A Single Acquisition Channel Receiver for GPS L1CA and L2C Signals Based on Orthogonal Signal Processing

Maher Al-Aboodi, Ihsan A. Lami, Ali Albu-rghaif, Patrick Van Torre, Hendrik Rogier

Abstract:	All GPS civilian signals are transmitted from the same GPS Satellite Vehicles constellation. It is desirable, especially in commercial GNSS receivers, to have more than one of these signals acquired by the same receiver so to assure better signal acquisition and improved reliability at wider operating areas. This paper proposes the integration of the received GPS L1CA and L2C signals orthogonally to enable acquiring them in a single processing channel. After removing the Doppler frequency, our receiver first adds the quadrature components of the L2C signal and the L1CA signal. This new signal is then shifted by 90o and then added to the remaining components of these two signals; thus creating an orthogonal form of these two signals. Secondly, our receiver will mix the FFT of this orthogonal signal with the complex conjugate of the FFT of a locally generated replica (the CA code combined with a 90o-shifted replica of the CM code). The resulting signal is then converted back to the time domain to acquire the signal’s peak. Our receiver’s implementation is half of the complexity of that used in other published methods. MATLAB Simulation results show that our acquisition compares favorably with other approaches in terms of detection of low sensitivity signals and false alarm probability.
Published in:	Proceedings of the 28th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2015) September 14 - 18, 2015 Tampa Convention Center Tampa, Florida
Pages:	1847 - 1858
Cite this article:	Al-Aboodi, Maher, Lami, Ihsan A., Albu-rghaif, Ali, Van Torre, Patrick, Rogier, Hendrik, "A Single Acquisition Channel Receiver for GPS L1CA and L2C Signals Based on Orthogonal Signal Processing," Proceedings of the 28th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2015), Tampa, Florida, September 2015, pp. 1847-1858.
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