| Summary: | 碩士 === 國立交通大學 === 電信工程系所 === 97 === For orthogonal frequency division multiplexing (OFDM) systems in high-mobility environment, channel variations within one OFDM symbol will introduce intercarrier interference (ICI), thus lowering the system performance. This becomes more severe as vehicle speed or OFDM symbol duration increase. In this paper, an iterative receiver architecture based on joint channel estimation and data detection is proposed for MIMO OFDM systems in mobile wireless channels. The iterative receiver mainly consists of three-stage processing. In the initialization stage, we employ a multipath interference cancellation technique to roughly estimate multipath delays and multipath complex gains through the preamble. In the tracking stage, a -tracker is applied first, followed by decision-feedback (DF) DFT-based channel estimation which is based on V-BLAST data detection, so as to estimate the average channel variations of each path. In the final stage, we adopt a linear model to approximate time variations of each path, and a two-dimensional V-BLAST method is utilized to perform ICI cancellation and data detection. Finally, computer simulations are conducted to verify the performance of the iterative receiver in high-mobility channels.
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