Study Of The Serial-parallel Combined Technique About Synchronization Of DS/SS

Spread spectrum communication is a foreword technique developing rapidly in current information domain. It started from the military communication and already deep into such many fields as navigation, measurement and telecontrol. Now, it is permeating fast in individual communication and computer communication. It is one of the hot points of new technique used in international information processing and transferring in twenty-one century.The synchronization of Direct Sequence Spread Spectrum (DS/SS) is the most important but much more difficult one. This paper studies the parallel acquisition scheme and the serial acquisition scheme, and the acquisition problem of long sequences buried deeply in noise in particular. The parallel acquisition scheme has the shorter acquisition time at cost of times of complexity in hardware. The serial acquisition scheme has the less complexity at cost of increasing the acquisition time. For the limitation of the parallel acquisition and the serial acquisition, a new serial-parallel combined acquisition scheme had been discussed in the paper.In the fourth chapter, we introduced the special work in the paper. A block diagram had been given for the implementation of hardware, a mathematical model had been established for the acquisition system, and a mathematic expression had been derived using the state transfer function for the average acquisition time. The acquisition performance of the system had been analyzed in detail with phase error of PN sequences, Doppler shift and background noise taken into consideration.