Performance Evaluation Of New Light Marking Based On DQPSK Load In High Speed OLS Systems

The increasing of transmission rate caused by the big data lead to a great challenge on the electrical switching. The electrical switching rate cannot match the optical transmission rate, optical switching must be studied. As a kind of optical switching, optical label switching(OLS) can solve the problem of system capacity limitation caused by electrical switching to a certain extent, and implement the data transmission in optical domain. Orthogonal modulation OLS is one of OLS technology which has many advantages, such as simple structure, high spectral efficiency, easy to implement and so on, it is a promising scheme for the optical network. The payload and label in orthogonal modulation OLS system combined into an optical packet before transmit in optical fiber, this is similar with combination modulation. Combine different modulation formats to generate a new modulation format that has high receiver sensitivity is the research key point of orthogonal modulation OLS system.In this paper, the theoretical bit error rate(BER) of three modulation formats and three combination modulation formats are studied, they are differential quadrature phase shift key(DQPSK),duobinary(DB), pulse position modulation(PPM) and polarization multiplexing(POLMUX)-DQPSK, POLMUX-DQPSK-DB, POLMUX-DQPSK-PPM, respectively. In addition, two orthogonal modulation OLS schemes which are based on payload of POLMUX-DQPSK with label identifications of DB and PPM are designed. The main contents are as follows:First, some optical technology and principle based on OLS system are introduced.Then, the principle of coding, modulation and demodulation of DQPSK, POLMUX-DQPSK, DB and PPM is analyzed, and the theoretical BER expressions are given. By comparing with traditional modulation formats such as on-off keying(OOK), the receiver sensitivity advantages of DQPSK, POLMUX-DQPSK, DB and PPM are illustrated. The theoretical BER expressions of POLMUX-DQPSK-DB and POLMUX-DQPSK-PPM are also given, by refer to researches on combination modulation. When POLMUX-DQPSK combined with DB or PPM, the system receiver sensitivity can be improved, and always better than combined with OOK.Finally, two high bit-rate orthogonal modulation OLS schemes which are based on payload of 100Gb/s POLMUX-DQPSK with label identifications of 2.5Gb/s DB and PPM are designed. With help of OptiSystem, the transmission performance of these two OLS systems is analyzed, and the influence of label on payload is studied. By comparing the simulation results with theory conclusion, the advantages of DB and PPM as optical label are confirmed.The main work of this paper is providing theoretical BER expressions of POLMUX-DQPSK payload, DB label, PPM label and the combination optical packet, and designing two orthogonal modulation OLS schemes to verify the advantages of DB and PPM as optical label, giving some theory research for the future large capacity and long distance OLS system.