Direct-Sequence Ultrasonic Wideband Technology for Intra-Body Communications

This letter proposes a direct-sequence ultrasonic wideband (DS-UsWB) for intra-body communications (IBCs). The DS technology superimposed channel coding is proposed to enable simultaneous multi-node communications in body area networks (BANs). We simulate the channel impulse response model in a human arm by $k$ -Wave, and analyze the chip duration and pulse duration requirements to avoid an inter-symbol interference (ISI) and an inter-pulse interference (IPI) for the DS-UsWB. We then derive the closed-form formulations for data rate and bit error rate (BER) for the DS-UsWB system. Simulation results verify our theoretical analysis, and show that the proposed DS-UsWB system performance is better than the existing ultrasonic wideband (UsWB) system.