Widely-linear processing for distributed passive radar systems with strictly non-circular sources

摘要

In this paper, we address the design of a distributed passive radar system which operates on a strictly non-circular source. The goal of a passive distributed radar is to provide a reliable estimation from the source signal, by collecting and combining the individual observations from the network in a centralized node. We take advantage of the non-circular nature of the source, and propose widely linear signal processing algorithms, which achieve around 3 dB of gain in the estimation accuracy compared to the available linear strategies. In this regard, a minimum mean squared error (MMSE) problem is formulated for unbiased class of estimators, where the widely-linear processing is enabled at the distributed sensors, or at a centralized entity. An optimal power allocation and information fusion is achieved in each case, by studying the optimality conditions of the corresponding problems. The performance of the proposed methods are then compared to the known linear strategies via numerical simulations.