BEAM REFERENCE SIGNAL BASED NARROWBAND CHANNEL MEASUREMENT AND CQI REPORTING

• US 20170303141A1
• Filed: 03/24/2017
• Published: 10/19/2017
• Est. Priority Date: 04/19/2016
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: ISLAM, Muhammad Nazmul, LUO, Tao, SADIQ, Bilal, CEZANNE, Juergen, SUBRAMANIAN, Sundar, LI, Junyi
• Granted Patent: US 10,237,857 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04B 7/0639 Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
• CPC Class Codes: H04B 7/0695 using beam selection
• CPC Class Codes: H04B 7/088 using beam selection
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/046 the resource being in the space domain, e.g. beams
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

When beamforming (e.g., via a millimeter wave system (mmW)) is used for wireless communication, a base station may transmit beams that are directed to certain directions. Due to the directional nature of the beams in the mmW system, an approach to determine a beam that provides a desirable gain is studied. The apparatus may be a user equipment (UE). The apparatus receives, from a base station, a plurality of signals through a plurality of beams of the base station, each of the plurality of beams corresponding to a respective antenna port of a plurality of antenna ports of the base station. The apparatus performs channel estimation for each beam of the plurality of beams from the plurality of antenna ports based on the plurality of signals. The apparatus transmits, to the base station, a feedback signal including information about one or more beams selected from the plurality of beams, the feedback signal further including one or more candidate uplink precoders.

Claims

1. A method of wireless communication by a user equipment (UE), comprising:

receiving, from a base station, a plurality of signals through a plurality of beams of the base station, each of the plurality of beams corresponding to a respective antenna port of a plurality of antenna ports of the base station;

performing channel estimation for each beam of the plurality of beams from the plurality of antenna ports based on the plurality of signals; and

transmitting, to the base station, a feedback signal including information about one or more beams selected from the plurality of beams, the feedback signal further including one or more candidate uplink precoders.

2. The method of claim 1, further comprising:

selecting the one or more candidate uplink precoders from a predefined codebook.

3. The method of claim 2, wherein the one or more candidate uplink precoders are selected based on the channel estimation.

4. The method of claim 2, wherein the one or more candidate uplink precoders are each a candidate for a precoder used for scheduling a physical uplink shared channel (PUSCH).

5. The method of claim 1, wherein a millimeter wave (MMW) band is used for the wireless communications.

6. The method of claim 1, wherein the plurality of signals include a plurality of beam reference signals, a plurality of beam refinement reference signals, a plurality of channel state information reference signals (CSI-RS), or a combination thereof.

7. The method of claim 1, wherein the channel estimation includes at least one of narrowband channel estimation or wideband channel estimation.

8. The method of claim 1, wherein the channel estimation is based on a measurement of at least one of a signal-to-noise ratio, an antenna gain, or a reference signal measurement of each of the plurality of beams.

9. The method of claim 1, wherein the feedback signal is transmitted to the base station via at least one of a physical uplink control channel (PUCCH) or uplink control information (UCI) in a physical uplink shared channel (PUSCH).

10. The method of claim 1, wherein the feedback signal is transmitted to the base station through a random access channel (RACH) subframe.

11. A method of wireless communication by a base station, comprising:

transmitting, to a user equipment (UE), a plurality of signals through a plurality of beams of the base station, each of the plurality of beams corresponding to a respective antenna port of a plurality of antenna ports of the base station;

receiving, from the UE, a feedback signal including information about one or more beams selected from the plurality of beams; and

scheduling a physical uplink shared channel (PUSCH) based on the feedback signal.

12. The method of claim 11, wherein the feedback signal further includes one or more candidate uplink precoders, and wherein the scheduling the PUSCH further comprises:

selecting a final uplink precoder from the one or more candidate uplink precoders; and

scheduling the PUSCH based on the final uplink precoder.

13. The method of claim 12, wherein the one or more candidate uplink precoders are from a predefined codebook.

14. The method of claim 11, wherein a millimeter wave (MMW) band is used for the wireless communication.

15. The method of claim 11, wherein the plurality of signals include a plurality of beam reference signals, a plurality of beam refinement reference signals, a plurality of channel state information reference signals (CSI-RS), or a combination thereof.

16. The method of claim 11, wherein the channel estimation includes at least one of narrowband channel estimation and wideband channel estimation.

17. The method of claim 11, wherein the channel estimation is based on at least one of a signal-to-noise ratio, an antenna gain, or a reference signal measurement of each of the plurality of beams.

18. The method of claim 11, wherein the feedback signal is received from the UE via at least one of a physical uplink control channel (PUCCH) or in uplink control information (UCI) conveyed via a physical uplink shared channel (PUSCH).

19. The method of claim 11, wherein the feedback signal is received from the UE through a random access channel (RACH) subframe.

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

a memory; and

at least one processor coupled to the memory and configured to;

receive, from a base station, a plurality of signals through a plurality of beams of the base station, each of the plurality of beams corresponding to a respective antenna port of a plurality of antenna ports of the base station;

perform channel estimation for each beam of the plurality of beams from the plurality of antenna ports based on the plurality of signals; and

transmit, to the base station, a feedback signal including information about one or more beams selected from the plurality of beams, the feedback signal further including one or more candidate uplink precoders.

21. The UE of claim 20, wherein the at least one processor is further configured to:

select the one or more candidate uplink precoders from a predefined codebook.

22. The UE of claim 21, wherein the one or more candidate uplink precoders are selected based on the channel estimation.

23. The UE of claim 21, the one or more candidate uplink precoders are each a candidate for a precoder used for scheduling a physical uplink shared channel (PUSCH).

24. The UE of claim 20, wherein the plurality of signals include a plurality of beam reference signals, a plurality of beam refinement reference signals, a plurality of channel state information reference signals (CSI-RS), or a combination thereof.

25. The UE of claim 20, wherein a millimeter wave (MMW) band is used for the wireless communication.

26. A base station for wireless communication, comprising:

a memory; and

at least one processor coupled to the memory and configured to;

transmit, to a user equipment (UE), a plurality of signals through a plurality of beams of the base station, each of the plurality of beams corresponding to a respective antenna port of a plurality of antenna ports of the base station;

receive, from the UE, a feedback signal including information about one or more beams selected from the plurality of beams; and

schedule a physical uplink shared channel (PUSCH) based on the feedback signal.

27. The base station of claim 26, wherein the feedback signal further includes one or more candidate uplink precoders, and wherein the at least one processor configured to schedule the PUSCH is further configured to:

select a final uplink precoder from the one or more candidate uplink precoders; and

schedule the PUSCH based on the final uplink precoder.

28. The base station of claim 27, wherein the one or more candidate uplink precoders are from a predefined codebook.

29. The base station of claim 28, wherein a millimeter wave (MMW) band is used for the wireless communication.

30. The base station of claim 26, wherein the plurality of signals include a plurality of beam reference signals, a plurality of beam refinement reference signals, a plurality of channel state information reference signals (CSI-RS), or a combination thereof.