Performance evaluation of various hybrid modulation techniques transmitted by EDFA in radio-over-fibre communication

Optical Communication system consists of three main blocks, such as a transmitter, a transmission channel and a receiver. The modulation and demodulation techniques are the most important for the transmitter and receiver, respectively, to transmit and receive the useful information to the longer distance without compromising the minimum error, maximum Q factor and also maintaining sufficient power and other parameters at the receiver to reproduce the original signal with minimum noise and distortion. A hybrid modulation technique is used which will optimize the merits of both digital and analogue modulation. Moreover, the impact of amplification at the transmitter and receiver has been studied and analyzed. The present paper highlights the design of various hybrid modulation techniques mainly DPSK-FM and QAM-FM in this context. Furthermore, the evaluation and performance analysis of various designed systems in terms of Q factor, bit error rate and the number of users and received power has been done.