REFERENCE SIGNAL TRANSMISSION AND AVERAGING FOR WIRELESS COMMUNICATIONS

• US 20160065341A1
• Filed: 07/13/2015
• Published: 03/03/2016
• Est. Priority Date: 08/28/2014
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Luo, Xiliang, Gaal, Peter, Luo, Tao, Malladi, Durga Prasad, Wei, Yongbin, Chen, Wanshi, Xu, Hao, Damnjanovic, Aleksandar, Chendamarai Kannan, Arumugam, Yoo, Taesang
• Granted Patent: US 10,680,771 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/1273 of downlink data flows
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Techniques are provided for combining different types of reference signals. A wireless communications network may be configured to allow a user equipment (UE) to combine multiple demodulation reference signals (DM-RSs) to support demodulation of a physical downlink shared channel (PDSCH), and/or other downlink transmissions, transmitted from a base station to the UE. The base station may provide explicit signaling that reference signals transmitted in two or more transmission time intervals may be combined, or a determination that reference signals transmitted in two or more transmission time intervals may be combined may be made implicitly based on system configuration and previous transmissions. Based on the explicit signaling and/or implicit determination, a UE may combine reference signals included in each of two or more reference signals for use in demodulation of downlink transmissions.

Claims

1. A method for wireless communication, comprising:

receiving an indication that reference signals transmitted in two or more transmission time intervals are combinable, wherein the reference signals are transmitted using resources associated with a group identification or a user equipment (UE) identification;

receiving transmissions during the two or more transmission time intervals; and

combining the reference signals included in the transmissions during the two or more transmission time intervals based at least in part on the indication.

2. The method of claim 1, wherein the indication is received through explicit signaling.

3. The method of claim 1, wherein the indication is received in one or more control signals.

4. The method of claim 1, wherein the receiving the indication comprises:

receiving a downlink grant for one or more transmission time intervals; and

determining that the reference signals from the two or more transmission time intervals can be combined based at least in part on the downlink grant.

5. The method of claim 4, wherein the two or more transmission time intervals are consecutive transmission time intervals.

6. The method of claim 4, wherein the two or more transmission time intervals are within a predetermined number of non-consecutive transmission time intervals.

7. The method of claim 1, wherein the indication is received through a scheduling grant.

8. The method of claim 7, wherein the indication is received through a control channel format used to transmit the scheduling grant.

9. The method of claim 7, wherein the combination of the reference signals is determined based at least in part on determining that the scheduling grant and at least one other transmission are transmitted within a set number of consecutive transmission time intervals.

10. The method of claim 1, further comprising:

determining a presence of a reference signal according to a scrambling sequence, wherein the group identification is associated with the scrambling sequence.

11. The method of claim 1, wherein the reference signals are combined when the group identification associated with the reference signals are the same in the two or more transmission time intervals.

12. The method of claim 1, wherein the combining comprises:

combining reference signals from a first transmission time interval and a second transmission time interval of the two or more transmission time intervals during the second transmission time interval; and

combining reference signals from the first transmission time interval, the second transmission time interval, and a third transmission time interval of the two or more transmission time intervals during the third transmission time interval.

13. The method of claim 12, wherein physical downlink shared channel (PDSCH) transmissions use an initial low rank until the reference signals are combined over at least the first transmission time interval and the second transmission time interval, and PDSCH transmissions use a higher rank following the second transmission time interval.

14. The method of claim 1, wherein the two or more transmission time intervals each comprise a transmission time interval of a first type having a duration that is less than a duration of a transmission time interval of a second type.

15. An apparatus for wireless communication, comprising:

means for receiving an indication that reference signals transmitted in two or more transmission time intervals are combinable, wherein the reference signals are transmitted using resources associated with a group identification or a user equipment (UE) identification;

means for receiving transmissions during the two or more transmission time intervals; and

means for combining the reference signals included in the transmissions during the two or more transmission time intervals based at least in part on the indication.

16. An apparatus for wireless communication, comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory, the instructions being executable by the processor to;

receive an indication that reference signals transmitted in two or more transmission time intervals are combinable, wherein the reference signals are transmitted using resources associated with a group identification or a user equipment (UE) identification;

receive transmissions during the two or more transmission time intervals; and

combine the reference signals included in the transmissions during the two or more transmission time intervals based at least in part on the indication.

17. The apparatus of claim 16, wherein the instructions are further executable by the processor to:

receive the indication through explicit signaling.

18. The apparatus of claim 16, wherein the indication is received in one or more control signals.

19. The apparatus of claim 16, wherein the instructions are further executable by the processor to:

receive a downlink grant for one or more transmission time intervals; and

determine that the reference signals from the two or more transmission time intervals can be combined based at least in part on the downlink grant.

20. The apparatus of claim 19, wherein the two or more transmission time intervals are consecutive transmission time intervals.

21. The apparatus of claim 19, wherein the two or more transmission time intervals are within a predetermined number of non-consecutive transmission time intervals.

22. The apparatus of claim 16, wherein the indication is received through a scheduling grant.

23. The apparatus of claim 22, wherein the indication is received through a control channel format used to transmit the scheduling grant.

24. The apparatus of claim 22, wherein the combination of the reference signals is determined based at least in part on determining that the scheduling grant and at least one other transmission are transmitted within a set number of consecutive transmission time intervals.

25. The apparatus of claim 16, wherein the group identification is associated with a scrambling sequence, and wherein the instructions are further executable by the processor to:

determine a presence of a reference signal according to the scrambling sequence.

26. The apparatus of claim 16, wherein the instructions are further executable by the processor to:

combine the reference signals when the group identification associated with the reference signals are the same in the two or more transmission time intervals.

27. The apparatus of claim 16, wherein the instructions are further executable by the processor to:

combine the reference signals from a first transmission time interval and a second transmission time interval of the two or more transmission time intervals during the second transmission time interval; and

combine the reference signals from the first transmission time interval, the second transmission time interval, and a third transmission time interval of the two or more transmission time intervals during the third transmission time interval.

28. The apparatus of claim 27, wherein physical downlink shared channel (PDSCH) transmissions use an initial low rank until the reference signals are combined over at least the first transmission time interval and the second transmission time interval, and PDSCH transmissions use a higher rank following the second transmission time interval.

29. The apparatus of claim 16, wherein the two or more transmission time intervals each comprise a transmission time interval of a first type having a duration that is less than a duration of a transmission time interval of a second type.

30. A non-transitory computer-readable medium storing a computer-executable code for wireless communication, the code executable by a processor to:

receive an indication that reference signals transmitted in two or more transmission time intervals are combinable, wherein the reference signals are transmitted within resources associated with a group identification or a user equipment (UE) identification;

receive transmissions during the two or more transmission time intervals; and

combine the reference signals included in the transmissions during the two or more transmission time intervals based at least in part on the indication.