Simulative analysis of influence of RF sub-carriers on performance of 10 GHz-band bidirectional radio over fiber (RoF) system

Abstract

In this paper, bidirectional radio over fiber (RoF) communication system (10 GHz) is simulated (bit rate, 1.0 Gb/s) for different RF sub-carriers to observe impact on system parameters [bit error rate (BER), quality value (Q), signal to noise ratio etc]. Influence of increasing sub-carriers/channels has been observed for 100 km long bidirectional single mode fiber each in uplink and downlink connections. To reduce crosstalk among RF sub-carriers, carrier frequency (50 MHz) and channel frequency spacing (12 MHz) are carefully chosen for simulative model of RoF system. Transmission of 78 channels with externally modulated continuous wave laser source gave satisfied results for improved Q values both in uplink and downlink connections at receiver sections. To avoid heavy cost of implementing extra electronic circuits at uplink site, same optical frequency for uplink analysis has been used. The Q-factor having maximum values of 22.63 dB and 8.36 dB at N = 70 channels with minimum BER [less than optimal threshold value (< 10^-9)] have been achieved both for uplink and downlink sites for RoF communication system.