IQ imbalance can result in severe performance degradation in direct-detection architectures. We build two back-to-back direct-detection optical OFDM systems, which implement DSB and SSB transmission, ...respectively. The tolerance to IQ imbalance of them is analyzed and compared using EVM and SER. We conclude that the DSB system has a stronger robustness to IQ imbalance than the SSB system.
We propose and experimentally demonstrate a novel architecture for OFDM-PON system. The down link is based on single side band OFDM modulation while the up link makes use of the carrier information ...retained in another side band to intensity modulate the data.
In-phase/quadrature-phase (IQ) imbalance can result in severe performance degradation in optical direct-detection orthogonal-frequency-division-multiplexing (DD-OFDM) systems. We build two optical ...back-to-back DD-OFDM systems, which implement double-sideband (DSB) and single-sideband (SSB) modulation, respectively. The tolerance to IQ imbalance of these two systems is analyzed and compared using error vector magnitude (EVM) and symbol error rate (SER). We find that, in the back-to-back case, the DSB system has stronger robustness to IQ imbalance than the SSB System. We further build two optical DD-OFDM systems each with 40-km transmission, which respectively implement DSB and SSB transmission. Similarly, we analyze and compare the tolerance to IQ imbalance of these two systems in terms of EVM and SER. We find that, however, in the case of 40-km transmission, the SSB system has stronger robustness to IQ imbalance than the DSB system. As a result, we conclude that, in the case of transmission, SSB modulation can enhance the tolerance to IQ imbalance of DD-OFDM systems.
In this paper, all-optical OFDM transmitter and receiver with 5×20Gbit/s were simulated. The 100-Gbits/s signal was successfully transmitted over 40-km-SMF without dispersion companion in the ...simulation experiment. We have analyzed the principle of orthogonal carrier generation, and obtained the optimal configuration for two, three and five orthogonal carriers. Through designing proper system parameters, the clearly eye diagrams were obtained. The BER curves of five orthogonal signals were detected.
We propose and experimentally demonstrate a novel architecture for OFDM-PON system. The down link is based on single side band OFDM modulation while the up link makes use of the carrier information ...retained in another side band to intensity modulate the data. The downstream transmission will be demonstrated experimentally to exceed 10Gb/s using 4-QAM while the upstream transmission will exceed 2.5-Gb/s using ASK modulation and Time Division Multiple Access (TDMA). This architecture can perfectly overcome the Rayleigh scattering effect. It has been proved the transmission for both directions can reach 10km without bit error. And if the scattering effect is considered, the power penalty will be less than 0.8dB for downlink and 1.8dB for uplink.
Two novel optical phase modulation formats, the staggered differential phase-shift keying (SDPSK) with return-to-zero (RZ) and carrier-suppressed return-to-zero (CSRZ) shape, are proposed and ...compared by numerical simulation for 100 Gbit/s medium-range transmission applications. The demodulation of two phase formats can be achieved on 1 bit rate through only one Mach-Zehnder delay interferometer and a balanced receiver. Superimposed RZ and CSRZ signals are extracted and recovered to compare their transmission performance.
