對基於衰減通道的正交分頻多工系統，我們運用具有遞迴均方演算法的頻域等化器來估測信號。本論文採用的衰減通道模型為加入Walsh-Hadamard編碼的修正型傑克模型，我們並以此模型模擬具頻率選擇特性的雷利衰減通道，且都卜勒漂移、頻率偏移和雜訊對系統的影響都會被考慮在其中。我們運用正方形4-QAM的信號於具有16個子通道的正交分頻多工系統做為實驗模擬的基本架構。實驗及討論結果顯示慢速衰減通道整體而言有相當不錯的表現。 For orthogonal frequency division multiplexing (OFDM) systems over fading channels, we apply recursive least-squares (RLS) algorithm to a frequency domain equalizer (FEQ) for signal detection. For fading channel model, we use modified Jakes model with Walsh-Hadamard precoding to simulate frequency-selective Rayleigh fading in our simulation works. Effects on system performance of Doppler spread, frequency offset, and noise are studied. In simulations, square 4-QAM signaling in a 16 subband OFDM system is employed. Study results show that the scheme works well for slow fading channels.
