Narrow-band interference suppression technology of OTH radar

In over-the-horizon (OTH) radar, the frequency band is limited by crowded and powerful interference. It is difficult to find an uncontaminated and broad band, which leads to low range resolution and signal-to-interference and noise ratio (SINR). A desired method is the suppression of interference in a definite bandwidth. Considering the poor sidelobe of pulse compression by the notch filtering method, the projection algorithm (PA) and adaptive cancellation algorithm (ACA) are introduced in this paper. It follows that PA has the advantage of low complexity of computation and low sidelobe by designing a sub-band filter group, which may introduce temporal response. Furthermore, ACA can eliminate interference effectively by adjusting the weights although resulting in an increase in the burden of computation. A further lower sidelobe is obtained which leads to a significant increase in detection probability.