Weak GNSS signal acquisition using prolate spheroid wave function based compressive sensing

Abstract

GNSS signal is contaminated with noise when it reaches the ground receiver because of which the receiver has poor performance. To enhance the performance of receiver, we use a large bandwidth or high complexity platform or a combination of both in the receiver's acquisition unit, where code-offset and Doppler frequencies are measured. In either case, the GNSS signal can be effectively sampled at a rate higher than the Nyquist frequency rate. The signal of interest (SOI) occupies a much smaller bandwidth and by using Compressive Sensing (CS), we derive the sparsity of the signal and minimize sampling points that are needed for acquisition. Prolate spheroid wave function (PSWF) is used as a replacement for Fourier or wavelet bases in CS as it is well localized both in time and frequency domain simultaneously. We use dynamic grouping of sparse data in the CS framework to achieve a higher successful acquisition rate of GNSS signal.