煤矿井下OFDM自适应调制技术

煤矿井下环境恶劣,多径效应带来噪声增加和误码率上升,使通信质量下降。针对这一情况,将正交频分复用（OFDM）自适应调制技术引入井下无线通信系统,选择瑞利衰落信道模型,采用SVD算法和低通滤波、三次样条插值算法进行信道估计和插值,并对OFDM自适应调制算法进行性能仿真。结果表明,自适应调制算法的误码率性能明显优于固定调制;SBLA自适应调制算法比Greedy、Fishcher和Chow算法更易实现;低通滤波插值算法比三次样条插值法更能准确估计信道特性。该研究为煤矿井下信息的实时、高速、准确传输提供了技术参考。

OFDM adaptive techniques in coal mine

The response to the communication quality degradation resulting from increasing noise and bit error rate due to the hostile communication environment of coal mine and occurrence of multi-path effect in underground mines leads to the use of OFDM of adaptive modulation to underground wireless communication systems,as dictated by features of the coal mine wireless communication,selection of rayleigh fading channel model,and use of SVD algorithm,low-pass filter interpolation algorithm and cubic spline interpolation algorithm for channel estimation and simulation of the system performance.The results show that BER of adaptive modulation algorithm is superior to the fixed modulation;SBLA adaptive modulation algorithm is easier to achieve than the Greedy,Fishcher and Chow algorithm;Low-pass filter interpolation algorithm gives more accurate estimation of channel characteristics than Cubic spline interpolation.The study provides a technical reference for real-time,high-speed and accurate transmission of information in underground coal mine.