A Spread Spectrum Communication Method Based on GNSS Positioning and Timing System

Abstract

Application of spread spectrum technology can effectively solve the problem of power constraints in satellite communication. A difficulty of spread spectrum communication is fast acquisition of spread spectrum signal. For the lack of priori information, code phase and frequency offset are both random quantities, it usually takes a long time in signal acquisition, which would reduce the efficiency of the communication especially for the burst communication. Traditional methods realized spread spectrum signal fast acquisition at the expense of acquisition algorithm complexity and hardware resources cost. This article presents a low cost new code phase and carrier frequency of spread spectrum signal correction method that is easy to implement based on GNSS positioning and timing system. In order to correct the frequency offset and code phase difference, position and time information given by GNSS system are used to build the network-wide time synchronization system and indirect loopback correction system in ground station. At the same time, with the aid of satellite timing, the influence of clock error is eliminated in the way of DDS. With the above measures, the spread spectrum signal fast acquisition could be realized in the network-wide time synchronization system.