as a data server, or middleware components, such as an application server, or frontend components, such as a client computer having a graphical user interface or web browser through which a user can interact with the embodiments, or any combination of such backend, middleware, or frontend components. The components can be interconnected via digital data communication (e.g., a communication network) of any form or medium. Examples of communication networks include local area networks (LANs) and wide area networks (WANs), such as the Internet.

[0117] While certain features of the described embodiments have been shown as described herein, many modifications, substitutions, alterations, and equivalents will now occur to those skilled in the art. Therefore, it should be understood that the appended claims are intended to cover all such modifications and alterations falling within the true spirit of the various embodiments.

[0118] Some examples will be described.

[0119] Example 1. An apparatus comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least: send to a network node information about a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; receive from the network node configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates at least one of the following: selecting a bandwidth portion (BWP) of the at least one uplink transmission of the at least one MIMO layer; selecting a frequency within an intermediate portion of the operating bandwidth of the at least one uplink transmission of the at least one MIMO layer; or deactivating the DPD function for one or more MIMO layers; sending to the network node an acknowledgment including an indication of configuration for executing the at least one uplink transmission, wherein the configuration is based on the configuration information; and executing the at least one uplink transmission of the at least one MIMO layer, at least in part based on the configuration information.

[0120] Example 2. The apparatus according to Example 1, wherein the information of the DPD function includes the state of the DPD function, wherein the state indicates the activation or deactivation of the DPD function.

[0121] Example 3. The apparatus according to Example 1 or 2, wherein the configuration information indicates at least one of the following: activating the DPD function for a first at least one MIMO layer; or deactivating the DPD function for a second at least one MIMO layer.

[0122] Example 4. An apparatus according to any one of Examples 1 to 3, wherein: selecting the BWP comprises selecting the narrowest BWP for all MIMO layers; and deactivating the DPD function for one or more MIMO layers comprises at least one of: deactivating the DPD function for all MIMO layers; or deactivating the DPD function for a first at least one MIMO layer, wherein the DPD function is active for the first at least one MIMO layer.

[0123] Example 5. An apparatus according to any one of Examples 1 to 4, wherein the configuration information further includes at least one of the following: at least one parameter of at least one power amplifier PA; information of a reference signal, including at least one of the following: information of one or more codes for transmission of the reference signal; information indicating the period or repetition rate of the reference signal; information indicating the frequency pattern of the reference signal; or information indicating the mapping of one or more codes to the frequency resources of the BWP; and wherein the reference signal includes at least one of the following: a sounding reference signal SRS; or an uplink SRS for MIMO calibration.

[0124] Example 6. An apparatus according to any one of Examples 1 to 5, wherein the configuration information is received as part of at least one of: Radio Resource Control (RRC) signaling; or Media Access Control (MAC-CE) control element.

[0125] Example 7. An apparatus according to any one of Examples 1 to 6, wherein the apparatus is further configured to perform: the configuration for performing the at least one uplink transmission, wherein the configuration is based on the configuration information.

[0126] Example 8. An apparatus according to any one of Examples 1 to 7, wherein the transmission of the information associated with the DPD function of each of the at least one MIMO layer comprises at least one of: transmitting information associated with the DPD function of each DPD activation layer of the at least one MIMO layer; transmitting information associated with the DPD function of each DPD deactivation layer of the at least one MIMO layer; or transmitting information associated with the DPD function of each DPD activation layer and each DPD deactivation layer of the at least one MIMO layer.

[0127] Example 9. An apparatus according to any one of Examples 1 to 8, wherein the configuration information further includes information on adjacent channel leakage ratio (ACLR); and wherein the apparatus is further configured to perform, based on the ACLR information, to determine whether to activate or deactivate the DPD function for one or more MIMO layers.

[0128] Example 10. An apparatus according to any one of Examples 1 to 9, wherein the apparatus is further configured to perform: sending an update of the information associated with the DPD function of each of the at least one MIMO layer.

[0129] Example 11. The apparatus according to any one of Examples 1 to 10, wherein the at least one uplink transmission includes the transmission of at least one of the following: a reference signal; a sounding reference signal (SRS); or an uplink SRS for MIMO calibration.

[0130] Example 12. An apparatus comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least: receive from a user equipment information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; send to the user equipment configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates at least one of the following: selecting a bandwidth portion (BWP) of the at least one uplink transmission of the at least one MIMO layer; selecting a frequency within an intermediate portion of the operating bandwidth of the at least one uplink transmission of the at least one MIMO layer; or deactivating the DPD function for one or more MIMO layers; receiving from the user equipment an acknowledgment including an indication of configuration for executing the at least one uplink transmission, wherein the configuration is based on the configuration information; and receiving from the user equipment the at least one uplink transmission of the at least one MIMO layer, at least in part based on the configuration information.

[0131] Example 13. The apparatus according to Example 12, wherein the information of the DPD function includes the state of the DPD function, wherein the state indicates the activation or deactivation of the DPD function.

[0132] Example 14. The apparatus according to Example 12 or 13, wherein the configuration information further includes at least one of the following: at least one parameter of at least one power amplifier PA; information of a reference signal, including at least one of the following: information of one or more codes for transmission of the reference signal; information indicating the period or repetition rate of the reference signal; information indicating the frequency pattern of the reference signal; or information indicating the mapping of one or more codes to the frequency resources of the BWP; and wherein the reference signal includes at least one of the following: a probe reference signal SRS; or an uplink SRS for MIMO calibration.

[0133] Example 15. A method comprising: sending information from a user equipment to a network node about a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; receiving from the network node configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates at least one of the following: selecting a bandwidth portion (BWP) of the at least one uplink transmission of the at least one MIMO layer; selecting a frequency within an intermediate portion of the operating bandwidth of the at least one uplink transmission of the at least one MIMO layer; or deactivating the DPD function for one or more MIMO layers; sending an acknowledgment to the network node including an indication of configuration for performing the at least one uplink transmission, wherein the configuration is based on the configuration information; and performing the at least one uplink transmission of the at least one MIMO layer, at least in part based on the configuration information.

[0134] Example 16. According to the method of Example 15, the information of the DPD function includes the state of the DPD function, wherein the state indicates the activation or deactivation of the DPD function.

[0135] Example 17. According to the method of Example 15 or 16, the configuration information indicates at least one of the following: activating the DPD function for a first at least one MIMO layer; or deactivating the DPD function for a second at least one MIMO layer.

[0136] Example 18. The method according to any one of Examples 15 to 17, wherein: selecting the BWP includes selecting the narrowest BWP for all MIMO layers; and deactivating the DPD function for one or more MIMO layers includes at least one of: deactivating the DPD function for all MIMO layers; or deactivating the DPD function for a first at least one MIMO layer, wherein the DPD function is active for the first at least one MIMO layer.

[0137] Example 19. The method according to any one of Examples 15 to 18, wherein the configuration information further includes at least one of the following: at least one parameter of at least one power amplifier PA; information of a reference signal, including at least one of the following: information of one or more codes for transmission of the reference signal; information indicating the period or repetition rate of the reference signal; information indicating the frequency pattern of the reference signal; or information indicating the mapping of one or more codes to the frequency resources of the BWP; and wherein the reference signal includes at least one of the following: a probe reference signal SRS; or an uplink SRS for MIMO calibration.

[0138] Example 20. A method comprising: receiving from a user equipment information by a network node information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; sending to the user equipment configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates at least one of the following: selecting a bandwidth portion (BWP) of the at least one uplink transmission of the at least one MIMO layer; selecting a frequency within an intermediate portion of the operating bandwidth of the at least one uplink transmission of the at least one MIMO layer; or deactivating the DPD function for one or more MIMO layers; receiving from the user equipment an acknowledgment including an indication of configuration for performing the at least one uplink transmission, wherein the configuration is based on the configuration information; and receiving from the user equipment the at least one uplink transmission of the at least one MIMO layer, at least in part based on the configuration information.

[0139] Example 21. A non-transitory computer-readable medium comprising instructions stored thereon for performing a method according to any one of Examples 15 to 19.

[0140] Example 22. A computer program including instructions stored thereon for performing the method according to any one of Examples 15 to 19.

[0141] Example 23. An apparatus comprising components for performing the method according to any one of Examples 15 to 19.

[0142] Example 24. An apparatus comprising components for causing the apparatus to perform at least the following: sending information to a network node about a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; receiving configuration information from the network node corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates at least one of the following: selecting a bandwidth portion (BWP) of the at least one uplink transmission of the at least one MIMO layer; selecting a frequency within an intermediate portion of the operating bandwidth of the at least one uplink transmission of the at least one MIMO layer; or deactivating the DPD function for one or more MIMO layers; sending an acknowledgment to the network node including an indication of a configuration for performing the at least one uplink transmission, wherein the configuration is based on the configuration information; and performing the at least one uplink transmission of the at least one MIMO layer, at least in part based on the configuration information.

[0143] Example 25. An apparatus comprising components for causing the apparatus to perform at least the following: receiving from a user equipment information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; sending to the user equipment configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates at least one of the following: selecting a bandwidth portion (BWP) of the at least one uplink transmission of the at least one MIMO layer; selecting a frequency within an intermediate portion of the operating bandwidth of the at least one uplink transmission of the at least one MIMO layer; or deactivating the DPD function for one or more MIMO layers; receiving from the user equipment an acknowledgment including an indication of configuration for performing the at least one uplink transmission, wherein the configuration is based on the configuration information; and receiving from the user equipment the at least one uplink transmission of the at least one MIMO layer, at least in part based on the configuration information.

[0144] Example 26. An apparatus comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least: transmit to a network node information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; receive from the network node configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; receive from the network node at least one parameter associated with a transmission of a reference signal for calibration of the at least one MIMO layer, wherein the at least one parameter includes at least one of: information of a resource associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to the at least one MIMO layer; deactivate the DPD function for the one or more layers; and transmit the reference signal to the network node at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0145] Example 27. The apparatus according to Example 26, wherein the at least one parameter further includes: information on one or more codes for transmission of the reference signal; information indicating the period or repetition rate of the reference signal; information indicating the frequency pattern of the reference signal; or information indicating frequency resources for mapping one or more codes to a bandwidth portion (BWP).

[0146] Example 28. The apparatus according to Example 27, wherein the one or more codes for transmitting the reference signal include at least one of the following: Gold code; Zadoff-Chu code; or a sequence of modulation symbols.

[0147] Example 29. The apparatus according to any one of Examples 26 to 28 further includes: amplifying the reference signal based on the at least one parameter of at least one PA, wherein the transmission of the reference signal is based on the output power of at least one PA and is determined based on at least one parameter of at least one PA.

[0148] Example 30. An apparatus according to any one of Examples 26 to 29, wherein the configuration information further indicates at least one of the following: selecting the narrowest BWP for all MIMO layers of the at least one uplink transmission of the at least one MIMO layer; or selecting a frequency within the middle portion of the operating bandwidth of the at least one uplink transmission of the at least one MIMO layer.

[0149] Example 31. The apparatus according to Example 30, wherein the uplink transmission is based on Orthogonal Frequency Division Multiplexing (OFDM), and wherein the apparatus is further configured to: adjust the uplink transmission to a selected frequency within the middle portion of the operating bandwidth of the at least one uplink transmission in the at least one MIMO layer.

[0150] Example 32. The apparatus according to any one of Examples 26 to 31, wherein the reference signal includes at least one of: an uplink reference signal; a probe reference signal (SRS); or an uplink SRS for MIMO calibration.

[0151] Example 33. The apparatus according to any one of Examples 26 to 32, wherein the information of the DPD function includes the state of the DPD function, wherein the state indicates whether the DPD function is activated or deactivated.

[0152] Example 34. An apparatus according to any one of Examples 26 to 33, wherein the configuration information is received as part of at least one of: Radio Resource Control (RRC) signaling; or Media Access Control (MAC-CE) control element.

[0153] Example 35. An apparatus according to any one of Examples 26 to 34, wherein the transmission of the information associated with the DPD function of each of the at least one MIMO layer comprises at least one of: transmitting information associated with the DPD function of each DPD activation layer of the at least one MIMO layer; transmitting information associated with the DPD function of each DPD deactivation layer of the at least one MIMO layer; or transmitting information associated with the DPD function of each DPD activation layer and each DPD deactivation layer of the at least one MIMO layer.

[0154] Example 36. An apparatus comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least: receive from a user equipment information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; send to the user equipment configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; send to the user equipment at least one parameter associated with a transmission of a reference signal for calibration of the at least one MIMO layer, wherein the at least one parameter includes at least one of: information of a resource associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to the at least one MIMO layer; and receive the reference signal from the user equipment at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0155] Example 37. The apparatus according to Example 36, wherein the at least one parameter further includes: information on one or more codes for transmission of the reference signal; information indicating the period or repetition rate of the reference signal; information indicating the frequency pattern of the reference signal; or information indicating frequency resources for mapping one or more codes to a bandwidth portion (BWP).

[0156] Example 38. A method comprising: transmitting from a user equipment to a network node information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; receiving from the network node configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; receiving from the network node at least one parameter associated with a transmission of a reference signal for calibration of the at least one MIMO layer, wherein the at least one parameter includes at least one of: information of a resource associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to the at least one MIMO layer; deactivating the DPD function for the one or more layers; and transmitting the reference signal to the network node at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0157] Example 39. The method according to Example 38, wherein the at least one parameter further includes: information on one or more codes for transmission of the reference signal; information indicating the period or repetition rate of the reference signal; information indicating the frequency pattern of the reference signal; or information indicating frequency resources for mapping one or more codes to a bandwidth portion (BWP).

[0158] Example 40. The method according to Example 39, wherein the one or more codes used for the transmission of the reference signal include at least one of the following: Gold code; Zadoff-Chu code; or a sequence of modulation symbols.

[0159] Example 41. The method according to any one of Examples 38 to 40, further comprising: amplifying the reference signal based on the at least one parameter of at least one PA, wherein the transmission of the reference signal is based on the output power of at least one PA and is determined based on at least one parameter of at least one PA.

[0160] Example 42. The method according to any one of Examples 38 to 41, wherein the configuration information further indicates at least one of the following: selecting the narrowest BWP for all MIMO layers of the at least one uplink transmission of the at least one MIMO layer; or selecting a frequency within the middle portion of the operating bandwidth of the at least one uplink transmission of the at least one MIMO layer.

[0161] Example 43. The method according to Example 42, wherein the uplink transmission is based on Orthogonal Frequency Division Multiplexing (OFDM), and the method further comprises: adjusting the uplink transmission to a selected frequency within the middle portion of the operating bandwidth of the at least one uplink transmission in the at least one MIMO layer.

[0162] Example 44. The method according to any one of Examples 38 to 43, wherein the reference signal includes at least one of the following: an uplink reference signal; a probe reference signal (SRS); or an uplink SRS for MIMO calibration.

[0163] Example 45. A method comprising: receiving from a user equipment information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers by a network node; sending to the user equipment configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; sending to the user equipment at least one parameter associated with a transmission of a reference signal for calibration of the at least one MIMO layer, wherein the at least one parameter includes at least one of: information of a resource associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to the at least one MIMO layer; and receiving the reference signal from the user equipment at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0164] Example 46. A non-transitory computer-readable medium including instructions stored thereon for performing the method according to any one of Examples 38 to 44.

[0165] Example 47. A computer program including instructions stored thereon for performing the method according to any one of Examples 38 to 44.

[0166] Example 48. An apparatus comprising components for performing the method according to any one of Examples 38 to 44.

[0167] Example 49. An apparatus comprising components for causing the apparatus to perform at least the following: transmitting to a network node information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; receiving from the network node configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; receiving from the network node at least one parameter associated with a transmission of a reference signal for calibration of the at least one MIMO layer, wherein the at least one parameter includes at least one of: information of a resource associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to the at least one MIMO layer; deactivating the DPD function for the one or more layers; and transmitting the reference signal to the network node at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0168] Example 50. An apparatus comprising components for causing the apparatus to perform at least the following: receiving from a user equipment information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; sending to the user equipment configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; sending to the user equipment at least one parameter associated with a transmission of a reference signal for calibration of the at least one MIMO layer, wherein the at least one parameter includes at least one of: information of a resource associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to the at least one MIMO layer; and receiving the reference signal from the user equipment at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0169] Example 51. An apparatus comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least: transmit to a network node information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; receive from the network node configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates at least one of the following: one or more conditions for activating or deactivating the DPD function based on a value of an adjacent channel leakage ratio (ACLR); selecting a bandwidth portion (BWP) of the at least one uplink transmission of the at least one MIMO layer; or selecting a frequency within an intermediate portion of the operating bandwidth of the at least one uplink transmission of the at least one MIMO layer; receiving the value of the ACLR from the network node; determining, at least based on the value of the ACLR and the configuration information, whether to activate or deactivate the DPD function for the at least one MIMO layer; and executing the at least one uplink transmission of the at least one MIMO layer, at least in part based on the determination.

[0170] Example 52. The apparatus according to Example 51, wherein the information of the DPD function includes the state of the DPD function, wherein the state indicates the activation or deactivation of the DPD function.

[0171] Example 53. The apparatus according to Example 51 or 52, wherein determining to activate or deactivate the DPD function includes determining to activate the DPD function, and wherein the apparatus is further caused to perform: sending a state of the DPD function, the state of the DPD function indicating activation of the DPD function.

[0172] Example 54. An apparatus according to any one of Examples 51 to 53, wherein determining to activate or deactivate the DPD function includes determining to deactivate the DPD function, and wherein the apparatus is further caused to perform: sending a state of the DPD function, the state of the DPD function indicating the deactivation of the DPD function.

[0173] Example 55. An apparatus according to any one of Examples 51 to 54, wherein selecting the BWP includes selecting the narrowest BWP for all MIMO layers.

[0174] Example 56. An apparatus according to any one of Examples 51 to 55, wherein the configuration information is received as part of at least one of: Radio Resource Control (RRC) signaling; or Media Access Control (MAC) control element-CE.

[0175] Example 57. An apparatus according to any one of Examples 51 to 56, wherein the transmission of the information associated with the DPD function of each of the at least one MIMO layer comprises at least one of: transmitting information associated with the DPD function of each DPD activation layer of the at least one MIMO layer; transmitting information associated with the DPD function of each DPD deactivation layer of the at least one MIMO layer; or transmitting information associated with the DPD function of each DPD activation layer and each DPD deactivation layer of the at least one MIMO layer.

[0176] Example 58. The apparatus according to any one of Examples 51 to 57, wherein the at least one uplink transmission includes the transmission of at least one of the following: a reference signal; an uplink reference signal; a probe reference signal (SRS); or an uplink SRS for MIMO calibration.

[0177] Example 59. An apparatus comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least: receive from a user equipment information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; transmit to the user equipment configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates at least one of the following: one or more conditions for activating or deactivating the DPD function based on a value of an adjacent channel leakage ratio (ACLR); select a bandwidth portion (BWP) of the at least one uplink transmission of the at least one MIMO layer; or select a frequency within an intermediate portion of the operating bandwidth of the at least one uplink transmission of the at least one MIMO layer; transmit the value of the ACLR to the user equipment; and receive from the user equipment the at least one uplink transmission of the at least one MIMO layer at least in part based on the value of the ACLR.

[0178] Example 60. The apparatus according to Example 59, wherein the information of the DPD function includes the state of the DPD function, wherein the state indicates the activation or deactivation of the DPD function.

[0179] Example 61. A method comprising: sending information from a user equipment to a network node about a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; receiving from the network node configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates at least one of the following: one or more conditions for activating or deactivating the DPD function based on a value of an adjacent channel leakage ratio (ACLR); selecting a bandwidth portion (BWP) of the at least one uplink transmission of the at least one MIMO layer; or selecting a frequency within an intermediate portion of the operating bandwidth of the at least one uplink transmission of the at least one MIMO layer; receiving the value of the ACLR from the network node; determining, at least based on the value of the ACLR and the configuration information, whether to activate or deactivate the DPD function for the at least one MIMO layer; and performing the at least one uplink transmission of the at least one MIMO layer at least in part based on the determination.

[0180] Example 62. The method according to Example 61, wherein the information of the DPD function includes the state of the DPD function, wherein the state indicates the activation or deactivation of the DPD function.

[0181] Example 63. The method according to Example 61 or 62, wherein determining to activate or deactivate the DPD function includes determining to activate the DPD function, and the method further includes sending a status of the DPD function, the status of the DPD function indicating the activation of the DPD function.

[0182] Example 64. The method according to any one of Examples 61 to 63, wherein determining to activate or deactivate the DPD function includes determining to deactivate the DPD function, and the method further includes sending a status of the DPD function, the status of the DPD function indicating the deactivation of the DPD function.

[0183] Example 65. The method according to any one of Examples 61 to 64, wherein selecting the BWP includes selecting the narrowest BWP for all MIMO layers.

[0184] Example 66. The method according to any one of Examples 61 to 65, wherein the configuration information is received as part of at least one of: Radio Resource Control (RRC) signaling; or Media Access Control (MAC) control element-CE.

[0185] Example 67. The method according to any one of Examples 61 to 66, wherein the transmission of the information associated with the DPD function of each of the at least one MIMO layer comprises at least one of: transmitting information associated with the DPD function of each DPD activation layer of the at least one MIMO layer; transmitting information associated with the DPD function of each DPD deactivation layer of the at least one MIMO layer; or transmitting information associated with the DPD function of each DPD activation layer and each DPD deactivation layer of the at least one MIMO layer.

[0186] Example 68. The method according to any one of Examples 61 to 67, wherein the at least one uplink transmission includes the transmission of at least one of the following: a reference signal; an uplink reference signal; a probe reference signal (SRS); or an uplink SRS for MIMO calibration.

[0187] Example 69. A method comprising: receiving from a user equipment by a network node information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; sending to the user equipment configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates at least one of the following: one or more conditions for activating or deactivating the DPD function based on a value of an adjacent channel leakage ratio (ACLR); selecting a bandwidth portion (BWP) of the at least one uplink transmission of the at least one MIMO layer; or selecting a frequency within an intermediate portion of the operating bandwidth of the at least one uplink transmission of the at least one MIMO layer; sending the value of the ACLR to the user equipment; and receiving from the user equipment the at least one uplink transmission of the at least one MIMO layer based at least in part on the value of the ACLR.

[0188] Example 70. The method according to Example 69, wherein the information of the DPD function includes the state of the DPD function, wherein the state indicates the activation or deactivation of the DPD function.

[0189] Example 71. A non-transitory computer-readable medium including instructions stored thereon for performing the method according to any one of Examples 61 to 70.

[0190] Example 72. A computer program including instructions stored thereon for performing the method according to any one of Examples 61 to 70.

[0191] Example 73. An apparatus comprising components for performing the method according to any one of Examples 61 to 70.

[0192] Example 74. An apparatus comprising components for causing the apparatus to perform at least the following: transmitting to a network node information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; receiving from the network node configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates at least one of the following: one or more conditions for activating or deactivating the DPD function based on a value of an adjacent channel leakage ratio (ACLR); selecting a bandwidth portion (BWP) of the at least one uplink transmission of the at least one MIMO layer; or selecting a frequency within an intermediate portion of the operating bandwidth of the at least one uplink transmission of the at least one MIMO layer; receiving the value of the ACLR from the network node; determining, at least based on the value of the ACLR and the configuration information, whether to activate or deactivate the DPD function for the at least one MIMO layer; and performing the at least one uplink transmission of the at least one MIMO layer, at least in part based on the determination.

[0193] Example 75. An apparatus comprising components for causing the apparatus to perform at least the following: receiving from a user equipment information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; transmitting to the user equipment configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates at least one of the following: one or more conditions for activating or deactivating the DPD function based on a value of an adjacent channel leakage ratio (ACLR); selecting a bandwidth portion (BWP) of the at least one uplink transmission of the at least one MIMO layer; or selecting a frequency within an intermediate portion of the operating bandwidth of the at least one uplink transmission of the at least one MIMO layer; transmitting the value of the ACLR to the user equipment; and receiving from the user equipment the at least one uplink transmission of the at least one MIMO layer at least in part based on the value of the ACLR.

[0194] Furthermore, the various implementations of this disclosure can be described with reference to the following terms, and their features can be combined in any reasonable manner.

[0195] Clause 1. An apparatus comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least: transmit to a network node information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; receive from the network node configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; receive from the network node at least one parameter associated with a transmission of a reference signal for calibration of the at least one MIMO layer, wherein the at least one parameter includes at least one of: information of a resource associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to the at least one MIMO layer; deactivate the DPD function for the one or more layers; and transmit the reference signal to the network node at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0196] Clause 2. The apparatus according to Clause 1, wherein the at least one parameter further comprises: information on one or more codes for transmission of the reference signal; information indicating the period or repetition rate of the reference signal; information indicating the frequency pattern of the reference signal; or information indicating frequency resources for mapping one or more codes to a bandwidth portion (BWP).

[0197] Clause 3. The apparatus according to Clause 2, wherein the one or more codes used for the transmission of the reference signal include at least one of the following: Gold code; Zadoff-Chu code; or a sequence of modulation symbols.

[0198] Clause 4. The apparatus according to any one of Clauses 1 to 3 further comprises: amplifying the reference signal based on the at least one parameter of at least one PA, wherein the transmission of the reference signal is based on the output power of at least one PA and is determined based on at least one parameter of at least one PA.

[0199] Clause 5. The apparatus according to any one of Clauses 1 to 4, wherein the configuration information further indicates at least one of the following: selecting the narrowest BWP for all MIMO layers of the at least one uplink transmission of the at least one MIMO layer; or selecting a frequency within the middle portion of the operating bandwidth of the at least one uplink transmission of the at least one MIMO layer.

[0200] Clause 6. The apparatus according to Clause 5, wherein the uplink transmission is based on Orthogonal Frequency Division Multiplexing (OFDM), and wherein the apparatus is further configured to: adjust the uplink transmission to a selected frequency within the middle portion of the operating bandwidth of the at least one uplink transmission in the at least one MIMO layer.

[0201] Clause 7. The apparatus according to any one of Clauses 1 to 6, wherein the reference signal includes at least one of: an uplink reference signal; a probe reference signal (SRS); or an uplink SRS for MIMO calibration.

[0202] Clause 8. The apparatus according to any one of Clauses 1 to 7, wherein the information of the DPD function includes the state of the DPD function, wherein the state indicates whether the DPD function is activated or deactivated.

[0203] Clause 9. The apparatus according to any one of Clauses 1 to 8, wherein the configuration information is received as part of at least one of: Radio Resource Control (RRC) signaling; or Media Access Control (MAC-CE) control element.

[0204] Clause 10. The apparatus according to any one of Clauses 1 to 9, wherein the transmission of the information associated with the DPD function of each of the at least one MIMO layer comprises at least one of: transmitting information associated with the DPD function of each DPD activation layer of the at least one MIMO layer; transmitting information associated with the DPD function of each DPD deactivation layer of the at least one MIMO layer; or transmitting information associated with the DPD function of each DPD activation layer and each DPD deactivation layer of the at least one MIMO layer.

[0205] Clause 11. An apparatus comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to at least: receive from a user equipment information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; send to the user equipment configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; send to the user equipment at least one parameter associated with a transmission of a reference signal for calibration of the at least one MIMO layer, wherein the at least one parameter includes at least one of: information of a resource associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to the at least one MIMO layer; and receive the reference signal from the user equipment at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0206] Clause 12. The apparatus according to Clause 11, wherein the at least one parameter further comprises: information on one or more codes for transmission of the reference signal; information indicating the period or repetition rate of the reference signal; information indicating the frequency pattern of the reference signal; or information indicating frequency resources for mapping one or more codes to a bandwidth portion (BWP).

[0207] Clause 13. A method comprising: transmitting from a user equipment to a network node information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; receiving from the network node configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; receiving from the network node at least one parameter associated with a transmission of a reference signal for calibration of the at least one MIMO layer, wherein the at least one parameter includes at least one of: information of a resource associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to the at least one MIMO layer; deactivation of the DPD function for the one or more layers; and transmitting the reference signal to the network node at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0208] Clause 14. The method according to Clause 13, wherein the at least one parameter further comprises: information on one or more codes for transmission of the reference signal; information indicating the period or repetition rate of the reference signal; information indicating the frequency pattern of the reference signal; or information indicating frequency resources for mapping one or more codes to a bandwidth portion (BWP).

[0209] Clause 15. The method according to Clause 14, wherein the one or more codes used for the transmission of the reference signal include at least one of the following: Gold code; Zadoff-Chu code; or a sequence of modulation symbols.

[0210] Clause 16. The method according to any one of Clauses 13 to 15 further comprises: amplifying the reference signal based on the at least one parameter of at least one PA, wherein the transmission of the reference signal is based on the output power of at least one PA and is determined based on at least one parameter of at least one PA.

[0211] Clause 17. The method according to any one of Clauses 13 to 16, wherein the configuration information further indicates at least one of the following: selecting the narrowest BWP for all MIMO layers of the at least one uplink transmission of the at least one MIMO layer; or selecting a frequency within the middle portion of the operating bandwidth of the at least one uplink transmission of the at least one MIMO layer.

[0212] Clause 18. The method according to Clause 17, wherein the uplink transmission is based on Orthogonal Frequency Division Multiplexing (OFDM), and the method further comprises: adjusting the uplink transmission to a selected frequency within the middle portion of the operating bandwidth of the at least one uplink transmission in the at least one MIMO layer.

[0213] Clause 19. The method according to any one of Clauses 13 to 18, wherein the reference signal includes at least one of: an uplink reference signal; a sounding reference signal (SRS); or an uplink SRS for MIMO calibration.

[0214] Clause 20. A method comprising: receiving from a user equipment information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers by a network node; sending to the user equipment configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; sending to the user equipment at least one parameter associated with a transmission of a reference signal for calibration of the at least one MIMO layer, wherein the at least one parameter includes at least one of: information of a resource associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to the at least one MIMO layer; and receiving the reference signal from the user equipment at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0215] Clause 21. A non-transitory computer-readable medium comprising instructions stored thereon for performing a method according to any one of Clauses 13 to 19.

[0216] Clause 22. A computer program comprising instructions stored thereon for performing the method according to any one of Clauses 13 to 19.

[0217] Clause 23. An apparatus comprising components for performing the method according to any one of Clauses 13 to 19.

[0218] Clause 24. An apparatus comprising components for causing the apparatus to perform at least the following: transmitting to a network node information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; receiving from the network node configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; receiving from the network node at least one parameter associated with a transmission of a reference signal for calibration of the at least one MIMO layer, wherein the at least one parameter includes at least one of: information of a resource associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to the at least one MIMO layer; deactivating the DPD function for the one or more layers; and transmitting the reference signal to the network node at least in part based on the at least one parameter associated with the transmission of the reference signal.

[0219] Clause 25. An apparatus comprising components for causing the apparatus to perform at least the following: receiving from a user equipment information of a digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layers; sending to the user equipment configuration information corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; sending to the user equipment at least one parameter associated with a transmission of a reference signal for calibration of the at least one MIMO layer, wherein the at least one parameter includes at least one of: information of a resource associated with the transmission of the reference signal; or at least one parameter of at least one power amplifier (PA) corresponding to the at least one MIMO layer; and receiving the reference signal from the user equipment at least in part based on the at least one parameter associated with the transmission of the reference signal.

Claims

1. A 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 device to perform at least the following: Send information to network nodes about the digital predistortion (DPD) function associated with each of at least one multiple-input multiple-output (MIMO) layer; Receive configuration information from the network node corresponding to at least one uplink transmission of the at least one MIMO layer, wherein the configuration information indicates deactivation of the DPD function for one or more MIMO layers; At least one parameter is received from the network node in connection with the transmission of a reference signal for calibration of the at least one MIMO layer, wherein the at least one parameter includes at least one of the following: Information about the resources associated with the transmission of the reference signal; or At least one parameter of at least one power amplifier PA corresponding to the at least one MIMO layer; The DPD function is deactivated for one or more layers; as well as The reference signal is transmitted to the network node based at least in part on the at least one parameter associated with the transmission of the reference signal.

2. The apparatus according to claim 1, wherein the at least one parameter further comprises: Information of one or more codes used for the transmission of the reference signal; Information indicating the period or repetition rate of the reference signal; Information indicating the frequency pattern of the reference signal; or Information indicating the mapping of one or more codes to frequency resources of the bandwidth portion of the BWP.

3. The apparatus of claim 2, wherein the one or more codes for transmitting the reference signal comprise at least one of the following: Gold code; Zadoff-Chu code; or A sequence of modulation symbols.

4. The apparatus according to any one of claims 1 to 3, further comprising: The reference signal is amplified based on at least one parameter of at least one PA. The transmission of the reference signal is based on the output power of at least one PA and is determined based on at least one parameter of at least one PA.

5. The apparatus according to any one of claims 1 to 3, wherein the configuration information further indicates at least one of the following: Select the narrowest BWP for all MIMO layers transmitted on the at least one uplink for the at least one MIMO layer; or Select a frequency within the middle portion of the operating bandwidth of the at least one uplink transmission in the at least one MIMO layer.

6. The apparatus of claim 5, wherein the uplink transmission is based on orthogonal frequency division multiplexing (OFDM), and wherein the apparatus is further configured to: adjust the uplink transmission to a selected frequency within the middle portion of the operating bandwidth of the at least one uplink transmission in the at least one MIMO layer.

7. The apparatus according to any one of claims 1 to 3, wherein the reference signal comprises at least one of the following: Uplink reference signal; Detection reference signal SRS; or Uplink SRS for MIMO calibration.

8. The apparatus according to any one of claims 1 to 3, wherein the information of the DPD function includes the state of the DPD function, wherein the state indicates whether the DPD function is activated or deactivated.

9. The apparatus according to any one of claims 1 to 3, wherein the configuration information is received as part of at least one of the following: Radio Resource Control (RRC) signaling; or Media Access Control (MAC-CE) element.

10. The apparatus according to any one of claims 1 to 3, wherein the transmission of the information associated with the DPD function of each of the at least one MIMO layer comprises at least one of the following: Send information about the DPD function associated with each DPD activation layer of the at least one MIMO layer; Send information about the DPD function associated with each DPD deactivation layer of the at least one MIMO layer; or Send information about the DPD functions associated with each DPD activation layer and each DPD deactivation layer of the at least one MIMO layer.

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