DocumentCode :
1489852
Title :
Analysis of interpolated channel estimation for mobile OFDM systems
Author :
Tomasin, Stefano ; Butussi, Matteo
Author_Institution :
Dept. of Inf. Eng., Univ. of Padova, Padova, Italy
Volume :
58
Issue :
5
fYear :
2010
fDate :
5/1/2010 12:00:00 AM
Firstpage :
1578
Lastpage :
1588
Abstract :
In an OFDM system using pilots for channel estimation, time interpolation among pilots of different OFDM symbols is commonly used to improve the estimate. The estimated channel impulse response may be also windowed to further reduce noise and disturbances. However, for a transmission over a time-varying channel, suboptimal time interpolation, implemented with a filter having only a few taps not matched to the maximum Doppler frequency, degrades channel estimation. In this paper we provide an analysis of the effects of pilot time interpolation over time-varying channels. We show in particular that suboptimal time interpolation yields aliases in the estimated channel impulse response and we derive a closed-form expression of the aliases¿ variance. As aliases can lead to an erroneous estimate of channel length and consequent errors in windowing, we propose a technique to detect aliases and correct the channel length estimate. Parameters of the detection techniques are optimized by an analysis that provides closed-form expressions of the false alarm and miss detection probabilities. Numerical results show the merits of the proposed techniques in a mobile transmission of the terrestrial digital video broadcasting standard (DVB-T).
Keywords :
OFDM modulation; channel estimation; digital video broadcasting; interpolation; mobile radio; time-varying channels; channel estimation; channel impulse response; channel length; channel length estimate; consequent errors; filter; maximum Doppler frequency; mobile OFDM systems; mobile transmission; pilot time interpolation; suboptimal time interpolation; terrestrial digital video broadcasting standard; time-varying channel; Channel estimation; Closed-form solution; Degradation; Digital video broadcasting; Frequency estimation; Interpolation; Matched filters; Noise reduction; OFDM; Time-varying channels; Broadcasting, channel estimation, interpolation, OFDM;
fLanguage :
English
Journal_Title :
Communications, IEEE Transactions on
Publisher :
ieee
ISSN :
0090-6778
Type :
jour
DOI :
10.1109/TCOMM.2010.05.090052
Filename :
5464257
Link To Document :
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