학술논문
Channel estimation versus equalization in an OFDM WLAN system
Document Type
Conference
Author
Source
IEEE VTS 53rd Vehicular Technology Conference, Spring 2001. Proceedings (Cat. No.01CH37202) Vehicular technology Vehicular Technology Conference, 2001. VTC 2001 Spring. IEEE VTS 53rd. 1:653-657 vol.1 2001
Subject
Language
ISSN
1090-3038
Abstract
We study an OFDM system, following the IEEE 802.11a standard, with QPSK modulation, allowing a 10 Mbps data rate when using convolutional coding. We compare one-tap equalization and channel estimation structures in the frequency domain by theoretical analysis and floating point simulations. We use the minimum mean square error (MMSE) and the zero-forcing (ZF) criteria. In the adaptive case, we use the RLS algorithm. We compare data aided (using pilot tones), and decision directed modes. The analysis is made for AWGN, one path Rayleigh fading, one path Ricean fading and multipath Ricean fading channels. The ZF criterion performs better than the MMSE criterion. The channel estimator is simpler and performs better than the equalizer in Ricean fading channels. This paper proposes new insights on the ZF and MMSE criteria, equalization and channel estimation.