超声波穿金属无线通信噪声智能抑制方法研究

Research on Intelligent Noise Suppression Method of Ultrasonic through Metal Wireless Communication

超声波是面向密闭金属腔体内外间进行无线通信时一种较为理想的信息传输媒介,回波是超声波穿金属无线通信系统的主要噪声来源。针对现有超声波穿金属无线通信系统中回波消除技术的局限,该文引入深度学习方法来实现一种新的回波消除技术方案进行通信接收端信号信噪比的改善。搭建了由摄像头、发射端FPGA、发射端超声换能器、金属铝块、接收端超声换能器和接收端FPGA组成的试验型超声波穿金属无线通信系统,作为信道的铝块其厚度为50 mm,基带频率为10 MHz。使用全卷积时域音频分离网络对超声波穿金属通信系统接收端的信号进行盲源分离,模型经过45次训练后较好实现了去除混合信号中的无用噪声而增强超声波信号的信噪比,在通信速率2 Mbps条件下实现了13.57 dB的SDR提升量和39.70 dB的SI-SDR提升量。

Ultrasonic wave is a kind of ideal information transmission medium for wireless communication between the inside and outside of closed metal cavity.Echo is the main noise source of ultrasonic wireless communication system through metal.Aiming at the limitation of echo cancellation technology in the existing ultrasonic metal-penetrating wireless communication system,we introduce a new echo cancellation technology scheme to improve the signal to noise ratio of communication receiver.An experimental ultrasonic metal-penetrating wireless communication system composed of camera,transmitter FPGA,transmitter ultrasonic transducer,metal-aluminum block,receiver ultrasonic transducer and receiver FPGA was built.The thickness of the aluminum block as the channel was 50 mm and the baseband frequency was 10 MHz.The blind source separation of the signals at the receiving end of the ultrasonic metal communication system is carried out by using the full convolution time domain audio separation network.After 45 training,the model can effectively remove the useless noise in the mixed signal and enhance the signal-to-noise ratio of the ultrasonic signal.Under the condition of communication rate of 2 Mbps,13.57 dB SDR boost and 39.70 dB SI-SDR boost are achieved.