高阶伪随机信号在对地通讯中的应用

A Through-The-Earth Communication method based on high-order pseudo-random signal

对地通讯(Through-The-Earth Communication,TTEC)以大地为传播介质,使用低频电磁波来传输信息,在地下工程建设调度、预警、救援中有着重要作用.高阶伪随机信号可同时包含数十个频率,其具有易于实现、频率可控、抗干扰能力强的特点,有应用于对地通讯的潜力和价值.鉴于此,本文提出一种基于高阶伪随机信号的对地通讯新方法.通过在高阶伪随机信号中设置静态频组和动态频组,利用静态频组保证多个主频的平均幅值以维持发射稳定性,利用动态频组对通讯信息编码,传输有效信息.在实际工作时,发射端将通讯信息编码转换为高阶伪随机信号,利用长导线源向大地发射,接收端利用电极或者线圈接收电磁信号,经模式识别、时频变换、反向解码转换为有效通讯信息.通过仿真测试和在济南市某煤矿井下试验,完成有效通讯信息的发射、传输、解译等过程,实现了基于高阶伪随机信号的对地通讯方法,验证了方法在地下工程通讯的可行性和可靠性.

Through-The-Earth Communication(TTEC)is a method using low-frequency electromagnetic wave through the earth to transmit information,which plays an essential role in the management,warning and rescue of underground engineering.The high-order pseudo-random signal,with the capability to incorporate multiple frequencies simultaneously,is characterized by its ease of implementation,controllable frequencies,and strong resistance to interference.This makes it potentially valuable for TTEC.This paper presents a TTEC method based on high-order pseudo-random signal.The method sets the static frequency group and the dynamic frequency group in the signal.The static frequency group ensures the average amplitude of main frequencies in the multi-frequency signal and the dynamic frequency group encodes the communication information.In practical work,the high-order pseudo-random signal is encoded at the transmitting end and transmitted to the earth by using the long wire source.The signal received at the receiving end is converted into effective communication information by pattern recognition,time-frequency transformation and reverse decoding.Through the simulation test and field experiment at a closed coal mine in Jinan City,the transmission and interpretation of effective communication information are completed,and the method based on high-order pseudo-random signal is realized,which verifies the feasibility of the method in the TTEC in underground engineering.