Physical carrier to interference-plus-noise ratio techniques for wideband wireless communication networks

1. A method comprising:

receiving wireless transmission frames;

for each frame:

storing data representing a first vector of received signals in active subcarriers;

detecting a preamble;

storing, based on the detected preamble, data representing a second vector for a pseudo-noise code in the active subcarriers;

computing an estimate of a sum of signal power and interference-plus-noise power from the first and second vectors;

computing an estimate of the signal power from the first and second vectors; and

computing an estimate of the interference-plus-noise power from the sum and the estimate of the signal power;

computing a physical carrier to interference-plus-noise ratio from the estimate of the signal power and the estimate of the interference-plus-noise power; and

adjusting a system parameter associated with wireless communication between wireless communication devices based on the physical carrier to interference-plus-noise ratio.

2. The method of claim 1 , and further comprising, for each frame, computing a dot product of the first and second vectors, and wherein computing the estimate of the sum of the signal power and the interference-plus-noise power is based on the dot product, and wherein computing the estimate of the signal power is based on the dot product.

3. The method of claim 1 , for each frame, further comprising comparing the estimate of the signal power with the estimate of the interference-plus-noise power to determine whether the estimate of the signal power is substantially greater than the estimate of the interference-plus-noise power.

4. The method of claim 3 , wherein for each frame, when it is determined that the estimate of the signal power is substantially greater than the estimate of the interference-plus-noise power, computing a more stable estimate of the interference-plus-noise power, and wherein computing the physical carrier to interference-plus-noise ratio is based on the more stable estimate of the interference-plus-noise power.

5. The method of claim 1 , and further comprising computing a mean of the physical carrier to interference-plus-noise ratio for a plurality of frames, and determining whether the mean is greater than a threshold.

6. The method of claim 5 , wherein when it is determined that the mean is greater than the threshold, computing the physical carrier to interference-plus-noise ratio from a mean of the physical carrier to interference-plus-noise ratio and from received signals in multiple frames.

7. An apparatus comprising:

a receiver that is configured to receive wireless transmission frames;

a controller coupled to the receiver, wherein the controller is configured to:

for each frame:

store data representing a first vector of received signals in active subcarriers;

detect a preamble;

store, based on the detected preamble, data representing a second vector for a pseudo-noise code in the active subcarriers;

compute an estimate of a sum of signal power and interference-plus-noise power from the first and second vectors;

compute an estimate of the signal power from the first and second vectors;

compute an estimate of the interference-plus-noise power from the sum and the estimate of the signal power;

compute a physical carrier to interference-plus-noise ratio from the estimate of the signal power and the estimate of the interference-plus-noise power.

8. The apparatus of claim 7 , and further comprising a transmitter that is coupled to the controller and configured to transmit a signal that contains data representing the physical carrier to interference-plus-noise ratio to another apparatus.

9. The apparatus of claim 7 , wherein the controller is further configured to adjust a system parameter associated with wireless communication with another apparatus based on the physical carrier to interference-plus-noise ratio.

10. The apparatus of claim 7 , wherein the controller is configured to, for each frame, compute a dot product of the vectors R and C, compute the estimate of the sum of the signal power and the interference-plus-noise power based on the dot product, and compute the estimate of the signal power is based on the dot product, wherein R is the first vector and C is the second vector.

11. The apparatus of claim 10 , wherein the controller is configured to, for each frame, compare the estimate of the signal power with the estimate of the interference-plus-noise power to determine whether the estimate of the signal power is substantially greater than the estimate of the interference-plus-noise power.

12. The apparatus of claim 11 , wherein the controller is configured to, for each frame, compute a more stable estimate of the interference-plus-noise power when it is determined that the estimate of the signal power is substantially greater than the estimate of the interference-plus-noise power, and compute the physical carrier to interference-plus-noise ratio based on the more stable estimate of the interference-plus-noise power.

13. The apparatus of claim 7 , wherein the controller is further configured to compute a mean of the physical carrier to interference-plus-noise ratio for a plurality of frames, determine whether the mean is greater than a threshold, and compute the physical carrier to interference-plus-noise ratio from a mean of the physical carrier to interference-plus-noise ratio and from received signals in multiple frames.

14. One or more non-transitory computer readable storage media encoded with software comprising computer executable instructions and when the software is executed by a processor operable to:

for each received frame of a wireless transmission:

store data representing a first vector of received signals in active subcarriers;

detect a preamble;

store, based on the detected preamble, data representing a second vector for a pseudo-noise code in the active subcarriers;

compute an estimate of a sum of signal power and interference-plus-noise power from the first and second vectors;

compute an estimate of the signal power from the first and second vectors; and

compute an estimate of the interference-plus-noise power from the sum and the estimate of the signal power;

compute a physical carrier to interference-plus-noise ratio from the estimate of the signal power and the estimate of the interference-plus-noise power; and

adjust a system parameter associated with wireless communication between wireless communication devices based on the physical carrier to interference-plus-noise ratio.

15. The computer readable storage media of claim 14 , and further comprising instructions operable to, for each frame, compute a dot product of the first and second vectors, and wherein the instructions that compute the estimate of the sum is based on the dot product, and the instructions that compute the estimate of the signal power is based on the dot product.

16. The computer readable storage media of claim 14 , and further comprising instructions operable to, for each frame, compare the estimate of the signal power with the estimate of the interference-plus-noise power to determine whether the estimate of the signal power is substantially greater than the estimate of the interference-plus-noise power, and instructions operable to compute a more stable estimate of the interference-plus-noise power when it is determined that the estimate of the signal power is substantially greater than the estimate of the interference-plus-noise power, and wherein the instructions operable to compute the physical carrier to interference-plus-noise ratio is based on the more stable estimate of the interference-plus-noise power.

17. A method comprising:

receiving wireless transmissions that include pilot signals in subcarriers;

for each block of contiguous subcarriers in a symbol:

storing data for a matrix representing received pilot signals in subcarriers;

computing an estimate of a sum of estimated signal power and estimated interference-plus-noise power from the received pilot signals;

computing a difference between two rows in the matrix representing received pilot signals in adjacent subcarriers;

computing an estimate of the interference-plus-noise power from the difference;

computing an estimate of the signal power from the sum and the estimate of the interference-plus-noise power;

computing a physical carrier to interference-plus-noise ratio from the estimate of the signal power and the estimate of the interference-plus-noise power;

adjusting a system parameter associated with wireless communication between wireless communication devices based on the physical carrier to interference-plus-noise ratio.

18. The method of claim 17 , wherein storing data for a matrix representing received pilot signals in subcarriers comprises:

storing data for a matrix having two rows and three columns.

19. The method of claim 17 , further comprising:

computing the physical carrier to interference-plus-noise for each block at a mobile station; and

transmitting the physical carrier to interference-plus-noise for each block from the mobile station to a base station.

20. The method of claim 19 , wherein adjusting a system parameter associated with wireless communication between wireless communication devices based on the physical carrier to interference-plus-noise ratio comprises:

at the base station, scheduling and assigning transmissions to a block of contiguous subcarriers based on the physical carrier to interference-plus-noise ratio received from the mobile station.

21. One or more non-transitory computer readable storage media encoded with software comprising computer executable instructions and when the software is executed by a processor operable to:

for each block of contiguous subcarriers in a symbol contained in a wireless transmission:

store data representing a matrix of received pilot signals in subcarriers;

compute an estimate of a sum of estimated signal power and estimated interference-plus-noise power from the received pilot signals;

compute a difference between two rows in the matrix representing received pilot signals in adjacent subcarriers;

compute an estimate of the interference-plus-noise power from the difference;

compute an estimate of the signal power from the sum and the estimate of the estimate of the interference-plus-noise power;

compute a physical carrier to interference-plus-noise ratio from the estimate of the signal power and the estimate of the interference-plus-noise power;

adjust a system parameter associated with wireless communication between wireless communication devices based on the physical carrier to interference-plus-noise ratio.

22. The computer readable storage media of claim 21 , wherein the instructions operable to store data for a matrix representing received pilot signals in subcarriers comprise instructions operable to:

store data for a matrix having two rows and three columns.

23. The computer readable storage media of claim 21 , further comprising instructions operable to:

compute the physical carrier to interference-plus-noise for each block at a mobile station; and

transmit the physical carrier to interference-plus-noise for each block from the mobile station to a base station.

24. The computer readable storage media of claim 23 , wherein the instructions operable to adjust a system parameter associated with wireless communication between wireless communication devices based on the physical carrier to interference-plus-noise ratio comprise instructions operable to:

at the base station, schedule and assign transmissions to a block of contiguous subcarriers based on the physical carrier to interference-plus-noise ratio received from the mobile station.