Communication system with narrowband interference mitigation and related methods

Patent metadata

Field	Value
Publication number	US-9379768-B2
Application number	US-201414169447-A
Country	US
Kind code	B2
Filing date	Jan 31, 2014
Priority date	Jan 31, 2014
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

A communications device may include a wireless receiver, and a processor coupled to the wireless receiver. The processor may be configured to receive a spread OFDM signal having narrowband interference associated with the same, the spread OFDM signal having subcarriers with data distributed among the subcarriers. The processor may be configured to excise the narrowband interference from the spread OFDM signal, and despread the spread OFDM signal after excising and based upon the excising to recover the data.

First claim

That which is claimed is:

1. A communications device comprising:
a wireless receiver; and
a processor coupled to the wireless receiver and configured to
receive a spread orthogonal frequency-division multiplexing (OFDM) signal having narrowband interference associated therewith, the spread OFDM signal comprising a plurality of subcarriers with data distributed among the subcarriers,
excise the narrowband interference from the spread OFDM signal based upon first and second parallel processing paths, each parallel processing path including an excision operation,
despread the spread OFDM signal after excising and based upon band excision information from the excision operation, and
equalize the spread OFDM signal also based upon the band excision information from the excision operation, the band excision information comprising a spectrum removal percentage.

2. The communications device of claim 1 wherein said processor is configured to equalize the spread OFDM signal by at least selectively enabling at least one equalizer tap using the band excision information.

3. The communications device of claim 1 wherein said processor is configured to respread the excised OFDM signal before the equalizing.

4. The communications device of claim 1 wherein said processor is configured to equalize the spread OFDM signal using decision feedback equalization.

5. The communications device of claim 1 further comprising a decoder coupled to said processor.

6. The communications device of claim 1 wherein said processor is configured to perform a frequency transformation on the spread OFDM signal so that the spread OFDM signal is processed in a plurality of frequency bins.

7. The communications device of claim 6 wherein said processor is configured to excise the narrowband interference by setting at least one frequency bin to a set value.

8. The communications device of claim 7 wherein said set value comprises one of a zero value, a mean value, and a random value.

9. The communications device of claim 1 wherein the spread OFDM signal is based upon Walsh coding.

10. A communication system comprising:
a first communications device comprising a wireless transmitter, and a processor coupled to said wireless transmitter and configured to transmit a spread orthogonal frequency-division multiplexing (OFDM) signal; and
a second communications device communicating with said first communications device over a communication channel and comprising a wireless receiver, and a processor coupled to said wireless receiver and configured to
receive the spread OFDM signal having narrowband interference associated therewith from the communication channel, the spread OFDM signal comprising a plurality of subcarriers with data distributed among the subcarriers,
excise the narrowband interference from the spread OFDM signal based upon first and second parallel processing paths, each parallel processing path including an excision operation,
despread the spread OFDM signal after excising and based upon band excision information from the excision operation, and
equalize the spread OFDM signal also based upon the band excision information from the excision operation, the band excision information comprising a spectrum removal percentage.

11. The communication system of claim 10 wherein said processor of said second communications device is configured to equalize the spread OFDM signal by at least selectively enabling at least one equalizer tap using the band excision information.

12. The communication system of claim 10 wherein said processor of said second communications device is configured to respread the excised OFDM signal before the equalizing.

13. The communication system of claim 10 wherein said processor of said second communications device is configured to equalize the spread OFDM signal using decision feedback equalization.

14. The communication system of claim 10 wherein said second communications device comprises a decoder coupled to said processor.

15. The communication system of claim 10 wherein said processor of said second communications device is configured to perform a frequency transformation on the spread OFDM signal so that the spread OFDM signal is processed in a plurality of frequency bins.

16. The communication system of claim 15 wherein said processor of said second communications device is configured to excise the narrowband interference by setting at least one frequency bin to a set value.

17. A method of operating a communications device comprising a wireless receiver, and a processor coupled to the wireless receiver, the method comprising:
operating the processor to receive a spread orthogonal frequency-division multiplexing (OFDM) signal having narrowband interference associated therewith, the spread OFDM signal comprising a plurality of subcarriers with data distributed among the subcarriers;
operating the processor to excise the narrowband interference from the spread OFDM signal based upon first and second parallel processing paths, each parallel processing path including an excision operation;
operating the processor to despread the spread OFDM signal after excising and based upon band excision information from the excision operation; and
operating the processor to equalize the spread OFDM signal also based upon the band excision information from the excision operation, the band excision information comprising a spectrum removal percentage.

18. The method of claim 17 further comprising operating the processor to equalize the spread OFDM signal by at least selectively enabling at least one equalizer tap using the band excision information.

19. The method of claim 17 further comprising operating the processor to respread the excised OFDM signal before the equalizing.

20. The method of claim 17 further comprising operating the processor to equalize the spread OFDM signal using decision feedback equalization.

21. The method of claim 17 further comprising operating the processor to perform a frequency transformation on the spread OFDM signal so that the spread OFDM signal is processed in a plurality of frequency bins.

22. The method of claim 21 further comprising operating the processor to excise the narrowband interference by setting at least one frequency bin to a set value.

23. The method of claim 22 wherein the set value comprises one of a zero value, a mean value, and a random value.

Assignees

• Harris Corp

Inventors

• Moffatt Christopher D
• Hoffmann John
• Lilley Richard
• Browning David M

Classifications

• H04L27/2647

  Arrangements specific to the receiver only (equalisation H04L27/01) · CPC title

• H04L25/03057

  with a recursive structure (H04L25/03031 takes precedence) · CPC title

• H04L5/0012

  Hopping in multicarrier systems · CPC title

• H04L27/265 Primary

  Fourier transform demodulators, e.g. fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators (H04L27/26524 takes precedence) · CPC title

• H04B1/715 Primary

  Interference-related aspects · CPC title