Coherent and Envelope OOK Performance Comparisons with BPSK and Orthogonal BFSK in AWGN and Coherent OOK Analysis in Flat Rayleigh Fading

Abstract

Binary amplitude shift keying in the form of on-off keying (OOK) provides a simple signal format, but its reliability depends on the receiver and channel conditions. MATLAB simulations compared coherent and envelope OOK detection in additive white Gaussian noise (AWGN) and examined coherent OOK under independent flat Rayleigh fading. A separate AWGN comparison evaluated OOK, binary phase shift keying (BPSK), and orthogonal binary frequency shift keying (BFSK), all with coherent detection. All comparisons used equal average bit energy and five million bits per scheme at each test point. Analytical and numerical reference curves were used to determine the ratio of average bit energy to noise power spectral density (E_b/N₀) required to reach a bit error rate of 1 × 10⁻³. In AWGN, coherent OOK required 9.80 dB, compared with 10.51 dB for the modeled envelope receiver. Coherent BPSK required 6.79 dB, about 3.01 dB less than coherent OOK and orthogonal BFSK. Rayleigh fading raised the coherent OOK requirement to 26.98 dB, despite ideal channel information and gain compensation. Under the selected pulse and tone-spacing assumptions, OOK and BPSK also had narrower first-null spectral spans than BFSK. These results support initial modulation and receiver selection under the stated assumptions. Hardware cost and total power consumption still require practical measurements.