Calibration measurements and reporting

Abstract

Embodiments of the present disclosure relate to calibration measurement and reporting. In one aspect, a terminal device receives, from a network device, a configuration and activation of DL / UL calibration measurement for one or more TRPs in a CJT. The terminal device determines one or more SRS ports for the calibration measurement. The terminal device performs the calibration measurement for the one or more TRPs based on the one or more SRS ports. The terminal device sends, to the network device, information of the calibration measurement of the one or more TRPs. In this way, UE-assisted cross-TRP phase calibration for uplink (UL) and downlink (DL) channels is provided by utilizing multiple UE antennas mapped to respective SRS ports, thereby improving communication performance related to the CJT.

Description

Technical Field

[0001] Various example embodiments relate to the field of communications, and more specifically, to devices, methods, apparatuses, and computer-readable storage media for calibrating measurements and reporting. Background Technology

[0002] A communication network can be viewed as a facility that enables communication between two or more communication devices, or provides communication devices with access to a data network. Mobile or wireless communication networks are an example of communication networks.

[0003] Such communication networks operate according to standards such as those issued by 3GPP (3rd Generation Partnership Project) or ETSI (European Telecommunications Standards Institute). Examples of such standards include the so-called 5G (fifth generation) standard or other standards issued by 3GPP. Summary of the Invention

[0004] Generally, the exemplary embodiments of this disclosure provide a solution for calibration measurements and reporting, particularly for cross-transmitter-receiver point (cross-TRP) phase calibration aided by multiple user equipment (UE) antennas. Using this solution, UE-assisted cross-transmitter / receiver point (TRP) phase calibration for uplink UL and downlink DL channels is provided by utilizing multiple UE antennas mapped to corresponding sounding reference signal (SRS) ports, thereby improving communication performance associated with coherent joint transmission (CJT).

[0005] In a first aspect, a terminal device is provided. The terminal device includes: at least one processor; and at least one memory storing instructions. When executed by the at least one processor, the instructions cause the terminal device to at least: receive configuration and activation from a network device for DL / UL calibration measurements for one or more TRPs in a CJT. The terminal device is further caused to determine one or more SRS ports for the calibration measurements. The terminal device is further caused to perform calibration measurements for one or more TRPs based on the one or more SRS ports. The terminal device is further caused to send information about the calibration measurements for one or more TRPs to the network device.

[0006] In a second aspect, a network device is provided. The network device includes: at least one processor; and at least one memory storing instructions. When executed by the at least one processor, the instructions cause the network device to at least: send configuration and activation of DL / UL calibration measurements for one or more TRPs in a CJT to an end device. The network device is also caused to receive calibration measurement information from the end device. The network device is further caused to determine calibration coefficients based on the calibration measurement information and SRS measurements for one or more SRS ports associated with the calibration measurements.

[0007] In a third aspect, a method implemented at a terminal device is provided. The method includes: receiving configuration and activation of DL / UL calibration measurements for one or more TRPs in a CJT from a network device. The method further includes: determining one or more SRS ports for the calibration measurements. The method further includes performing calibration measurements for the one or more TRPs based on the one or more SRS ports. The method further includes: sending information about the calibration measurements for the one or more TRPs to the network device.

[0008] In a fourth aspect, a method implemented at a network device is provided. The method includes: sending configuration and activation of DL / UL calibration measurements for one or more TRPs in a CJT to an end device. The method also includes: receiving calibration measurement information from the end device. The method further includes: determining calibration coefficients based on the calibration measurement information and SRS measurements for one or more SRS ports associated with the calibration measurements.

[0009] In a fifth aspect, an apparatus is provided. The apparatus includes: components for configuring and activating DL / UL calibration measurements for one or more TRPs in a CJT from a network device. The apparatus also includes: components for determining one or more SRS ports for the calibration measurements. The apparatus further includes: components for performing calibration measurements for one or more TRPs based on the one or more SRS ports. The apparatus also includes: components for transmitting information about the calibration measurements for one or more TRPs to the network device.

[0010] In a sixth aspect, an apparatus is provided. The apparatus includes components for: configuring and activating DL / UL calibration measurements for one or more TRPs in a CJT by sending them to a terminal device. The apparatus also includes components for: receiving information about the calibration measurements from the terminal device. Furthermore, the apparatus includes components for: determining calibration coefficients based on the information about the calibration measurements and SRS measurements for one or more SRS ports associated with the calibration measurements.

[0011] In a seventh aspect, a non-transitory computer-readable medium is provided, comprising program instructions for causing a device to perform at least the method according to any one of the fourth to sixth aspects described above.

[0012] In an eighth aspect, a computer program is provided that includes instructions, which, when executed by a device, cause the device to perform at least the method according to any one of the fourth to sixth aspects described above.

[0013] In a ninth aspect, a terminal device is provided. The terminal device includes a receiving circuitry configured to receive configuration and activation of DL / UL calibration measurements for one or more TRPs in a CJT from a network device. The terminal device also includes a determining circuitry configured to determine one or more SRS ports for the calibration measurements. The terminal device further includes an executing circuitry configured to perform calibration measurements for one or more TRPs based on the one or more SRS ports. The terminal device also includes a transmitting circuitry configured to transmit information about the calibration measurements for the one or more TRPs to the network device.

[0014] In a tenth aspect, a network device is provided. The network device includes a transmitting circuitry configured to transmit configuration and activation of DL / UL calibration measurements for one or more TRPs in a CJT to an end device. The network device also includes a receiving circuitry configured to receive calibration measurement information from the end device. The network device further includes a determining circuitry configured to determine calibration coefficients based on the calibration measurement information and SRS measurements for one or more SRS ports associated with the calibration measurements.

[0015] It should be understood that the summary section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to be used to limit the scope of this disclosure. Other features of this disclosure will become apparent from the following description. Attached Figure Description

[0016] Some exemplary embodiments will now be described with reference to the accompanying drawings, in which:

[0017] Figure 1A An example communication network in which embodiments of the present disclosure may be implemented is shown;

[0018] Figure 1B Examples of Tx-Rx phase offsets at TRP and UE for CJT in a TDD system according to some embodiments of the present disclosure are shown;

[0019] Figure 1C Examples of channel phase difference recovery according to some embodiments of this disclosure are shown;

[0020] Figure 2 A flowchart illustrating an example of a process for calibrating measurements and reporting according to some embodiments of this disclosure is shown;

[0021] Figure 3 A flowchart illustrating another example of a process for calibrating measurements and reporting according to some embodiments of this disclosure is shown;

[0022] Figure 4 A flowchart illustrating another example of a process for filtering operations for UEIBM according to some embodiments of the present disclosure is shown;

[0023] Figure 5 A flowchart illustrating another example of a process for filtering operations for UEIBM according to some embodiments of the present disclosure is shown;

[0024] Figures 6A-6D Examples of UCI mappings for phase offset reporting according to some embodiments of this disclosure are shown;

[0025] Figure 7 Examples of multi-TRP calibration according to some embodiments of this disclosure are shown;

[0026] Figure 8 A flowchart is shown illustrating a method implemented at a terminal device according to some other embodiments of the present disclosure;

[0027] Figure 9 A flowchart is shown illustrating a method implemented at a network device according to some other embodiments of the present disclosure;

[0028] Figure 10 A simplified block diagram of an apparatus suitable for implementing embodiments of the present disclosure is shown; and

[0029] Figure 11 A block diagram of an example computer-readable medium according to some embodiments of the present disclosure is shown.

[0030] In all the accompanying drawings, the same or similar reference numerals denote the same or similar elements. Detailed Implementation

[0031] The principles of this disclosure will now be described with reference to some exemplary embodiments. It should be understood that these embodiments are described for illustrative purposes only and to assist those skilled in the art in understanding and implementing this disclosure, and do not imply any limitation on the scope of this disclosure. This disclosure described herein can be implemented in various ways other than those described below.

[0032] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0033] References to "an embodiment," "an example embodiment," etc., in this disclosure indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment includes that particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it should be understood that, whether explicitly described or not, in conjunction with other embodiments, affecting such feature, structure, or characteristic is within the knowledge of those skilled in the art.

[0034] It should be understood that although the terms “first” and “second” may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of the exemplary embodiments, a first element may also be referred to as a second element, and similarly, a second element may also 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.

[0035] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that, when used herein, the terms “comprising,” “including,” “having,” “containing,” and / or “including” specify the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements is connected by “and” or “or”, means at least any one element, or at least any two or more elements, or at least all elements.

[0036] As used in this application, the term "circuit system" may refer to one or more of the following: (a) Hardware circuit implementation only (such as implementation only in analog and / or digital circuit systems); and (b) A combination of hardware circuitry and software, such as (if applicable): (i) A combination of (multiple) analog and / or digital hardware circuits and software / firmware, and (ii) Any part of a hardware processor (including (multiple) digital signal processors), software, and (multiple) memories, which work together to enable a device (such as a mobile phone or server) to perform various functions and (c) (Multiple) hardware circuits and / or (multiple) processors (such as (multiple) microprocessors or a portion of (multiple) microprocessors) that require software (e.g., firmware) to operate, but may be absent when no software is required for operation.

[0037] This definition of "circuit system" applies to all uses of the term in this application, including in any claim. As another example, as used in this application, the term "circuit system" also covers only the implementation of hardware circuitry or a processor (or multiple processors) or portions thereof and their accompanying software and / or firmware. The term "circuit system" also covers, for example, if applicable to a particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in a server, cellular network device, or other computing or networking device.

[0038] As used herein, the term "communication network" refers to a network that conforms to any suitable communication standard, such as Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), etc. Furthermore, communication between terminal devices and network devices in a communication network can be performed according to any suitable generation of communication protocols, including but not limited to first-generation (1G), second-generation (2G), 2.5G, 2.75G, third-generation (3G), fourth-generation (4G), 4.5G, future fifth-generation (5G) communication protocols, and / or any other protocols currently known or to be developed in the future. Embodiments of this disclosure can be applied to various communication systems. Given the rapid development of communications, there will naturally be future types of communication technologies and systems that this disclosure can utilize. This should not be construed as limiting the scope of this disclosure to the systems described above.

[0039] As used herein, the terms "network device" and "access network device" refer to nodes in a communication network through which terminal devices access the network and receive services. Depending on the terminology and technology used, network devices can refer to base stations (BS) or access points (APs), such as Node B (NodeB or NB), evolved Node B (eNodeB or eNB), NRNB (also known as gNB), Remote Radio Unit (RRU), Radio Head (RH), Remote Radio Head (RRH), relays, low-power nodes (such as femtonodes, piconodes), etc.

[0040] The term "terminal device" refers to any terminal device capable of wireless communication. By way of example and not limitation, a terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), or access terminal (AT). Terminal devices may include, but are not limited to, mobile phones, cellular phones, smartphones, Voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices (such as digital cameras), gaming terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded devices (LEEs), laptop-mounted devices (LMEs), USB dongles, smart devices, wireless client devices (CPEs), Internet of Things (IoT) devices, watches or other wearables, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated processing chains), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. In the following description, the terms “terminal equipment”, “communication equipment”, “terminal”, “user equipment”, and “UE” may be used interchangeably.

[0041] Massive Multiple-Input Multiple-Output (MIMO) is a key component for 5G and the emerging 6G. One current development direction is Cooperative Joint Transmission (CJT). In Cooperative Joint Transmission, one or more sets of TRPs can coherently transmit to UEs serving in a network area. In the future, this may evolve into more general deployments, such as Cellless Massive MIMO, where several TRPs can cooperate to transmit, thereby improving network capacity and removing the capacity degradation effect at cell edges.

[0042] The 3GPP Rel.19 MIMO work project is investigating further enhancements to the previous framework proposed in Rel.18 CJT. These enhancements focus on addressing issues related to frequency and timing alignment in non-ideal backhauls, as well as hardware misalignment. This work project covers both TDD and FDD aspects. It is well known that in FDD systems, the DL and UL channels reside in different frequency bands, and reciprocity cannot be directly assumed. In this case, after measuring the Channel State Information Reference Signal (CSI-RS) from one or more TRPs, the quantized CSI feedback from the UE is reported to the NW. However, in TDD systems, since the DL and UL channels share the same transmission frequency band, and duplexing is performed through alternating downlink and uplink transmission processes, the DL and UL channels can be considered reciprocal. Channel acquisition is performed using the SRS transmitted from the UE to the NW.

[0043] For a single TRP transmission scheme, even after calibration, residual phase misalignment may still exist between the hardware used for uplink and downlink transmission. This residual misalignment is negligible during Physical Downlink Shared Channel (PDSCH) transmission because it can be corrected during the reception phase.

[0044] However, if multiple TRPs are transmitted from coherent transmissions, it becomes difficult to identify the phase offset for each TRP, which reduces the ability to coherently transmit from multiple TRPs. How to utilize a UE with multiple antenna ports in a UE-assisted cross-TRP calibration mechanism is not defined in the current standard. Specifically, in TDD-based CJT, DL CSI acquisition is based on utilizing SRS from the UE, meaning that phase differences across multiple TRP transmission arrays are not seen during the CSI acquisition phase, and therefore cannot be interpreted without some cross-TRP phase difference compensation mechanism. In TDD operation, if SRS probing is possible and of sufficient quality, the gNB can acquire DL channel information using SRS measurements by relying on UL-DL channel reciprocity. Antenna array self-calibration is typically performed by the gNB to compensate for phase differences between antenna elements relative to a reference antenna element. Receive antenna calibration is usually performed separately from transmit antenna calibration, although the same antenna elements are often used as a reference. Due to hardware differences between the receive and transmit radio circuit systems, there is often a phase difference between the Tx and Rx antennas that is unknown to the gNB. The Tx-Rx phase difference can be assumed to be common to all antenna elements of the TRP, but the Tx-Rx phase difference is different between different TRPs.

[0045] If the Tx-Rx phase offset is common across all transmitting MIMO layers, then DL transmission from a single TRP's MIMO layer is unaffected by this Tx-Rx phase offset. Therefore, single TRP and incoherent joint transmission NCJT DL transmission are unaffected by this phase offset. However, since the TRP is assumed to be... n Tx-Rx phase difference The DL signal sent from each TRP will be affected by different phase offsets, thus affecting CJT transmission. Indicates TRP n The Tx phase difference. Indicates TRP n The Rx phase difference, Indicates TRP n The DL / UL phase difference. Therefore, unless these phase offsets are taken into account in the MIMO precoder, coherent transmission cannot be achieved between multiple TRPs.

[0046] According to some embodiments of this disclosure, a solution for calibrating measurements and reporting is provided. The principles and embodiments of this disclosure will be described in detail below with reference to the accompanying drawings.

[0047] Figure 1A A schematic diagram of an example communication network 100A in which some embodiments of this disclosure can be implemented is shown. For example... Figure 1A As shown, the communication network 100A may include terminal device 110, network device 120, network device 121 and network device 122.

[0048] It should be understood that the number of network devices and terminal devices is for illustrative purposes only and does not imply any limitation. System 100A may include any suitable number of network devices and terminal devices appropriate for implementing embodiments of this disclosure.

[0049] Communication in the communication system 100A can be implemented according to any suitable communication protocol(s), including but not limited to cellular communication protocols such as first-generation (1G), second-generation (2G), third-generation (3G), fourth-generation (4G), and fifth-generation (5G), as well as wireless local area network communication protocols such as IEEE 802.11, and / or any currently known or future-developed protocols. Furthermore, communication can utilize any suitable wireless communication technology, including but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiplexing (OFDM), Discrete Fourier Transform Extended OFDM (DFT-s-OFDM), and / or any other currently known or future-developed technologies.

[0050] like Figure 1A As shown, terminal device 110 receives CSI-RS-DL from network devices 120, 121, and 122. Terminal device 110 sends SRS-UL to network devices 120, 121, and 122.

[0051] Figure 1B Examples of TRP and Tx-Rx phase offsets at the UE for a CJT in a TDD system according to some embodiments of the present disclosure are shown. Figure 1B It can involve, for example Figure 1A The terminal device 110, network device 120, and network device 121 are shown. It should be understood that although the process 200 for the link has been... Figure 1A The process is described in the communication system 100A, but it is equally applicable to other communication scenarios in which different network devices are jointly deployed to provide corresponding service cells.

[0052] like Figure 1B As shown, TRP 1 (network device 121) is the reference device. One solution for calibration measurements and reporting with multiple TRPs is for the gNB to obtain an estimate of the Tx-Rx phase calibration error for each TRP relative to the reference TRP (such as TRP 1), i.e., the phase offset for all TRPs except the reference TRP. The estimate is obtained, and the corresponding phase compensation is applied from the TRP. n The transmitted DL signal. This phase compensation is possible relative to the reference TRP because of the common phase error across all transmitting antennas. It does not affect performance. Indicates TRP n The DL / UL phase difference. This indicates the phase error of the reference TRP. Indicates a TRP other than the reference TRP. n Phase shift.

[0053] like Figure 1B As shown, a model for the Tx-Rx phase offset at the TRP (network devices 120 and 121) and UE (terminal device 110) in a TDD system is presented, where it is assumed that each TRP performs self-calibration of its antenna array for UL reception and DL transmission independently. n The phase shift at each point is determined by the phase shift for transmission. and for receiving This indicates that they are assumed to be the same for all tx and rx antenna ports for this TRP. The phase offset at the UE is respectively determined by the signals from the antenna ports. i For transmission and for receiving The instruction assumes that no phase calibration is performed by the UE on the transmit or receive antennas. For general subcarriers, from the TRP n To UE antenna i The DL channel consists of row vectors It means that, among them P This represents the number of antennas for each TRP. The corresponding UL channel is represented by a column vector. This indicates that, under perfect UL-DL channel reciprocity, In this model, it is assumed that... From UE Tx antenna i The EPRE sent by UL, and From TRP n The EPRE sent.

[0054] Assumption It is the selected beamforming weight, which is determined by gNB from TRP. n The received SRS is calculated, and for example, corresponds to the data from the TRP. n The strongest beam to the UE, among which P This refers to the number of antennas per TRP. gNB measurements are based on the number of antennas per TRP. n and reference TRP received and by SRS port i Phase difference between transmitted signals ,For example: (1)

[0055] This indicates that it is for ports i TRP n UL phase offset. Indicates TRP n The Rx ratio. Indicates that it has a port i The Tx ratio of the UE. This indicates the Rx ratio of the reference TRP. Indicates TRP n Beamforming weights. This indicates the beamforming weights referenced to the TRP. Indicates TRP n UL channel. This indicates the UL channel referenced by the TRP. Indicates TRP n The Rx phase difference. This represents the Rx phase difference of the reference TRP.

[0056] gNB then sends the configuration from CSI-RS resources / resource sets with the same weights for beamforming of each TRP within a TRP. For example, a single-port TRS resource set from each TRP, or a set with... A single CSI-RS resource set, or having A single CSI-RS resource set for a single resource on a single port, where each resource or port corresponds to a signal transmitted from the TRP. The UE measures and reports this information via the TRP. n And reference TRP sent, and by the antenna i Phase difference between received CSI-RS signals (2)

[0057] Indicates that it is composed of ports i The DL phase offset measured by the UE. Indicates TRP n The Tx ratio. Indicates that it has a port i The Rx ratio of the UE. This indicates the Tx ratio of the reference TRP. This represents the beamforming weight. This indicates the beamforming weights referenced to the TRP. Indicates TRP n DL channel. This indicates the DL channel referenced to the TRP. Indicates TRP n The Tx phase difference. This represents the Tx phase difference of the reference TRP.

[0058] Under the assumption of UL-DL channel reciprocity, and if the SRS port is measured by gNB i Corresponding to the UE antenna port used for UE measurement i Then gNB can be based on two measurements and The difference between them is used to calculate the phase shift. ,Right now: (3)

[0059] Therefore, the phase offset measurement reported by the UE needs to be measured from a single UE antenna port, and the gNB needs to know which UE antenna port the reported measurement corresponds to. It should be noted that for each reported TRP, multiple measurements performed by different UE antenna ports can be reported by the UE. The same UE antenna port can be used to measure the phase offset for all configured TRPs relative to a reference TRP. Furthermore, for UEs with multiple antenna ports, utilizing measurements from each UE antenna port can be advantageous, thereby providing an additional estimate of the same phase offset for the configured TRPs, which can improve the accuracy of the phase offset estimation. Moreover, the additional estimate of the same phase offset can also be obtained by utilizing multiple CSI-RS ports for each TRP, as well as additional phase measurements performed by multiple UE antenna ports. In the case of multiple UE antenna ports, when using multiple CSI-RS ports at each TRP, the phase offset measurement can be obtained for each combination of CSI-RS ports and UE SRS ports for each TRP using the methods described herein. For each combination of CSI-RS port and UE SRS port, the TRP will transmit the additional CSI-RS port using the same weight vector used to receive SRS from the UE SRS port. For a given TRP, each CSI-RS port will be beamformed using a different weight vector (i.e., different beams are used to create different CSI-RS ports).

[0060] Figure 1C Examples of channel phase difference recovery according to some embodiments of this disclosure are shown. Figure 1C It can involve, for example Figure 1A The terminal device 110, network device 120, and network device 121 are shown. It should be understood that although the process 200 for the link has been... Figure 1A The process is described in the communication system 100A, but it is equally applicable to other communication scenarios in which different network devices are jointly deployed to provide corresponding service cells.

[0061] like Figure 1C The diagram illustrates a basic example of DL / UL calibration for two TRPs. For example, network device 121 is shown relative to a reference TRP. In a broadband scenario, without loss of generality, for single-port calibration, and for both reference TRP (network device 121) and TRP... i (Network device 120) The corresponding ratios of the measurement signals in the UL and DL of each TRP are obtained separately, i.e. = , .

[0062] This indicates the measurement value in the UL referenced by TRP. This refers to the measurement value in the DL of the reference TRP. This indicates the ratio of the reference TRP. Indicates TRP i The UL measurement value. Indicates TRP i The measured values ​​in DL. Indicates TRP i The ratio.

[0063] To enable this, measurements are performed in both DL and UL. UL measurements can be obtained from a single SRS port measured at each TRP, and similarly, in DL, the UE (Terminal Device 110) can measure the DL channel from each TRP via CSI-RS on the same port. Figure 1C As shown, the received downlink signal can be measured, and the obtained... The ratio is used to recover the channel phase difference between the two TRPs, i.e. To obtain the composite phase angle The composite phase angle includes the desired phase shift between two TRPs with different channels. If the ratio If it can be measured on the NW side, then obtain The ratio can be removed. It should be noted that this example can be extended to multiple UE Tx / Rx ports and multiple antennas for each TRP. Measurements received at the UE side can be obtained from multiple independent measurements for each TRP, either for a single antenna port, a combined / aggregated antenna port, or a beamforming port.

[0064] Figure 2 A flowchart illustrating an example of a process for calibrating measurements and reporting according to some embodiments of the present disclosure is shown. For discussion purposes, process 200 will be referred to Figure 1A Described. Process 200 may involve, for example... Figure 1A The terminal device 110, network device 120, and second network device 122 are shown. It should be understood that although the process 200 for the link has been... Figure 1A The communication system 100A is described, but this configuration can also be applied to other communication scenarios in which different network devices are jointly deployed to provide corresponding service cells.

[0065] In some embodiments, network device 120 sends configuration and activation for DL / UL calibration measurements for one or more TRPs in the CJT to terminal device 110. Terminal device 110 then receives the configuration and activation. Specifically, as... Figure 2 As shown, network device 120 sends configuration and activation for DL / UL calibration measurement 202 to terminal device 110 via 201. Terminal device 110 receives 203 configuration and activation.

[0066] In some embodiments, terminal device 110 determines one or more SRS ports for calibration measurements. Specifically, such as Figure 2 As shown, terminal device 110 identifies one or more SRS ports 204 for calibration measurements.

[0067] In some embodiments, terminal device 110 performs calibration measurements for one or more TRPs based on one or more SRS ports. Specifically, such as Figure 2 As shown, terminal device 110 performs 205 calibration measurements based on one or more SRS ports.

[0068] In one embodiment, terminal device 110 sends calibration measurement information for one or more TRPs to network device 120. Network device 120 then receives this calibration measurement information. Specifically, as... Figure 2 As shown, terminal device 110 sends calibration measurement information 207 to network device 120 (206). Network device 120 then receives the calibration measurement information 207 (208).

[0069] In some embodiments, network device 120 determines calibration coefficients based on information from calibration measurements and SRS measurements for one or more SRS ports associated with the calibration measurements. Specifically, such as Figure 2 As shown, network device 120 determines calibration coefficient 209 based on information from calibration measurements and SRS measurements.

[0070] The solution utilizing this process provides UE-assisted cross-TRP phase calibration for the uplink UL and downlink DL channels by leveraging multiple UE antennas mapped to the corresponding SRS ports, thereby improving CJT-related communication performance.

[0071] Figure 3 Another example illustrating a process for calibrating measurements and reporting according to some embodiments of this disclosure is shown. Figure 3 The document provides a detailed signaling workflow supporting the above solutions. For discussion purposes, procedure 300 will refer to... Figure 1A Described. Process 300 may involve, for example: Figure 1A The terminal device 110 and network device 120 are shown. It should be understood that although process 300 has... Figure 1A The process is described in the communication system 100A, but it can also be applied to other communication scenarios where different network devices are jointly deployed to provide corresponding service cells.

[0072] like Figure 3 As shown, in some embodiments, network device 120 triggers calibration measurement 301. Network device 120 then sends calibration report configuration and activation 303 to terminal device 110. Terminal device 110 receives calibration report configuration and activation 304. Then, terminal device 110 prepares for Tx using all SRS ports 305 and sends SRS 306 to network device 120 307. Network device 120 receives UL SRS measurement and estimates UL channels in each TRP 309. Network device 120 sends CSI-RS 311 to terminal device 110 310. Terminal device 110 receives CSI-RS 311 312.

[0073] In some embodiments, one or more SRS ports used for calibration measurements are available antenna ports of the terminal device 110. Specifically, such as Figure 3As shown, terminal device 110 uses all 313 SRS ports for calibration measurements. In this scenario, UL / DL multi-TRP calibration is triggered by enabling all antennas in terminal device 110 to participate in the calibration process. In this case, calibration is performed using DL (CSI-RS) and UL (SRS) information from all ports of terminal device 110. The signaling will only include the reference signal, the triggering of the calibration process, and the calibration amount to be reported.

[0074] In some embodiments, such as Figure 3 As shown, terminal device 110 sends calibration report information 315 to network device 120. Network device 120 receives calibration report information 315. Network device 120 calculates calibration coefficients based on the measurements in the calibration report and the UL SRS measurements.

[0075] Figure 4 Another example illustrating a process for calibrating measurements and reporting according to some embodiments of this disclosure is shown. Figure 4 The document provides a detailed signaling workflow supporting the above solutions. For discussion purposes, procedure 400 will refer to... Figure 1A The process 400 can involve, for example: Figure 1A The terminal device 110 and network device 120 are shown. It should be understood that although process 400 has... Figure 1A The process is described in the communication system 100A, but it can also be applied to other communication scenarios where different network devices are deployed together to provide their respective service cells.

[0076] In some embodiments, such as Figure 4 As shown, network device 120 triggers calibration measurement 401. Network device 120 then sends calibration report configuration and activation 403 to terminal device 110. Terminal device 110 receives calibration report configuration and activation 404. Then, terminal device 110 prepares for Tx using all SRS ports 405 and sends SRS 307 to network device 120. Network device 120 receives UL SRS measurement and estimates the UL channel in each TRP 409. Network device 120 sends CSI-RS 411 to terminal device 110. Terminal device 110 receives CSI-RS 411 412.

[0077] In some embodiments, the terminal device 110 associates one or more antenna ports with one or more SRS ports based on the quality of the signal received in the DL. Specifically, as Figure 4As shown, terminal device 110 selects the SRS ports for calibration measurements based at least on CSI-RS selection 413. In this scenario, calibration involves sensing all ports but with UE assistance, and then selecting a subset of SRS ports to participate in the calibration at the UE layer.

[0078] In some embodiments, the calibration measurement information sent to network device 120 includes information from one or more SRS ports. Specifically, such as Figure 4 As shown, terminal device 110 sends 414 information about the selection of the SRS port and calibration report information 415 to network device 120. In other words, additional signaling is required to report the SRS port index of terminal device 110 to network device 120, along with the corresponding calibration values.

[0079] In some embodiments, the information for one or more SRS ports includes one or more antenna port indices associated with those SRS ports. The terminal device 110 associates one or more antenna ports with one or more SRS ports based on the quality of the signal received in the DL. Specifically, assuming the number of selected TRPs used for reporting... If terminal device 110 is configured for use with respect to a reference CSI-RS signal... If each of the selected CSI-RS signals (port, resource, or resource set) reports a single phase offset measurement, then the terminal device 110 selects and indicates in the report the corresponding SRS port. Antenna port index ,in This refers to the number of antenna ports used for DL ​​CSI acquisition. For example, the selection of antenna ports for terminal equipment 110 used for measurement and reporting can be based on the RSRP measured on the received CSI-RS signal.

[0080] As another example, if terminal device 110 is configured to report multiple phase offset measurements, assuming that the phase offset is relative to a reference CSI-RS signal... Each of the selected CSI-RS signals (port, resource, or resource set), Then, terminal device 110 indicates the strongest [indicator] in the report. r The selection of each antenna port, and the measurements are mapped to the uplink control information (UCI) in ascending order of antenna port index.

[0081] In some embodiments, network device 110 receives calibration report information 416. The network device then calculates a calibration coefficient 417 based on the measurements from the calibration report and the UL SRS measurements. The UL SRS measurements are associated with the selected SRS port.

[0082] Figure 5 A flowchart illustrating another example of a process for calibrating measurements and reporting according to some embodiments of this disclosure is shown. Figure 5 The document provides a detailed signaling workflow supporting the above solutions. For discussion purposes, Procedure 500 will refer to... Figure 1A The process 500 may involve terminal device 110, network device 120, such as... Figure 1A As shown in the diagram. It should be understood that although process 500 has been... Figure 1A The process is described in the communication system 100A, but it is equally applicable to other communication scenarios where different network devices are deployed together to provide corresponding service cells.

[0083] In some embodiments, such as Figure 5 As shown, network device 120 triggers a 501 calibration measurement. In some embodiments, network device 120 sends an indication to terminal device 110 for one or more SRS ports for the calibration measurement. Figure 5 As shown, network device 120 sends a calibration report configuration and activation, along with an SRS port indication, to terminal device 110 at step 502. Terminal device 110 receives the calibration report configuration and activation, along with the SRS port indication, at step 504. Then, terminal device 110 prepares for Tx using a subset of SRS ports at step 505. In other words, network device 120 selects a subset of SRS ports from the outset and notifies terminal device 110. Therefore, terminal device 110 will only report calibration values ​​associated with the specific selected ports.

[0084] In some embodiments, the indication includes a bitmap of one or more instances for one or more SRS ports. Specifically, the indication of the terminal device 110 antenna port corresponding to the reported phase offset can be represented by a bitmap of size [missing information]. The bitmap is used for measurement. If measurements from all 110 antenna ports of all terminal devices are configured, this bitmap can be ignored. Note that the gNB can dynamically configure the number of measurements for each TRP. r For example, by triggering a CSI report with a desired value r in the triggered state. Dynamic configuration of the number of measurements for each TRP is useful because the gNB can determine, based on SRS measurements, how many terminal devices' 110 antenna ports have good signal strength, and r The configuration allows for a fixed payload size, thus eliminating the need for a variable-size portion 2 in the CSI report.

[0085] like Figure 5As shown, in some embodiments, terminal device 110 sends 506 SRS 507 to network device 120. Network device 120 receives UL SRS measurements and estimates 509 UL channels in each TRP. Network device 120 sends 510 CSI-RS 511 to terminal device 110. Terminal device 110 receives 512 CSI-RS 511. Terminal device 110 performs calibration measurements using 513 SRS port indication. Terminal device 110 sends 514 calibration report information 515 to network device 120. And network device 110 receives 516 calibration report information 515. The network device calculates 517 calibration coefficients based on the measurements from the calibration report and the UL SRS measurements. And the UL SRS measurements are associated with the indicated SRS port.

[0086] Figures 6A-6D Examples of UCI mappings for phase offset reporting according to some embodiments of this disclosure are shown. Figure 6A As shown, the UE reports for Individual phase offset measurements for each TRP in each configured TRP. And Figure 6A The report includes an indication of the UE antenna port corresponding to the measurement.

[0087] like Figure 6B As shown, the UE reports data from... In each configured TRP A single phase offset measurement of the selected TRP. And Figure 6A and Figure 6B The report includes an indication of the UE antenna port corresponding to the measurement. And... Figure 6B The report includes an indication of the UE antenna port corresponding to the measurement.

[0088] like Figure 6C As shown, the UE is configured to report against Each TRP in the configured TRP r Phase offset measurement. Figure 6C The report includes an indication of the selected UE antenna port (e.g., by using a bitmap), and measurements are reported in ascending order of antenna port index.

[0089] like Figure 6D As shown, the UE is configured to report data from... In each configured TRP The selected TRP r Phase offset measurement. Figure 6D The report includes an indication of the selected UE antenna port (e.g., by using a bitmap), and measurements are reported in ascending order of antenna port index.

[0090] In some embodiments, the calibration measurement information includes the phase difference between a first TRP and a reference TRP. Specifically, for UE-assisted phase compensation, a phase difference measurement is obtained between the two TRPs, wherein the phase difference measurement corresponds to a CSI-RS port and a UE antenna port on each of the two TRPs.

[0091] In some embodiments, the calibration measurement information includes multiple phase differences between a first TRP and a reference TRP. The network device then determines the final phase difference between the first TRP and the reference TRP based on these multiple phase differences. Specifically, this scenario is used to increase the number of estimated phase differences between two TRPs by using additional CSI-RS ports for each TRP and additional UE SRS ports. A measurement is used for each combination of CSI-RS ports and UE SRS ports. In an example configuration with two TRPs, two CSI-RS ports, and two SRS ports, four estimates of the cross-TRP phase difference between TRP 2 and TRP 1 are possible (one for each combination of CSI-RS ports and UE SRS ports). Extending to more than two TRPs and / or UEs with more than two antenna ports is straightforward. The UE is configured to transmit dual-port SRS from UE antenna 1 (which is SRS port 1) and UE antenna 2 (which is SRS port 2).

[0092] Specifically, the gNB performs the following channel estimations based on the SRS received on both TRPs (the channel estimation can be per RE, per subband, average across REs, etc.) (depending on the gNB implementation). M11 = Channel estimation for TRP 1 from SRS port 1 (received using RX beam 1 on TRP 1). M12 = Channel estimation for TRP 1 from SRS port 2 (received using RX beam 2 on TRP 1). M21 = Channel estimation for TRP 2 from SRS port 1 (received using RX beam 1 on TRP 2). M22 = Channel estimation for TRP 2 from SRS port 2 (received using RX beam 2 on TRP 2).

[0093] The gNB configures the UE to receive dual-port CSI-RS from TRP1 (reference TRP), including TRP1 CSI-RS port 1 (transmitted using TX beam 1 on TRP1) and TRP1 CSI-RS port 2 (transmitted using TX beam 2 on TRP1). The gNB also configures the UE to receive dual-port CSI-RS from TRP2, including TRP2 CSI-RS port 1 (transmitted using TX beam 1 on TRP2) and TRP2 CSI-RS port 2 (transmitted using TX beam 2 on TRP2). Furthermore, for each TRP, the RX beam j has the same weight vector as the TX beam j (the design of the TX and RX weight vectors is implemented by the gNB).

[0094] The UE performs measurements and is configured to provide reporting quantities 1-4 to the gNB. Reporting quantity 1 is the phase difference between TRP 2 CSI-RS port 1 and TRP 1 CSI-RS port 1 associated with SRS port 1. This is an estimate by the UE based on the phase difference between TRP2 and TRP1 from the CSI-RS ports 1 of the two TRPs, as received by the UE antenna port 1. Reporting quantity 2 is the phase difference between TRP 2 CSI-RS port 1 and TRP 1 CSI-RS port 1 associated with SRS port 2. This is an estimate by the UE based on the phase difference between TRP2 and TRP1 from the CSI-RS ports 1 of the two TRPs, as received by the UE antenna port 2. Reporting quantity 3 is the phase difference between TRP 2 CSI-RS port 2 and TRP 1 CSI-RS port 2 associated with SRS port 1. This is an estimate by the UE based on the phase difference between TRP2 and TRP1 from the CSI-RS ports 2 of the two TRPs, as received by the UE antenna port 1. Report quantity 4 is the phase difference between TRP 2 CSI-RS port 2 and TRP 1 CSI-RS port 2 associated with SRS port 2. This is an estimate of the UE's phase difference based on the phase difference between TRP2 and TRP1 on the two TRPs' CSI-RS ports 2, as received by the UE's antenna port 2. The gNB then uses M11…M22 and report quantities 1…4 to calculate the final estimate of the phase difference between the two TRPs. This final estimate is used to pre-compensate for any future CJT PDSCH transmissions involving these two TRPs.

[0095] Figure 7 Examples of multi-TRP calibration according to some embodiments of this disclosure are shown. Figure 7As shown, subsets of the four TRPs are measured by specific UEs served by those CJT subsets. 710 is a graph for TRP 1. 720 is a graph for TRP 2. 730 is a graph for TRP 3. 740 is a graph for TRP 4. In this example, single-port measurements for each TRP of each calibration subset within the calibration subset are selected. Without quantization constraints, the residual error is zero. However, as the quantization resolution is reduced, the percentage of UEs with errors becomes larger. In this example, it is determined that, for example, 4 bits provide very poor channel phase offset resolution, and values ​​greater than 6 bits or larger are needed to minimize this error.

[0096] In view of the above description of various embodiments of this disclosure, these embodiments of this disclosure take advantage of the following: by utilizing measurements from multi-antenna UEs to enable additional averaging and improved estimation performance, the performance of UE-assisted cross-TRP phase offset compensation techniques is improved, thereby improving communication performance related to CJT.

[0097] Figure 8 A flowchart of an example method 800 implemented at a terminal device according to some embodiments of the present disclosure is shown. For discussion purposes, method 800 will be referred to Figure 1A It is described from the perspective of terminal device 110.

[0098] At block 810, terminal device 110 receives configuration and activation from network device 120 for DL / UL calibration measurements for one or more TRPs in the CJT. At block 820, terminal device 110 determines one or more SRS ports for the calibration measurements. At block 830, terminal device 110 performs calibration measurements for one or more TRPs based on one or more SRS ports. At block 840, the terminal device sends information about the calibration measurements for one or more TRPs to network device 120.

[0099] In some embodiments, the calibration measurement information includes information about one or more SRS ports. In some embodiments, the information about one or more SRS ports includes one or more antenna port indices associated with one or more SRS ports. In some embodiments, terminal device 110 associates one or more antenna ports with one or more SRS ports based on the quality of the received signal in the DL. In some embodiments, terminal device determines one or more SRS ports for calibration measurements by receiving an indication of one or more SRS ports for calibration measurements from network device 120.

[0100] In some embodiments, the indication includes a bitmap that includes one or more instances for one or more SRS ports. In some embodiments, the one or more SRS ports are available antenna ports of a terminal device. In some embodiments, the calibration measurement information includes a phase difference between a first TRP and a reference TRP, the phase difference being determined based on a CSI-RS port of the first TRP, a CSI-RS port of the reference TRP, and an associated SRS port among the one or more SRS ports. In some embodiments, the calibration measurement information includes multiple phase differences between the first TRP and the reference TRP, the phase differences being determined based on multiple CSI-RS ports of the first TRP, multiple CSI-RS ports of the reference TRP, and multiple associated SRS ports, respectively.

[0101] Figure 9 A flowchart of an example method 900 implemented at a network device according to some embodiments of the present disclosure is shown. For discussion purposes, method 900 will refer to Figure 1A It is described from the perspective of network device 120.

[0102] At block 910, network device 120 sends configuration and activation for DL / UL calibration measurements for one or more TRPs in the CJT to terminal device 110. At block 920, network device 120 receives calibration measurement information from terminal device 110. At block 930, network device 120 determines calibration coefficients based on the calibration measurement information and SRS measurements for one or more SRS ports associated with the calibration measurements.

[0103] In some embodiments, the calibration measurement information includes information about one or more SRS ports. In some embodiments, the information about one or more SRS ports includes one or more antenna port indices. In some embodiments, network device 120 sends an indication of one or more SRS ports for calibration measurement to terminal device 110. In some embodiments, the indication is a bitmap that includes one or more instances for one or more SRS ports. In some embodiments, one or more SRS ports are determined based on the quality of the received probe signal.

[0104] In some embodiments, one or more SRS ports are available antenna ports of the terminal device. In some embodiments, the calibration measurement information includes the phase difference between a first TRP and a reference TRP. In some embodiments, the calibration measurement information includes multiple phase differences between the first TRP and the reference TRP. The network device determines the final phase difference between the first TRP and the reference TRP based on these multiple phase differences.

[0105] In some embodiments, an apparatus capable of performing any of the methods of method 800 (e.g., terminal device 110) may include components for performing the corresponding steps of method 800. These components may be implemented in any suitable form. For example, the components may be implemented in a circuit system or a software module.

[0106] In some embodiments, the apparatus includes: components for configuring and activating DL / UL calibration measurements for one or more TRPs in a CJT from a network device; components for determining one or more SRS ports for calibration measurements; components for performing calibration measurements for one or more TRPs based on one or more SRS ports; and components for transmitting information about the calibration measurements for one or more TRPs to the network device.

[0107] In some embodiments, the calibration measurement information includes information about one or more SRS ports. In some embodiments, the information about one or more SRS ports includes one or more antenna port indices associated with one or more SRS ports. In some embodiments, the apparatus includes: components for associating one or more antenna ports with one or more SRS ports based on the quality of the received signal in the DL. In some embodiments, the apparatus includes: components for determining one or more SRS ports for calibration measurements by receiving an indication of one or more SRS ports for calibration measurements from a network device.

[0108] In some embodiments, the indication includes a bitmap that includes one or more instances for one or more SRS ports. In some embodiments, the one or more SRS ports are available antenna ports of a terminal device. In some embodiments, the calibration measurement information includes a phase difference between a first TRP and a reference TRP, the phase difference being determined based on a CSI-RS port of the first TRP, a CSI-RS port of the reference TRP, and an associated SRS port among the one or more SRS ports. In some embodiments, the calibration measurement information includes multiple phase differences between the first TRP and the reference TRP, the phase differences being determined based on multiple CSI-RS ports of the first TRP, multiple CSI-RS ports of the reference TRP, and multiple associated SRS ports, respectively.

[0109] In some embodiments, an apparatus capable of performing any of the methods of method 900 (e.g., network device 120) may include components for performing the corresponding steps of method 900. These components may be implemented in any suitable form. For example, the components may be implemented in a circuit system or a software module.

[0110] In some embodiments, the apparatus includes: components for configuring and activating DL / UL calibration measurements for one or more TRPs in the CJT to a terminal device. The apparatus includes: components for receiving information about the calibration measurements from the terminal device 110. The apparatus includes: components for determining calibration coefficients based on the information about the calibration measurements and SRS measurements for one or more SRS ports associated with the calibration measurements.

[0111] In some embodiments, the calibration measurement information includes information about one or more SRS ports. In some embodiments, the information about one or more SRS ports includes one or more antenna port indices. In some embodiments, the apparatus includes components for transmitting an indication of one or more SRS ports for calibration measurements to a terminal device. In some embodiments, the indication is a bitmap that includes one or more instances for one or more SRS ports. In some embodiments, the one or more SRS ports are determined based on the quality of the received probe signal.

[0112] In some embodiments, one or more SRS ports are available antenna ports of the terminal device. In some embodiments, the calibration measurement information includes the phase difference between a first TRP and a reference TRP. In some embodiments, the calibration measurement information includes multiple phase differences between the first TRP and the reference TRP. The network device determines the final phase difference between the first TRP and the reference TRP based on these multiple phase differences.

[0113] Figure 10 This is a simplified block diagram of a device 1000 suitable for implementing embodiments of the present disclosure. Device 1000 can be provided to implement a communication device, such as... Figure 1A The terminal device 110 and network device 120 are shown. As shown, device 1000 includes one or more processors 1010, one or more memories 1020 coupled to processor 1010, and one or more communication modules 1040 coupled to processor 1010.

[0114] The communication module 1040 is used for bidirectional communication. The communication module 1040 has at least one antenna to facilitate communication. The communication interface can represent any interface required for communication with other network elements; for example, the communication interface can be wireless or wired to other network elements, or a software-based interface for communication.

[0115] Processor 1010 can be of any type suitable for a local technology network, and by way of non-limiting example, can include one or more of the following: general-purpose computer, special-purpose computer, microprocessor, digital signal processor (DSP), and processor based on a multi-core processor architecture. Device 1000 can have multiple processors, such as application-specific integrated circuit chips that are time-dependent on a clock synchronized with the main processor.

[0116] Memory 1020 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 1024, electrically programmable read-only memory (EPROM), flash memory, hard disk, optical disc (CD), digital video disc (DVD), and other magnetic and / or optical storage. Examples of volatile memories include, but are not limited to, random access memory (RAM) 1022 and other volatile memories that will not persist during power outages.

[0117] Computer program 1030 includes computer-executable instructions that are executed by the associated processor 1010. Program 1030 may be stored in ROM 1024. Processor 1010 may perform any suitable actions and processes by loading program 1030 into RAM 1022.

[0118] The embodiments of this disclosure can be implemented by a program, enabling device 1000 to execute any process of this disclosure, as referenced. Figure 1B , Figure 1C ,as well as Figures 2 to 9 The embodiments of this disclosure can also be implemented in hardware or by a combination of software and hardware.

[0119] In some embodiments, program 1030 may be tangibly contained in a computer-readable medium, which may be included in device 1000 (e.g., in memory 1020) or in other storage devices accessible by device 1000. Device 1000 may load program 1030 from the computer-readable medium into RAM 1022 for execution. The computer-readable medium may include any type of tangible non-volatile memory, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. Figure 11 An example of a computer-readable medium 1100 in the form of a CD or DVD is shown. A program 1030 is stored on the computer-readable medium.

[0120] Generally, the various embodiments of this disclosure can be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while others may be implemented in firmware or software, which may be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of this disclosure are shown and described as block diagrams, flowcharts, or using some other graphical representation, it should be understood that, as non-limiting examples, the blocks, apparatuses, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0121] This disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions (such as those included in program modules) that are executed in a device on a target real or virtual processor to perform the functions described above. Figures 8-9 The methods described are 800-900. Typically, a program module includes routines, programs, libraries, objects, classes, components, data structures, etc., that perform specific tasks or implement specific abstract data types. The functionality of a program module can be combined or split among program modules as needed in various embodiments. The machine-executable instructions used for a program module can be executed on a local or distributed device. In a distributed device, a program module can reside on both local and remote storage media.

[0122] Program code used to perform the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a stand-alone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0123] In the context of this disclosure, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations described above. Examples of carriers include signals, computer-readable media, etc.

[0124] Computer-readable media can be computer-readable signal media or computer-readable storage media. Computer-readable media can include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any suitable combination thereof. More specific examples of computer-readable storage media will include electrical connections having one or more lines, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable optical disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. As used herein, the term “non-transient” is a limitation of the medium itself (i.e., tangible, not signaling), not a limitation of the persistence of data storage (e.g., RAM and ROM).

[0125] Furthermore, although the operations are described in a specific order, this should not be construed as requiring that these operations must be performed in the specific order or sequence shown, or that all of the operations shown must be performed to achieve the desired result. In some cases, multitasking and parallel processing may be more advantageous. Similarly, while several specific implementation details are included in the foregoing discussion, these implementation details should not be considered as limiting the scope of this disclosure, but rather as a description of features that may be specific to a particular embodiment. Certain features described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented separately or in any suitable sub-combination in multiple embodiments.

[0126] Although this disclosure has been described in language specific to structural features and / or methodological actions, it should be understood that this disclosure as defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are disclosed as examples of implementing the claims.

Claims

1. A terminal device, comprising: At least one processor; as well as At least one memory storing instructions that, when executed by the at least one processor, cause the terminal device to at least: Receive configuration and activation from network devices for downlink (DL) / uplink (UL) calibration measurements for one or more transmit / receive points (TRPs) in Coherent Joint Transmission (CJT); Identify one or more probe reference signal (SRS) ports for the calibration measurements; Based on the one or more SRS ports, perform the calibration measurements for the one or more TRPs; as well as Send the calibration measurement information of the one or more TRPs to the network device.

2. The terminal device according to claim 1, wherein the information of the calibration measurement includes information of the one or more SRS ports.

3. The terminal device according to claim 2, wherein the information of the one or more SRS ports includes one or more antenna port indices associated with the one or more SRS ports.

4. The terminal device according to any one of claims 1-3, wherein the terminal device is further configured to: Based on the quality of the received signal in the DL, one or more antenna ports are associated with the one or more SRS ports.

5. The terminal device of claim 1, wherein the terminal device is configured to determine the one or more SRS ports for the calibration measurement by: Receive indications from the network device for the calibration measurements from one or more SRS ports.

6. The terminal device of claim 5, wherein the indication includes a bitmap, the bitmap including one or more instances for the one or more SRS ports.

7. The terminal device according to claim 1, wherein the one or more SRS ports are available antenna ports of the terminal device.

8. The terminal device according to any one of claims 1-7, wherein the information of the calibration measurement includes a phase difference between a first TRP and a reference TRP, the phase difference being determined based on a port of the channel state information reference signal (CSI-RS) of the first TRP, a port of the CSI-RS of the reference TRP, and an associated SRS port of one or more SRS ports.

9. The terminal device according to any one of claims 1-8, wherein the information of the calibration measurement includes a plurality of phase differences between the first TRP and the reference TRP, the phase differences being determined based on a plurality of CSI-RS ports of the first TRP, a plurality of CSI-RS ports of the reference TRP, and a plurality of associated SRS ports.

10. A network device, comprising: At least one processor; as well as At least one memory storing instructions that, when executed by the at least one processor, cause the network device to at least: Send the configuration and activation of downlink (DL) / uplink (UL) calibration measurements for one or more transmit / receive points (TRPs) in Coherent Joint Transmission (CJT) to the terminal device; Receive the calibration measurement information from the terminal device; as well as Based on the information from the calibration measurement and the SRS measurements for one or more probe reference signal (SRS) ports associated with the calibration measurement, the calibration coefficients are determined.

11. The network device of claim 10, wherein the information of the calibration measurement includes information of the one or more SRS ports.

12. The network device of claim 11, wherein the information of the one or more SRS ports includes one or more antenna port indices.

13. The network device of claim 10, wherein the network device is further configured to: Send an indication to the terminal device of the one or more SRS ports for the calibration measurement.

14. The network device of claim 13, wherein the indication is a bitmap, the bitmap comprising one or more instances for the one or more SRS ports.

15. The network device of claim 13 or 14, wherein the one or more SRS ports are determined based on the quality of the received probe signals.

16. The network device of claim 10, wherein the one or more SRS ports are available antenna ports of the terminal device.

17. The network device according to any one of claims 10 to 16, wherein the information of the calibration measurement includes the phase difference between the first TRP and the reference TRP.

18. The network device according to any one of claims 10-17, wherein the information of the calibration measurement includes a plurality of phase differences between the first TRP and the reference TRP, and the network device is further configured such that: Based on the multiple phase differences, the final phase difference between the first TRP and the reference TRP is determined.

19. A method comprising: Receive configuration and activation from network devices for downlink (DL) / uplink (UL) calibration measurements for one or more transmit / receive points (TRPs) in Coherent Joint Transmission (CJT); Identify one or more probe reference signal (SRS) ports for the calibration measurements; Based on the one or more SRS ports, perform the calibration measurements for the one or more TRPs; as well as Send the calibration measurement information of the one or more TRPs to the network device.

20. A method comprising: Send the configuration and activation of downlink (DL) / uplink (UL) calibration measurements for one or more transmit / receive points (TRPs) in Coherent Joint Transmission (CJT) to the terminal device; Receive the calibration measurement information from the terminal device; as well as Based on the information from the calibration measurement and the SRS measurements for one or more probe reference signal (SRS) ports associated with the calibration measurement, the calibration coefficients are determined.

21. An apparatus comprising: A component for configuring and activating downlink (DL) / uplink (UL) calibration measurements for one or more transmit / receive points (TRPs) in Coherent Joint Transmission (CJT) from network devices; Components for determining one or more probe reference signal (SRS) ports used for the calibration measurement; A component for performing the calibration measurements for the one or more TRPs based on the one or more SRS ports; as well as A component for sending information about the calibration measurements of the one or more TRPs to the network device.

22. An apparatus comprising: Components for configuring and activating downlink (DL) / uplink (UL) calibration measurements for one or more transmit / receive points (TRPs) in Coherent Joint Transmission (CJT) to terminal devices; Components for receiving information about the calibration measurement from the terminal device; as well as A component for determining calibration coefficients based on the information from the calibration measurement and SRS measurements for one or more probe reference signal (SRS) ports associated with the calibration measurement.

23. A non-transitory computer-readable medium comprising program instructions that, when executed by a device, cause the device to perform at least the method according to claim 19 or 20.

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