The principle of a novel orthogonal modulation format of differential 8-1evel phase-shift keying amplitude-shift keying （D8PSK/ASK） with differential bi-phase encoding （DBC） is introduced. Based on it, an optical labeling scheme, in which the payload is 100 Gbit/s D8PSK signal and the label is 10 Gbit/s DBC-ASK signal, is proposed and simulated. The results arc compared with other current schemes, and the effects of transmission range, modulation extinction ratio （ER） and received power on system performance are analyzed, respectively. The results show that the spectrum efficiency and bit error rate （BER） are improved greatly, and when the modulation ER is increased to 11 dB, the balanced performance between the payload and label is achieved.
We experimentally demonstrate and analyze a 10 Gbit/s full duplex wavelength division multiplexing passive optical net- work （WDM-PON） system. A non-return-to-zero differential phase shift keying （NRZ-DPSK） modulation technique is first utilized for downlink direction, and then the downlink signal is re-modulated for the uplink direction using intensity modulation technique of on-off keying （0OK） with a data rate of 10 Gbit/s per channel. An effective colorless WDM-PON full duplex transmission system is achieved for the data rate of 10 Gbit/s per channel with a channel spacing of 60 GHz over the distance of 25 km with low power penalty.
In order to achieve higher spectral efficiency, mode division multiplexing (MDM) in few-mode fibers is a new research area. The idea faces lots of technical issues including intermodal delay and mode coupling which limit the achievable length of the system. This paper is designated to complete the analysis of intermodal delay in step-index few-mode fibers. We analyze numerically all the parameters of fiber, which could impact intermodal delay in few-mode fibers and identify the conditions which can increase the number of multiplex modes without significant increase in maximum intermodal delay.
Abid Munir忻向军刘博Abdul LatifAftab HussainShahab Ahmad Niazi
We propose the single feeder fiber architecture for wavelength division multiplexing passive optical network(WDM-PON)based on directly modulated chirp managed laser(CML).The downlink(DL)signal output from the laser is converted to return-to-zero(RZ)differential phase shift signal using a pulse carver.The downstream signal is reused as a carrier for the upstream using intensity modulation technique.Simulation results show the error-free performance at symmetric data rate of 10 Gbit/s per channel with negligible power penalty and improved receiver sensitivity for the uplink(UL),over 25 km standard single-mode fiber(SSMF).A low-cost and reduced circuitry network design is implemented on a single feeder fiber with the elimination of differential encoder and one external modulator.
We propose an arrayed waveguide grating(AWG)-based 10 Gbit/s per channel full duplex wavelength division multiplexing passive optical network(WDM-PON).A chirp managed directly modulated laser with return-to-zero(RZ) differential phase shift keying(DPSK) modulation technique is utilized for downlink(DL) direction,and then the downlink signal is re-modulated for the uplink(UL) direction using intensity modulation technique with the data rate of 10 Gbit/s per channel.A successful WDM-PON transmission operation with the data rate of 10 Gbit/s per channel over a distance of 25 km without any optical amplification or dispersion compensation is demonstrated with low power penalty.
Abdul Latif余重秀忻向军Aftab HusainAshiq HussainAbid MunirYousaf Khan
The performance of colorless wavelength-division multiplexed passive optical network(WDM-PON) systems suffers from the transmission impairments mainly due to Rayleigh backscattering(RB).In this paper,we propose and demonstrate a single fiber colorless WDM-PON which enhances the tolerance to RB induced noise.The high extinction ratio in both return-to-zero(RZ)-shaped differential phase shift keying(DPSK) downstream(DS) data signal and intensity-remodulated upstream(US) data signal helps to improve the tolerance to RB induced noise.Simulation results show that downstream and upstream signals can achieve error-free performance at 10 Gbit/s with negligible penalty and improve the tolerance to RB induced noise over 25 km standard single-mode fiber.
This paper proposes a kind of modulation architecture for wavelength-division-multiplexing passive optical network （WDM- PON） employing optical differentia/quadrature phase shift keying （DQPSK） downstream signals and two different modulation formats of re-modulated upstream signals. At the optical line terminal （OLT）, 10 Gbit/s signal is modulated with DQPSK. At the optical network unit （ONU）, part of the downstream signal is re-modulated with on-offkeying （0OK） or inverse-return-to-zero （IRZ）. Simulation results show the impact on the system employing NRZ, RZ and carrier-suppressed return-to-zero （CSRZ）. The analyses also reflect that the architecture can restrain chromatic dispersion and channel crosstalk, which makes it the best architecture of access network in the future.
