Abstract: The circular correlation algorithm can be used for acquiring Global Positioning System (GPS) C/A code signals. In the algorithm, the input data and the local code were converted into the frequency domain by means of Fast Fourier Transform (FFT) on input data and local code, where their correlation processing can be carried out. After taking the inverse FFT, the maximum absolute value can be found. The value is compared with predetermined threshold. If the value is higher than the threshold, the signals are acquired successfully. This correlation algorithm opens a new way for acquisition of GPS C/A code signals rapidly and accurately.

Key words: acquisition of GPS C/A code signals, fast Fourier transform, circular convolution