Joint transmission of precoded and unprecoded sounding reference signals in uplink

• US 10,469,224 B2
• Filed: 08/29/2017
• Issued: 11/05/2019
• Est. Priority Date: 09/30/2016
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Huang, Yi, Zeng, Wei, Chen, Wanshi, Xu, Hao, Ji, Tingfang
• Primary Examiner(s): Nguyen, David Q
• Application Number:
  US15/689,476
• Publication Number:
  US 20180097595A1
• Time in Patent Office: 798 Days
• Field of Search: 370329, 370336, 370252
• CPC Class Codes: H04B 7/0404 the mobile station comprising multiple antennas, e.g. to provide uplink diversity
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0615 of weighted versions of same signal
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0051 of dedicated pilots, i.e. pilots destined for a single user or terminal
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Both precoded sounding reference signals (SRS) and unprecoded SRS are transmitted from a UE to an eNB. The UE may transmit both in the same subframe using either TDM or FDM. Or the UE may transmit each in different subframes from each other. The eNB uses some combination of the precoded SRS and the unprecoded SRS in scheduling resources for the UE. The eNB may also provide instruction to the UE for PUSCH precoding for data transmission. The eNB may signal the UE to use the same precoding as for the precoded SRS. The eNB may instead signal the UE to use different precoding by including the precoding information or delta information between the precoding used for the precoded SRS and the selected precoding for the PUSCH data.

Claims

1. A method, comprising:

generating, by a first wireless communications device, a precoded sounding reference signal (SRS);

generating, by the first wireless communications device, an unprecoded SRS separate from the precoded SRS;

transmitting, by the first wireless communications device, the precoded SRS and the unprecoded SRS to a second wireless communications device via an uplink channel; and

receiving, by the first wireless communications device, a resource scheduling message based on the precoded SRS and the unprecoded SRS from the second wireless communications device.

2. The method of claim 1, wherein:

the precoded SRS and the unprecoded SRS are configured for resource scheduling by the second wireless communications device, and

the generating the precoded sounding reference signal is based on a downlink reference signal received from the second wireless communications device.

3. The method of claim 1, wherein the transmitting further comprises:

transmitting the precoded SRS during a first symbol period of a subframe and transmitting the unprecoded SRS during a second symbol period of the subframe.

4. The method of claim 1, wherein the transmitting further comprises:

transmitting the precoded SRS during a symbol period of a subframe using a first plurality of frequency resources, and transmitting the unprecoded SRS during the symbol period of the subframe using a second plurality of frequency resources.

5. The method of claim 1, wherein the transmitting further comprises:

transmitting the precoded SRS during a first subframe and transmitting the unprecoded SRS during a second subframe after the first subframe.

6. The method of claim 1, wherein the resource scheduling message comprises a precode instruction from the second wireless communications device.

7. The method of claim 6, wherein the precode instruction directs the first wireless communications device to apply a precoding used for the precoded SRS for data transmission.

8. The method of claim 6, wherein the precode instruction identifies a precoding for data transmission to apply by the first wireless communications device.

9. The method of claim 6, wherein the precode instruction identifies a delta between a desired precoding and an existing precoding used for the precoded SRS, the method further comprising:

deriving, by the first wireless communications device, a data precoding for data transmission from a combination of the delta and the existing precoding; and

applying, by the first wireless communications device, the data precoding for data transmission.

10. An apparatus, comprising:

a processor configured to;

generate a precoded sounding reference signal (SRS); and

generate an unprecoded SRS separate from the precoded SRS; and

a transceiver configured to;

transmit the precoded SRS and the unprecoded SRS to a wireless communications device via an uplink channel; and

receive a resource scheduling message based on the precoded SRS and the unprecoded SRS from the wireless communications device.

11. The apparatus of claim 10, wherein:

the precoded SRS and the unprecoded SRS are configured for resource scheduling by the wireless communications device, and

the generating the precoded sounding reference signal is based on a downlink reference signal received from the wireless communications device.

12. The apparatus of claim 10, wherein the transceiver is further configured to:

transmit the precoded SRS during a first symbol period of a subframe and transmit the unprecoded SRS during a second symbol period of the subframe.

13. The apparatus of claim 10, wherein the transceiver is further configured to:

transmit the precoded SRS during a symbol period of a subframe using a first plurality of frequency resources, and transmit the unprecoded SRS during the symbol period of the subframe using a second plurality of frequency resources.

14. The apparatus of claim 10, wherein the transceiver is further configured to:

transmit the precoded SRS during a first subframe and transmit the unprecoded SRS during a second subframe after the first subframe.

15. The apparatus of claim 10, wherein the resource scheduling message comprises a precode instruction from the wireless communications device.

16. The apparatus of claim 15, wherein the precode instruction directs the processor to apply a precoding used for the precoded SRS for data transmission.

17. The apparatus of claim 15, wherein the precode instruction identifies a precoding for data transmission to apply by the processor.

18. The apparatus of claim 15, wherein the precode instruction identifies a delta between a desired precoding and an existing precoding used for the precoded SRS, the processor further configured to:

derive a data precoding for data transmission from a combination of the delta and the existing precoding; and

apply the data precoding for data transmission.