Multiband FM-based passive bistatic radar: target range resolution improvement

FM-based passive bistatic radars (PBRs), exploiting a single broadcasted channel, have limited range resolution due to low modulation bandwidth and high dependence on the content broadcasted from an FM station. This may be alleviated by exploiting multiple broadcasted channels from a single transmitter. To reach these goals, the authors formulate the problem of detecting a target in the presence of interference signals, such as receiver noise, direct signal, multipath/clutter echoes, and interfering targets, as a composite hypothesis test. So, they derive a multiband uniformly most powerful invariant test. In the proposed detector, they analytically show how the exploitation of the multiple broadcasted channels can improve the target range resolution. The false alarm rate and detection probability of the proposed detector are also derived in the closed-form expressions. Finally, they provide some simulation examples to validate the authors' theoretical analysis. Simulation results show that a multiband PBR system offers advantages in terms of coherent combined diversity gain and target range resolution improvement as compared to a single band PBR system.