Elimination Filter for Co-Channel Interference in Asynchronous SSMA Systems Using Polyphase Modulatable Orthogonal Sequences


IEICE TRANSACTIONS on Communications   Vol.E75-B   No.6   pp.494-498
Publication Date: 1992/06/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Communication Theory)
CDMA,  SSMA,  co-channel interference,  

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It is difficult for a receiver in Asynchronous SSMA systems to eliminate co-channel interference, when the receiver doesn't know the sequence of the co-channel interference. In this paper, a filter for eliminating co-channel interference without using the knowledge of the sequence of co-channel interference in an asynchronous SSMA system, in which each transmitter/receiver is assigned an infinite number of sequences and select a sequence secretly for information security. The filter gathers the co-channel interference energy into some puleses and scatters the signal energy widely. The receiver can clip the co-channel interference energy by losing small amount of signal energy. This is a new solution for the near-far problem in an asynchronous SSMA system using secret sequences.