Analysis of Coherent Integration Loss due to FSE in PBR

In passive bistatic radar system, the receiver needs to independently solve the problem of frequency synchronization via the fluctuating direct-path signal. Under the circumstance, it is difficult to achieve highly accurate frequency synchronization since the instantaneous frequency measurement accuracy depends on the signal to noise ratio of the direct-path signal. In this paper, we focused on the impact of FSE on passive bistatic radar system. Since the imbalance between the in-phase(I) and quadrature(Q) component is a function of frequency, the imperfection arises from FSE in digital I and Q components has been introduced. The integration loss was calculated with respect to amplitude and phase imbalance factors. An analysis that explains how the extraneous components generated is presented. Then NIP was defined to evaluate the impact of FSE in quantity. Simulation results demonstrated that the interference frequencies caused by FSE will deteriorate the performance of weak target detection and parameter estimation.