System and method for canceling interference in a communication system
View Patent ↗A filter settings generation operation includes sampling a communication channel to produce a sampled signal. The sampled signal is spectrally characterized across a frequency band of interest to produce a spectral characterization of the sampled signal. This spectral characterization may not include a signal of interest. The spectral characterization is then modified to produce a modified spectral characterization. Filter settings are then generated based upon the modified spectral characterization. Finally, the communication channel is filtered using the filter settings when the signal of interest is present on the communication channel. In modifying the spectral characterization, pluralities of spectral characteristics of the spectral characterization are independently modified to produce the modified spectral characterization. Modifications to the spectral characterization may be performed in the frequency domain and/or the time domain. One particular spectral modification that is performed is raising of the noise floor of the spectral characterization to meet a budgeted signal-to-noise ratio. Other spectral modifications include modifying spectral components corresponding to an expected interfering signal. In modifying these spectral characterizations, spectral components corresponding to a plurality of expected interfering signals may be modified.
1. A method for canceling narrow band interference on a communication channel, the method comprising the steps of:
sampling the communication channel to produce a sampled signal, at least some of the narrow band interference not present in the sampled signal;
spectrally characterizing the sampled signal across a frequency band of interest to produce a spectral characterization of the sampled signal, wherein the spectral characterization does not include a signal of interest;
modifying the spectral characterization of the sampled signal to produce a modified spectral characterization by altering frequency components of the spectral characterization of the sampled signal in anticipation of presence of at least a portion of the band interference;
generating filter settings based upon the modified spectral characterization; and
filtering the communication channel using the filter settings when the signal of interest is present on the communication channel.
2. The method of claim 1 , wherein in modifying the spectral characterization of the sampled signal to produce the modified spectral characterization, a plurality of spectral characteristics are modified.
3. The method of claim 1 , wherein in modifying the spectral characterization of the sampled signal to produce the modified spectral characterization, a noise floor of the spectral characterization is raised to meet a budgeted signal-to-noise level.
4. The method of claim 1 , wherein in modifying the spectral characterization of the sampled signal to produce the modified spectral characterization, spectral components corresponding to an expected interfering signal are modified.
5. The method of claim 1 , wherein in modifying the spectral characterization of the sampled signal to produce the modified spectral characterization, spectral components corresponding to a plurality of expected interfering signals are modified.
6. The method of claim 1 , wherein in modifying the spectral characterization of the sampled signal to produce the modified spectral characterization, spectral components of prior sampled signals are employed.
7. The method, of claim 6 , wherein in considering the spectral components of prior sampled signals in modifying the spectral characterization of the sampled signal to produce the modified spectral characterization, the presence of an interfering signal in a prior sampled signal is weighted more heavily than the absence of the interfering signal in the current sampled signal.
8. The method of claim 1 , wherein the frequency band of interest corresponds to the frequency band of the signal of interest.
9. The method of claim 1 , wherein the sampling is performed when the signal of interest is not present on the communication channel.
10. The method of claim 1 , wherein:
the sampling is performed while the signal of interest is present on the communication channel; and
the method further comprises removing the signal of interest from the sampled signal.
11. The method of claim 1 , wherein modifying the spectral characterization of the sampled signal to produce a modified spectral characterization is performed in the frequency domain.
12. The method of claim 1 , wherein modifying the spectral characterization of the sampled signal to produce a modified spectral characterization is performed in the time domain.
13. The method of claim 1 , wherein modifying the spectral characterization of the sampled signal to produce a modified spectral characterization is performed both in the frequency domain and in the time domain.
14. The method of claim 1 , further comprising discarding the sampled signal when total spectral density of the spectral characterization of the sampled signal exceeds a threshold.
15. A method for canceling narrow band interference on a communication channel, the method comprising the steps of:
sampling the communication channel to produce a sampled signal;
spectrally characterizing the sampled signal across a frequency band of interest to produce a spectral characterization of the sampled signal;
modifying the spectral characterization of the sampled signal to produce a modified spectral characterization by raising a noise floor of the spectral characterization to meet a budgeted signal-to-noise level;
generating filter settings based upon the modified spectral characterization; and
filtering the communication channel using the filter settings when the signal of interest is present on the communication channel.
16. The method of claim 15 , wherein in modifying the spectral characterization of the sampled signal to produce the modified spectral characterization, a plurality of spectral characteristics are modified.
17. The method of claim 15 , wherein in modifying the spectral characterization of the sampled signal, to produce the modified spectral characterization, spectral components corresponding to an expected interfering signal are modified.
18. A method for canceling narrow band interference on a communication channel, the method comprising the steps of:
sampling the communication channel to produce a sampled signal, at least some of the narrow band interference not present in the sampled signal;
spectrally characterizing the sampled signal across a frequency band of interest to produce a spectral characterization of the sampled signal;
modifying at least one spectral component of the spectral characterization based upon anticipated presence of at least a portion of the narrow band interference to produce a modified spectral characterization;
generating filter settings based upon the modified spectral characterization; and
filtering the communication channel using the filter settings when the signal of interest is present on the communication channel.
19. The method of claim 18 , wherein in modifying the spectral characterization of the sampled signal to produce the modified spectral characterization, a noise floor of the spectral characterization is raised to meet a budgeted signal-to-noise level.
20. The method of claim 18 , wherein in modifying the spectral characterization of the sampled signal to produce the modified spectral characterization, spectral components corresponding to a plurality of expected interfering signals are modified.