本論文中，我們運用波長再技術，設計出以WDM-PON為基礎架構之光纖-無線寬頻接取網路，此方案可以同時提供數據以及RoF傳輸服務。在光線路終端(Optical Line Terminal, OLT)採用10 Gbps直調式DFB雷射載送10 Gbps下行數據，再經法布里-珀羅析光器(Fabry-Perot Etalon)提升下行數據訊號品質以及提供再生光源作為下行RoF訊號載送，每一再生光源以反射式半導體光放大器(Reflective Semiconductor Optical Amplifier, RSOA)再次調變上速率5 Mbps下行2.5-GHz RoF訊號。在光網路單元(Optical Network Unit, ONU)則採用單顆RSOA將下行類比射頻訊號光源再次調上1.25Gbps上行數據訊號以及速率5 Mbps上行1.5-GHz RoF訊號。因此，本方案以最佳成本效益方式達成光纖-無線寬頻接取網路之需求。 Recently, the research and development of wavelength-division-multiplexed passive optical network (WDM-PON) is considered as a solution to next generation network technology providing higher data rates and long-distance transmission. On the other hand, accompanying the latest development of the fourth generation wireless communication technology, the research in radio over fiber (RoF) has also been widely discussed.
In this thesis, we utilize the wavelength reuse technologies to design a fiber-wireless (FiWi) broadband access network based on the WDM-PON architecture. The proposed scheme can provide the transmission services for data and RoF simultaneously. At the optical line terminal (OLT), directly modulated DFB lasers with the data rate of 10-Gbps carry the own downstream data, and then Fabry-Perot etalons are used to enhance the signal quality of the downstream data and to provide reusable lights for transporting downstream RoF signals. Each of those reusable lights is modulated by a reflective semiconductor optical amplifier (RSOA) with 2.5-GHz downstream RoF signal at the data rate of 5 Mbps. In the optical network unit (ONU), we use the downstream RoF light as the upstream source and choose a single RSOA to re-modulate 1.25-Gbps upstream data signal and 1.5-GHz upstream RoF signal with the data rate of 5 Mbps. Therefore, this scheme can achieve the best cost-effective way to meet the demands for FiWi broadband access networks.
