Measurement and analysis of underground ultra wide band signal path loss

In view of problem that theoretical modeling and simulation experiment are mostly used in research of underground path loss characteristics of high -precision ultra wide band (UWB) signal, actual measurement research of UWB signal is less. The path loss measurement and analysis of UWB signal are carried out in two typical scenarios of running roadway of overhead passenger device (monkey car) with relatively common environmental conditions such as roadway size, roadway wall material and pipe facilities，and heading face with bad environment, high coal dust concentration and serious water accumulation. The results show that: ① The path loss index of UWB signal in two kinds of roadway environments is less than 2, and wave guide effect of roadway leads to better propagation characteristics of UWB signal than that of free space. The base station deployment interval of the UWB positioning system in roadway is larger than that of the ground free space propagation scene.② In the same mine, the roadway environment is different, and the path loss characteristics are also different. The path loss index and shadow fading variance of heading face are significantly different from those of monkey car running roadway. ③ From comparison of single test point in roadway of heading face, the path loss in NLOS environment is larger than that in LOS environment. More intensive positioning base stations need to be deployed in roadway in NLOS environment.The results can be used to guide deployment scheme design of mine UWB precise positioning system.