煤炭作为国家的重要能源，为国民经济的发展提供动力，在煤炭行业向智能化、安全化和信息化发展的过程中，离不开高效可靠的煤矿井下无线通信系统，因此如何在复杂的矿井环境中建立一个稳定实用的无线通信系统成为煤矿行业的关注热点。无线通信系统的性能与无线信道息息相关，无线电波在井下信道中传输时会产生多种衰落，对信号的传输带来不确定性。为了解矿井无线信道中电波的传播规律，提高通信系统的性能，本文创建了矿井无线通信系统的路径损耗预测模型，同时对于多径衰落问题，建立了中继协作MIMO系统模型，为实际中矿井无线通信系统的设计和建立提供了合理的参考价值。
本文分析了矿井无线信道衰落特性，通过波导模式法研究了矩形巷道中的电磁波传播衰减特性，并仿真天线工作频率、巷道电参数、粗糙度和倾斜度等环境因素带来的影响。在此基础上，利用LS-SVM算法建立了矿井巷道路径损耗预测模型，以上几个影响因子作为预测输入，信道的路径损耗值作为输出，将仿真结果与测试样本曲线进行拟合比较，说明该模型能较好的实现预测。接着，利用模拟退火算法寻找最佳的LS-SVM核函数参数和正则化参数，得到了优化后SA+LS-SVM预测模型。将优化后的模型与LS-SVM模型和BP模型进行对比，可以看出其预测精度得到了明显提高，验证了该模型的有效性和优越性。
针对矿井无线信道中的多径衰落问题，建立了基于中继MIMO技术的矿井无线通信模型，推导出关于中断概率与信道容量的公式并以此为评价指标，分别仿真分析了不同天线数目、不同中继协议以及不同能量阈值下的系统通信性能，得出不同条件下的传输性能规律，说明所建立的模型能明显提升系统的传输速率，可以有效地对抗多径衰落问题。

Coal, as an important energy source of the country, provides power for the development of the national economy. In the coal industry to intelligent, security and information development process, can not do without efficient and reliable wireless communication system in the coal mine.So how to establish a stable and practical wireless communication system in the complex mine environment has become the focus of attention of the coal mine industry.
Firstly, This paper analyzes the fading characteristics of mine wireless channel, selects rectangular roadway as the object, uses the waveguide mode method to study the electromagnetic wave propagation and attenuation characteristics.And the effects of environmental factors,such as roadway electrical parameters, roadway roughness,antenna working frequency and inclination are simulated and analyzed.On this basis, the path loss prediction model of mine roadway is established by using LS-SVM algorithm. The above influence factors are used as the prediction input and the path loss value of channel is used as the prediction output. The simulation results are fitted and compared with the test sample curve, which shows that the model can better realize the prediction.Next, the simulated annealing(SA) algorithm is used to optimize the kernel function parameters and regularization parameters in LS-SVM, and the optimized SA+LS-SVM prediction model is obtained.Comparing the optimized model with LS-SVM model and BP model, it can be seen that the prediction accuracy has been significantly improved, which verifies the effectiveness and superiority of the model.
Aiming at the problem of multipath fading in mine wireless channel, a mine wireless channel based on relay cooperation and MIMO technology is established.The formula of outage probability and channel capacity is derived and used as the evaluation index.The system communication performance under different antenna numbers, different relay protocols and different energy thresholds is simulated and analyzed respectively, and the transmission performance laws under different conditions are obtained. It shows that the model can significantly improve the transmission rate of the system and effectively combat the problem of multipath fading.

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