Distortion Compensation for Block Transmission System with Cyclic
نویسنده
چکیده
あらまし サイクリックプレフィックス (CP)を用いたブロック伝送では,CPの付加及び除去を含めた通信路 が巡回行列で記述されるが,ガード時間 (GI) を超える遅延波が存在する場合などには巡回行列の一部の成分が 欠落した行列(不完全巡回行列)による信号ひずみが観測される.本論文では,CP を用いたブロック伝送方式, 特にシングルキャリヤのブロック伝送 (SC-CP) 方式を対象に,不完全巡回行列による信号ひずみを少ない要求 演算量で補償する手法を提案する.提案方式では,新たに導出したMMSE (Minimum Mean-Square-Error)基 準離散周波数領域等化器重みとその等化器出力信号の信頼度の違いを利用した擬似逆行列による等化器によって, 不完全巡回行列による信号ひずみを巡回行列による信号ひずみに変換することで,従来からの離散周波数領域等 化器を利用可能にする.計算機シミュレーションにより提案方式の特性を評価し,離散周波数領域等化器のみを 用いる手法と比べて大幅な特性改善が得られ,要求演算量の大きい線形 MMSE等化器よりも良好な特性が得ら れることを明らかにする. キーワード サイクリックプレフィックス,ブロック伝送,離散周波数領域等化,巡回行列
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