Performance evaluation of broadband radio-over-fiber systems under frequency and link parameter variations

This paper analyses the performance of a single-channel radio-over-fiber (RoF) communication system operating at a carrier frequency of 10 GHz at different data rates of 5 Gb/s, 10 Gb/s, and 20 Gb/s. The system is initially evaluated over link distance of 20 km (baseline) and then subsequently analyzed for extended transmission distances from 20 km to 50 km. It is observed that beyond 20 km, the system performance degrades severely, with complete signal failure occurring at intermediate link length of 30–40 kms, indicating a Q-factor of zero and BER equal to one. Partial recovery in the system performance is observed at 50 km, indicating the presence of dispersion-induced RF power fading. To diminish the effect of these impairments, dispersion-compensating fiber (DCF) is introduced for longer spans, which results in significant improvement in system performance. Additionally, the effect of laser launch power is evaluated over a range of −10 dBm to 15 dBm. The results indicate that the system operates in a power-tolerant regime up to 10 dBm, beyond which nonlinear effects degrade performance. The proposed system limitations are primarily governed by dispersion-induced fading rather than optical power and represent the effectiveness of dispersion compensation in improving RoF link performance.