Irregular Shifting of RF Driving Signal Phase to Overcome Dispersion Power Fading

The main problem with the radio-over-fiber (RoF) link is the decrease in the recovered radio frequency (RF) power due to the chromatic dispersion of the fiber known as dispersion power fading. One of the methods for dealing with dispersion power fading is to use the optical single sideband (OSSB) modulation scheme. The OSSB modulation scheme can be generated by biasing the dual-drive Mach&ndash
Zehnder modulator (DD-MZM) to the quadrature bias point (QBP) and shifting the RF drive signal phase (&theta
) by 90&deg
which is called the regular &theta
However, the OSSB modulation scheme only overcomes dispersion power fading well at the modulation index (m) &lt
0.2. This paper proposes an irregular &theta
method to overcome dispersion power fading at all m. There are two irregular &theta
for every m used. The irregular &theta
managed to handle dispersion power fading better than OSSB modulation scheme did at every m. Specifically, the irregular &theta
could handle the dispersion power fading well at m &le
1. In sum, the irregular &theta
could overcome the dispersion power fading at any RF frequency and optical wavelength without having to re-adjust the transmitter.