Joint Throughput Equalization Power Control and Cell-Free Model for Enhancing Performance of WBANs

Wireless body area networks (WBANs) have gained significant attention due to their versatile applications in healthcare and the rapid development of personal healthcare devices. This paper proposes a novel cell-free (CF) model for WBANs, where multiple access points (APs) instantaneously support distributed sensors placed on the body by allowing all sensors to share the same time and frequency resources. Unlike multiple access schemes, such as non-orthogonal multiple access (NOMA), “cell-free” in our context denotes a decentralized architecture where multiple distributed APs cooperatively serve multiple sensors without the traditional cell boundaries. In NOMA systems, APs communicate with sensors in a cell by superimposing signals at different power levels, whereas CF systems enhance signal quality through joint processing across APs. Different from the traditional star topology WBAN where one AP communicates with only one sensor at a time, the CF model allows all sensors to transceive information data at the same time. Furthermore, a joint CF model and transmit power control algorithm is proposed to control the transmit power of sensors in the uplink and APs in the downlink of the CF model WBAN based on channel conditions in order to reduce the inter-user interference, maintain fairness among all sensors, and thereby improve the per-sensor throughput. The achievable uplink and downlink rates are derived using matched filtering and computational algorithms, resulting in a closed-form solution. The proposed joint method of the CF model and transmit power control algorithm is compared with the CF model without power control and traditional star topology WBANs to assess the effectiveness of the proposed approaches via several key parameters, including the number of sensors, the number of APs, and the length of pilot sequences. Simulation results demonstrate that the proposed approaches enhance system performance in both uplink and downlink across all tested scenarios. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.