Performance and transmission power bound analysis for optical wireless based mobile healthcare applications

In the context of healthcare monitoring, it is necessary to transmit vital information from the patient to an interface managed by the hospital staff. In this work we consider a system where the patient can move within a hospital room and the data collected by sensors are transmitted to a distant receiver placed on the ceiling. We investigate the potentiality of using infrared (IR) communication for the transmission of information in this mobile context. Considering two main IR propagation types (Line Of Sight and diffuse), we characterize the IR mobile channel by using a Gaussian model for the patient location in the room. Thanks to our model, we evaluate the outage probability of this mobile monitoring scheme. From the results, the power efficiency of IR technology to ensure the communication between sensors and the collecting point is established. Moreover, to optimize the system performance and ensure the highest power autonomy, we investigate the possibility of using channel coding. For this purpose, the mobile IR channel outage capacity versus transmission power for different monitoring data rates is calculated. The analysis shows that for a typical data rate of 500 Kbps, it is theoretically possible to optimize the transmission power considering the use of a forward error correction code while maintaining the targeted effective data rate.