可重構MIMO-OFDM系統於FPGA平台之實現

Abstract

正交分頻多工(OFDM)技術在新一代無線通訊系統佔有相當關鍵性的地位，它可提供高速數據傳輸，且適合操作在多重路徑所引起之頻率選擇性通道下;另一方面，多輸入多輸出(MIMO)技術可提升傳輸率及鏈路品質。因此，在新一代通訊系統中，MIMO-OFDM將成為極具有潛力之關鍵技術之一。在本論文中，吾人在PC上開發一套通訊系統軟體，經由該軟體上的通訊參數設定後，予以重新建構MIMO-OFDM系統模式與基頻收發機結構，其中，通訊參數包含通訊系統模式、收發機傳送與接收兩架構與RF模組等相關設定；並接著使用自行研發FPGA數位平台，整合了DAC、ADC、RF與USB等模組，來完成通訊系統硬體，最後由USB來連結兩系統的運作，而完成2×2 MIMO-OFDM無線通訊系統的整合。在系統實現上，吾人使用了即時影像技術來做為傳送與接收，並透過USB將訊號傳回PC進行顯示與分析，基於目前系統架構上，使本論文所實現的MIMO-OFDM系統能具有可重構無線電之概念。

In recent years, orthogonal frequency division multiplexing (OFDM) becomes a key technology in the development of new wireless communication systems. It enables high data rate transmission and is suitable for frequency selective channels caused by multipath propagation. On the other hand, multiple-input multiple-output (MIMO) technique has a great potential of delivering either a dramatic increase of throughput or improvement of link quality. Combined with the MIMO technique, OFDM systems become more suited to next generation wireless communications. In this thesis, a complete verification tool and environment for 2×2 MIMO-OFDM are developed. First, a PC application software is developed; most of the communication parameters, including adopted transmitter and receiver algorithm and structure, RF related settings, and so on, are all configurable on this tool. Second, a couple of self-designed FPGA boards are implemented. In particular, DAC, ADC, RF, and USB modules are integrated into this platform. Finally, to verify the system, real time video frames are transmitted from and received by PC through the USB interface, and the received picture and post analyzed results are calculated and displayed on PC. Based on this system, a MIMO-OFDM system combined with Reconfigurable radio concept can be verified and analysed.