Two blind DS-CDMA code synchronization methods for multipath channels

Two blind near-far robust code synchronisation algorithms are proposed for multipath delay estimation in asynchronous direct sequence code division multiple access systems. The algorithms are multidimensional versions of the early presented (one-dimensional) multiple signal classification (MUSIC) and minimum output energy (MOE) estimators. The proposed algorithms overcome the problem of one-dimensional versions that they can not separate closely spaced delays in a fixed channel without additional work. The proposed estimators are blind in the sense that only the knowledge of the waveform of the desired signal is required. The performance of the proposed estimators is investigated by simulations, where it is shown that near-far robust estimators outperform the multidimensional correlator if there is near-far problem.