Narrowband interference suppression techniques in direct sequence spread spectrum communication system

The presence of a spread signal in the suppression of narrowband interference process leads to nonlinear filtering which is usually too complex to implement in real time systems. In this paper, we propose a feedback directed Kalman filter receiver that efficiently detects and suppresses the incoming narrowband interference prior to spread signal detection. The filter uses a real time estimate of spread spectrum signal therefore the computation is reduced substantially as compared to conventional receivers. Further, the real time estimate of the spread signal is more accurate as it uses the knowledge of processing gain of the spread signal.