符合IEEE802.16e 時域雙工之正交分頻多工下鏈之碼框同步效能研究

Abstract

OFDM的系統效能對於時序與頻率的同步相當敏感，符號時序的錯誤會造成系統效能的嚴重下降。針對時序同步的問題上我們引用了pseudo path的概念，藉由pseudo path的介入來改善系統的效能。 本文是架構在IEEE Std. 802.16e的環境下，提出了modified pseudo multipath algorithm，主要藉由pseudo path的強度以及pseudo path加入的時間點來改善系統碼框同步的效能；該方法也實現了不需增加大量硬體以及大量運算複雜度下，無論在靜止或是移動的環境之下也能夠達到更好的系統效能。

OFDM system is very sensitive to timing and frequency synchronization. A symbol timing error may dramatically degrade the system performance. We introduce the concept of pseudo path to solve the problem of frame timing synchronization. It can improve the system performance by adding the pseudo path. The thesis is based on IEEE Std. 802.16e and brings up pseudo multipath algorithm which can improve the system performance by using properly chosen strength of pseudo path and timing of pseudo path inserted. The proposed scheme is able to achieve better system performance in both fixed and mobile environment without adding lots of hardware and computing complexity.