Raptor Codes in Wireless Body Area Networks

The use of wireless body area networks requires correct delivery of the vital signs of the patient while managing precious energy in tiny biosensors. Toward these goals, we present an energy-efficient protocol suitable for the narrow band physical layer of the IEEE 802.15.6 standard in on-body sensor networks. This study considers a realistic channel model inspired by the Gilbert-Elliott channel including the erasure mode and a binary symmetric channel model. This work studies the feasibility of Raptor codes, the most efficient rateless codes, with the Frequency Shift Keying (FSK) modulation to overcome the reliability and power cost concerns in on-body sensor devices. The main advantage of using Raptor codes is to provide an inherent adaptive power management, due to the flexibility of the code rate and coding gain. Numerical results show that the Raptor coded FSK is more energy efficient and robust than that of the uncoded FSK and LDPC codes, in various channel realization, in particular, when patients make sequential position changes.