High-Speed Synchronization Acquisition Methods of Quasi-Synchronous CDMA

Abstract

The quasi-synchronous direct sequence code division multiple access system can realize fast frame acquisition and interference-free performance if a shift orthogonal code is used as a spreading sequence set, and synchronization among users is quickly established within a permissible time interval. In this paper, we presents high-speed synchronization acquisition methods, which can be established by the correlation handling of one received data frame. They utilize one of the spreading sequences in the shift orthogonal code as a synchronization control sequence, and a matched filter bank that provides all the correlation functions between a received signal and any sequence. The effectiveness of the proposed methods, in which output is close to an impulse function, is shown by the synchronization error rate over the additive white Gaussian noise and Rayleigh fading channels.