A Fast Acquisition Algorithm Based on FFT for DSSS Signal and FPGA Realization

Traditional methods have some defects for DSSS signal acquisition, large quantities of calculation, high source occupation, worse dynamic performance, etc. As these taken into account, an fast acquisition algorithm based on FFT was put forward. In this method, multiple correlators were used to search code phase in the same time and a FFT function was shared to find the carrier Doppler frequency. As the frequency search eliminated from the acquisition process, the acquisition speed was increased and dynamic performance was improved. The principle of this method was described in detail. CycloneII EP2C70 FPGA of Altera Company was used to realize and verify the acquisition method. Key parameters design was given. The results of test show that it has a high speed of acquisition while saving the hardware resources.