针对现有的复合调制信号参数估计方法在Alpha稳定分布噪声中性能严重退化的问题,提出一种基于L-DFT(L-Filter-Based DFT)的线性调频与相位编码(Linear Frequency Modulation and Binary Phase Shift Keying,LFM-BPSK)复合调制信号参数...针对现有的复合调制信号参数估计方法在Alpha稳定分布噪声中性能严重退化的问题,提出一种基于L-DFT(L-Filter-Based DFT)的线性调频与相位编码(Linear Frequency Modulation and Binary Phase Shift Keying,LFM-BPSK)复合调制信号参数估计方法。该方法首先定义了L-DCFT(L-Filter Based Discrete Chirp-Fourier Transform),平方倍频法消除编码调相后,采用L-DCFT估计信号的起始频率和调制斜率;分析了循环自相关函数中脉冲出现概率增大的问题,提出了基于改进L-DFT和循环统计量的码速率估计方法。仿真结果表明,基于L-DFT的参数估计方法能有效抑制脉冲噪声,在强脉冲噪声中具有良好的参数估计性能。展开更多
自动调制识别在无线通信领域发挥了巨大作用。多数研究中假设的加性高斯白噪声信道已不再满足实际信道环境的准确描述。实际中,由于闪电、雷暴、多用户干扰、设备故障等原因,信道环境中广泛存在Alpha稳定分布噪声。因此对其开展研究更...自动调制识别在无线通信领域发挥了巨大作用。多数研究中假设的加性高斯白噪声信道已不再满足实际信道环境的准确描述。实际中,由于闪电、雷暴、多用户干扰、设备故障等原因,信道环境中广泛存在Alpha稳定分布噪声。因此对其开展研究更符合实际且具有挑战性。该文针对Alpha稳定分布噪声提出了一种预处理联合轻量级网络的调制识别方法。首先,通过对数域映射及阈值限制对接收信号进行预处理,抑制由Alpha稳定分布噪声带来的尖锐脉冲将信号幅度控制到合理范围;然后,提出一种基于Ghost模块的轻量级网络来完成信号的调制识别分类任务。实验结果表明,与现有的CLDNN(Convolutional Long Short-term Deep Neural Network)、CNN(Convolutional Neural Network)、ResNe(t Residual Network)相比,本文所提方法具有较高的识别准确率及较低的计算复杂度。展开更多
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O...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。展开更多
We investigate the effect of alpha stable noise on stochastic resonance in a single-threshold sensor system by analytic deduction and stochastic simulation. It is shown that stochastic resonance occurs in the threshol...We investigate the effect of alpha stable noise on stochastic resonance in a single-threshold sensor system by analytic deduction and stochastic simulation. It is shown that stochastic resonance occurs in the threshold system in alpha stable noise environment, but the resonant effect becomes weakened as the alpha stable index decreases or the skewness parameter of alpha stable distribution increases. In particular, for Cauchy noise a nonlinear relation among the optimal noise deviation parameter, the signal amplitude and the threshold is analytically obtained and illustrated by using the extreme value condition for the output signal-to-noise ratio. The results presented in this communication should have application in signal detection and image restoration in the non-Gaussian noisy environment.展开更多
文摘针对现有的复合调制信号参数估计方法在Alpha稳定分布噪声中性能严重退化的问题,提出一种基于L-DFT(L-Filter-Based DFT)的线性调频与相位编码(Linear Frequency Modulation and Binary Phase Shift Keying,LFM-BPSK)复合调制信号参数估计方法。该方法首先定义了L-DCFT(L-Filter Based Discrete Chirp-Fourier Transform),平方倍频法消除编码调相后,采用L-DCFT估计信号的起始频率和调制斜率;分析了循环自相关函数中脉冲出现概率增大的问题,提出了基于改进L-DFT和循环统计量的码速率估计方法。仿真结果表明,基于L-DFT的参数估计方法能有效抑制脉冲噪声,在强脉冲噪声中具有良好的参数估计性能。
文摘自动调制识别在无线通信领域发挥了巨大作用。多数研究中假设的加性高斯白噪声信道已不再满足实际信道环境的准确描述。实际中,由于闪电、雷暴、多用户干扰、设备故障等原因,信道环境中广泛存在Alpha稳定分布噪声。因此对其开展研究更符合实际且具有挑战性。该文针对Alpha稳定分布噪声提出了一种预处理联合轻量级网络的调制识别方法。首先,通过对数域映射及阈值限制对接收信号进行预处理,抑制由Alpha稳定分布噪声带来的尖锐脉冲将信号幅度控制到合理范围;然后,提出一种基于Ghost模块的轻量级网络来完成信号的调制识别分类任务。实验结果表明,与现有的CLDNN(Convolutional Long Short-term Deep Neural Network)、CNN(Convolutional Neural Network)、ResNe(t Residual Network)相比,本文所提方法具有较高的识别准确率及较低的计算复杂度。
文摘针对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。
基金Supported by National Natural Science Foundation of China under Grant Nos.11072182 and 11272241
文摘We investigate the effect of alpha stable noise on stochastic resonance in a single-threshold sensor system by analytic deduction and stochastic simulation. It is shown that stochastic resonance occurs in the threshold system in alpha stable noise environment, but the resonant effect becomes weakened as the alpha stable index decreases or the skewness parameter of alpha stable distribution increases. In particular, for Cauchy noise a nonlinear relation among the optimal noise deviation parameter, the signal amplitude and the threshold is analytically obtained and illustrated by using the extreme value condition for the output signal-to-noise ratio. The results presented in this communication should have application in signal detection and image restoration in the non-Gaussian noisy environment.
