A Novel Method of Interference Suppression in DSSS Based on Adaptive Digital Heterodyne Notch Filters

The degradation of receiver performance due to narrowband interference in DSSS can be improved by mitigation. The adaptive digital heterodyne notch filter can suppress strong narrowband interference efficiently by interference cancellation. Combined with the idea of FFT spectral analysis and time-domain adaptive notch, the paper presents a new structure improving on digital heterodyne adaptive notch filters. This filter can adaptively track the interference frequency and control the bandwidth and depth of notch, which has the excellent agility and utility. Through simulation, it is demonstrated that this method enhances the stability of the filter system, can quickly track the interference frequency, and has little influence on signal spectrum.