Stockwell transform reduces the Doppler frequency bin size of GPS receiver

Abstract

GPS or GNSS signal is contaminated with noise when it reaches the ground receiver because of which the receiver has poor performance. The Doppler frequency also make the acquisition system of receiver, more ambiguous. The acquisition system uses a code delay-Doppler frequency bin to detect the correct signal with threshold. Generally the resolution of code delay-Doppler frequency bin, depends upon the sampling frequency or the maximum number of FFT points for correlation and Doppler frequency spacing. In literature, we can find that the sampling rate or the FFT points are reduced by estimating the sparsity of the received signal. Till now, the Doppler frequency estimation using few number of measurement, is very much limited. So, we propose a novel Doppler frequency detection technique which reduces the size of delay-Doppler frequency bin drastically in software defined radio (SDR), using Stockwell transform.