An Optical IM/DD Channel Based Relay Scheme for Indoor Healthcare Communication System

This paper presents a wireless relay scheme for indoor healthcare communication system, in which an optical relay link, instead of a traditional radio frequency (RF) relay link, is established between the relay station (RS) and the mobile terminal (MT). To simplify the structures of RS and the additional optical parts that shall be installed in the MT, the subcarrier-modulation based intensity-modulated direct- detection (IM/DD) is also adopted for both the up-link and the down-link. The proposed relay scheme not only enhances the transmission power, but also creates safe signal propagation environment, which is much meaningful for wireless and pervasive healthcare communication. Simulation results show that the proposed interference-reduced relay scheme provides a stable and high quality communication link when the average optical receiving power is larger than -25 dBm.