基于导频信号和最大似然估计算法的离散小波包调制的研究

摘要

目前,紧张的无线频谱资源已经使频谱利用率成为无线通信系统面临的重要问题.多载波调制技术能有效解决上述问题并以其高效的频谱利用率和良好的抗多径衰落性能成为4G的核心传输技术之一.本文提出一种基于导频信号和最大似然估计算法的离散小波包多载波调制系统.通过对导频信号的设计,获得信道状态信息,利用最大似然估计算出最优信道状态信息,最后利用基于迫零算法消除由多径衰落引起的码间干扰.通过理论分析和仿真验证,基于导频信号和最大似然估计的算法的离散小波包调制是值得考虑的多载波调制技术.%Recently,the efficiency of frequency spectrum is very important for wireless communication system because of the lack of frequency spectrum resource.Multicarrier modulation can availably solve the above-mentioned problem.For its high efficiency of frequency spectrum and effectively eliminating the inter-symbol interference(ISI)resulted from the multipath fading channel,multicarrier modulation because one of the important technologies of the fourth generation wireless communication.Novel DWPM(Discrete Wavelet Packet Modulation)system based on pilot signal MLEA(Maximum Likelihood Estimation Algorithm).Channel state information(CSI)is obtained with the design of the pilot and the optimum CSI is estimated by MLEA,then inter-symbol interference is suppressed by zero forcing algorithm.It is demonstrated by theoretical analysis and simulation results that DWPM system base on pilot signal MLEA is considerable multicarrier modulation.