Portable hardware for real-time channel estimation on wireless body area networks

We present the design and implementation of a portable and economic device that can estimate wireless body area network (WBAN) channels in the 2.4-2.5 GHz frequency range. The equipment conventionally used for WBAN channel estimation is accurate, but bulky and expensive. Our channel estimator consists of multiple transmitters and a receiver, powered by consumer batteries, and small enough to fit in the palm of a hand. The transmitter includes an impulse generator fabricated in a 0.13μm CMOS process that continuously excites the channel with BPSK-modulated pulses. The receiver is implemented with COTS and records the impulse response in memory, storing up to 1.6M channel snapshots, which can be extracted later. The transmitter and receiver are described in this paper, along with experimental results. The measured data show the dynamics of WBAN channels in relation to the environment and the human body motion, in scenarios where it isn´t practical to use conventional channel modeling equipment.