MUSIC type algorithm for joint modulation phase-shift, time-delay and frequency-shift estimation in asynchronous DS CDMA systems

A subspace-based MUSIC type algorithm for joint modulation phase-shift time-delay and frequency-shift estimation in multi-user asynchronous DS CDMA communications is proposed. The algorithm is based on spatio-temporal processing of signals received by a non-uniform volume antenna array. The proposed algorithm is near-far resistant and as expected it is well suited for joint parameter estimation and detection in a fading multipath channel. In the proposed algorithm the modulation phase shift is estimated before despreading and we believe it is very promising approach to modulation parameter estimation.