超高頻無線射頻辨識系統，因受到多重路徑衰減的影響，導致系統效能降低。本論文提出符合台灣超高頻無線射頻辨識操作頻段規範之925MHz反向散射分集射頻辨識系統，以改善此問題。
該系統由具反向散射分集之標籤和其對應之讀取器組成。在順向鏈結方向(由讀取器到標籤)，標籤使用選擇性合併技術來改善效能；反向鏈結方向(由標籤到讀取器)，標籤使用空-時區塊編碼回傳訊號，讀取器利用最大比合併技術得到分集增益，以改善多重路徑衰減的問題。
此外考慮軟體無線電平台之複雜度限制，本論文對讀取器提出新的設計架構，改善先前文獻之標籤讀取錯誤率。

The multi-path fading problem causes Ultra High Frequency (UHF) Radio Frequency Identification (RFID) system performance degradation. To overcome this problem, a 925MHz RFID system with backscatter diversity that complies with Taiwan regulations is proposed in this thesis.
The proposed system is composed of RFID tag with backscatter diversity and its corresponding reader. In the forward (Reader to tag) link, the RFID tag uses selective combining technique to improve its performance. In the reverse (Tag to reader) link, the tag backscatters space-time block coded signals, and the reader uses maximum ratio combining technique to obtain diversity gain to mitigate the multi-path fading problem.
In addition, considering the complexity limit of the software defined radio platform that used in this thesis, a reader with new design, which has higher tag read rate than its preceding design, is proposed.

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