人体通信信道测试系统的研究与实现

摘要

Human body communication (HBC) ,which uses the human body itself as the propagation medium,has advantages of low power consumption,high rate and high security. It is regarded as an ideal communication method for body sensor network. A channel testing system of HBC is designed, which has character of floating ground and behaved like the real HBC scenarios. ARM7TDMI based Samsung S3C44B0X chip is adopted as development platform. In the transmitter end, the direct digital synthesizer ( DDS) chip AD9910 is used to design adjustable frequency signal generator, and the logarithmic amplifier chip AD8310 is performed to realize the signal strength indicator in the received end. The output signal frequency range of the proposed adjustable frequency signal generator is 0 ~ 200 MHz, and the narrow-band spurious free dynamic range is larger than 80dB, the Ininimum resolution of the signal strength indicator is up to 0. 1 dB. The system is battery-powered. A large amount of measuremental experiments are conducted successfully in the shield chamber to investigate the human body characteristics by using this system.%人体通信以人体为通信媒介,具有低功耗、高速率、高安全性等优点,其为人体传感器网络提供了一种理想的通信方式.设计了一种人体通信信道测试系统,具有“浮地”特性,能真实反映人体通信的耦合或感应机制.该系统采用ARM7TDMI内核的S3C44B0X系统作为开发平台,使用直接数字合成器(DDS)芯片AD9910设计可调频率信号源,使用对数放大器芯片AD8310设计信号强度检测器.测试结果表明:可调频率信号源频率范围为0～200 MHz,窄带无杂散动态范围大于80dB;信号强度检测器检测分辨率可达0.1dB.该系统采用电池供电,成功地在电磁屏蔽室做大量实验,并测试得到人体信道特性.