Optimal linear MMSE design for passive distributed radar sensor network systems

In this paper we present optimal power allocation, together with optimal linear signal fusion, considering a passive distributed radar sensor network system. The goal of a passive distributed radar is to obtain a reliable estimation from a source signal, by collecting and combining the individual observations from the network of sensor nodes (SN)s in a fusion center (FC). In this respect, a linear minimum-mean-square-error (MMSE) optimization strategy is considered, where optimal linear operation at the SNs as well as the FC are obtained analytically. The obtained solutions are then analytically and numerically compared to the previously studied unbiased linear MMSE (ULMMSE) approach. It is observed that both schemes share the same strategy for the optimal power allocation among the SNs, but differ in the corresponding linear fusion. As expected, the proposed approach reaches a lower estimation MSE compared to the ULMMSE one.