Resource unit detection in high-efficiency wireless system

1. A method of identifying an active resource unit in a high-efficiency wireless system, the method comprising:

receiving samples in a high-efficiency short training field of a transmission, each respective one of the samples being a respective complex number;

deriving a respective phase angle value for each respective one of the samples from components of the respective complex number;

quantizing each respective phase angle value to yield a respective quantized phase-only sample;

performing a transform operation on quantized phase-only samples to derive transmitted power;

comparing transmitted power of an individual resource unit as determined solely from transformed quantized phase-only samples to transmitted power of other resource units as determined from transformed quantized phase-only samples; and

identifying, as active, a resource unit whose transmitted power, as determined solely from transformed quantized phase-only samples, bears a first predetermined relationship to transmitted power of the other resource units.

2. The method of claim 1 wherein the comparing transmitted power of the individual resource unit as determined solely from transformed quantized phase-only samples to transmitted power of other resource units as determined solely from transformed quantized phase-only samples comprises comparing the transmitted power of the individual resource unit to the total transmitted power of all resource units.

3. The method of claim 2 wherein the identifying, as active, a resource unit whose transmitted power, as determined solely from transformed quantized phase-only samples, bears the first predetermined relationship to transmitted power of the other resource units, comprises identifying, as active, a resource unit whose transmitted power exceeds a predetermined fraction of the total transmitted power of all resource units.

4. The method of claim 1 wherein the comparing transmitted power of the individual resource unit as determined solely from transformed quantized phase-only samples to transmitted power of other resource units as determined solely from transformed quantized phase-only samples comprises comparing the transmitted power of the individual resource unit to the transmitted power of a particular one of the other resource units.

5. The method of claim 4 wherein the comparing transmitted power of the individual resource unit as determined solely from transformed quantized phase-only samples to transmitted power of other resource units as determined solely from transformed quantized phase-only samples comprises comparing the transmitted power of the individual resource unit to the transmitted power of one of the other resource units whose transmitted power is a maximum transmitted power of all resource units.

6. The method of claim 5 wherein:

the comparing the transmitted power of the individual resource unit to the transmitted power of one of the other resource units whose transmitted power is a maximum transmitted power of all resource units, comprises determining a difference between the transmitted power of the one of the other resource units whose transmitted power is the maximum transmitted power of all resource units, and the transmitted power of the individual resource unit; and

the identifying, as active, a resource unit whose transmitted power, as determined solely from transformed quantized phase-only samples, bears the first predetermined relationship to transmitted power of the other resource units, comprises identifying, as active, a resource unit for which the difference at most equals a threshold.

7. The method of claim 5 wherein the identifying, as active, a resource unit whose transmitted power, as determined solely from transformed quantized phase-only samples, bears the first predetermined relationship to transmitted power of the other resource units, comprises identifying, as active, a resource unit whose transmitted power, as determined solely from transformed quantized phase-only samples, exceeds a predetermined fraction of the transmitted power of the one of the other resource units whose transmitted power is the maximum transmitted power of all resource units.

8. The method of claim 1 further comprising:

identifying, as inactive, a resource unit whose transmitted power, as determined solely from transformed quantized phase-only samples, bears a second predetermined relationship to transmitted power of the other resource units; and

deactivating operations on a resource unit that has been identified as inactive.

9. The method of claim 8 wherein:

the comparing transmitted power of the individual resource unit as determined solely from transformed quantized phase-only samples to transmitted power of other resource units as determined solely from transformed quantized phase-only samples comprises comparing the transmitted power of the individual resource unit to the total transmitted power of all resource units; and

the identifying, as inactive, a resource unit whose transmitted power, as determined solely from transformed quantized phase-only samples, bears the second predetermined relationship to transmitted power of the other resource units, comprises identifying, as inactive, a resource unit whose transmitted power at most equals a predetermined fraction of the total transmitted power of all resource units.

10. The method of claim 8 wherein:

the comparing transmitted power of an individual resource unit as determined solely from transformed quantized phase-only samples to transmitted power of other resource units as determined solely from transformed quantized phase-only samples comprises comparing the transmitted power of the individual resource unit to the transmitted power of a particular one of the other resource units whose transmitted power is a maximum transmitted power of all resource units; and

the identifying, as inactive, a resource unit whose transmitted power, as determined solely from transformed quantized phase-only samples, bears the second predetermined relationship to transmitted power of the other resource units, comprises identifying, as inactive, a resource unit whose transmitted power bears the second predetermined relationship to the transmitted power of the particular one of the other resource units whose transmitted power is a maximum transmitted power of all resource units.

11. The method of claim 10 wherein:

the comparing the transmitted power of the individual resource unit to the transmitted power of the particular one of the other resource units whose transmitted power is a maximum transmitted power of all resource units comprises determining a difference between the transmitted power of the one of the other resource units whose transmitted power is the maximum transmitted power of all resource units, and the transmitted power of the individual resource unit; and

the identifying, as inactive, a resource unit whose transmitted power, as determined solely from transformed quantized phase-only samples, bears the second predetermined relationship to transmitted power of the other resource units, comprises identifying, as inactive, a resource unit for which the difference exceeds a threshold.

12. The method of claim 10 wherein:

the identifying, as inactive, a resource unit whose transmitted power, as determined solely from transformed quantized phase-only samples, bears the second predetermined relationship to the transmitted power of the particular one of the other resource units whose transmitted power is a maximum transmitted power of all resource units, comprises identifying, as inactive, a resource unit whose transmitted power at most equals a predetermined fraction of the transmitted power of the one of the other resource units whose transmitted power is the maximum transmitted power of all resource units.

13. The method of claim 1 wherein the transmission is a UL-OFDMA transmission.

14. The method of claim 1 wherein the transmission is a DL-OFDMA transmission.

15. A receiver for a high-efficiency wireless system, the receiver comprising a controller configured to identify an active resource unit in the high-efficiency wireless system, by:

receiving samples in a high-efficiency short training field of a transmission, each respective one of the samples being a respective complex number;

deriving a respective phase angle value for each respective one of the samples from components of the respective complex number;

quantizing each respective phase angle value to yield a respective quantized phase-only sample;

performing a transform operation on quantized phase-only samples to derive transmitted power;

comparing transmitted power of an individual resource unit as determined solely from transformed quantized phase-only samples to transmitted power of other resource units as determined from transformed quantized phase-only samples; and

identifying, as active, a resource unit whose transmitted power, as determined solely from transformed quantized phase-only samples, bears a first predetermined relationship to transmitted power of the other resource units.

16. The receiver of claim 15 wherein the controller is configured to compare the transmitted power of the individual resource unit as determined solely from transformed quantized phase-only samples to total transmitted power of all resource units as determined solely from transformed quantized phase-only samples.

17. The receiver of claim 16 wherein the controller is configured to identify, as active, a resource unit whose transmitted power, as determined solely from transformed quantized phase-only samples, exceeds a predetermined fraction of the total transmitted power of all resource units.

18. The receiver of claim 15 wherein the controller is configured to compare transmitted power of an individual resource unit as determined solely from transformed quantized phase-only samples to transmitted power of a particular one of the other resource units.

19. The receiver of claim 18 wherein the controller is configured to compare transmitted power of an individual resource unit as determined solely from transformed quantized phase-only samples to transmitted power of one of the other resource units whose transmitted power is a maximum transmitted power of all resource units.

20. The receiver of claim 19 wherein the controller is configured to:

compare the transmitted power of the individual resource unit to the transmitted power of one of the other resource units whose transmitted power is a maximum transmitted power of all resource units, by determining a difference between the transmitted power of the one of the other resource units whose transmitted power is the maximum transmitted power of all resource units, and the transmitted power of the individual resource unit; and

identify, as active, a resource unit for which the difference at most equals a threshold.

21. The receiver of claim 19 wherein the controller is configured to identify, as active, a resource unit whose transmitted power, as determined solely from transformed quantized phase-only samples, exceeds a predetermined fraction of the transmitted power of the one of the other resource units whose transmitted power is the maximum transmitted power of all resource units.

22. The receiver of claim 15 wherein the controller is further configured to:

identify, as inactive, a resource unit whose transmitted power, as determined solely from transformed quantized phase-only samples, bears a second predetermined relationship to transmitted power of the other resource units; and

deactivate operations on a resource unit that has been identified as inactive.