Impact of bandwidth alignment and RF–data rate interaction in single-drive Mach–Zehnder modulator–based radio-over-fiber systems

Abstract A radio frequency (RF) signal, when transmitted through an optical fiber network after modulating the light signal with the RF signal, is known as radio over fiber or RoF. This technology can utilize a large bandwidth so that it can support more users compared to regular wireless technology. RoF is a cost-effective and flexible alternative to fulfill the high and rapidly increasing consumer and commercial demands, such as internet services, which need bandwidth. In this paper, a hybrid 10 GHz RoF system is designed, which operates at multiple data rates of 5, 10, 15, and 20 Gbps. In this system, RF signal is used to modulate the light signal using a single-drive Mach–Zehnder modulator. The signal is transmitted through fiber, and coherent detection is implemented using a mixer and a local oscillator. Performance of the system is analyzed in terms of Q-factor, BER, and SNR. At 5 and 10 Gbps, system exhibits excellent performance, and at 20 Gbps, system performs moderately, while a significant degradation is observed at 15 Gbps due to spectral overlap and filtering limitations. This paper highlights the effect of bandwidth alignment and RF–data rate interaction in RoF systems.