Cross-Band RF-Lightwave Communications With Integrated Passive Receiver

The integration of radio frequency (RF) with optical wireless communications is a promising approach to cope with the increasing network requirements in future generations of wireless networks. In this context, a cross-band RF-lightwave communication system with a passive receiver is introduced, integrating an RF receiver based on power detection and an optical one, which offers high energy efficiency and high reliability. Considering that the cross-band system aims at diversity and the two subsystems transmit the same information, the mutual information between the common input and the outputs of the subsystems is derived. Moreover, to facilitate the practical use of the introduced cross-band system, an optimal and a baseline modulation scheme are proposed, in which the superimposed constellation is a pulse amplitude modulation (PAM). In addition, the exact expression for the symbol error probability is derived for both schemes in closed form. The theoretical analysis is validated by simulations, which also evaluate the performance of the cross-band system.