Maximum likelihood signal estimation using polarized arrays

The problem of separating and estimating the waveforms of superimposed signals received by a polarization sensitive antenna array is considered. Signal estimation is accomplished by a two-step maximum likelihood procedure: (i) the directions of arrival and polarization parameters of all the signals are estimated; (ii) the estimated signal is obtained as a linear combination of the array outputs, with weights which are computed from the estimated direction and polarization parameters. Expressions are derived for the output signal-to-interference ratio (SIR) and output signal-to-noise ratio (SNR). Numerical examples illustrate the performance improvement that can be achieved using polarized arrays