Energy-Efficient and QoS Assurance Link Adaptation Scheme for Wireless Body Area Networks

Abstract

Due to limited power supply and long-life service requirements for wireless sensor nodes, energy and time-efficient methods are critical to in the wireless body area networks (WBAN). Link adaptation (LA) technique, in which modulation and coding are applied to change per channel conditions to maximize link throughput are widely investigated in the field of mobile communications. On the basis of LA and transmit power control (TPC) techniques, we propose a model-based calibration scheme to maintain a transmit power threshold table WBAN which satisfies the target quality of service (QoS) while minimizing transmission power of sensor nodes. Rather than existing methods that compare the SNR threshold with instantaneous channel SNR, we contrast the target bit error rate (BER) with instantaneous received BER, and calibrate the path loss and shadowing model, and receiver sensitivity. The proposed method lower bounds the transmit power given a pair of prescribed data rate and BER for a set of feasible combinations of modulation and coding schemes (MCSs). The performance evaluation show that the proposed method outperforms previous link adaptation methods in execution overheads and energy efficiency.