On Cramer Rao bounds and optimal beamspace transformation in radar array processing

This paper treats a scenario where a sinusoidal target signal, of unknown amplitude, phase, and frequency impinges on an array of antenna elements. The signal is assumed to be disturbed by spatially colored, but temporally white, additive Gaussian noise. In array signal processing, a beamspace transformation, T, is often used in order to arrive at a reduced computational complexity. Conditioned on a particular T, the Cramer Rao bounds for the unknown parameters are computed, from which an optimality condition on how to choose the beamspace transformation is derived. Finally, some computer simulation results comparing different T:s are given