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给出了 90 0MHz无线电波在两个地下煤矿采煤工作区的测量结果 ,并用混合传播模型解释了以上结果 .得到的结论为 :在巷道中 ,传播区域被转折点分为两段 ,在转折点前面 ,接收信号电平在 4 2m内下降了 2 7dB ;而在转折点之后 ,接收信号电平下降得很缓慢 ,胶带巷道和车辆巷道中衰减分别为 13 3dB/10 0m ,(6 75 + 10 )dB/10 0m .在采煤区进风巷中 ,传播损耗为 2 2dB/10 0m ,标准偏差为 1 75dB ;在采煤区长壁工作面上 ,传播衰减率均为 75dB/10 0m ,标准偏差小于 2 2dB ;在井下可以采用微蜂窝无线通信系统 .
The measurement results of 90 0MHz radio wave in the coal mining work area of two underground coal mines are given and the above results are explained by the mixed propagation model.The conclusion is as follows: In the roadway, the propagation area is divided into two sections by turning point, , The received signal level dropped by 27dB in 4 2m. After the turning point, the received signal level dropped very slowly. The attenuation in the tape and vehicle tunnels was 13 3dB / 10 0m and (6 75 + 10) dB, respectively / 10 0m. In the air intake tunnel of coal mining area, the propagation loss is 2 2 dB / 100 m and the standard deviation is 1 75 dB. On the longwall face in coal mining area, the propagation attenuation rate is 75 dB / 100 m, and the standard deviation Less than 2 2dB; micro-cellular wireless communication system can be used downhole.