Robust transform domain signal processing for GNSS

A Robust Image Denoising Technique in the Contourlet Transform Domain

The contourlet transform has the benefit of efficiently capturing the oriented geometrical structures of images. In this paper, by incorporating the ideas of Stein’s Unbiased Risk Estimator (SURE) approach in Nonsubsampled Contourlet Transform (NSCT) domain, a new image denoising technique is devised. We utilize the characteristics of NSCT coefficients in high and low subbands and apply SURE sh...

Fourier Transform – Signal Processing

Signal-Level Integrity Monitoring Metric for Robust GNSS receivers

This paper deals with the problem of detecting distortions on the received signals of Global Navigation Satellite Systems (GNSS) that may degrade the measurements accuracy and compromise the overall receiver operation. Amongst others, multipath and spoofing are two of the most concerning threats for the robustness of GNSS receivers. These two phenomena have similar effects on the received signa...

Multicore Software-Defined Radio Architecture for GNSS Receiver Signal Processing

We describe a multicore Software-Defined Radio (SDR) architecture for Global Navigation Satellite System (GNSS) receiver implementation. A GNSS receiver picks up very low power signals from multiple satellites and then uses dedicated processing to demodulate and measure the exact timing of these signals from which the user’s position, velocity, and time (PVT) can be estimated. Three GNSS SDR ar...

Complex Wavelet Transform for Analog Signal Processing

For signal processing, the Wavelet transform (WT) has been shown to be a very promising mathematical tool. WT is efficient for local analysis of nonstationary and fast transient signals due its good estimation of time and frequency localization. In the complex wavelet transform analysis, the modulus maxima and the ± π/2 phase crossings point out the locations of sharp signal transitions. The ph...