Space frequency direction finding in wide-band and multi-path contexts

Over the two last decades, a great number of narrow band direction finding methods have been developed in order to estimate the DOA (Directions Of Arrival) of impinging sources received on an array of sensors. In a radiocommunication context, the signal of each emitter propagates through different multi-path channels. In this context, the emitted signals may have various spectrum characteristics, either narrow-band with normalized frequency channels or wide-band such as spread spectrum signals PN (Pseudo Noise). Ln order to take into account these frequency and wide-band characteristics we can apply a space-frequency technique as presented in [1][7] for the DOA estimation. The first purpose of this paper is to adapt these algorithms for correlated sources such as in multi-path propagation channels and the second purpose is to decrease the high computation cost of this new method by simplifying the space-frequency criterion.