Systems, methods, and apparatus for impulse noise mitigation

• US 20070036239A1
• Filed: 01/11/2006
• Published: 02/15/2007
• Est. Priority Date: 08/12/2005
• Status: Active Grant

• Current Assignee: ATI Technologies Incorporated (Advanced Micro Devices, Inc.)
• Original Assignee: ATI Technologies Incorporated (Advanced Micro Devices, Inc.)
• Inventors: Touzni, Azzedine, Ma, Xiaoqiang
• Granted Patent: US 7,558,337 B2
• Time in Patent Office: Days
• US Class Current: 375/316
• CPC Class Codes: H04L 2025/03636 Algorithms using least mean square [LMS]
• CPC Class Codes: H04L 25/022 of frequency response
• CPC Class Codes: H04L 25/0228 with direct estimation from sounding signals
• CPC Class Codes: H04L 25/0232 by interpolation between sounding signals
• CPC Class Codes: H04L 25/0234 by non-linear interpolation
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01

Abstract

A method of signal processing according to one of several embodiments includes estimating a deterministic component of a received signal. The estimating is based on an estimated response of a transmission channel. Based on the estimated deterministic component, a non-deterministic component of the received signal is estimated. Based on corrupted portions of the estimated non-deterministic component, a noise estimate is obtained, and the received signal is compensated based on the noise estimate. A method according to another embodiment includes replacing received samples at corrupted locations with values from a calculated model.

Claims

1. A method of signal processing, said method comprising:

based on a multicarrier signal received over a transmission channel, estimating a response of the transmission channel; and

estimating a plurality of data values carried by the received multicarrier signal, said estimating including;

calculating a reference signal based on (A) the estimated response of the transmission channel and (B) a known pattern of data values carried by the received multicarrier signal;

based on a time-domain difference between the reference signal and a portion of the received multicarrier signal carrying the plurality of data values, calculating a noise estimate; and

in a frequency domain and according to the noise estimate, compensating the portion of the received multicarrier signal carrying the plurality of data values.

2. The method of signal processing according to claim 1, wherein said calculating a reference signal is based on (A) the estimated response of the transmission channel and (B) a known pattern of data values carried by pilot carriers of the received multicarrier signal.

3. The method of signal processing according to claim 1, wherein said calculating a noise estimate includes identifying corrupted values of the time-domain difference.

4. The method of signal processing according to claim 3, wherein said identifying corrupted values includes performing, for each value of the time-domain difference, a comparison to a threshold value.

5. The method of signal processing according to claim 3, wherein said identifying corrupted values includes deriving a plurality of measures from the values of the time-domain difference and comparing each of the plurality of measures to a threshold value.

6. The method of signal processing according to claim 1, wherein said compensating includes subtracting the noise estimate from the portion of the received multicarrier signal carrying the plurality of data values.

7. A method of signal processing, said method comprising:

estimating a symbol carried by a multicarrier signal received over a transmission channel;

based on the estimated symbol, a set of reference values, and an estimated response of the transmission channel, calculating a model of the portion of the received multicarrier signal carrying the symbol;

in a time domain, identifying corrupted values of the estimated symbol; and

based on the locations of the corrupted values, compensating the received multicarrier signal according to values of the calculated model.

8. The method of signal processing according to claim 7, wherein the estimated response of the transmission channel is based on the received multicarrier signal.

9. The method of signal processing according to claim 7, wherein said calculating a model includes selecting one among the set of reference values for each frequency-domain value of the estimated symbol.

10. The method of signal processing according to claim 7, wherein said calculating a model includes selecting one among a set of constellation points for each value of the estimated symbol.

11. The method of signal processing according to claim 10, wherein said calculating a model includes selecting, for each value of the estimated symbol, the nearest among the set of constellation points.

12. The method of signal processing according to claim 7, wherein said identifying corrupted values includes performing, for each value of the estimated symbol, a comparison to a threshold value.

13. The method of signal processing according to claim 7, wherein said identifying corrupted values includes deriving a plurality of measures from the values of the estimated symbol and comparing each of the plurality of measures to a threshold value.

14. The method of signal processing according to claim 7, wherein said compensating includes replacing samples of the received multicarrier signal with corresponding values of the calculated model.

15. The method of signal processing according to claim 7, said method comprising equalizing the compensated received multicarrier signal according to an estimated response of the transmission channel.

16. A method of signal processing, said method comprising:

estimating a response of a transmission channel;

identifying at least one corrupted component of a multicarrier signal received over the transmission channel;

for each identified corrupted component, modifying the estimated response of the transmission channel at a frequency corresponding to the corrupted component; and

estimating a plurality of data values carried by the received multicarrier signal, said estimating including;

calculating a reference signal based on (A) the modified estimated response of the transmission channel and (B) a known pattern of data values carried by the received multicarrier signal;

based on a difference between the reference signal and a portion of the received multicarrier signal carrying the known pattern, calculating a noise estimate; and

according to the noise estimate, compensating the portion of the received multicarrier signal carrying the plurality of data values.

17. The method of signal processing according to claim 16, wherein the estimated response of the transmission channel is based on the received signal.

18. The method of signal processing according to claim 16, wherein said modifying an estimated response of the transmission channel at a frequency corresponding to the corrupted component includes calculating a replacement value for the estimated response at the frequency corresponding to the corrupted component.

19. The method of signal processing according to claim 18, wherein said calculating a replacement value comprises interpolating the replacement value based on values of the estimated response at other frequencies.

20. The method of signal processing according to claim 16, wherein said calculating a reference signal is based on a known pattern of data values carried by pilot carriers of the received signal.

21. The method of signal processing according to claim 16, wherein said calculating a noise estimate is based on a difference between the reference signal and a portion of the received signal including a plurality of pilot carriers.

22. The method of signal processing according to claim 21, wherein said calculating a noise estimate includes interpolating values of the noise estimate at frequencies other than those of the pilot carriers.

23. The method of signal processing according to claim 16, wherein said compensating includes subtracting the noise estimate from the portion of the received multicarrier signal carrying the plurality of data values.