A modified constant modulus algorithm for adaptive channel equalization for QAM signals

Author

Amin, Moeness ; He, Lin ; Reed, Charles, Jr. ; Malkemes, Robert

Author_Institution

Dept. of Electr. & Comput. Eng., Villanova Univ., PA, USA

fYear

2001

fDate

6/23/1905 12:00:00 AM

Firstpage

563

Lastpage

566

Abstract

A modified constant modulus algorithm (MCMA) for adaptive equalization of the wireless indoor channel for QAM signals is presented. The algorithm minimizes an error cost function that includes both the amplitude and phase of the equalizer output. In addition to the amplitude-dependent term that is provided by the conventional constant modulus algorithm (CMA), the cost function includes a signal constellation matched error (CME) term. This term speeds up convergence and allows the equalizer to switch to decision directed (DD), or any soft-decision mode, faster than the CMA applied alone. The constellation-matched error term is constructed using polynomials with desirable properties. The MCMA is applied to a decision feedback equalizer and shown to provide improved performance over dual mode techniques

Keywords

adaptive equalisers; decision feedback equalisers; error analysis; indoor radio; minimisation; polynomials; quadrature amplitude modulation; CMA; CME term; DFE; MCMA; QAM signals; adaptive equalization; amplitude-dependent term; convergence; decision directed mode; decision feedback equalizer; error cost finiction; modified constant modulus algorithm; phase; polynomials; signal constellation matched error; soft-decision mode; wireless indoor channel; Adaptive equalizers; Computer errors; Constellation diagram; Convergence; Cost function; Decision feedback equalizers; Laboratories; Polynomials; Quadrature amplitude modulation; Switches;

fLanguage

English

Publisher

ieee

Conference_Titel

Statistical Signal Processing, 2001. Proceedings of the 11th IEEE Signal Processing Workshop on

Print_ISBN

0-7803-7011-2

Type

conf

DOI

10.1109/SSP.2001.955349

Filename

955349