DocumentCode :
3254073
Title :
Phase Noise Suppression for OFDM Systems Over Fast Time-Varying Channels
Author :
Can, Okan ; Huaping Liu
Author_Institution :
Oregon State Univ., Corvallis
fYear :
2007
fDate :
24-28 June 2007
Firstpage :
4346
Lastpage :
4350
Abstract :
This paper derives a phase-noise suppression scheme for orthogonal frequency division multiplexing (OFDM) systems. This scheme is a maximum likelihood approach that exploits the pilot subcarriers that exist in almost all practical OFDM systems. Compared with existing work, the proposed scheme has the following features: (a) we focus on phase-noise suppression for time-varying environments, which also cause intercarrier interference (ICI) along with phase noise. Most of the existing work considers quasi-static channels and tries to suppress the common phase error (CPE). As will be shown in this paper, in more realistic fast time-varying channels, the CPE term becomes much more complex and might significantly degrade the performance of estimators that assume a time-invariant channel, (b) the proposed algorithm is applicable for the two most common types of local oscillators: phase-locked and free-running, which have different phase-noise characteristics, (c) the proposed phase-noise suppression scheme does not require perfect channel equalization, whereas in some of the existing work the channel is assumed to be known a priori, and (d) doubly-selective fading is considered rather than assuming a time-invariant and/or flat- fading channel.
Keywords :
OFDM modulation; fading channels; intercarrier interference; interference suppression; maximum likelihood estimation; time-varying channels; OFDM systems; doubly-selective fading; fast time-varying channels; intercarrier interference; maximum likelihood approach; orthogonal frequency division multiplexing; phase noise suppression; phase-locked oscillators; Autoregressive processes; Fading; Local oscillators; Maximum likelihood estimation; OFDM; Phase estimation; Phase locked loops; Phase noise; Time-varying channels; Voltage-controlled oscillators;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Communications, 2007. ICC '07. IEEE International Conference on
Conference_Location :
Glasgow
Print_ISBN :
1-4244-0353-7
Type :
conf
DOI :
10.1109/ICC.2007.717
Filename :
4289388
Link To Document :
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