Cai Zibo, Seyedi MirHojjat, Zhang Weiwei, Rivet Francois, Lai Daniel T H
College of Engineering and Science, Victoria University, Melbourne, Australia.
Jiangxi Engineering Laboratory for Optoelectronics Testing Technology, Nanchang Hang Kong University, Nanchang, China.
J Med Biol Eng. 2017;37(1):74-84. doi: 10.1007/s40846-016-0198-9. Epub 2017 Jan 6.
Intrabody communication (IBC) is a promising data communication technique for body area networks. This short-distance communication approach uses human body tissue as the medium of signal propagation. IBC is defined as one of the physical layers for the new IEEE 802.15.6 or wireless body area network (WBAN) standard, which can provide a suitable data rate for real-time physiological data communication while consuming lower power compared to that of radio-frequency protocols such as Bluetooth. In this paper, impulse radio (IR) IBC (IR-IBC) is examined using a field-programmable gate array (FPGA) implementation of an IBC system. A carrier-free pulse position modulation (PPM) scheme is implemented using an IBC transmitter in an FPGA board. PPM is a modulation technique that uses time-based pulse characteristics to encode data based on IR concepts. The transmission performance of the scheme was evaluated through signal propagation measurements of the human arm using 4- and 8-PPM transmitters, respectively. 4 or 8 is the number of symbols during modulations. It was found that the received signal-to-noise ratio (SNR) decreases approximately 8.0 dB for a range of arm distances (5-50 cm) between the transmitter and receiver electrodes with constant noise power and various signal amplitudes. The SNR for the 4-PPM scheme is approximately 2 dB higher than that for the 8-PPM one. In addition, the bit error rate (BER) is theoretically analyzed for the human body channel with additive white Gaussian noise. The 4- and 8-PPM IBC systems have average BER values of 10 and 10, respectively. The results indicate the superiority of the 8-PPM scheme compared to the 4-PPM one when implementing the IBC system. The performance evaluation of the proposed IBC system will improve further IBC transceiver design.
体内通信（IBC）是一种用于人体区域网络的很有前景的数据通信技术。这种短距离通信方法将人体组织用作信号传播的媒介。IBC被定义为新的IEEE 802.15.6或无线人体区域网络（WBAN）标准的物理层之一，与蓝牙等射频协议相比，它能为实时生理数据通信提供合适的数据速率，同时功耗更低。在本文中，使用IBC系统的现场可编程门阵列（FPGA）实现来研究脉冲无线电（IR）IBC（IR-IBC）。在FPGA板上使用IBC发射机实现了无载波脉冲位置调制（PPM）方案。PPM是一种调制技术，它基于IR概念利用基于时间的脉冲特性对数据进行编码。分别使用4-PPM和8-PPM发射机通过对人体手臂的信号传播测量来评估该方案的传输性能。4或8是调制期间的符号数。研究发现，在发射电极和接收电极之间的手臂距离范围为5至50厘米、噪声功率恒定且信号幅度不同的情况下，接收信噪比（SNR）大约降低8.0 dB。4-PPM方案的SNR比8-PPM方案的大约高2 dB。此外，对具有加性高斯白噪声的人体信道进行了误码率（BER）的理论分析。4-PPM和八PPM IBC系统的平均BER值分别为10和10。结果表明，在实现IBC系统时，8-PPM方案优于4-PPM方案。所提出的IBC系统的性能评估将进一步改进IBC收发器设计。
