On the performance of multipath in reference signal for passive radar interference cancellation

On the condition of pure reference signal, different methods of interference cancellation would achieve ideal performance. However, there is a limited understanding of its performance in passive sensing environments with non-negligible multipath in reference channel. This paper examines such effects on the performance of interference cancellation, especially by Least Square (LS) filter. Closed-form expression for cancellation loss ratio (CLR) is derived, which quantifies to what extent the SNR and interference noise ratio of reference signal and surveillance signal should be achieved to guarantee an acceptable SNR loss of interested target after interference cancellation.