Externally controlled time-varying constrained notch filter

Dov Wulich, Eugene I. Plotkin, M. N.S. Swamy, Wen Tong

Research output: Contribution to journalConference articlepeer-review


An application of a constrained notch filter (CNF) for filtering a sine signal with arbitrary varying frequency is considered. It is shown that the concept of CNF can be easily extended to time-varying CNF (TVCNF) whose coefficients vary with time according to the rule of frequency variation of the considered FM signal. Such a TVCNF is able to reject the FM signal and at the same time remain transparent to any other signal. The main problem in TVCNF implementation is to provide a proper control (synchronization) of its coefficients. An application of the TVCNF for the enhancement of an arbitrary signal corrupted by a strong FM interference is investigated. It is shown that if the synchronization is based on the input mixture, then for any negative signal-to-interference ratio (SIR ≪ 0 dB) at the input of the TVCNF, the SIR at its output reaches 0 dB.

Original languageEnglish
Pages (from-to)1440-1443
Number of pages4
JournalProceedings - IEEE International Symposium on Circuits and Systems
StatePublished - 1 Dec 1991
Event1991 IEEE International Symposium on Circuits and Systems Part 4 (of 5) - Singapore, Singapore
Duration: 11 Jun 199114 Jun 1991

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


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