Key Techniques For Converged UWB Wireless And Baseband Wired Access Over WDM-PON

In recentyears,communication has become a part of people’s daily life. With the increased newbusiness and users, the capacity of communication networks faces great challenges. Wavelengthdivision multiplexing passive optical network (WDM-PON), with the advantages of high-speed,large-capacity, transparent transmission, has become the most promisingaccess network. In the aspectof wireless communication, ultra-wideband (UWB) technologyhas drawnmuch attention for its highdata-rate, high reliability of transmission,good confidentiality and security, simple structure andelectromagnetic compatibility. In order to meet the future demands for higher transmission data-rate,higher communication capacity, more flexibilityforup gradationand wavelength routing, theconvergence between WDM-PON and UWB over fiber technologies is of great importance.Based on analysis of the convergence of WDM-PON and UWB over fiber technology, mainresearch contentsare: wavelength reuse based on the gain saturation in a SOA, photonic generationand transmission of UWB signals and evaluation of the direct modulation in a distributed feedbacklaser diode (DFB-LD) in the central office.When investigating the gain saturation effect in the SOA, the relationship of gain in the SOA tothe input optical power and carrier lifetime is theoretically analyzed. Furthermore, experiment iscarried out to prove that the gain saturation in the SOA is frequency-dependent, based on which acolorless remote antenna unit is established, achieving the up and down link of a500Mb/s PRBSsignal, which is up-converted to2GHz.Next, UWB over fiber systems based on the SOA and the microwave photonic filter aredemonstrated respectively.1.5625Gb/s and1.25Gb/s UWB signalsare generated and transmitted via20km SMF. These systems are flexible and can be compatiblewith the WDM-PON networks.For the evaluation of direct modulation of a DFB-LD, the frequency response and the dynamicrange of the DFB-LD is estimated, achieving the direct modulation and transmission via10kmsingle-mode fiber (SMF) of300Mb/s base band signal and1.5625Gb/s UWB signal. The waveforms,spectra and the bit error rate all prove that the system is stable and suitable for WDM-PONapplications.