Method and Apparatus for Non-Codebook Based Uplink Multiple-Input and Multiple-Output

Patent metadata

Field	Value
Publication number	US-2018367205-A1
Application number	US-201715821338-A
Country	US
Kind code	A1
Filing date	Nov 22, 2017
Priority date	Jun 16, 2017
Publication date	Dec 20, 2018
Grant date	—

Abstract

A method and an apparatus for selecting beams for non-codebook based uplink multiple-input and multiple-output are disclosed. In an embodiment, a method implemented by a user equipment (UE) includes receiving an allocation of at least one sounding reference signal (SRS) resource in an uplink subframe from a transmission and reception point (TRP) for a first set of uplink transmission beams, transmitting precoded SRSs in the at least one SRS resource to the TRP, wherein the precoded SRSs are precoded with UE-selected precoders and at least one rank and receiving an identification of two or more precoders for a second set of uplink transmission beams, wherein the second set of uplink transmission beams is selected from the first set of uplink transmission beams, and wherein the two or more precoders are based on the precoded SRSs.

First claim

What is claimed is:

1 . A method implemented by a user equipment (UE), the method comprising:
receiving an allocation of at least one sounding reference signal (SRS) resource in an uplink subframe from a transmission and reception point (TRP) for a first set of uplink transmission beams; transmitting precoded SRSs in the at least one SRS resource to the TRP, wherein the precoded SRSs are precoded with UE-selected precoders and at least one rank; and receiving an identification of two or more precoders for a second set of uplink transmission beams, wherein the second set of uplink transmission beams is selected from the first set of uplink transmission beams, and wherein the two or more precoders are based on the precoded SRSs.

2 . The method of claim 1 , wherein the at least one SRS resource is a single SRS resource comprising a plurality of antenna ports corresponding to the uplink transmission beams.

3 . The method of claim 1 , wherein the at least one SRS resource comprises at least one SRS resource for each uplink transmission beam, and wherein the at least one SRS resource includes at least one antenna port.

4 . The method of claim 1 , wherein the at least one SRS resource comprises a plurality of SRS resources for each uplink transmission beam, and wherein each SRS resource has at least one SRS antenna port.

5 . The method of claim 1 , wherein transmitting the precoded SRSs comprises transmitting the precoded SRSs with a UE-selected single rank, and wherein the single rank is determined by the UE over all selected uplink transmission beams.

6 . The method of claim 1 , wherein transmitting the precoded SRSs comprises transmitting the precoded SRSs with a plurality of UE-selected ranks.

7 . The method of claim 1 , wherein the first set of uplink transmission beams is selected from a third set of uplink transmission beams reported to the TRP by the UE.

8 . The method of claim 1 , wherein a precoder and a rank for each uplink transmission beam are determined based on downlink channel estimation and channel reciprocity.

9 . The method of claim 1 , further comprising receiving co-phasing between selected antenna ports from the TRP.

10 . A method implement by a transmission and reception point (TRP), the method comprising:
sending an allocation of at least one sounding reference signal (SRS) resource in a uplink subframe to a user equipment (UE) for a first set of uplink transmission beams; receiving precoded SRSs sent in the at least one SRS resource, wherein the precoded SRSs are precoded with UE selected precoders and at least one rank; and sending an identification of two or more precoders for a second set of uplink transmission beams to the UE, wherein the second set of uplink transmission beams is selected from the first set of uplink transmission beams, and wherein the two or more precoders for the uplink transmission beams are based on the precoded SRSs.

11 . The method of claim 10 , wherein the at least one SRS resource is a single SRS resource comprising a plurality of antenna ports corresponding to the uplink transmission beams.

12 . The method of claim 10 , wherein the at least one SRS resource comprises at least one SRS resource for each uplink transmission beam, and wherein the at least one SRS resource includes at least one antenna port.

13 . The method of claim 10 , wherein the at least one SRS resource comprises a plurality of SRS resources for each uplink transmission beam, and wherein each SRS resource has at least one SRS antenna port.

14 . The method of claim 10 , wherein receiving the SRSs comprises receiving the SRSs with a single UE-selected rank, and wherein the single rank is determined by the UE over all selected UL transmission beams.

15 . The method of claim 10 , wherein receiving the SRSs comprises receiving the SRSs with a plurality of UE-selected selected ranks.

16 . The method of claim 10 , wherein the first set of uplink transmission beams is selected from a third set of uplink transmission beams reported to the TRP by the UE.

17 . The method of claim 10 , wherein a precoder and a rank for each selected uplink transmission beam is based on downlink channel estimation and channel reciprocity.

18 . The method of claim 10 , further comprising sending co-phasing between selected antenna ports from the TRP.

19 . A user equipment (UE) comprising:
a processor; and a computer readable storage medium storing programming for execution by the processor, the programming including instructions to: receive an allocation of at least one sounding reference signal (SRS) resource in an uplink subframe from a transmission and reception point (TRP) for a first set of uplink transmission beams; transmit precoded SRSs in the at least one SRS resource to the TRP, wherein the precoded SRSs are precoded with UE-selected precoders and at least one rank; and receive an identification of two or more precoders for a second set of uplink transmission beams, wherein the second set of uplink transmission beams is selected from the first set of uplink transmission beams, and wherein the two or more precoders are based on the precoded SRSs.

20 . A transmission and reception point (TRP) comprising:
a processor; and a computer readable storage medium storing programming for execution by the processor, the programming including instructions to: send an allocation of at least one sounding reference signal (SRS) resource in a uplink subframe to a user equipment (UE) for a first set of uplink transmission beams; receive precoded SRSs sent in the at least one SRS resource, wherein the precoded SRSs are precoded with UE selected precoders and at least one rank; and send an identification of two or more precoders for a second set of uplink transmission beams to the UE, wherein the second set of uplink transmission beams is selected from the first set of uplink transmission beams, and wherein the two or more precoders for the uplink transmission beams are based on the precoded SRSs.

Assignees

• Futurewei Technologies Inc

Inventors

• Liu Bin
• Xia Pengfei
• Stirling-Gallacher Richard

Classifications

• H04W24/10

  Scheduling measurement reports {; Arrangements for measurement reports} · CPC title

• H04W72/046

  the resource being in the space domain, e.g. beams · CPC title

• H04W72/563

  of the wireless resources · CPC title

• H04L5/0048

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title

• H04B7/0486

  taking channel rank into account · CPC title