A Splitting-Detection Joint-Decision Receiver for Ultrasonic Intra-Body Communications

Ultrasonic intra-body communication (IBC) is a promising enabling technology for many future healthcare applications, due to the low attenuation and medical safety of ultrasonic waves for human body. This paper proposes a splitting-detection joint-decision (SDJD) receiver structure for ultrasonic pulse-based IBCs. The core idea is to split the received signal into two steams for the coherent-detection (CD) and energy detection (ED), and then the two detection outputs are summed up as joint decision variables to estimate the received signals. The theoretical channel capacity and bit-error rate (BER) expressions are derived, considering receive noise, tissue attenuation, and channel fading in intra-body channels. Both simulation and theoretical results show that the SDJD receiver outperforms the pure CD, ED, and splitting-detection separate-decision receivers in terms of BER performance. In addition, the proposed receiver has a low complexity requirement on the hardware and decision algorithm. Therefore, SDJD is an important structure to receive signals correctly and efficiently for ultrasonic IBCs.