Performance comparison of radar receivers subject to amplitude and frequency modulated audio interference

This paper deals with the evaluation and comparison of radar performance, when the receiver is subject to electromagnetic interference (EMI) from communication systems. The interference is modelled as a random process, representative of voice signal, which produces an RF signal by amplitude modulation (AM), double side band (DSB) modulation or frequency modulation (FM). Several schemes for the radar receiver/signal processor are analyzed to evaluate the effects of interference. The statistical model used for the voice modulating signal is presented, along with the generation of the audio modulated interference. Radar performance evaluation has been carried out by Monte Carlo simulation and the results are presented in terms of the receiver operating characteristics, namely P_d and P_fa vs. signal-to-noise ratio (SNR) and interference-to-noise ratio (INR). The results are interpreted by means of a statistical analysis of the underlying signals at some relevant points in the receiver. The processing schemes and the type of modulation that correspond to minimum effect are finally identified