Proposal of cascaded radio-optic direct conversion radio highway

This paper newly proposes a cascaded Radio-Optic direct Conversion(ROC) Radio Highway The ROC system can convert a radio signal into an optical signal with the same signal format. The transmission performance of the proposed system is theoretically analyzed and the way to set modulation index for each base station is presented. The ROC system is shown to provide about 2.5 dB improvement over the cascaded phase modulation coherent system.