Low-complexity and low-latency implementation of the Godard/CMA update

Author

Endres, Thomas J. ; Hulyalkar, Samir N. ; Strolle, Christopher H. ; Schaffer, Troy A.

Author_Institution

NxtWave Commun. Inc., Langhorne, PA, USA

Volume

49

Issue

2

fYear

2001

fDate

2/1/2001 12:00:00 AM

Firstpage

219

Lastpage

225

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 chip area and signal latency are both substantially reduced. One approach uses a decision-directed CMA update term, and another uses region-based quantization. The quantized error term can be calculated using a look-up table in place of costly multipliers and adders. Baseband and passband implementations are discussed, and computer simulations verify our methods

Keywords

adaptive equalisers; blind equalisers; computational complexity; error analysis; quantisation (signal); table lookup; Godard´s algorithm,; Godard/CMA update; adaptive equalizer; baseband implementation; blind equalization algorithm; computer simulations; constant modulus algorithm; decision-directed CMA update term; look-up table; low-complexity implementation; low-latency implementation; passband implementation; quantized error term; region-based quantization; update error term; Baseband; Computer errors; Delay; Equalizers; Passband; Pulse modulation; Quadrature amplitude modulation; Quantization; Signal processing algorithms; Table lookup;

fLanguage

English

Journal_Title

Communications, IEEE Transactions on

Publisher

ieee

ISSN

0090-6778

Type

jour

DOI

10.1109/26.905869

Filename

905869