Mitigation of the navigation signals from the pulsar observations based on the adaptive side-lobe cancellation

Abstract

Pulsar study is one of the important issues on radio astronomy; however, the quality of pulsar observations is affected by the spectrum overlaps with navigation signals. Actually, pulsar signals and navigation signals are usually overwhelmed in the noise. Thus this paper focuses on the application of observation data to build two evaluation indexes, which are the interference suppression ratio and the signal loss ratio. The method to eliminate navigation signals is guided by these two indexes. Combined with the spatial characteristic of navigation signals, this paper proposed a modified adaptive side-lobe cancellation method based on noise suppression. The noise component in the interference subspace is estimated and eliminated by the eigenvalue decomposition, and then the optimum weight vector is obtained. Finally navigation signals in observation data are effectively suppressed. Simulation results show that compared with the eigenspace-based algorithm for adaptive antenna side-lobe cancellation, the interference suppression ratio of the proposed method has been increased by 10~20dB.