Frequency-domain interference excising at radio frequencies

A simple interference excising algorithm was employed to remove discrete narrow-band interferers from wide-band radio frequency noise measurements made in the North Atlantic during three seasons of the year. Narrow-band signals were reduced by 9 to 18 dB in average data samples with only 5 to 25 percent of the effective bandwidth being sacrificed. Both the amount of bandwidth and interference power excised from samples of data were found to increase as the spectral resolution used in the excising process was increased. (The amount of interference power removed was still increasing at the narrowest spectral resolution of 122 Hz utilized.) It was concluded that frequency-domain-excising techniques can be employed to advantage in lowering the effective interference level for spread-spectrum system signal processing.