Analytical formulation for the synchronization performance of Q-level M-sequences in DS-CDMA

In the context of DS-CDMA asynchronous system applications, as in the uplink cellular environment, a spreading process theory based on q-level m-sequences is developed with the aim of improving the acquisition performance with respect to the classic binary case. A very simple sequential acquisition strategy, two-threshold based, is introduced and its performance studied for a generic number of levels of the spreading sequence elements. Moreover, the possibility of avoiding the tracking subsystem is considered. Some synchronization merit factors are defined and characterized to permit fast and easy performance comparison and physical observability. The results presented show that by using q-level m-sequences the tradeoff between acquisition reliability and time can be improved