Adaptive narrowband interference cancellation method, and apparatus

1. A receiving apparatus, comprising:

a processor; and

memory comprising instructions that, when executed by the processor, cause the apparatus to:

measure a delay spread of a multipath channel passed by a received time-domain signal, and determine a channel type of the multipath channel according to a measurement result,

select a weighting coefficient according to the channel type,

select the weighting coefficient that matches the channel type from a preset channel parameter configuration table according to the channel type, wherein the weighting coefficient comprises a time-domain window length, a time-domain windowing coefficient, a maximum quantity of subcarriers on which interference needs to be canceled, and an interference estimation weighting coefficient,

perform time-domain windowing processing on the time-domain signal according to the weighting coefficient, and

perform, according to the weighting coefficient, frequency-domain interference cancellation processing on a signal that is output after the time-domain windowing processing, so as to cancel narrowband interference of the time-domain signal.

2. The apparatus according to claim 1 , wherein the instructions, when executed by the processor, cause the apparatus to:

measure the delay spread of the multipath channel passed by the time-domain signal, to obtain a measured delay spread value; and

determine the channel type according to a result of a comparison between the measured delay spread value and a preset delay spread value.

3. The apparatus according to claim 2 , wherein the instructions, when executed by the processor, cause the apparatus to:

determine whether the measured delay spread value is less than a first preset delay spread value; and

when the measured delay spread value is less than the first preset delay spread value, the channel type is an extended pedestrian model A (EPA); or

when the measured delay spread value is greater than or equal to the first preset delay spread value, and the measured delay spread value is less than a second preset delay spread value, the channel type is an extended vehicular model A (EVA); or

when the measured delay spread value is greater than or equal to the first preset delay spread value, and the measured delay spread value is greater than or equal to the second preset delay spread value, the channel type is an extended typical urban model (ETU).

4. The apparatus according to claim 1 , wherein the instructions, when executed by the processor, cause the apparatus to:

perform the time-domain windowing processing on the time-domain signal according to the time-domain window length and the time-domain windowing coefficient, wherein the time-domain windowing processing comprises windowing processing and cyclic prefix CP combination processing.

5. The apparatus according to claim 1 , wherein the instructions, when executed by the processor, cause the apparatus to:

perform fast Fourier transformation (FFT) on the signal on which the time-domain windowing processing has been performed, to obtain a frequency-domain signal.

6. The apparatus according to claim 5 , wherein the instructions, when executed by the processor, cause the apparatus to:

determine a center frequency location of the narrowband interference, and calculate narrowband interference power according to the center frequency location and the frequency-domain signal;

determine, according to the maximum quantity of interference cancellation subcarriers and the narrowband interference power, a quantity of subcarriers on which interference needs to be canceled;

calculate, according to the weighting coefficient and the quantity of subcarriers on which interference needs to be canceled, interference on the subcarrier on which interference needs to be canceled; and

cancel the interference according to the interference on the subcarrier on which interference needs to be canceled and a frequency-domain signal that is corresponding to the subcarrier on which interference needs to be canceled, so as to cancel the narrowband interference of the time-domain signal.

7. The apparatus according to claim 6 , wherein the instructions, when executed by the processor, cause the apparatus to:

accumulate, by using the center frequency location as a center, power of frequency-domain signals that are corresponding to Q subcarriers, to obtain the narrowband interference power, wherein Q is determined by narrowband interference bandwidth and a subcarrier interval, and Q is a natural number.

8. The apparatus according to claim 6 , wherein the instructions, when executed by the processor, cause the apparatus to:

search a preset subcarrier quantity mapping table for a power level that matches the narrowband interference power, and determine, according to the power level and the maximum quantity of interference cancellation subcarriers, the quantity of subcarriers on which interference needs to be canceled.

9. The apparatus according to claim 6 , wherein the instructions, when executed by the processor, cause the apparatus to:

select M subcarriers as observation samples by using the center frequency location as a center, and calculate, according to the observation samples, the weighting coefficient, the quantity of subcarriers on which interference needs to be canceled, and the interference on the subcarrier on which interference needs to be canceled, wherein M is a natural number.

10. The apparatus according to claim 6 , wherein the instructions, when executed by the processor, cause the apparatus to:

determine the center frequency location according to control signaling.

11. The apparatus according to claim 6 , wherein the instructions, when executed by the processor, cause the apparatus to:

determine the center frequency location by traversing subcarriers corresponding to the frequency-domain signal.

12. An adaptive narrowband interference suppression method, comprising:

measuring a delay spread of a multipath channel passed by a received time-domain signal, and determining a channel type of the multipath channel according to a measurement result;

selecting a weighting coefficient that matches the channel type from a preset channel parameter configuration table according to the channel type, wherein the weighting coefficient comprises a time-domain window length, a time-domain windowing coefficient, a maximum quantity of interference cancellation subcarriers, and an interference estimation weighting coefficient;

performing time-domain windowing processing on the time-domain signal according to the weighting coefficient; and

performing, according to the weighting coefficient, frequency-domain interference cancellation processing on the signal that is output after the time-domain windowing processing, so as to cancel narrowband interference of the time-domain signal.

13. The method according to claim 12 , wherein measuring a delay spread of a multipath channel passed by a received time-domain signal, and determining a channel type according to a measurement result comprises:

measuring the delay spread of the multipath channel passed by the time-domain signal, to obtain a measured delay spread value; and

determining the channel type according to a result of comparison between the measured delay spread value and a preset delay spread value.

14. The method according to claim 13 , wherein determining the channel type according to a result of comparison between the measured delay spread value and a preset delay spread value comprises:

determining whether the measured delay spread value is less than a first preset delay spread value; and

when the measured delay spread value is less than the first preset delay spread value, the channel type is an extended pedestrian model A (EPA); or

when the measured delay spread value is greater than or equal to the first preset delay spread value, and the measured delay spread value is less than the second preset delay spread value, the channel type is an extended vehicular model A (EVA); or

when the measured delay spread value is greater than or equal to the first preset delay spread value, and the measured delay spread value is greater than or equal to the second preset delay spread value, the channel type is an extended typical urban model (ETU).

15. The method according to claim 12 , wherein performing time-domain windowing processing on the time-domain signal according to the weighting coefficient comprises:

performing the time-domain windowing processing on the time-domain signal according to the time-domain window length and the time-domain windowing coefficient, wherein the time-domain windowing processing comprises windowing processing and cyclic prefix CP combination processing.

16. The method according to claim 12 , before performing, according to the weighting coefficient, frequency-domain interference cancellation processing on the signal that is output after the time-domain windowing processing, so as to cancel narrowband interference of the time-domain signal, further comprising:

performing faster Fourier transformation (FFT) on the signal on which the time-domain windowing processing has been performed, to obtain a frequency-domain signal.

17. The method according to claim 16 , wherein performing, according to the weighting coefficient, frequency-domain interference cancellation processing on the signal that is output after the time-domain windowing processing, so as to cancel narrowband interference of the time-domain signal comprises:

determining a center frequency location of the narrowband interference;

calculating narrowband interference power according to the center frequency location and the frequency-domain signal;

determining, according to the maximum quantity of interference cancellation subcarriers and the narrowband interference power, a quantity of subcarriers on which interference needs to be canceled;

calculating, according to the weighting coefficient and the quantity of subcarriers on which interference needs to be canceled, interference on the subcarrier on which interference needs to be canceled; and

canceling the interference according to the interference on the subcarrier on which interference needs to be canceled and the frequency-domain signal that is corresponding to the subcarrier on which interference needs to be canceled, so as to cancel the narrowband interference of the time-domain signal.

18. The method according to claim 17 , wherein calculating narrowband interference power according to the center frequency location and the frequency-domain signal comprises:

accumulating, by using the center frequency location as a center, power of frequency-domain signals that are corresponding to Q subcarriers, to obtain the narrowband interference power, wherein Q is determined by narrowband interference bandwidth and a subcarrier interval, and Q is a natural number.