近年來由於數位訊號處理器(DSP)及超大型積體電路(VLSI)技術的進步,加上人們對於高速率的資料傳輸需求逐漸增加,所以擁有高效能的OFDM系統已廣泛應用於高速率數位通訊技術,如數位視頻廣播(DVB)、非對稱式數位用戶迴路(ADSL)、同時也是第四代行動通訊系統規範的核心技術。克服使用導頻符號後資源浪費的缺點,本文將探討一種基於DSP的OFDM同步系統的設計:使用OFDM符號(後半部分)插入到符號起始位置,構成循環字首(CP),並且配合符號定時同步和載波頻率同步的最大相似估計同步算法。通過軟體模擬建立系統的架構設計,硬體實現使用德州儀器的TMS320C6713完成OFDM同步系統。經過實驗的證明,驗證硬體實現的可行性。
Since the rapid development of the Digital Signal Processor (DSP) and Very-Large-Scale Integration (VLSI) technology the requirement of high-speed data transmission increase gradually. Therefore, high-performance OFDM system has been widely used in high-speed digital communication technology, such as Digital Video Broadcasting (DVB), Asymmetric Digital Subscriber Line (ADSL) and the Fourth Generation Mobile communication System Standardized kernel Technologies. Using the pilot symbols to overcome the disadvantages of the waste of resources, this thesis investigates a DSP-based design of OFDM synchronization system. insert the OFDM symbol (rear part) into the symbol start position to establish compose the Cyclic Prefix (CP), and imply the Symbol Timing Synchronization and Frequency Carrier Synchronization Algorithm for the Maximum Likelihood Estimate Synchronization. more over, OFDM Synchronization system is implemented by simulation of software system and Hardware Implementation - the Texas Instruments (TI) of the TMS320C6713. The feasibility of hardware implementation is verified by experiments.