Abstract:

Aiming at the acquisition problem of weak global position system (GPS) signals, a GPS signal acquisition algorithm based on stochastic resonance (SR) is proposed. After a partial matched filter is adopted in GPS signal pre processing, the signal to noise ratio (SNR) is improved by employing SR. By introducing twice sampling and adaptive techniques in SR, signals with the large frequence can be acquired, and the parameters of SR can match up with the acquired siganls. Fast Fourier transform (FFT) spectrum analysis is used to realize higher sensitive acquisition of GPS signals in shorter coherent integration time. Experiment results show that the acquisition system improves acquiring performance obviously using the proposed algorithm, and it can be seen that correct detection probabilities achieve 100% for a coherent integration time of 10 ms and SNR of -38 dB.