DocumentCode :
1158451
Title :
RLS-Based Joint Estimation and Tracking of Channel Response, Sampling, and Carrier Frequency Offsets for OFDM
Author :
Nguyen-Le, Hung ; LE-NGOC, THO ; Ko, Chi Chung
Author_Institution :
Dept. of Electr. & Comput. Eng., McGill Univ., Montreal, QC
Volume :
55
Issue :
1
fYear :
2009
fDate :
3/1/2009 12:00:00 AM
Firstpage :
84
Lastpage :
94
Abstract :
This paper proposes a pilot-aided joint channel estimation and synchronization scheme for burst-mode orthogonal frequency division multiplexing (OFDM) systems. Based on the received signal samples containing pilot tones in the frequency domain, a cost function that includes the carrier frequency offset (CFO), sampling clock frequency offset (SFO) and channel impulse response (CIR) coefficients is formulated and used to develop an accompanying recursive least-squares (RLS) estimation and tracking algorithm. By estimating the channel CIR coefficients instead of the channel frequency response in the frequency domain, the proposed scheme eliminates the need for an IFFT block while reducing the number of parameters to be estimated, leading to lower complexity without sacrificing performance and convergence speed. Furthermore, a simple maximum-likelihood (ML) scheme based on the use of two long training symbols (in the preamble) is developed for the coarse estimation of the initial CFO and SFO to suppress dominant ICI effects introduced by CFO and SFO and to enhance the performance and convergence of the fine RLS estimation and tracking. Simulation results demonstrate that, over large ranges of CFO and SFO values, the proposed pilot-aided joint channel estimation and synchronization scheme provides a receiver performance that is remarkably close to the ideal case of perfect channel estimation and synchronization in both AWGN and Rayleigh multipath fading channels.
Keywords :
AWGN channels; OFDM modulation; Rayleigh channels; channel estimation; least squares approximations; maximum likelihood estimation; multipath channels; recursive estimation; synchronisation; AWGN channel; IFFT block; OFDM; RLS; Rayleigh multipath fading channel; burst-mode orthogonal frequency division multiplexing; carrier frequency offset; carrier frequency offsets; channel response; channel sampling; joint channel estimation; maximum-likelihood scheme; recursive least-squares estimation; sampling clock frequency offset; synchronization; AWGN; Channel estimation; Convergence; Frequency domain analysis; Frequency estimation; Frequency synchronization; Maximum likelihood estimation; OFDM; Resonance light scattering; Sampling methods; Carrier frequency offset; channel impulse response; inter-carrier interference (ICI); joint channel estimation and synchronization; orthogonal frequency division multiplexing (OFDM); recursive least square (RLS) algorithm; sampling frequency offset;
fLanguage :
English
Journal_Title :
Broadcasting, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9316
Type :
jour
DOI :
10.1109/TBC.2008.2012361
Filename :
4782999
Link To Document :
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