A method for fast synchronization in spread spectrum multiple access communication systems

Abstract

A feature of the spread‐spectrum multiple‐access communication system is that multiple users can simultaneously utilize a common frequency spectrum, and applications to vehicle and satellite communications are anticipated. A problem, however, is that several seconds are required to establish synchronization for the PN code used on the receiving side. To solve this problem, it is proposed that the information for synchronization be acquired using a surface acoustic wave matched filter, but this is difficult in multiple‐access communication owing to the restriction on the number of taps. A new code applicable to the spread‐spectrum multiple‐access communication system with direct spread scheme aimed at the communication of analog information is proposed. It is shown that the surface acoustic wave matched filter, which has fewer taps and is more practical, can be used to drastically decrease the time required for the establishment of synchronization.