Rejection of CW Interference in QPSK Systems Using Decision-Feedback Filters

Author

Li, Loh-ming ; Milstein, Laurence B.

Author_Institution

Chengdu Institute of Radio Engineering, Chengdu, China and Univ. of California at San Diego, La Jolla, CA, USA

Volume

31

Issue

4

fYear

1983

fDate

4/1/1983 12:00:00 AM

Firstpage

473

Lastpage

483

Abstract

In this paper, the performance of QPSK systems using complex transversal filters with additional decision-feedback taps, in the presence of Gaussian noise and a single CW interferer, is analyzed. Both one-sided (with lagging taps) and two-sided transversal filters with additional decision-feedback taps are considered. Analytic expressions for the tap weights and the minimum mean square errors are obtained. The effect of error propagation on the error probability is discussed and an approximate solution for the error probability is obtained. The transient behavior of the filters using the LMS adaptation algorithm is analyzed. It is shown that if the filter is used for rejecting CW interference only, the one-sided decision-feedback filter is preferred.

Keywords

Decision-feedback communication; Electromagnetic interference (EMI); Phase-shift keying; Transversal filters; Algorithm design and analysis; Error probability; Gaussian noise; Interference; Least squares approximation; Mean square error methods; Performance analysis; Quadrature phase shift keying; Transient analysis; Transversal filters;

fLanguage

English

Journal_Title

Communications, IEEE Transactions on

Publisher

ieee

ISSN

0090-6778

Type

jour

DOI

10.1109/TCOM.1983.1095836

Filename

1095836