TECHNIQUES FOR ACQUIRING MEASUREMENTS OF A SHARED SPECTRUM AND PERFORMING CHANNEL SELECTION FOR ACCESS POINTS USING THE SHARED SPECTRUM

• US 20150280847A1
• Filed: 02/24/2015
• Published: 10/01/2015
• Est. Priority Date: 03/28/2014
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Somasundaram, Kiran Kumar, Lin, Dexu, Bhushan, Naga, Damnjanovic, Aleksandar, Chen, Wanshi, Gaal, Peter, Stamoulis, Anastasios, Horn, Gavin Bernard, Wei, Yongbin, Malladi, Durga Prasad, Ji, Tingfang, Xu, Hao, Dabeer, Onkar
• Granted Patent: US 9,531,494 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04J 11/0056 Inter-base station aspects
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

Techniques are described for wireless communication. A first method may include transmitting a reference signal from an access point over a shared spectrum to a user equipment (UE), and receiving a measurement of the reference signal from the UE. A second method may include receiving at a UE over a shared spectrum a reference signal from an access point, and transmitting a measurement of the reference signal to the access point. In each of the first and second methods, the measurement may indicate interference with the shared spectrum from outside of a clear channel assessment (CCA) range of the access point. A third method may include receiving a plurality of reference signal measurements, where each reference signal measurement corresponds to one of a plurality of access points and indicates interference with a shared spectrum from outside of a CCA range of the corresponding access point, and performing channel selection for the plurality of access points based at least in part on the received reference signal measurements.

Claims

1. A method of wireless communication, comprising:

transmitting a reference signal from an access point over a shared spectrum to a user equipment (UE); and

receiving a measurement of the reference signal from the UE, the measurement indicating interference with the shared spectrum from outside of a clear channel assessment (CCA) sense range of the access point.

2. The method of claim 1, wherein transmitting the reference signal comprises:

transmitting a CCA-exempt transmission (CET) to the UE over the shared spectrum, the CET comprising the reference signal.

3. The method of claim 2, further comprising:

performing a CCA for the shared spectrum before transmitting the CET;

wherein the CET comprises an indication of whether the CCA was successful.

4. The method of claim 3, further comprising:

determining that the measurement of the reference signal indicates the interference with the shared spectrum from outside of the CCA sense (CS) range of the access point when the CCA is successful.

5. The method of claim 3, wherein the measurement of the reference signal comprises a Reference Signal Received Power (RSRP) measurement and a Reference Signal Received Quality (RSRQ) measurement, the method further comprising:

using only the RSRP measurement when the CCA is unsuccessful.

6. The method of claim 1, further comprising:

tuning the access point from a first channel within the shared spectrum to a second channel within the shared spectrum; and

performing a CCA on the second channel.

7. The method of claim 6, wherein transmitting the reference signal comprises:

transmitting the reference signal over the second channel when the CCA is successful.

8. The method of claim 7, further comprising:

signaling a transition to the second channel to the UE prior to transmitting the reference signal over the second channel.

9. The method of claim 7, further comprising:

tuning the access point back to the first channel following the transmission of the reference signal.

10. The method of claim 6, wherein the measurement of the reference signal is received over one of the first channel or the second channel.

11. An apparatus for wireless communication, comprising:

a processor; and

memory coupled to the processor, wherein the processor is configured to;

transmit a reference signal from an access point over a shared spectrum to a user equipment (UE); and

receive a measurement of the reference signal from the UE, the measurement indicating interference with the shared spectrum from outside of a clear channel assessment (CCA) sense range of the access point.

12. The apparatus of claim 11, wherein the processor is configured to:

transmit a CCA-exempt transmission (CET) to the UE over the shared spectrum, the CET comprising the reference signal.

13. The apparatus of claim 12, wherein the processor is configured to:

perform a CCA for the shared spectrum before transmitting the CET;

wherein the CET comprises an indication of whether the CCA was successful.

14. The apparatus of claim 13, wherein the processor is configured to:

determine that the measurement of the reference signal indicates the interference with the shared spectrum from outside of the CCA sense (CS) range of the access point when the CCA is successful.

15. The apparatus of claim 11, wherein the processor is configured to:

tune the access point from a first channel within the shared spectrum to a second channel within the shared spectrum; and

perform a CCA on the second channel.

16. The apparatus of claim 15, wherein transmitting the reference signal comprises:

transmitting the reference signal over the second channel when the CCA is successful.

17. The apparatus of claim 16, wherein the processor is configured to:

signal a transition to the second channel to the UE prior to transmitting the reference signal over the second channel.

18. A method of wireless communication, comprising:

receiving at a user equipment (UE) over a shared spectrum a reference signal from an access point; and

transmitting a measurement of the reference signal to the access point, the measurement indicating interference with the shared spectrum from outside of a clear channel assessment (CCA) sense range of the access point.

19. The method of claim 18, wherein receiving the reference signal comprises:

receiving a CCA-exempt transmission (CET) from the access point over the shared spectrum, the CET comprising the reference signal.

20. The method of claim 19, further comprising:

determining whether a CCA performed by the access point before transmission of the CET was successful based at least in part on the CET.

21. The method of claim 20, wherein the measurement of the reference signal indicates the interference with the shared spectrum from outside of the CCA sense (CS) range of the access point when the CCA performed by the access point was successful.

22. The method of claim 20, wherein the measurement of the reference signal comprises a Reference Signal Received Power (RSRP) measurement or a Reference Signal Received Quality (RSRQ) measurement.

23. The method of claim 18, further comprising:

tuning the UE from a first channel within the shared spectrum to a second channel within the shared spectrum; and

receiving the reference signal over the second channel.

24. The method of claim 23, further comprising:

tuning the UE back to the first channel following the receipt of the reference signal.

25. The method of claim 23, wherein the measurement of the reference signal is transmitted over one of the first channel or the second channel.

26. An apparatus for wireless communication, comprising:

a processor; and

memory coupled to the processor, wherein the processor is configured to;

receive at a user equipment (UE) over a shared spectrum a reference signal from an access point; and

transmit a measurement of the reference signal to the access point, the measurement indicating interference with the shared spectrum from outside of a clear channel assessment (CCA) sense range of the access point.

27. The apparatus of claim 26, wherein receiving the reference signal comprises:

receiving a CCA-exempt transmission (CET) from the access point over the shared spectrum, the CET comprising the reference signal.

28. The apparatus of claim 27, wherein the processor is configured to:

determine whether a CCA performed by the access point before transmission of the CET was successful based at least in part on the CET.

29. The apparatus of claim 26, wherein the processor is configured to:

tune the UE from a first channel within the shared spectrum to a second channel within the shared spectrum; and

receive the reference signal over the second channel.

30. The apparatus of claim 29, wherein transmitting the measurement of the reference signal comprises:

transmitting the measurement of the reference signal over one of the first channel or the second channel.