Spectrum-sliced wavelength division multiplexing based free space optical communication employing Differential quadrature phase-shift keying

Abstract

With the motive to reduce the high cost incurred in Wavelength division multiplexing (WDM) based free-space optics (FSO) communication system, Spectrum-sliced (SS) WDM based FSO communication system at a data rate of 2.5 Gbps per channel is proposed in this research article. Utilizing the broadening of the spectrum by means of supercontinuum generation in a highly non linear Fiber (HNLF), an economical SS-WDM based FSO system is designed. The narrow spectrum of laser light source is broadened by means of self phase modulation (SPM). The proposed work confirms that the DQPSK based SS-WDM FSO system has higher performance in terms of Q-factor and BER compared to other intensity modulation formats as well as differential phase modulation formats. Considering various values of FSO link distances, antenna diameters of transmitter and receiver, beam divergence and thus, determining the values of Q-factor and BER, Differential quadrature phase shift keying (DQPSK) based SS-WDM FSO system is simulated.