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CN-121986446-A - Apparatus and method for MIMO communication in a mobile network

CN121986446ACN 121986446 ACN121986446 ACN 121986446ACN-121986446-A

Abstract

The present disclosure relates to a user equipment, UE, (110) for communicating with a base station, BS, (120) over a channel (130). The UE (110) is configured to send a reciprocity indicator to the BS (120) informing the BS (120) whether the communication between the UE (110) and the BS (120) over the channel (130) satisfies reciprocity. Further, a BS (120) for communicating with a UE (110) over a channel (130) is disclosed. The BS (120) is configured to send a reciprocity indicator to the UE (110) informing the UE (110) whether the communication between the BS (120) and the UE (110) over the channel (130) satisfies reciprocity.

Inventors

  • Tobias Christian Las
  • REN XIANG
  • Ronaldo Burnke
  • MARTIN SCHUBERT
  • XU WEN

Assignees

  • 华为技术有限公司

Dates

Publication Date
20260505
Application Date
20231012

Claims (20)

  1. 1. A user equipment, UE, (110) for communicating with a base station, BS, (120) over a channel (130), the UE (110) being configured to: -sending a reciprocity indicator to the BS (120) informing the BS (120) whether the communication between the UE (110) and the BS (120) over the channel (130) satisfies reciprocity.
  2. 2. The UE (110) of claim 1, wherein the UE (110) is configured to determine whether the communication between the UE (110) and the BS (120) over the channel (130) satisfies reciprocity.
  3. 3. The UE (110) according to claim 1 or 2, wherein the UE (110) comprises a UE antenna array (112) having a plurality of UE antenna elements and a plurality of radio frequency, RF, chains (113) for operating in a MIMO communication mode with the BS (120), wherein the UE antenna array (112) and the plurality of RF chains (113) define a plurality of UE antenna coupling coefficients (300 a), the UE (110) being configured to further send a capability indicator to the BS (120), the capability indicator indicating whether the UE (110) supports reporting the plurality of UE antenna coupling coefficients (300 a) to the BS (120).
  4. 4. A UE (110) according to claim 3, characterized in that the UE (110) is adapted to operate with the BS (120) in a super gain MIMO communication mode, wherein in the super gain MIMO communication mode the coupling between the UE antenna elements of the UE antenna array (112) achieves an array gain that is larger than the number of UE antenna elements.
  5. 5. The UE (110) according to claim 3 or 4, wherein the UE (110) is configured to determine whether the communication between the UE (110) and the BS (120) over the channel (130) satisfies reciprocity based on the plurality of UE antenna coupling coefficients (300 a).
  6. 6. The UE (110) according to any of claims 3 to 5, wherein the plurality of UE antenna coupling coefficients (300 a) are defined by the plurality of UE antenna arrays and the plurality of RF chains (113) of the UE antenna array (112) or the plurality of UE antenna coupling coefficients (300 a) are defined by a plurality of UE antenna ports of the UE antenna array (112) each feeding one or more UE antenna arrays of the UE antenna array (112) and the plurality of RF chains (113).
  7. 7. The UE (110) according to any of claims 3 to 6, wherein the UE (110) is configured to receive a plurality of BS antenna coupling coefficients (300 b) from the BS (120), wherein the plurality of BS antenna coupling coefficients (300 b) are defined by a BS antenna array (122) of the BS (120) having a plurality of BS antenna elements and a plurality of RF chains (123) of the BS (120) for operating in a MIMO communication mode with the UE (110).
  8. 8. The UE (110) of claim 7, wherein for uplink communication with the BS (120), the UE (110) is configured to determine a precoder based on a downlink channel (130 a) between the BS (120) and the UE (110), the plurality of UE antenna coupling coefficients (300 a), and the plurality of BS antenna coupling coefficients (300 b).
  9. 9. The UE (110) according to claim 8, wherein the UE (110) is configured to receive a reference signal from the BS (120) and to estimate the downlink channel (130 a) between the BS (120) and the UE (110) based on the reference signal.
  10. 10. The UE (110) according to any of claims 3 to 9, wherein the UE (110) is configured to transmit the plurality of UE antenna coupling coefficients (300 a) to the BS (120).
  11. 11. The UE (110) according to claim 10, wherein the UE (110) is configured to send a reference signal to the BS (120).
  12. 12. The UE (110) according to any of the preceding claims, wherein the UE (110) is configured to send a further capability indicator to the BS (120), wherein the further capability indicator indicates whether the UE (110) supports reporting the reciprocity indicator to the BS (120).
  13. 13. A method (500) for operating a user equipment, UE, (110) to communicate with a base station, BS, (120) on a channel (130), characterized in that the method (500) comprises sending (501) a reciprocity indicator to the BS (120) informing the BS (120) whether the communication between the UE (110) and the BS (120) on the channel (130) satisfies reciprocity.
  14. 14. A base station, BS, (120) for communicating with a user equipment, UE, (110) over a channel (130), the BS (120) being configured to: -sending a reciprocity indicator to the UE (110) informing the UE (110) whether the communication between the BS (120) and the UE (110) over the channel (130) satisfies reciprocity.
  15. 15. The BS (120) of claim 14, wherein the BS (120) is configured to determine whether the communication between the BS (120) and the UE (110) over the channel (130) satisfies reciprocity.
  16. 16. The BS (120) of claim 14 or 15, wherein the BS (120) comprises a BS antenna array (122) having a plurality of BS antenna arrays and a plurality of radio frequency, RF, chains (123) for operating in a MIMO communication mode with the UE (110), wherein the BS antenna array (122) and the plurality of RF chains (123) define a plurality of BS antenna coupling coefficients (300 b), the BS (120) being configured to further transmit a capability indicator to the UE (110), the capability indicator indicating whether the BS (120) supports reporting the plurality of BS antenna coupling coefficients (300 b) to the UE (110).
  17. 17. The BS (120) of claim 16, wherein the BS (120) is configured to operate with the UE (110) in a super-gain MIMO communication mode, wherein in the super-gain MIMO communication mode, coupling between the BS antenna elements of the BS antenna array (122) achieves an array gain that is greater than a number of the BS antenna elements.
  18. 18. The BS (120) according to claim 16 or 17, wherein the BS (120) is configured to determine whether the communication between the BS (120) and the UE (110) over the channel (130) satisfies reciprocity based on the plurality of BS antenna coupling coefficients (300 b).
  19. 19. The BS (120) of any of claims 16 to 18, wherein the plurality of BS antenna coupling coefficients (300 b) are defined by the plurality of BS antenna elements and the plurality of RF chains (123) of the BS antenna array (122), or wherein the BS antenna coupling coefficients (300 b) are defined by a plurality of BS antenna ports and the plurality of RF chains (123) of the BS antenna array (122), each BS antenna port feeding one or more BS antenna elements of the BS antenna array (122).
  20. 20. The BS (120) of any of claims 16 to 19, wherein the BS (120) is configured to receive a plurality of UE antenna coupling coefficients (300 a) from the UE (110), wherein the plurality of UE antenna coupling coefficients (300 a) are defined by a UE antenna array (112) of the UE (110) having a plurality of UE antenna elements and a plurality of RF chains (113) of the UE (110) for operation in a MIMO communication mode with the BS (120).

Description

Apparatus and method for MIMO communication in a mobile network Technical Field The present disclosure relates to wireless communications. More particularly, the present disclosure relates to an apparatus and method for multiple-input multiple-output, MIMO, communication in a mobile network. Background Multiple Input Multiple Output (MIMO) is a technology for wireless communication that uses multiple antennas (typically implemented in the form of an antenna array) at the transmitting and/or receiving end. The signals of the antennas at each end of the communication path may be combined to minimize errors and/or optimize the data rate of the wireless transmission by enabling data to be transmitted on many signal paths simultaneously and to achieve beamforming. In current 5G antenna arrays, the distance between individual antenna elements of the antenna array is typically greater than half the operating wavelength of the antenna array. For future communication systems, such as 6G communication systems, it has been proposed to achieve super-gain by optimizing the spacing between antenna elements of an antenna array, and using mutual coupling between antenna elements of an antenna array to achieve better MIMO performance for the antenna array, especially when the antenna element distance is less than half the operating wavelength of the antenna array. Disclosure of Invention It is an object of the present disclosure to provide improved apparatus and methods for MIMO communication in a mobile network. The above object and other objects are achieved by the subject matter of independent claims. Other implementations are apparent from the dependent claims, the description and the drawings. According to a first aspect, a user equipment, UE, for communicating with a base station, BS, over a channel in a cellular communication network is provided. The UE is configured to send a reciprocity indicator to the BS informing the BS whether the communication between the UE and the BS over the channel currently satisfies reciprocity, i.e., time division duplex, TDD, reciprocity. In one implementation, the reciprocity indicator may be a reciprocity flag bit. Thus, the UE according to the first aspect provides information to the BS, enabling the BS to optimize its communication with the UE according to the reciprocity indicator, thereby achieving better system performance. More specifically, based on the reciprocity indicator received from the UE, the BS for communicating with the UE may efficiently determine and use the downlink channel based on the uplink channel (e.g., the BS estimates by measuring the reference signal from the UE) to determine the improved precoder. In another possible implementation, the UE is configured to determine whether the communication between the UE and the BS over the channel currently satisfies reciprocity. Thus, in one implementation, the UE itself may be used to determine whether the communication channel satisfies reciprocity. In one implementation, the UE may include a measurement device to adaptively determine whether the non-reciprocity is strong enough to indicate the non-reciprocity. In another possible implementation, the UE includes a UE antenna array having a plurality of UE antenna elements and a plurality of radio frequency, RF, chains for operating in a MIMO communication mode with the BS, wherein the UE antenna array and the plurality of RF chains define a plurality of UE antenna coupling coefficients (which may include a plurality of UE antenna noise coupling coefficients and a plurality of UE antenna power coupling coefficients), i.e., are associated with a plurality of UE antenna coupling coefficients, the UE is configured to further send a capability indicator to the BS, the capability indicator indicating whether the UE supports reporting (i.e., is configured to report) the plurality of UE antenna coupling coefficients to the BS. In one implementation, the capability indicator may be a capability flag bit. Thus, the UE according to the first aspect may inform the BS whether the UE is able to report multiple UE antenna coupling coefficients to the BS. In another possible implementation, the UE is configured to operate with the BS in a super-gain MIMO communication mode, wherein in the super-gain MIMO communication mode, coupling between the UE antenna elements of the UE antenna array achieves an array gain greater than a number of UE antenna elements, i.e., greater than an array gain achievable by decoupling between a plurality of UE antenna elements. In another possible implementation, the UE is configured to determine whether the communication between the UE and the BS over the channel currently satisfies reciprocity based on the plurality of UE antenna coupling coefficients. In one implementation, the UE may be configured to compare the plurality of UE antenna coupling coefficients to one or more thresholds and determine whether the communication between the UE and the BS ov