A new channel equalizer for OFDM-based wireless communications

Author

Chang, Yuan-Mao ; Kuang, Cheng-Wei ; Lin, Chien-Ching ; Sang, Tzu-Shien ; Chang, Hsie-Chia ; Lee, Chen-Yi

Author_Institution

Dept. of Electron. Eng., National Chiao Tung Univ., Hsinchu, Taiwan

fYear

2005

fDate

27-29 April 2005

Firstpage

104

Lastpage

107

Abstract

This paper presents a new channel equalizer for OFDM-based communication systems. The channel equalizer consists of the adaptive estimation of channel frequency response (CFR) and the signal recovery. CFR is obtained by the two-dimensional linear interpolation of pilots from the frequency axis and the time axis. To avoid the noise enhancement in signal recovery, maximum-likelihood sequence estimation (MLSE) is applied to improve 1.5dB in SNR while using Rayleigh fading channel model with 30Hz Doppler frequency shift. As compared to the linear equalizer without feedback, the division free approach provides more accurate signal recovery in circuit implementation.

Keywords

Doppler shift; OFDM modulation; Rayleigh channels; adaptive equalisers; adaptive estimation; channel estimation; frequency response; interpolation; maximum likelihood sequence estimation; mobile communication; 1.5 dB; 2D linear interpolation; 30 Hz; CFR; Doppler frequency shift; MLSE; OFDM; Rayleigh fading channel model; adaptive estimation; channel equalizer; channel frequency response; frequency axis; linear equalizer; maximum-likelihood sequence estimation; signal recovery; time axis; wireless communications; Adaptive estimation; Circuit noise; Equalizers; Fading; Frequency estimation; Frequency response; Interpolation; Maximum likelihood estimation; Signal to noise ratio; Wireless communication;

fLanguage

English

Publisher

ieee

Conference_Titel

VLSI Design, Automation and Test, 2005. (VLSI-TSA-DAT). 2005 IEEE VLSI-TSA International Symposium on

Print_ISBN

0-7803-9060-1

Type

conf

DOI

10.1109/VDAT.2005.1500030

Filename

1500030