透地信道中BPSK信号传输特性的实验研究

Experimental studies on characteristics of BPSK signal transmitting in through-the-earth communication channel

利用搭建的弹性波透地通信系统试验平台,对BPSK调制信号通过模拟分层大地信道的传输幅频特性和衰落特性进行了试验测试,得到了BPSK信号在大地信道中传播的衰减和衰落情况,通过对比发送和接收信号得出结论:时域上,接收的BPSK调制信号有明显的衰落现象,从频谱上看,其越高的频率成分在通过大地信道时幅度衰减越大.另外实验结果表明,现有平台在信号中心频率200～300Hz时传输效果最好.

By a simplified elastic wave through - the - earth communication system model, an experiment using BPSK modulated elastic wave as source signal to transmit the simulated stratified earth channel is performed in order to test the earth channel characteristics. Hence the through- the -earth channel amplitude- frequency and fading characteristics are achieved. By comparing features of the sending and receiving signals, conclusions can be drawn as follows： from the time domain, the receiving BPSK signal fading is an evident feature, and high frequency components attenuate greater than low frequency component. Experiment results also show that the experiment channel attenuation is up to the minimum level at 200 -300 Hz.