Résumé
This paper presents a low power approach for Galvanic Coupling (GC) Intra-Body Communication (IBC) using binary sequence. The idea is to replace the conventional modulated sine-wave signal conveying the message by a modulated square-wave signal. This modulated square-wave signal is basically a binary sequence that can be generated directly from a microcontroller, avoiding the use of power-hungry analog components. In order to ensure correct communication, the binary sequence must be generated with a specific encoding that respects the targeted modulation format. In this paper, the approach is illustrated for BPSK communication at 500 kHz with a data rate of 16.67 kbps. The proposed solution is validated through hardware measurements. Results under controlled conditions demonstrate that high communication quality is achieved, with a Bit Error Rate (BER) of less than 1 × 10−8 for a Signal-to-Noise Ratio (SNR) down to −5 dB, while a 10x reduction in power consumption is obtained compared to a conventional transmitter implementation where the micro-controller is associated with a Direct Digital Synthesizer (DDS). The solution is also validated under real GC-IBC conditions with measurements taken on a forearm, with the correct demodulation of 1 × 104 frames of 5-byte length.