Performance comparison of DS signal matched filter acquisition using median filter and transversal filter as an aiding device in AWGN channel and CW jamming

摘要

This paper introduces analysis results of a DS spread spectrum system in which code acquisition is based on a matched filter, a matched filter and a median filter, and a matched filter and a transversal filter. The probabilities of detection and false alarms and the mean acquisition times are calculated in the AWGN channel and with continuous tone jamming with ideal autocorrelation of the spreading code being assumed. The effect of CW jamming can be eliminated by both methods, so the comparisons are made in the AWGN channel. Fixed thresholds of the comparator and constant false alarm probabilities (CFAR criteria) are both used. The median filter structure has a competitive performance compared to transversal filter structures, even though the difference between the median filter and an equal length transversal filter is not significant in the CFAR case. The one-sided filter has the largest loss compared to the matched filter acquisition.