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A Comparative Study of Co-Channel Interference Suppression TechniquesWe describe three methods of combatting co-channel interference (CCI): a cross-coupled phase-locked loop (CCPLL); a phase-tracking circuit (PTC), and joint Viterbi estimation based on the maximum likelihood principle. In the case of co-channel FM-modulated voice signals, the CCPLL and PTC methods typically outperform the maximum likelihood estimators when the modulation parameters are dissimilar. However, as the modulation parameters become identical, joint Viterbi estimation provides for a more robust estimate of the co-channel signals and does not suffer as much from "signal switching" which especially plagues the CCPLL approach. Good performance for the PTC requires both dissimilar modulation parameters and a priori knowledge of the co-channel signal amplitudes. The CCPLL and joint Viterbi estimators, on the other hand, incorporate accurate amplitude estimates. In addition, application of the joint Viterbi algorithm to demodulating co-channel digital (BPSK) signals in a multipath environment is also discussed. It is shown in this case that if the interference is sufficiently small, a single trellis model is most effective in demodulating the co-channel signals.
Document ID
19980137507
Acquisition Source
Headquarters
Document Type
Conference Paper
Authors
Hamkins, Jon
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Satorius, Ed
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Paparisto, Gent
(University of Southern California Los Angeles, CA United States)
Polydoros, Andreas
(University of Southern California Los Angeles, CA United States)
Date Acquired
August 18, 2013
Publication Date
June 1, 1997
Publication Information
Publication: IMSC 1997
Subject Category
Communications And Radar
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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