Journal of South China University of Technology(Natural Science Edition) ›› 2023, Vol. 51 ›› Issue (11): 10-17.doi: 10.12141/j.issn.1000-565X.220797

Special Issue: 2023年电子、通信与自动控制

• Electronics, Communication & Automation Technology • Previous Articles     Next Articles

Simulation Study on BER Performance of DS-UsWB Intrabody Communication

LIU Jiaojiao CHEN Ayue MA Biyun   

  1. School of Electronic and Information Engineering,South China University of Technology,Guangzhou 510640,Guangdong,China
  • Received:2022-12-05 Online:2023-11-25 Published:2023-06-08
  • Contact: 马碧云(1982-),女,博士,副教授,主要从事超声检测、超声通信研究。 E-mail:eebyma@scut.edu.cn
  • About author:刘娇蛟(1976-),女,博士,副教授,主要从事超声通信、体域网研究。E-mail: jjliu@scut. edu. cn
  • Supported by:
    the General Program of the Natural Science Foundation of Guangdong Province(2022A1515011830);the Science and Technology Planning Program of Guangdong Province(2022A0505050011)

Abstract:

The water content of human soft tissues is as high as 65%, so ultrasound has advantages in low attenuation, low risk of disease, and limited interference range in human soft tissues, making it advantageous for communication in the body. However, the ultrasonic human channel has the characteristics of dense multipath, so the signals that reach the receiver through multiple paths of reflection and refraction overlap to generate multipath interference, which affects communication reliability. The existing research avoids multipath overlap and its interference by emitting extremely short pulses of ultrasound, but it is difficult to achieve ultra wideband ultrasound probes with large directional angles. The actual pulse width generated by the probe is not small enough, so multipath overlap will occur at the receiver and the interference cannot be ignored in signal judgment. In order to study the distribution characteristics of multipath interference in the body and its impact on wideband ultrasound human body communication, this paper used the k-Wave simulation toolkit to model the ultrasound human body channel in 3D. Then the channel impulse response was obtained through simulation experiments, and the statistical characteristics of multipath delay distribution were analyzed and curve fitting was performed. Based on the decision mechanism of the receiver, the multipath interference of the human channel was estimated, and the lower bound of the bit error rate (BER) for direct sequence spread spectrum ultrasonic broadband (DS-UsWB) was derived. The effectiveness of this lower bound of BER was verified through Monte Carlo experiments. Experimental results indicate that multipath interference cannot be ignored when the signal-to-noise ratio is low, and the communication performance can be improved by adjusting spread spectrum code length.

Key words: intrabody communication, DS-UsWB communication, multipath interference, bit error rate

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