Dynamic codebooks for active coordination sets

Patent metadata

Field	Value
Publication number	US-12483301-B2
Application number	US-202118264203-A
Country	US
Kind code	B2
Filing date	Feb 24, 2021
Priority date	Feb 24, 2021
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

This document describes methods, devices, systems, and means for determining a joint-codebook for wireless communication with a user equipment, UE, by a base station in an active coordination set, ACS, in which a base station receives capability information from one or more other base stations in the ACS. The base station generates a joint-codebook for the ACS based on the received capability information and sends the joint-codebook to the one or more other base stations in the ACS. The base station and the other base stations in the ACS jointly-transmit the joint-codebook to the UE and receive Precoding Matrix Indicator, PMI, feedback from the UE. The base station and the other base stations in the ACS jointly-process downlink data for the UE using the PMI feedback and the joint-codebook and jointly-transmit the downlink data to the UE.

First claim

What is claimed is:

1 . A method for determining a joint-codebook for wireless communication with a user equipment (UE) by a base station in an active coordination set (ACS) the method comprising the base station:
receiving capability information from one or more other base stations in the ACS; generating a joint-codebook for the ACS based on the received capability information; sending the joint-codebook to the one or more other base stations in the ACS; jointly-transmitting the joint-codebook to the UE; receiving Precoding Matrix Indicator (PMI) feedback from the UE; jointly-processing downlink data for the UE using the PMI feedback and the joint-codebook; and jointly-transmitting the downlink data to the UE.

2 . The method of claim 1 , wherein the receiving the capability information from one or more other base stations in the ACS comprises:
receiving a phase coherence capability from at least one of the one or more other base stations in the ACS.

3 . The method of claim 2 , further comprising the base station:
determining that the base station and the one or more other base stations in the ACS share a common phase coherence capability; and wherein the generating a joint-codebook for the ACS comprises: generating a set of precoding matrices that are common to the base station and the one or more other base stations in the ACS.

4 . The method of claim 2 , further comprising the base station:
determining that the base station and the one or more other base stations in the ACS have different phase coherence capabilities; and wherein the generating a joint-codebook for the ACS comprises: generating a first set of precoding matrices for a first subset of the base stations in the ACS that have a first phase coherence capability; generating a second set of precoding matrices for a second subset of the base stations in the ACS that have a second phase coherence capability; and including the first set of precoding matrices and the second set of precoding matrices in the joint-codebook for the ACS.

5 . The method of claim 4 , wherein the ACS includes the base station and multiple other base stations, the method further comprising the base station:
scheduling the first subset of the base stations in the ACS to transmit downlink data to the UE in a first timeslot using the first set of precoding matrices; and scheduling the second subset of the base stations in the ACS to transmit the downlink data to the UE in a second timeslot using second set of precoding matrices.

6 . The method of claim 2 , wherein the phase coherence capability indicates a source of a phase reference, and wherein the source of the phase reference includes a Global Navigation Satellite System (GNSS), IEEE 1588 Precision Time Protocol (PTP), or Synchronous Ethernet (SyncE).

7 . The method of claim 1 , wherein the receiving the capability information from one or more other base stations in the ACS comprises:
receiving an antenna configuration from at least one of the one or more other base stations in the ACS.

8 . The method of claim 7 , wherein the antenna configuration includes one or more of:
a number of antenna ports; a number of antenna panels; a number of beams for each row of antenna elements used for azimuth beamforming; or a number of beams for each column of the antenna elements used for elevation beamforming.

9 . The method of claim 1 , wherein the jointly-transmitting the joint-codebook to the UE comprises:
jointly transmitting a Channel State Information-Reference Signal (CSI-RS) configuration with the joint codebook.

10 . The method of claim 1 , further comprising the base station:
jointly-transmitting a start-time indication to the UE to direct the UE to begin using the joint-codebook at the indicated start-time.

11 . The method of claim 10 , wherein the jointly-transmitting a start-time indication to the UE directs the UE to measure a CSI-RS to generate the PMI feedback.

12 . The method of claim 1 , wherein the jointly-transmitting the joint-codebook to the UE comprises:
jointly-transmitting the joint-codebook to the UE using Radio Resource Control (RRC) messages or jointly-transmitting the joint-codebook to the UE using Non-Access Stratum (NAS) messages.

13 . The method of claim 1 , wherein the sending the joint-codebook to the one or more other base stations in the ACS comprises:
sending the joint-codebook to the one or more other base stations in the ACS using an Xn interface.

14 . The method of claim 1 , further comprising the base station:
sending PMI feedback results to the one or more other base stations in the ACS using an Xn interface.

15 . The method of claim 1 , further comprising the base station:
sending the downlink data to the one or more other base stations in the ACS using an Xn interface.

16 . The method of claim 1 , further comprising the base station:
receiving an updated PMI indication from the UE; and sending the updated PMI indication to the one or more other base stations in the ACS using an Xn interface.

17 . The method of claim 1 , further comprising the base station:
receiving a request for an updated joint-codebook from the UE; generating an updated joint-codebook for the base stations in the ACS; sending the updated joint-codebook to the base stations in the ACS; and jointly-transmitting the updated joint-codebook to the UE.

18 . The method of claim 1 , wherein based on a change to the base stations included in the ACS, the method further comprising the base station:
generating a revised joint-codebook for an updated set of base stations in the ACS; sending the revised joint-codebook to the updated set of base stations in the ACS; and jointly-transmitting the revised joint-codebook to the UE.

19 . A base station comprising:
a wireless transceiver; a processor; and instructions for a base station manager that are executable by the processor to configure the base station to:
receive capability information from one or more other base stations in an active coordination set (ACS);
generate a joint-codebook for the ACS based on the received capability information;
send the joint-codebook to the one or more other base stations in the ACS;
jointly-transmit the joint-codebook to a user equipment (UE);
receive Precoding Matrix Indicator (PMI) feedback from the UE;
jointly-process downlink data for the UE using the PMI feedback and the joint-codebook; and
jointly-transmit the downlink data to the UE.

20 . The base station of claim 19 , wherein the instruction to receive the capability information from one or more other base stations in the ACS are executable by the processor to configure the base station to:
receive a phase coherence capability from at least one of the one or more other base stations in the ACS.

Assignees

• Google Llc

Inventors

• Wang Jibing
• Stauffer Erik Richard

Classifications

• H04L25/03904

  cooperative design, e.g. exchanging of codebook information between base stations · CPC title

• H04B7/0639

  Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection · CPC title

• H04B7/0626

  Channel coefficients, e.g. channel state information [CSI] · CPC title

• H04B7/0456 Primary

  Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting · CPC title

• H04B7/024 Primary

  Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems · CPC title