Spread-Spectrum Code Acquisition Based on Pilot Symbols in the Presence of Large Doppler Shift
大Doppler频移条件下基于导频信号的扩频码捕获

The influence of Doppler shifts on traditional acquisition algorithms is analyzed. A new method for spread-spectrum code acquisition of pilot symbols in the presence of large Doppler shifts is proposed, in which the outputs of partial matched filters are delivered to an Adaptive Line Enhancer (ALE) directly and an estimated frequency is produced. After frequency offset compensation, spread-spectrum code acquisition is performed by traditional spread-spectrum code acquisition algorithm. Simulation results show that the new method eliminates the influence of large Doppler shifts effectively, with fast acquisition time.