A Signal Separation Algorithm for GNSS Signal Quality Assessment

With the wide application of multiplexing technology in navigation satellite system, the traditional processing method for one channel signal is no longer suitable for the analysis of composite baseband waveform, which requires signal separation. However, there is a lack of effective navigation signal separation methods currently. First, on the basis of the traditional average algorithm, a signal separation algorithm for signal quality assessment is proposed, and the mathematical model of the algorithm is presented. Utilizing the random of the data bits modulated on different channels, the algorithm can achieve the signal separation by accumulating the multiple code epochs which are selected from the composite signal conditionally. Second, the effect of the carrier phase error, code phase error, and Doppler shift on the separated signal is analyzed. What is more, the difference between the waveforms of the ideal signal and the separated signal is studied, and the estimation error of the separated signal waveform parameters is provided. Finally, the simulated and measured Galileo E1 signals are separated. The baseband waveforms of the composite signal and one channel signal are compared, and the eye diagrams of signal before and after separation are analyzed. The above theoretical analysis and experimental results show that the algorithm is reliable and effective.