A decision-directed constant modulus algorithm for higher-order source constellations

Author

Endres, T.J. ; Hulyalkar, S.N. ; Strolle, C.H. ; Schaffer, T.A. ; Casas, R.A.

Author_Institution

NxtWave Commun., Langhorne, PA, USA

Volume

6

fYear

2000

fDate

2000

Firstpage

3382

Abstract

This paper discusses methods for calculating and implementing the update error term for the popular blind equalization algorithm known as Godard´s (1980) algorithm, or the constant modulus algorithm (CMA), without the use of multipliers so that the chip area and signal latency are both substantially reduced. A decision-directed CMA update term is derived for higher-order (non-constant modulus) source alphabets. The modified update error term can be calculated using a look-up table in place of costly multipliers and adders. Baseband and passband implementations for one-dimensional and two-dimensional signaling are discussed

Keywords

adaptive equalisers; blind equalisers; decision theory; higher order statistics; table lookup; telecommunication signalling; Godard´s algorithm; adaptive equalizers; baseband implementation; blind equalization algorithm; chip area; decision-directed CMA update term; decision-directed constant modulus algorithm; higher-order source constellations; higher-order statistics; look-up table; modified update error term; nonconstant modulus source alphabets; one-dimensional signaling; passband implementation; signal latency; two-dimensional signaling; Baseband; Costs; Delay; Equalizers; Error correction; Passband; Quadrature amplitude modulation; Quantization; Robustness; Table lookup;

fLanguage

English

Publisher

ieee

Conference_Titel

Acoustics, Speech, and Signal Processing, 2000. ICASSP '00. Proceedings. 2000 IEEE International Conference on

Conference_Location

Istanbul

ISSN

1520-6149

Print_ISBN

0-7803-6293-4

Type

conf

DOI

10.1109/ICASSP.2000.860126

Filename

860126