Maryam Niknamfar

Comparative study of the performance of CATV channels over DWDM network using direct and external modulator

Different parameters that can be adjusted to obtain an acceptable performance for a Dense Wavelength Division Multiplexing (DWDM) network are considered. A comparison of various parameter settings between the external and direct optical modulation is made based on the simulation results. Different effects caused by varying the electrical power, while setting optical modulation index, is vital. A trade-off between higher signal to noise ratio and nonlinearity effect should be taken into account for sending radio frequency signals over a fiber channel. Several simulation results for transmitting 30 Cable Television (CATV) channels, 64-QAM modulated, over a DWDM network are given in order to find the best adjustments for the link parameters of both internal and external optical modulations. Two of the basic parameters, focused in this article, include the electrical power and optical modulation index.

Optimization of optical single sideband configurations for radio over fiber transmission and multi-type data communication over a DWDM link

Two new optical single side band (OSSB) configurations for radio frequency (RF) transmission of data are proposed based on the structures that have been designed for baseband digital data transmission. The performances of these schemes are evaluated based on the relevant eye diagrams and bit error rate (BER). The proposed configurations are studied and analyzed mathematically. Eye diagrams and BERs indicate an acceptable performance for the suggested structures. Feasible settings for the RF electrical power of the links are considered and the link performance for each setting is evaluated. A 4-dense wavelength division multiplexing (4-DWDM) link is considered for transmitting different types of data over a single mode fiber (SMF). Baseband digital data in the format of OSSB and RF-OSSB signals are transmitted over a 4-DWDM link. Furthermore, the link performance is considered for different electrical power settings of OSSB signal in order to achieve efficient transmission for DWDM network.

Big Data Analytic: Cases for Communications Systems Modeling and Renewable Energy Forecast

Data analytic-based approaches are proposed for different cases of communications systems modeling based on qualitative methods and solar energy forecasting based on artificial intelligence in order to represent the spread of areas to which such techniques are applicable.

Cost effective ROF communication system for CATV channels over WDM network and fuzzy modeling of the system

A radio over fiber (RoF) communication system is considered for cable television (CATV) channels over wavelength division multiplexing (WDM) network using an optical direct modulator (DM). Since the DM bandwidth is limited, increasing bandwidth efficiency of the system using M-ary quadrature amplitude modulation (MQAM) schemes will improve the link symbol error rate (SER) performance. Radio frequency (RF) signals with constellations of 16-64-256 QAM were simulated for CATV channels and the effect of using higher bit per symbol on the link performance was studied in order to reduce the cost of the network through utilizing financially feasible optical modulator. The 64-QAM scheme which is the most appropriate is used for the system of CATV channels. The link performance is studied for different combinations of effective parameters such as AC electrical power and Module to Bias ratio, which are crucial to be set properly, and SER is obtained at the front end of the receiver. The best setting options are proposed for 30 CATV channels with 64-QAM constellation with direct modulation transmitted over the 4-WDM link. Moreover, communication system is modeled by fuzzy logic using data-base obtained from simulation. Fuzzy reverse modeling of the system is also implemented in order to provide reasonable estimate of electrical power required to achieve a desired SER. Characteristics of forward and reverse fuzzy modeling are discussed. Simulation results represent satisfactory performance of the models.

Limitations of all optical circuit-switched high data rate networks

This paper presents a method of adding a second dimension of optical encoding, as an out-of-band label, to be used for routing data through a label-switched network. Combining wavelength and code multiplexing techniques generates an optical circuit-switched network that can handle a data capacity of up to several Tb/s on each point-to-point link in the network. The proposed architecture uses two stages to process and map labels for each bit transmitted through the network. The architecture for the Dual Stage Optical Label Switch (DSOLS) is presented along with simulation results of its expected performance. A simulation package is used to analyze system performance. Using data generated from simulations a performance metric, based on Bit Error Rate (BER) to be used by an upper level routing algorithm is presented. Finally, a method of measuring the metric for a 2×2 (two codes and two wavelengths) DSOLS is described.

Real-time monitoring of multi-mode industrial processes using feature-extraction tools

A real-time monitoring solution is presented for detection of faulty status in industrial processes which uses the input-output data features to set monitoring boundaries. The proposed solution uses independent components analysis (ICA) in order to extract features of data samples measured from the actual plant. The features extracted from the simulated model of the plant at normal operating condition will be used to compute values of the monitoring criteria. The detection threshold and monitoring boundaries are then determined based on the monitoring criteria obtained for normal condition. Measured data of the plant are fed into the monitoring system in order for the plants status to be detected for each and every sample time. The suggested approach will be implemented on a model of Continuous Stirred-Tank Reactor (CSTR) with two modes of normal operation for monitoring and fault detection. Simulation results are presented and performance of the proposed approach is discussed.

Electrical Power Setting for Optical Single Side-band Millimeter-wave Generation

A scheme is suggested to generate single side-band millimeter-wave signal. Mathematical analysis is considered for electrical power adjustment. Two Mach-Zehnders are used to up-convert the radio frequency to the 60 GHz range.