Channel estimation enhancements

• US 10,623,208 B2
• Filed: 05/03/2019
• Issued: 04/14/2020
• Est. Priority Date: 10/31/2014
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Jiang, Jing, Mukkavilli, Krishna Kiran, Bhushan, Naga, Ji, Tingfang, Soriaga, Joseph Binamira, Gaal, Peter, Smee, John Edward, Gorokhov, Alexei Yurievitch
• Primary Examiner(s): Anwar, Mohammad S
• Application Number:
  US16/403,445
• Publication Number:
  US 20190260611A1
• Time in Patent Office: 347 Days
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 47/12 Avoiding congestion; Recovering from congestion
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04L 5/0058 Allocation criteria
• CPC Class Codes: H04L 5/0082 at predetermined intervals
• CPC Class Codes: H04L 5/0096 Indication of changes in allocation
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames

Abstract

The disclosure relates in some aspects to techniques for improved channel estimation. For example, a device can specify a pilot structure where pilot density differs over time. As another example, a device can indicate that a pilot from a prior transmission time interval (TTI) can be used for channel estimation. As another example, a device can employ frequency domain physical resource block (PRB) bundling with the bundling information signaling. As yet another example, a device can use an adjustable traffic-to-pilot ratio (TPR) for throughput optimization. Other aspects, embodiments, and features are also discussed and claimed.

Claims

1. A user equipment (UE) for wireless communication, comprising:

a communication interface configured to receive an indication of a traffic-to-pilot ratio (TPR) for demodulation reference signals (DMRSs) from a base station based on at least a rate associated with the UE; and

a processing circuit coupled to the communication interface and configured to process one or more pilots received from the base station based on at least the TPR.

2. The UE of claim 1, wherein the processing circuit is further configured to select a transmit power based on at least the TPR.

3. The UE of claim 1, wherein the processing circuit is further configured to generate a channel estimate from the pilots received from the base station based on the TPR.

4. The UE of claim 1, wherein:

the communication interface is further configured to receive, from the base station, an indication of a pilot structure configured to have a pilot density that differs over time within a transmission period.

5. The UE of claim 4, wherein the pilot density at a beginning portion of the transmission period is higher than the pilot density at a later portion of the transmission period.

6. The UE of claim 4, wherein the pilot density is different for different transmission time intervals (TTIs) within the transmission period.

7. The UE of claim 4, wherein the pilot density further differs with respect to frequency during the transmission period.

8. The UE of claim 4, wherein the pilot structure indicates a change in a beamforming configuration.

9. The UE of claim 4, wherein:

the communication interface is further configured to receive, from the base station, an indication that a pilot from a prior transmission time interval (TTI) can be used for channel estimation as a result of a particular pilot structure being specified for successive TTIs; and

the processing circuit is further configured to generate a channel estimate for a current TTI based on the pilot from the prior TTI.

10. The UE of claim 4, wherein:

the communication interface is further configured to receive, from the base station, an indication of a selected other pilot structure selected for a physical resource block (PRB) bundle that comprises at least one PRB.

11. The UE of claim 10, wherein the other pilot structure comprises spacing for the pilots based on a bandwidth of the PRB bundle.

12. The UE of claim 10, wherein the indication of the selected other pilot structure comprises a precoding matrix indicator (PMI).

13. The UE of claim 10, wherein the indication of the selected other pilot structure indicates a difference between neighbor resource block (RB) PMIs.

14. A method of wireless communication at a user equipment (UE), comprising:

receiving an indication of a traffic-to-pilot ratio (TPR) for demodulation reference signals (DMRSs) from a base station based on at least a rate associated with the UE; and

processing one or more pilots received from the base station based on at least the TPR.

15. The method of claim 14, further comprising:

selecting a transmit power based on at least the TPR.

16. The method of claim 14, further comprising:

generating a channel estimate from the pilots received from the base station based on the TPR.

17. The method of claim 14, further comprising:

receiving, from the base station, an indication of a pilot structure configured to have a pilot density that differs over time within a transmission period.

18. The method of claim 17, wherein the pilot density at a beginning portion of the transmission period is higher than the pilot density at a later portion of the transmission period.

19. The method of claim 17, wherein the pilot density is different for different transmission time intervals (TTIs) within the transmission period.

20. The method of claim 17, wherein the pilot density further differs with respect to frequency during the transmission period.

21. The method of claim 17, wherein the pilot structure indicates a change in a beamforming configuration.

22. The method of claim 17, further comprising:

receiving, from the base station, an indication that a pilot from a prior transmission time interval (TTI) can be used for channel estimation as a result of a particular pilot structure being specified for successive TTIs; and

generating a channel estimate for a current TTI based on the pilot from the prior TTI.

23. The method of claim 17, further comprising:

receiving, from the base station, an indication of a selected other pilot structure selected for a physical resource block (PRB) bundle that comprises at least one PRB.

24. A user equipment (UE) for wireless communication, comprising:

means for receiving an indication of a traffic-to-pilot ratio (TPR) for demodulation reference signals (DMRSs) from a base station based on at least a rate associated with the UE; and

means for processing one or more pilots received from the base station based on at least the TPR.

25. The apparatus of claim 24, further comprising:

means for selecting a transmit power based on at least the TPR.

26. The apparatus of claim 24, further comprising:

means for generating a channel estimate from the pilots received from the base station based on the TPR.

27. The apparatus of claim 24, further comprising:

means for receiving, from the base station, a pilot structure configured to have a pilot density that differs over time within a transmission period.

28. The apparatus of claim 27, wherein the pilot structure indicates a change in a beamforming configuration.

29. The apparatus of claim 27, further comprising:

means for receiving, from the base station, an indication that a pilot from a prior transmission time interval (TTI) can be used for channel estimation as a result of a particular pilot structure being specified for successive TTIs; and

means for generating a channel estimate for a current TTI based on the pilot from the prior TTI.

30. The apparatus of claim 27, further comprising:

means for receiving, from the base station, an indication of a selected other pilot structure selected for a physical resource block (PRB) bundle that comprises at least one PRB.