| Summary: | 碩士 === 南開科技大學 === 電機與資訊工程研究所 === 99 === In orthogonal frequency division multiplexing (OFDM) system, the intercarrier interference (ICI) causes significant performance degradation. The successive interference cancellation (SIC) has been proved to have an excellent performance for mitigating the ICI in OFDM system. However, since the complexity of SIC is proportional to the number of OFDM subcarrier N, the realization of this detector becomes impractical, especially when large number of subcarrier is considered. In this thesis, a modified successive interference cancellation (SIC) algorithm which is referred to as qSIC is proposed for high mobility OFDM system. The qSIC algorithm not only significantly reduces the computational complexity of SIC algorithm, but its performance also approaches the performance of conventional SIC algorithm.
Furthermore, a fast matrix inversion for qSIC was purposed. In qSIC, the pseudo-inverse of the (2j+1)-dimensional matrices are repeatedly calculated and successively padded with zero columns. This means that the taken (2j+1)-square matrices are mostly non-full-rank. Thus this leaves room for improvement in decreasing computational complexity. The presented fast matrix inverse can obtain reliable and accurate approximations in the qSIC simulation cases.
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