ISSN: 2277-9655 [Tiwari * et al., 7(3): March, 2018] Impact Factor: 5.164 IC™ Value: 3.00 CODEN: IJESS7 http: // www.ijesrt.com© International Journal of Engineering Sciences & Research Technology [187] IJESRT INTERNATIONAL JOURNAL OF ENGINEERING SCIENCES & RESEARCH TECHNOLOGY A REVIEW ARTICLE OF OPTICAL FIBER SIGNAL TO NOISE RATION USING WAVELENGTH DIVISION MULTIPLEXING WITH RCIAN CHANNEL Amrita Tiwari *1 & Dr. Manish Jain 2 *1 Research scholar, Dept. of Electronics & Comm. SRK University, Bhopal 2 HOD, Dept. of Electronics & Comm. SRK University, Bhopal DOI: 10.5281/zenodo.1194288 ABSTRACT The demand for high-speed mobile wireless communications is growing at a very fast rate.WDM technology is a key technique for achieving the high data rate and spectral efficiency requirements for wireless communication systems. Wavelength division Multiplexing (WDM) [3–6] has emerged as a successful air- interfacetechnique. TheWavelength division Multiplexing was originally developed from the multi-carrier modulation techniques used in high wavelength military radios. This thesis presents, a simulink based simulation system is implemented using Additive White Gaussian Noise channel (AWGN) to study the performance analysis of Bit Error rate (BER) Vs Signal to Noise ratio (SNR). The model of WDM with Rician fading channel using simulink in MATLAB is discussed. This model is used for performance enhancement of the WDM with QPSK and QAM modulation schemes and channel condition. The throughput and packet error rate are used to evaluate the performance of MAC layer with the change in physical layer parameter.The performance analysis of different technique used in the QAM WDM is compared by visualizing the BER vs SNR curve. Keywords: WDM(Wavelength division Multiplexing), QAM, AWGN, etc. I. INTRODUCTION Increasing in telecommunicationsservices thatdemand large amounts of bandwidth. Services such as interactive multimedia, video conferencing and streaming audio have made the capacity of the existing optical fiber systems insufficient. To increase this capacity, time division multiplexing (TDM) has been used traditionally. However, TDM has a few drawbacks. The important is that the existing electronic technology allows multiplexing only up to about 10 Gb/s. Thus; an alternative optical multiplexing technique that avoids the 10Gb/s electronic bottleneck is very attractive. WDM is one such promising technique that can be used to exploit the huge available bandwidth of the optical fiber. In WDM, the optical transmission spectrum is divided into a number of no overlapping wavelength bands, with each wavelength supporting a single communication channel operating at peak electronic speed. Thus, by allowing multiple WDM channels to coexist on a single fiber, the huge bandwidth can be tapped into. WDM is a technique for simultaneous transmission of two or more optical signals on the same fiber. The signals from different sources are combined by a multiplexer and fed into an optical fiber which is the transmission medium. At the receiving end, different signals are separated by a demultiplexer and detected by photo detectors. The WDM scheme increases the transmission capacity of optical communication systems considerably. The two configurations of WDM systems that are possible are the one-way and the two-way (bidirectional optical fiber) transmission systems as illustrated in Figure (1), while the one-way system requires only one receiver or one transmitter per channel at each end, the two-way system requires both receiver and transmitter at each end of every channel. Optical multiplexers and demultiplexers may be classified into wavelength selective and wavelength nonselective devices .The wavelength selective devices are either active or passive. The active devices are implemented using multi-wavelength light Sources or multi wavelengthphotodiodes [5].