山洞环境中声信号的传播模型及其性能研究

Acoustic Signal Propagation Model and Its Performance in Cave Environment

针对山洞环境提出了一个全新的基于几何的模型,该环境中山洞两侧通道从入口处到深处逐渐变宽(变窄),根据几何模型,并且借助射线理论,假设通道两侧表面是近似光滑的,提出山洞环境下声信号通信系统单发送单接收的随机信道模型。根据几何模型研究了通道两侧张开角度对信道包络分布、即时信道容量、时间自相关函数、频率相关函数、多普勒功率谱密度以及功率延迟分布的影响。理论和仿真结果表明,相对于通道两侧平行(即两侧张开角度为0)的情况,通道两侧张开角度仅很小的变化就会对声信道无线通信系统的各项统计特性产生非常显著的影响,并且通道两侧平行为本研究内容的一个特殊情况。

In view of the cave environment,this paper presented a geometric model based on the new environment in the cave.The channel on both sides of the cave gradually widen (narrow) from the entrance to the depth.According to the geometric model,and by means of ray theory,this paper assumed that both sides of the channel surface are approximate smooth,and proposed a random channel model of single transmission and single reception for acoustic signal communication system in cave environment.According to the geometric model,the influence of channel opening angle on channel distribution,instant channel capacity,time autocorrelation function, frequency correlation function,Doppler power spectral density and power delay distribution is studied.The theoretical and simulation results show that compared with the case where both sides of the channel are parallel (i.e.the opening angle of both sides is 0),the statistical characteristics of the acoustic channel wireless communication system will be significantly affected by only a small change in the ope- ning angle of both sides of the channel,and the parallel is a special case of this research content.