Applied Research, Frequency Shift Keying In Passive Optical Networks

The development of access network is always driven by the demand for higher bandwidth nowadays. Passive optical network, featuring its low cost, high capacity and great reliability, has become the most promising access solution. Modulation formats with high bit rate and high spectral efficiency as well as coherent detection are both key techniques in increasing bandwidth and system performance, thus it has been universally accepted that their implementation is critical for improving passive optical network. Meanwhile, novel architecture, which enables service suppliers to deploy passive optical network better, has attracted increasing attention.We propose and demonstrate a passive optical network system utilizing high speed frequency shift keying generation method, re-modulation technique and image rejection receiver. High speed signal generation method enables higher system bit rate while re-modulation simplifies the structure of optical network unit. At the same time, obvious receiver sensitivity improvement can be obtained when image rejection receiver is adopted. We also analyzed several parameters which affect the receiver sensitivity to optimize performance. Results show the proposed scheme is suitable for super long reach access network, especially the metropolitan area network in future. Meanwhile, principle and key techniques for novel ring-tree hybrid architecture in passive optical network are illustrated in detail. We discuss advantage, shortcoming and application of the novel architecture and provide the basis for convergence of future access network and metropolitan area network.