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8×100 Gb/s All-optical Polarization-multiplexed OFDM Transceiver Technology Research

Posted on:2015-04-16Degree:MasterType:Thesis
Country:ChinaCandidate:P SuFull Text:PDF
GTID:2308330473953178Subject:Optical Engineering
Abstract/Summary:PDF Full Text Request
With the rapid growth of the modern communications networks information, and the improving of citizens’ information degree, people put forward higher requirements for the information transmission rate of communication networks. Optical orthogonal frequency division multiplexing(OOFDM) technology with its high bandwidth efficiency and strong anti-interference ability become one of the cost-effective technical solutions. However, due to the electronic signal processing rate "electronic bottleneck" restrictions, with the increasing of long-distance transmission, the traditional OFDM signal has been a great challenge.In order to solve the above issues, this article takes the generation and demodulation of OFDM signals directly on the optical field as the main object of study in order to reduce the system’s dependence on the electronic processing speed. Based on the depth analysis of the principle of all-optical OFDM transceiver system, built the eight carriers all-optical polarization multiplexed OFDM system in the VPItransmissionMaker, and the following three points are studied in this thesis:1. For the all-optical OFDM signal generation techniques, using the Mach Zehnder modulator(MZM) mechanism characteristic to generation the optical comb, study on a simple structure and easy to implement program by cascaded optical intensity modulators. And simulated it in the VPI, 16 optical spectrum are generated with the equal frequency interval and less than 3 dB flatness. It’s also analyzed the generation of discrete all-optical OFDM signal using optical delay and phase shifter, and on this basis further optimization with the planar waveguide(PLC) generating device.2. According to the principle of all-optical OFDM demodulation, utilize the discrete Fourier transform(ODFT) to get a demultiplexing method using the cascaded Mach Zehnder delay interferometer(MZDI) structure, demultiplexed the optical OFDM directly on the optical domain. Made on the basis, we proposed the specific parameter settings at any center frequency of the MZDIs. Thus there is no need then modulated the multiplexed signal to a particular frequency, achieved a real sense of all-optical OFDM signals’ modulation and demodulation.3. Utilize the VPI simulation platform to build the eight carriers all-optical OFDM back to back system, the transmitter using cascaded MZM optical frequency comb generator to select eight light spectrum, and each signal is modulated by QPSK, combined with polarization multiplexing to increase the bit-rate. In the receiver, using cascaded MZDIs to demultiplex optical OFDM signals, and then demodulated the original data with a usual coherent demodulation after an optical gate. The simulation results shows that it is available to update the current single carrier system using all-optical OFDM and common coherent optical receiver while without introducing signal impairment.
Keywords/Search Tags:All-optical OFDM, optical frequency comb generator, polarization multiplexing, Mach-Zehnder Delay Interferometer(MZDI)
PDF Full Text Request
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