Comparative Analysis of Spectral Efficiency and BER Performance for BPSK, BFSK-COH, and OOK Modulation Schemes

In this project, three basic digital modulation technologies are comprehensively evaluated based on Simulation: binary phase shift keying (BPSK), coherent binary frequency shift keying (BFSK COH), and on-off keying (OOK). This study aims to quantify the tradeoff between power efficiency and spectral efficiency in additive white Gaussian noise (AWGN) channels. Through the discrete-time simulation platform based on MATLAB, the bit error rate (BER) performance is analyzed by using the Adaptive Monte Carlo method to ensure the statistical confidence under high signal-to-noise ratio (SNR). The results show that BPSK performs better in terms of power efficiency. To achieve a bit error rate of 10-5, it needs about 10.65 dB of Eb/N0, which is about 2 dB and 4.8 dB better than BFSK COH and OOK, respectively. In terms of spectral efficiency, although the bandwidth utilization of the rectangular BPSK pulse is low due to slow sidelobe attenuation, the introduction of root raised cosine (RRC) pulse shaping significantly improves the performance. When the roll off factor is α=0.25, the spectral efficiency of BPSK increases from 0.077bit/s/Hz to 0.901bit/s/Hz, which indicates that pulse forming BPSK provides the best balance between power and bandwidth for band-limited communication systems.