Performance Evaluation of Radio Frequency Transmission over Fiber using Optical Amplifiers

The growth of mobile and wireless communication is increasing the demand for multimedia services with a guaranteed quality of service. This requires realization of broadband distribution and access networks. Radio over Fiber technology has various advantages when it applies to wireless systems, especially, mobile communication radio networks. Radio-over-Fiber (RoF) system mainly uses two modulation techniques ie; direct- and external-laser modulation. In RoF technology, the fiber dispersion and chirp parameters are the important parameters in degrading the performance of optical communication systems. External modulators of Mach-Zehnder type minimize the transmission power penalty due to fiber chromatic dispersion. So these modulators are also known as chirp-free modulators. Also, better suppression of nonlinear distortion is achieved by using Mach-Zehnder external modulator. Data is either externally modulated by using single-electrode (SEMZM) – and dual electrode (DEMZM) – Mach-Zehnder modulator. This work presents a simulation comparison of external modulation schemes using different optical amplifiers, comparison of received electric Rf power with different optical amplifiers and calculation of BER at received channel. Simulation of external modulation using EDFA and SOA are performed by using OPTSIM 5.3.