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In this paper, a novel polarization mode dispersion (PMD) monitoring method by adding auxiliary optical signal is presented. Based on four-wave mixing (FWM), the PMD can be monitored in all-optical domain by measuring the power of the idler wave. With the help of auxiliary signal, the change trend of idler wave power with PMD will be enlarged, which expands the scope of monitoring and improves the...
We demonstrated a dense sub-carrier uniform division labeling transmission system by using MATLAB software. The simulation results indicated that dense sub-carrier uniform division labeling has a good advantage over that ordinary OFDM system, and the signals at a bit rate 50Gbit/s have a good performance which is more than 10 when OSNR is equal to 25dB over 1000km optical fiber channel which only...
In this paper, a novel phase noise estimation method (PNE) for multi-level modulations is proposed based on local optimization (LO PNE). The effectiveness of this method is demonstrated and discussed in a 200G bit/s coherent transmission system. It has been proved, the usage of throwing-point (TP) test rotation and convex programming in LO_PNE reduce the complexity of phase estimation for arbitrary...
In this paper, we proposed an optical encryption /decryption system based on all-optical shift register. The key used for encryption and decryption is an all-optical pseudorandom bit sequence (PRBS). By analysing the performance of the core functional unit of this system, which is composed of SOA-based logic XOR and all-optical clocked D flip-flops, we demonstrated the system's capability of producing...
We introduced the image processing application to identify fracture and calculate fracture porosity based on the image logging for the gas-bearing shale. Shale gas is an unconventional gas resource and has been paid more attention in recent years. The pore structure of shale is very complicated, where fracture is the main flowing channel. The conventional logging and the imaging logging offer the...
With the introduction of virtual machine introspection into IaaS cloud, indirect inspection of the state about guest VMs is supported with strong isolation. But it requires the privilege access to the virtual machine monitor and lacks manageability due to the need of installing various security vendors' agents in a privileged VM. In this paper, we propose an agentless and uniform introspection framework,...
In order to reduce measure standard uncertainty and achieve precise calibration of Port Quick Leak Detector in different temperatures under full range, the special calibration apparatus was designed on basis of theoretical studies. This apparatus consists of pressure standard leak system, calibration system, temperature control system, gas supply and pump system. Pressure standard leak system is made...
In this paper, the robust quadrotor attitude regulation based on fault tolerant control schema is investigated. The hover stability is heavily dependent on the thrust forces generated by the four rotors of the quadrotor. Once the rotors are in fault and loss the efficiency, the quadrotor will be unstable, even out of control. To the end, this paper presents a robust fault tolerant control schema for...
Phylogeny model inference plays an important role in malware forensics. It aims at revealing the evolutionary relationship among malware instances. It is expected to be helpful for uncovering the trends of malware evolution and establishing a principled naming scheme. Although tree-based models are the mainstream direction, they are not suited to represent the reticulation events which are occasionally...
In this paper, we have proposed an optical pulse position modulation based on double-circle iteration, targeting at the next generation of high speed optical metropolitan area networks. The focuse of this paper lies on the performance of spectral efficiency, the bit error rate and chromatic dispersion. The proposed modulation format is also compared to on-off-keying(OOK) and 4-level pulse-amplitude...
Passive Optical Network (PON) is the most promising technology in optical access network, and the effective and reasonable upstream dynamic bandwidth allocation (DBA) is the key. This paper proposes a new software defined WDM-TDM PON frame that enable more users to share a single high-capacity fiber access as well as introduce a flexible DBA module to replace the hardware-configured DBA module. The...
We propose a first-order Polarization Mode Dispersion (PMD) monitoring technique for phase-modulated optical signals utilizing the cross-phase modulation (XPM) effect between the input signal and the inserted continuous-wave probe in parallel connection. Because of accumulation of PMD, the XPM effect in nonlinear fiber leads to variation of pump phase. This can cause spectrum broadening resulting...
We put forward and simulation demonstrated a multi-broadband radio over fiber (RoF) system based on Generalized Frequency Division Multiplexing (GFDM) by the using of Matlab software to call OptiSystem. The system simultaneously transmits four GFDM signals modulated to four different carriers. Each signal is with bit rate 10Gbit/s and bandwidth 2.5GHz and carriers are with frequency 10, 13, 16 and...
We demonstrated a direct-modulated multiple formats optical OFDM system based on Discrete Wavelet Transform by using MATLAB software. The simulation results indicated that DWT-OFDM has a good advantage over FFT-OFDM, and the signals at a bit rate 5Gbit/s have a good performance which is nearly equal to 10−3 when OSNR is equal to 25dB over 300km optical fiber channel which only concerns the influence...
The convergence of optical and wireless network has led to the trend of future access network . Under the study of Software Defined Radio Access Network(SD-RA) and Soft Frequency Reuse(SFR) system model, this paper presents a new inter-cell interference suppression algorithm of SD-RA network. The paper also summarizes and analyses the difference between the SFR based on coordinate multi-point transmission...
This paper presented a multi-rate Star-QAM encoding and decoding method based on the hierarchical coding which could be adjusted to achieve the channel coding efficiency and modulation. The design is based on the combination of soft / hard decision in layered decoding. We have successfully increased BER performance to 0.5dB which achieved 10−5 when SNR is 11 compared to no stratification codec considering...
A new feedback symbol timing recovery technique using timing estimation joint equalization is presented for digital receivers with two samples/symbol or higher sampling rate. The clock recovery algorithm in this paper is different from the traditional method, using different algorithm by distinguishing the phase of adjacent symbols. A new timing algorithm is proposed for the adjacent signals with...
In this paper, we propose and demonstrate an optical sampling scheme based on nonlinear polarization rotation (NPR) effect of semiconductor optical amplifier (SOA), the sampled signal is a pulse with 20 GHz repetition rate and 420 fs pulse width generated by a mode-locked fiber ring laser constituted by SOA and electro-absorption modulator (EAM). The working principle of proposed sampling scheme has...
In this paper, a new all optical flip-flop structure based on semiconductor optical amplifier (SOA) and Mach-Zehnder interferometer (MZI) is presented and demonstrated. Through carrying out a detailed analysis of SOA's NPR effect and the coupled SOA-MZI structure, we build up a theoretical SOA model with polarization dependent rate-equations and MZI model employing SOA cross-phase modulation in the...
Causal-based alert correlation is one of the mainstream techniques to detect multi-step threat behaviors. However, because large-scale network generates high-speed alerts and alert type distribution in dataflow changes over time, it is challenging to increase generality, scalability and reduce overhead for causal alert correlation method. In this paper, we propose a novel general, scalable and low-overhead...
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