Posterior Cramér-Rao bounds for Doppler biased multistatic range-only tracking

This paper investigates range-only tracking with range-Doppler coupling, where the range measurement of a target of interest is linearly biased by its range-rate (or Doppler). In previous treatments the situation was monostatic, and a simple Riccati analysis sufficed, but here the system is multistatic (notionally, a MIMO radar). Here, the closed form of posterior Cramér-Rao bound (PCRB) is derived for a multistatic system in the tracking of a kinematic target. As the coupling parameter λ can be zero, positive, or negative, a question arises: which kind of λ could result in a lower PCRB for a given system configuration? With the help of numerical analysis, we see that a positive λ may lead to the lowest PCRB, while a negative λ may result in the highest among these three possibilities.