Title :
Channel Estimation and Symbol Detection Using Superimposed Pilot for Rapidly Time-Varying OFDM System
Author :
Zhang, Han ; Dai, Xianhua ; Wu, Haifeng
Author_Institution :
Dept. of Electron. Eng. & Commun. Eng., Sun Yat-Sen Univ., Guangzhou
Abstract :
A superimposed-training (ST) based rapidly time-varying frequency selective channel estimation scheme for orthogonal frequency division multiplexing (OFDM) system is investigated. The time-varying coefficients of the rapidly time-varying channel are modeled by exponential basis expansion. Meanwhile, the optimal training sequences are derived with respect to minimizing the mean square error (MSE). Furthermore, an iterative technique for symbol detector is proposed to cancel the effects of the embedded training on symbol recovery. Simulation results confirm the effectiveness of the proposed approach, even for the rapidly time-varying channel with a great Doppler frequency.
Keywords :
Doppler shift; OFDM modulation; channel estimation; frequency estimation; iterative methods; mean square error methods; time-varying channels; Doppler frequency; MSE; embedded training; exponential basis expansion; iterative technique; mean square error; optimal training sequences; orthogonal frequency division multiplexing; rapidly time-varying OFDM system; superimposed pilot; superimposed-training; symbol detection; symbol recovery; time-varying frequency selective channel estimation scheme; Channel estimation; Detectors; Frequency division multiplexing; Frequency estimation; Mean square error methods; OFDM; Sun; Time varying systems; Time-varying channels; Wireless communication;
Conference_Titel :
Wireless Communications, Networking and Mobile Computing, 2007. WiCom 2007. International Conference on
Conference_Location :
Shanghai
Print_ISBN :
978-1-4244-1311-9
DOI :
10.1109/WICOM.2007.26
