In this research article Bit Error Rate for Different modulation techniques is analysed and compared for an AWGN channel with respect to Signal to Noise Ratio (SNR). The range for SNR which is applied for the calculation is from -4dB to 24 dB. In this research article, proposed structure of Radio over Fiber (RoF), is shown which maps the general components of the RoF system. We have also seen the deviation of Bit Error Rate by changing the Signal to Noise ratio Strength and we also prepared a mathematical model, using mostly utilized modulation schemes in the RoF system. In this research article, we compared the BER of mostly utilized modulation schemes like BPSK, QPSK, M-QAM and M-PSK with their associated SNR. The 4-QAM and the QPSK based RoF link has the lowest BER $10^{-28.855}$ and with highest SNR 18 dB and 32-PSK modulation schemes has the highest BER 1$0^{-}$0904 with lowest SNR 4 dB. A comparatively analysis is drawn with the help of MATLAB R2019B, to analyse the effectiveness of the used modulation schemes.