數位通訊中之碼框同步在3GPP與TDMA-PACS中的研討

Abstract

碼框同步的用途是在於觀察通訊傳輸的表現與提供接收端進一步解碼所需的資訊。碼框同步的作法是在要傳送的信號碼框中加入一些冗餘，之後在接收端利用這些冗餘以確定碼框的起使位置。 第三代行動通訊標準3GPP WCDMA FDD中，這些冗餘是一段事先定義的碼框同步字元。在上鏈傳輸中，碼框同步可以藉由觀察碼框同步字元的自相關係數而達成。在以分時多工為核心（TDMA）的PACS系統中，傳輸上鏈碼框同步字元則使用錯誤更正碼，並將碼框同步與錯誤偵測結合。本論文中分別對這兩種碼框同步的方式進行研討與電腦模擬。

Frame synchronization is basically used to identify bit component in a packet transmission communication. It can also used to monitor transmission performance and provide information for further decoding. Frame synchronization is achieved at the receiver by determining or locating the redundancy inserted into the transmitted sequence. In 3GPP WCDMA FDD system, the redundancy is a known sequence defined in 3GPP specification called frame synchronization words. Uplink frame synchronization can be achieved by correlation function of these frame synchronization words. In the TDMA-PACS system, the uplink frame synchronization words are combined with error-control coding. One algorithm is used for both frame synchronization and error detecting in PACS. This Thesis analyzes the performance of the two types of frame synchronization and do computer simulation under the two communication systems.