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Estimation of NON-WSSUS Channel for OFDM System: Exploiting Support Correlations through a Novel Adaptive Weighted Predict-Re-Estimate L1 Minimization

Chen Wang 1, Yong Fang 1, and Jin-Yan Li 2
1. Key Laboratory of Specialty Fiber Optics and Optical Access Networks, School of Communication and Information Engineering, Shanghai University, Shanghai, Shanghai, China
2. Advanced Analytics Institute, Faculty of Engineering & IT, University of Technology, Sydney, Australia

Abstract—It is challenging to estimate the wireless channel of the Orthogonal Frequency-Division Multiplexing (OFDM) broadband system under a changing communication environment. The difficulty is mainly attributed to this wireless channel’s Non Wide Sense Stationary Uncorrelated Scattering (Non-WSSUS) which has an implication that the delay and Doppler shift of such a channel are non-stationary and correlated. A Non-WSSUS channel is very different from the classical time-varying channel with constant delay and Doppler shift. In this paper, we propose an estimation method for the Non-WSSUS Channel Impulse Response (CIR) of the OFDM system. Based on the sparsity property of the delay-Doppler spread function, the delay and Doppler shift of Non-WSSUS channel can be extracted through a Compressive Sensing (CS) approach. Then a novel CS algorithm referred as Pre-Re L1 is proposed. The proposed CS algorithm exploits the correlations of the sparse supports to obtain adaptive weights for  L1 minimization. Numerical Simulation results show that the proposed CS method improves the performance of the Non-WSSUS wireless channel estimation.

Index Terms—OFDM, Non-WSSUS channel estimation, Compressive Sensing (CS), adaptive weighed  L1 minimization

Cite: Chen Wang, Yong Fang, and Jin-Yan Li, “Estimation of NON-WSSUS Channel for OFDM System: Exploiting Support Correlations through a Novel Adaptive Weighted Predict-Re-Estimate L1 Minimization," Journal of Communications, vol. 11, no. 2, pp. 149-156, 2016. Doi: 10.12720/jcm.11.2.149-156