针对Alpha稳定分布噪声下,循环谱估计正交频分复用(orthogonal frequency division multiplexing,OFDM)信号参数失效问题,提出一种基于广义循环谱的载波频率和符号速率联合估计方法.首先,对OFDM信号进行反正切变换及循环平稳分析,建立OFDM的广义循环谱数学模型;然后,分析广义循环谱谱线与OFDM信号载波频率及符号速率之间的关系,通过检测广义循环谱谱线位置实现OFDM信号的参数估计;最后,通用软件无线电外设(universal software radio peripheral,USRP)采集得到OFDM信号,使用真实采集I、Q中频信号对所提算法进行验证.实验结果表明:所提算法在Alpha稳定分布噪声下表现出良好的鲁棒性,具有一定的工程实用性.
Abstract
In order to solve the orthogonal frequency division multiplexing(OFDM)signal parameter failure problem under stable Alpha distribution noise,a joint carrier frequency and symbol rate estimation method based on generalized cyclic spectrum was proposed.Firstly,the generalized cyclic spectrum mathematical model of OFDM was established by arctangent transformation and cyclostationary analysis of OFDM signals.Then,the relationship between the generalized cyclic spectral line and the carrier frequency and symbol rate of OFDM signal was analyzed,and the parameter estimation of OFDM signal was realized by detecting the position of generalized cyclic spectral line.Finally,universal software radio peripheral(USRP)collected OFDM signals,and used real collection I and Q IF signals to verify the proposed algorithm.Experimental results show that the proposed algorithm has good robustness under Alpha stable distributed noise and has certain engineering practicability.
orthogonal frequency division multiplexing(OFDM)/carrier frequency estimation/generalized cyclic spectrum/Alpha stable distributed noise/universal software radio peripheral(USRP)
维普
万方数据