DESIGNING A 40 CHANNEL DWDM NETWORK USING RAMAN-DPSK

Abstract

With the advent of new technology in the field of optical communication system we had find numerous techniques to constraints the cost and to fulfill the challenging requirement of increasing capacity , now days carriers have two options first to install new fiber network second increase the effective bandwidth of existing fiber network. The dense wavelengthdivision multiplexing (DWDM) technology has recently resulted in a considerable increase in the transmission capacity of optical fiber communication systems up to several terabits per second. The high bit rate transmission improves spectral utilization which results in increased overall system capacity and reduces overall system cost. The further improvement of the transmission capacity of such systems can be achieved through the expansion of the spectral range of DWDM transmission toward the short-wavelength region. The goal of a WDM transmission network is to transmit the maximum number of bits per second over the maximum possible distance with the fewest errors. Therefore in this report we have proposed and investigated the new trends and progress of fiber Raman amplification using DPSK modulation for dense wavelength division multiplexing photonic communication networks. In this we simulate a realistic scenario of 40 individual channel , 40 Gbps DWDM link with inter channel spacing of 50 GHz. Forty individual channel carrying PRBS data are modulated using DPSK and transmitted over ITUT G.652 single mode fiber. The objective of this design is to utilize distributed backward pump raman amplification using unequal pump power to compensate for the link attenuation and Differential phase-shift keyed (DPSK) modulation, which carries the information by change in optical phase between bits, has been widely used in long-haul optical communication networks for its ~3dB lower optical signal-to-noise ratio (OSNR) requirement compare to on-off keying (OOK) signals when using balanced receiver.