多径信道下ZP-OFDM信号的时域参数盲估计  

Blind ZP-OFDM time-parameters estimation in multipath channel

作　　者：刘明骞[1] 李兵兵[1] 唐宁洁[1] 

机构地区：[1]西安电子科技大学综合业务网理论及关键技术国家重点实验室,陕西西安710071

出　　处：《系统工程与电子技术》2011年第11期2531-2535,共5页Systems Engineering and Electronics

基　　金：国家自然科学基金(60772138);国家高技术研究发展计划(863计划)(2007AA01Z288);高等学校学科创新引智计划(B08038)资助课题

摘　　要：针对低信噪比多径信道下,零前缀正交频分复用(zero prefix orthogonal frequency division multiplexing,ZP-OFDM)信号时域参数估计精度低的问题,提出了一种改进的ZP-OFDM信号时域参数盲估计方法。该方法首先计算信号的功率自相关函数,并利用小波消噪及平滑滤波对其进行预处理,通过检测峰峰值距离的方法完成符号总长度的估计。然后计算单位符号总长度数据的幅度平方值并对其进行小波分解与重构,设定门限提取一个零前缀估计值。最后通过多段数据联合估计确定最终的零前缀估计长度。仿真实验结果表明,在低信噪比多径信道条件下,提出ZP-OFDM信号的时域参数盲估计方法具有良好的估计性能。In view of poor performance of traditional blind estimation methods for zero prefix orthogonal frequency division multiplexing （ZP-OFDM） time-parameters, especially in low signal-to-noise ratio （SNR） and multipath channels, a novel blind estimation method is proposed. Firstly, the power autocorrelation function is calculated and then the pretreatments of wavelet de-noising and smoothing filtering are operated, the symbol duration is estimated by detecting of the distance between two peaks. Secondly, the amplitude square values for the received data length of unit symbol duration are calculated and then the wavelet decomposition and recon- struction are operated. The adaptive threshold is set to extract the estimated zero prefix （ZP） length. Finally, the final ZP length is decided by joint estimation of multiple segment data. Simulation results show that the proposed methods have the superior performance in low SNR and multipath channel conditions.

关 键 词：通信与信息系统 零前缀正交频分复用 参数估计 功率自相关 幅度平方值 小波分解 

分 类 号：TN911.7[电子电信—通信与信息系统]