A robust detection in the presence of multiple narrowband sources of external interferences with unknown powers

In this paper we develop a new approach to robust detector in the presence of multiple external interferences with unknown powers and target signal with unknown Doppler frequency. Our approach is based on the generalized likelihood ratio test (GLRT). The basic idea of the so-called projection method is the separation of the overall observation space into orthogonal subspaces; here it is offered to separate the overall space so that on each narrowband source of external interference it would be necessary on one subspace. This paper presents the synthesis and efficiency analysis of a new non-adaptive detection test, which has constant or robust false alarm rate (CFAR or RFAR). The aim of this work is two-fold. On one hand, we assess the detection performance, on the other we analyze their robustness with respect to accrual powers of the narrowband interferences. Numerical simulations attest to the validity of the analysis. The evaluation of its performance shows that the loss measured with respect to the corresponding optimum structure is kept within a few dBs.