3D Visualization of Indoor GPS L5Q Baseband Signal and Its Long-Coherent De-noising Using Graph Fourier Transform
作者单位：Department of Geomatics Engineering University of Calgary
会议名称：《第十三届中国卫星导航年会》
会议日期：2022年
学科分类：08[工学] 080401[工学-精密仪器及机械] 081105[工学-导航、制导与控制] 0804[工学-仪器科学与技术] 0825[工学-航空宇航科学与技术] 0811[工学-控制科学与工程]
关 键 词：cross-ambiguity function graph Fourier transform indoor GPS L5 long coherent integration GNSS baseband de-noising
摘 要：Graph signal processing（GSP） has been hotly debated in many research fields at present times. The GSP minimizes the irregular errors of the interfered input signals. An accurate time-of-arrival estimation from a weak and multipath channel is an extremely challenging case in the field of global navigation satellite systems（GNSSs）. To recover the contaminated signal power, the GSP is a promising tool to construct an optimal filter, and, then, differentiate the line-of-sight（LOS） signal power and the other irregular noise power. In this work, a threedimension（3 D） visualized graph is firstly presented with the cross-ambiguity function（CAF） between the incoming GPS L5 Q signal and its replica. Then, the long coherent integration is used to reduce the multipath effect on the correlation amplitude. After that, the graph Fourier transform（GFT） is used to further denoise the proposed baseband graph. The intermediate frequency（IF） L5 Q signal is collected in a real-world indoor situation and it is used to implement the experiments. The correlation amplitude and the s-curve distribution demonstrate the performance of the proposed algorithm.