An improved iterative channel estimation algorithm for high mobility OFDM systems

Author(s): Honggui Deng, Junzhi Zhao, Xu Deng, Songshan Ma

The inter-carrier interference caused by time-variant fading channels is analyzed in high mobility OFDM systems. An improved iterative channel estimation algorithm is proposed for the systems. The wireless channel is estimated through a weighted time-domain interpolation of the pilot channel coefficients. The interpolation weights are designed according to the Doppler spread, which is calculated by the velocity of the receiver. The pilot channel coefficients are iteratively estimated by pilot tones using a Least Square (LS) method. During the iterative process, the detected data symbols are feed back as new pilots to optimize the estimates of pilot channel coefficients. The simulation results show that the proposed algorithm outperforms the existing methods. When the receiver moving at a speed up to 300Km/h, the performance degradation of the proposed method compared to the performance of perfect channel estimation is only 1dB-2dB.

OFDM, ICI, time-variant channel, iterative channel estimation

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