Impact of the phase modulation index in the performance of CO-OFDM systems based on electrical domain constant-envelope signals

The impact of the electrical phase modulation index 2πh in the performance of coherent detection optical OFDM systems based on electrical constant-envelope signals is analytically and numerically evaluated in this paper. A compromise between 2πh and system performance, that considers the effect of nonlinearities inserted by Mach-Zehnder optical modulators, is established. Moreover, it is shown that this type of peak-to-average power ratio (PAPR) reduction technique reduces the impact of the optical modulation index in the performance.