井下OFDM信道估计算法研究

Research of underground OFDM channel estimation algorithm

针对煤矿井下信道情况复杂,多径效应会带来噪声增加和误码率上升等问题,建立了煤矿井下正交频分复用系统模型,研究了井下正交频分复用信道最小平方、最小均方误差估计算法;在矩形导频分配方案的基础上,提出了在时域利用曲线拟合方法实现数据符号处信道系数的估计算法。该算法与插值算法相比,对导频符号处信道系数的准确性要求不高,只要求所构造的函数尽可能接近真实值。仿真结果表明,提出的拟合估计算法和最小均方误差估计算法相比,在估计性能没有太大变化的前提下,大大降低了实现复杂度。仿真结果和理论分析基本一致。

In view of problems of complex underground channel environment and increasing of noise and error rate caused by multipath effect, a system model of orthogonal frequency division multiplexing was established, and the least squares error estimation algorithm and the minimum mean square error estimation algorithm were researched. Based on the rectangular pilot assignment, an estimation algorithm was proposed which uses curve fitting algorithm in the time domain to estimate the data signal channel coefficients. The proposed algorithm does not require high accuracy of the channel coefficients of pilot signals, only requires the constructed function as close as possible to the real value compared with the interpolation algorithm. The simulation results show that the proposed estimation algorithm can greatly reduce implementation complexity, and estimation performance hasn＇t big change compared with the minimum mean square error estimation algorithm. Simulation results and theoretical analysis are basically identical.