本論文主要是探討IEEE802.16e-2009規格的下行傳輸中,使用遞增冗餘尾端迴旋碼(Tail-Biting Convolutional Code;TBCC)的HARQ機制。在IEEE802.16e規格中,當對資訊要求較高的傳輸品質時,可採用混合型自動重傳請求(Hybrid Automatic Repeat Request;HARQ)機制傳送資訊。此機制是結合前向錯誤更正(Forward Error Correction;FEC)及自動重傳請求(Automatic Repeat Request;ARQ)的技術,其概念是利用傳送失敗的封包中存留下的資訊,提高重新傳送封包的正確性,以提升系統效能。本論文模擬不同調變及碼率的重傳機制,並找出最佳HARQ傳輸策略。
This paper investigates the IEEE802.16e-2009 standard in the downlink, the use of the incremental redundancy tail-biting convolutional codes(TBCC)in HARQ mechanism. In IEEE802.16e standard, when transmission of require higher quality information, we can use hybrid automatic repeat request(HARQ)mechanism to transmit information. This mechanism is a combination of forward error correction(FEC)and automatic repeat request(ARQ)technology, the concept is that using a packet transmitted fail kept the information to improve the correctness of re-transmitted packets, to increase system performance. This paper is simulating different modulation and code rate of retransmission mechanism, and find out best HARQ transmission strategy.