Research On The Performance Of Satellite Navigation Signal

In the top-level design of the navigation system, the design and optimization of thenavigation signal is the key points of the research. The quality of navigation signal will directlyaffect the performance of the navigation system. With the establishment of the navigationsystem, and the increase of while frequency resources is limited, the interference amongnavigation signals becomes more and more serious. With the continuous emergence of newsignal systems, the evaluation of the navigation signal performance has received more attention.At present, the design of a new type of navigation signal system is to be tested and proved in ourcountry, and it is required to analyze the performance of the new signal, so as to providereference and information for the design and proof of national navigation signal system. Inresponse to this demand, this paper, a research on the performance of the navigation signal.1、Summarize the future development trend of the signal structure by comparison of thefrequency structure, code length, the code type, the navigation message, channel coding andmodulation waveform, between the navigation system of GPS and Galileo.2、In this paper, BPSK modulation, BOC modulation, MBOC modulation and multipleconstant envelope modulation technique are introduced respectively. In terms of the multipleconstant envelope modulation technique, it includes AltBOC modulation, Interplex modulation,CASM modulation, as well as majority voting. The characteristic of each modulation waveformis concluded by comparison of their power spectrums and the auto-correlation characteristics.3、The theory of ranging accuracy is analyzed in this paper. The expression of the estimatederror variance is estimated according to the arrival time of the code phase tracking noise error,and further, the impact from Gabor band width on the ranging performance is also given. WithMatlab simulating calculation, analysis of the BDS, GPS and Galileo systems is conductedrespectively by comparison, in terms of the accuracy of civilian and military signal in the threefrequency ranges.4、The causes of signal multipath effect is analyzed. The expressions of signal multipatherror of envelope and multipath average error are inferred that a multi-path, coherent early-lateprocessing discriminator algorithm. By Matlab simulating calculation, the anti-interferenceperformance of civilian signal and military signal of the three systems are analyzed at threefrequency points respectively.5、Types of interference signals are summarized and expressions of anti-jamming qualityfactors are given. By Matlab simulating calculation, anti-jamming performance for civilian andmilitary signal are analyzed, comparing the BDS, GPS, and Galileo systems at three frequencypoints respectively. 6、Evaluation of compatibility of signal is conducted, with spectral separation coefficientsand the code tracking spectral sensitivity coefficient respectively. Compatibility of the threesystems at B1,B2and B3frequency points are compared and analyzed.7、The experimental scheme is designed for the B1and B3frequency signal system. Thereare two well-known signal combining methodologies: Coheret Adaptive Subcarrier Modulationand Majortity-Vote. In this paper modulation efficiency and combing loss are calculated, whichare used for evaluation of the best among several modulations. Meanwhile a constant envelopemodulation plan is suggested for navigation system according to the calculation result.