Channel estimation with effective co-channel interference suppression

• US 8,787,499 B2
• Filed: 03/26/2008
• Issued: 07/22/2014
• Est. Priority Date: 03/27/2007
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gaal, Peter, Luo, Tao, Wei, Yongbin
• Primary Examiner(s): Liu, Shuwang
• Assistant Examiner(s): MCKIE, GINA M
• Application Number:
  US12/055,745
• Publication Number:
  US 20080240314A1
• Time in Patent Office: 2,309 Days
• Field of Search: None
• US Class Current: 375/316
• CPC Class Codes: H04J 11/0056 Inter-base station aspects
• CPC Class Codes: H04L 25/022 of frequency response
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01

Abstract

A method for a wireless communication system is provided. The method includes isolating a set of pilot signals, where the pilot signals are associated with multiple base stations or multiple sectors of a single base station. This includes nulling a subset of the pilot signals to mitigate co-channel interference and to perform channel estimation in accordance with at least one of the pilot signals.

Claims

1. A method, comprising:

transforming received signals from a time domain to a frequency domain to generate a plurality of pilot signals and associated data in the frequency domain;

nulling the associated data to isolate the plurality of pilot signals;

converting the isolated plurality of pilot signals to the time domain;

isolating a particular pilot signal in the time domain by zeroing each pilot signal of the isolated plurality of pilot signals except the particular pilot signal; and

performing channel estimation using the particular pilot signal.

2. The method of claim 1, wherein each pilot signal of the plurality of pilot signals is associated with a different base station of multiple base stations.

3. The method of claim 1, further comprising:

after isolating the particular pilot signal;

analyzing the particular pilot signal from a particular base station or from a particular sector of a base station; and

.

4. The method of claim 1, wherein performing the channel estimation comprises performing a time domain channel estimation or performing a frequency domain channel estimation.

5. The method of claim 1, further comprising transforming the particular pilot signal from the time domain to the frequency domain.

6. The method of claim 1, wherein the plurality of pilot signals is associated with three base stations.

7. The method of claim 1, wherein the plurality of pilot signals is associated with three sectors of a single base station.

8. The method of claim 1, wherein performing the channel estimation includes performing a tone extraction on the particular pilot signal or performing an inverse discrete Fourier transform on the particular pilot signal.

9. The method of claim 1, wherein performing the channel estimation includes performing a discrete Fourier transform on the particular pilot signal, performing a zero padding operation on the particular pilot signal, or performing a time domain interpolation filter operation on the particular pilot signal.

10. A communications apparatus comprising:

a processor; and

a memory storing instructions executable by the processor to perform operations comprising;

transforming received signals from a time domain to a frequency domain to generate a plurality of pilot signals and associated data in the frequency domain;

nulling the associated data to isolate the plurality of pilot signals;

converting the isolated plurality of pilot signals to the time domain;

isolating a particular pilot signal in the time domain by zeroing each pilot signal of the isolated plurality of pilot signals except the particular pilot signal; and

performing channel estimation using the particular pilot signal.

11. The communications apparatus of claim 10, wherein performing the channel estimation comprises performing a time domain channel estimation or performing a frequency domain channel estimation.

12. The communications apparatus of claim 10, wherein the processor comprises a tone extraction circuit to facilitate the channel estimation.

13. The communications apparatus of claim 10, wherein the processor comprises a zero padding circuit to facilitate the channel estimation.

14. The communications apparatus of claim 10, wherein the processor comprises a time domain interpolation filter to facilitate the channel estimation.

15. The communications apparatus of claim 10, wherein the processor comprises a thresholding component to facilitate the channel estimation.

16. A communications apparatus comprising:

means for transforming received signals from a time domain to a frequency domain to generate a plurality of pilot signals and associated data in the frequency domain;

means for nulling the associated data to isolate the plurality of pilot signals;

means for converting the isolated plurality of pilot signals to the time domain;

means for isolating a particular pilot signal in the time domain by zeroing each pilot signal of the isolated plurality of pilot signals except the particular pilot signal;

means for generating a channel estimate using the particular pilot signal; and

means for transforming the channel estimate to the frequency domain for frequency domain processing.

17. The apparatus of claim 16, further comprising:

means for analyzing the particular pilot signal from a particular base station or from a particular sector of a base station after isolating the particular pilot signal in the time domain.

18. The apparatus of claim 16, wherein zeroing each pilot signal of the isolated plurality of pilot signals except the particular pilot signal includes nulling each pilot signal of the isolated plurality of pilot signals in the time domain except the particular pilot signal.

19. The apparatus 16, wherein each pilot signal of the plurality of pilot signals is associated with a different base station of multiple base stations.

20. A non-transitory computer-readable medium comprising instructions that, when executed by a processor, cause the processor to,

null data channels associated with orthogonal base stations or sectors to isolate a plurality of pilot tones

isolate a single pilot tone from among the plurality of isolated pilot tones in a time domain by zeroing each pilot tone of the isolated plurality of pilot tones except the single pilot tone, wherein a subset of the isolated plurality of pilot tones is associated with a first transmission source and a second transmission source, and wherein the single pilot tone is associated with a third transmission source;

and

perform a channel estimation using the single pilot tone.

21. The non-transitory computer-readable medium of claim 20, wherein the channel estimation includes at least one of a time domain channel estimation or a frequency domain channel estimation.

22. The non-transitory computer-readable medium of claim 20, further comprising instructions that, when executed by the processor, cause the processor to transform the subset of the plurality of pilot tones to a frequency domain.

23. An apparatus comprising:

a processor; and

a memory storing instructions executable by the processor to perform operations comprising;

nulling data channels associated with orthogonal base stations or sectors to isolate a plurality of pilot signals;

isolating a particular pilot signal of the isolated plurality of pilot signals in a time domain by zeroing each pilot signal of the isolated plurality of pilot signals except the particular pilot signal;

performing channel estimation using the the particular pilot signal.

24. The apparatus of claim 23, wherein the operations further comprise transforming received signals from the orthogonal base stations or sectors to generate the plurality of pilot signals and data channels.

25. The apparatus of claim 24, wherein transforming the received signals includes a time domain to frequency domain transform.

26. The apparatus of claim 23, wherein the operations further comprise transforming the plurality of pilot signals from a frequency domain to the time domain.