Characteristics of Multipath Radio Propagation of Received Signal in Mine Tunnel

Multipath propagation causes power attenuation and delay spread of the received signal.On the basis of the tent law model,the formula to solve incidence angle of the received signal and the calculation of the received power is derived.Results from simulation show that: the signal loss increases at first and then decreases when the carrier frequency increases from 1Hz to 5GHz;and the received power-attenuation increases gradually with increasing communication distance,moreover,the attenuation of the vertical polarized wave is greater than that of horizontal one.The delay spread is greater with lower carrier frequency;and the increasing communication distance results in increasing delay-spread;furthermore,the delay spread of vertical polarized wave is smaller than that of horizontal one.