為了要利用多輸入多輸出正交分頻多工系統中的空間多樣性，傳輸端的波束成形及接收端的結合為一種簡易的方法來達到要求。而這種技術可被應用在IEEE 802.22無線區域網路來維持其位元錯誤率的效能。我們將Grassmannian波束成形及天線選擇兩種方法結合來達到較好的位元錯誤率。此外，在考慮到無線區域網路的通道特性下，也結合了子載波分組的方法。最後我們對不同的通道模型做模擬，模擬結果在此被提出來比較並作討論。

Transmit beamforming and receive combining are simple methods for exploiting spatial diversity in multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) systems. Such techniques can be applied on the IEEE 802.22 wireless regional area network (WRAN) to maintain bit-error-rate (BER) performance. We combine Grasmannian beamforming and antenna selection algorithm to get superior BER performance. In addition, subcarrier grouping is also added by thinking of the characteristic of the WRANs. Simulation results in different WRAN reference channel models are shown here for comparison.

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