六倍頻60GHz光通訊系統載上7GHz之OFDM訊號研究及訊號預先編碼技術

Abstract

近年來多媒體影音的各種服務快速崛起，因此對於通訊系統的資料傳輸速率也有越來越高的要求。本篇論文提出一種新型的六倍頻光調變技術，且此種調變技術可以傳輸向量訊號。此技術使用兩顆外接式光調變器，第一顆提供修正型單邊帶(Modified SSB)調變系統，第二顆則提供四倍頻昇頻技術。系統載上88個次載波，符號率78.125-Mb/s的OFDM訊號，訊號格式使用QPSK及8QAM，故資料率分別可達13.75-Gb/s及20.625-Gb/s。此外，我們使用資料預先編碼技術，證明了即使是雙邊帶載波抑制(DSBCS)調變系統，仍然可以載上向量訊號。

Broad band wireless systems have been considered as a potential solution for the future quad play services. With the release of 7-GHz license free band, 60-GHz millimeter-wave wireless system has been widely investigated recently. In this work, a 60GHz Radio-over-Fiber (RoF) system with frequency sextupling is experimentally demonstrated. Two dual-parallel Mach-Zehnder modulators is used in this demonstration, one for modified single sideband (SSB) modulation with frequency doubling and one for frequency quadrupling. OFDM signal generation is applied to this system, and we demonstrate with data-rate 13.75-Gb/s OFDM-QPSK signal, and data-rate 20.625-Gb/s OFDM-8QAM signal. Additionally, we demonstrate that double sideband with carrier suppress (DSBCS) modulation scheme can also transmit vector signal by signal pre-coding.