Multiple Target Parameter Estimation in Bistatic Passive Radar

An expectation-maximization (EM)-based iterative algorithm is proposed for jointly estimating the delay and Doppler parameters of multiple moving targets in a bistatic passive radar system. In the E-step, the expectation of the log-likelihood function, with respect to the unobserved illuminator waveform and conditioned on the observed signals in the reference and surveillance channels and given estimates of the parameters, is derived. In the M-step, the derived expectation is maximized with respect to the unknown parameters which, in addition to the delay and Doppler parameters of each target include unknown reference channel (RC) and surveillance channel (SC) coefficients associated with each target. Computer simulation results are presented to illustrate the convergence behavior and the mean-square errors of the estimated parameters.