Gait-cycle Aware Relay Selection, Scheduling and Power Control for Wireless Body Area Networks

The channel conditions change frequently in dynamic wireless body area networks (WBANs) due to the people's periodic movement, which brings challenges to data transmission. To improve the energy efficiency, an algorithm for multi-hop relay-assisted cooperative communications integrated with transmit power control and time slot allocation, based on gait-cycle detection and channel prediction, is presented. Wiener Prediction is used to predict the channel conditions according to the statistical properties and autocorrelation functions of the channel samples in the past few cycles. After obtaining the predicted channel conditions, the algorithm dynamically adjusts the relay selection of each sensor node as the channel varies, arranges the time slots with good channel condition to each sensor node for data transmission and controls the transmit power to ensure the reliability requirements. The simulation results show that, the proposed algorithm not only improves energy efficiency, but also makes the energy consumption of each sensor more balanced and prolongs the life time of the sensors.