Analysis of Binary Sequences with better correlation performance compared to Gold code under different doppler conditions for GNSS applications

Abstract

Terrestrial applications of Global Navigation Satellite Systems (GNSS) systems are widely known and are growing. Apart from the terrestrial applications of the GNSS Systems, these systems are also being used as space borne GNSS receivers towards orbit estimation. The relative Doppler experienced by the GNSS receiver differs based on the location where these GNSS receivers are being placed namely, terrestrial receivers, space borne receivers, Medium Earth Orbit (MEO) receivers and Geostationary Earth Orbit (GEO) receivers. It is of importance to evaluate the correlation performance of the binary sequences being used in GNSS system under different relative Doppler conditions. In this paper mathematical expressions are derived for computing odd correlation (auto correlation and cross correlation) property and even correlation (auto correlation and cross correlation) property in the presence of Doppler frequencies using basic correlation functions. Doppler performance of the Gold code based Global Positioning Systems(GPS) L1 Course/Acquisition(C/A) signal is presented for both odd correlation and even correlation properties, and is compared with the new binary sequence generated using the proposed method. It is observed that the correlation properties of the proposed binary sequences are comparable to the state of the art Gold code based GPS L1 C/A signal under different the Doppler conditions.