Resource Allocation for Relay-Aided Cooperative Hospital Wireless Networks

In this paper, we investigate the relay-aided hospital wireless systems in cognitive radio environment, where multiple transmitter-relay pairs desire transmit their collected information to a data center. For the system, we propose a transmission framework, which follows IEEE 802.22 WRAN and adopts the listen-before-talk and geolocation/database methods to protect the primary users. The transmission strategy is presented, where in each subsystem, the wireless sensor device (WSD) with the highest signal-to-noise ratio (SNR) is selected to transmit signals at each time and then, a two-hop half-duplex decode-and forward (DF) relaying transmission is launched among the selected WSD, the corresponding personal wireless hub (PWH) and the data center. To explore the potential system performance, an optimization problem is formulated to maximize the system sum rate via power allocation. We then solve it by using convex optimization theory and KKT condition method and derive a closed-form solution of the optimal power allocation. Simulation results demonstrate the validity of our proposed scheme and also show the effects of the total power, the interference thresholds and the scale of the network on the system performance, which provide some insights for practical hospital wireless system design.