An analytical model to describe the BER and power penalty of a
radio-over-fiber system with different
modulation schemes is derived. It proves DPSK can provide 3-dB higher receiver sensitivities than OOK, and the
optimal radio-over-fiber structure is DPSK-PM or DPSK-IM, which is depended on the frequency of subcarrier and
optical fiber transmission distance.
The inconsistency of device performance leads to the power imbalance among all channels on optical beamforming
networks. The impact of power imbalance is analyzed and an improvement scheme is presented in this paper. Both
experiment and simulation results prove the power imbalance seriously impairs the system functions and a suitable
power-balanced element can improve the whole system performance remarkably.