A New GNSS Acquisition Method with Signal Down Sampling in Frequency Domain

A new GNSS acquisition method with down sampling in the frequency domain is proposed to reduce the computational load. The method has been developed based on the FFT-based method. The down sampling is done by first pruning the high frequency parts of FFT outputs and then performing IFFT in a smaller size. The new method allows the acquisition to be performed in the lowest sampling rate, regardless of the original sampling rate. The analysis and simulation results show that the operations of the new method can be significantly reduced compared to the conventional FFT-based method while the loss of the acquisition sensitivity is small.