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We experimentally demonstrate an effective hybrid equalizer with FFE and truncated Volterra filter for a 50-Gb/s PAM-4 over 50-km SSMF in a DML-based IM/DD system. The results show significant computational complexity savings without performance degradation.
Chaos generated by a semiconductor laser subject to self-phase-modulated optical feedback is proposed, where the time-delay-signature is concealed and complexity is enhanced. Fascinatingly, the probability density distribution of its output intensity is close to symmetry.
We have studied a non-orthogonal multiple access (NOMA) scheme combined with filter-bank multicarrier (FBMC) in radio over fiber (RoF) (NOMA/FBMC-RoF) downlink system for 5G communications. In this scheme, intensity modulation and direct detection (IM/DD) are employed, and we find that this NOMA/FBMC-based RoF-5G communication system can offer a high throughput, a high capacity for personnel dense...
The controller program is the core of a safety-critical control system. However, the testing of controller program has been facing challenges because of the oracle problem. Since Proportional-Integral-Derivative (PID) controller is the most commonly used controller in the industry, this paper proposes to apply Metamorphic Testing (MT) to test it. Our experimental results show that MT is effective...
A novel configuration for generation of triangular waveform is proposed. In this scheme, under the traditional condition of optoelectronic oscillator (OEO), the polarization angle of light beam is controlled and entered into the Mach-Zehnder modulator (MZM) with a unique angle for the optimum modulation axis. According to the characteristics of MZM, a part of light field executes carrier suppression,...
In this paper, we propose a method that can realize the phase stabilized of time and frequency between central office and remote antenna array simultaneously. The wavelength division multiplexing (WDM) technology is employed to transmit multiple radio frequencies and broadband time base signals possess stable phase which are based on phase conjugate and fiber dispersion method through the same single...
Datarace is a common problem on shared-memory parallel computers, including multicores. Due to its dependence on the thread scheduling scheme of its execution environment, the time to a datarace failure is usually very long. How to accelerate the occurrence of a datarace failure and further estimate the mean time to failure (MTTF) is an important topic to be studied. In this paper, the influencing...
An all-optical multilevel amplitude regenerator is optimized based on the transmission response of a nonlinear optical loop mirror (NOLM). Three regenerative regions defined by the power-transfer-function (PTF) slope of less than 1 are obtained, and noise suppression is shown for a PAM4 signal. Using amplitude dithering we were able to experimentally characterize the transfer function slope and confirm...
By an orchestra of multiple enabling techniques at the transmitter and receiver, we experimentally demonstrate a single-channel 102.4-Gb/s transmission up to 240-km standard single-mode fiber (SSMF) at C-band with direct detection. At the transmitter, we realize Nyquist-pulse shaping PAM-4 (NPAM-4) modulation and single-sideband modulation by using a dual-drive Mach-Zehnder modulator. At the receiver,...
This paper proposes a two-dimension encryption orthogonal frequency division multiplexing passive optical network (OFDM-PON) based on dynamic chaos-iteration. The correlation monitoring method is adopted to achieve dynamic key distribution between OLT and ONUs. It is shown that key space can be larger than 1086, which would be against exhaustive attack effectively. We experimentally demonstrate a...
We propose a scheme for fast random number generation with a bandwidth-enhanced chaotic signal generated by injecting the signal of a traditional chaotic external-cavity semiconductor laser (ECSL) into a spectrum expansion module (SE). Our simulation results show that the bandwidth-enhanced chaotic can be generated and its efficient bandwidth can be greatly enhanced up to 70 GHz. Random bits in our...
We study the artificial neural network (ANN) and feed forward equalizer jointly to mitigate the inter-symbol interference (ISI) and the nonlinear distortions in the optical single-side band and direct-detection (DD) system. The optical SSB signal is generated by a relatively low-cost dual-drive Mach-Zehnder modulator (DDMZM). The two driving signals are a pair of Hilbert signals with Nyquist pulse-shaped...
High extinction ratio is needed in high precision Optical Time Domain Reflectometer (OTDR) to enlarge the dynamic range. By transmitting part of pulse signal modulated by a Mach-Zehnder (MZ) optical modulator back to the input of the modulator via a feedback circuit, the pulse signal can be multi-modulated by one MZ optical modulation. And this technique offers great enhancements in the performance...
To achieve the better combination of cost and communication capacity, this paper proposes a colourless ONU remodulation scheme based on R-QDSOA in WDM-PON. The R-QDSOA can provide a modulation bandwidth over 20GHz and achieve directly modulation of high-order signal. Here, two remodulation schemes (respectively NRZ/4QAM and 4QAM/NRZ) at different modulation rates are implemented, which offers good...
A security-enhanced chaos communication scheme by expanding and compressing the spectrum of modulated chaotic carrier is proposed, in virtue of a spectrum expansion module composed of two phase modulators and two dispersion mediums. The numerical results demonstrate that the efficient bandwidth of modulated chaotic carrier can be expanded up to several tens of GHz and the RF spectrum is uniformly...
Chaos synchronization in closed-loop external cavity semiconductor lasers subject to phase-conjugate feedback is investigated theoretically and numerically. We theoretically analysed the injection-locking synchronization condition and numerically confirm it. The simulation results indicate that with introduction of feedback phase difference according to the theoretical synchronization condition, high...
We have numerically demonstrated a high-speed bidirectional chaotic communication, where chaotic optical signal with suppressed time delay signature is used. In this scheme, the output of a third semiconductor laser is used as the common signal driving the other two identical lasers with self-feedback to be synchronized. To enhance the bandwidth of the chaotic signal employing in the communication,...
By introducing sinusoidal phase-modulated feedback to semiconductor lasers of closed-loop chaos-based communication system, the efficient bandwidth of chaotic carrier can be broadened greatly, the BER performance can be improved, and the communication security is enhanced.
We propose and demonstrate a Hilbert Superposition (HS) scheme in an optical single side-band (SSB) modulation and direct-detection system. The optical SSB signal is generated by a relatively low-cost dual-drive Mach-Zehnder modulator (DDMZM) biased at the quadrature point. The two driving signals are a pair of Hilbert signals with Nyquist pulse-shaped four-level pulse amplitude modulation (NPAM-4)...
Utilizing digital filtering-enabled signal multiplexing and de-multiplexing, we propose and demonstrate a novel cost-effective all-optical virtual private network (VPN) in digital filter multiple-access (DMFA) based passive optical networks (PONs), which not only provides dynamic establishment and cancellation of the VPN communications, but also concurrently supports multiple VPN communications. In...
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