摘要
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。
In order to solve the problem that the existing parameter estimation algorithm for hybrid modulated signals significantly degrades under Alpha stable noise,an L-DFT （L-Filter-Based DFT）based algorithm for hybrid modulated signals with binary phase shift keying （BPSK）and linear frequency modulation （LFM）parameter estimation is proposed.Firstly,the definition of L-DCFT （L-Filter Based Discrete Chirp-Fourier Transformation）is given.Then,the square frequency doubling method is applied to eliminate the binary phase modulation of the reconstructed signals,the initial frequency and chirp rate are estimated with L-DCFT.The problem of the probability growth of pulses in cyclic autocorrelation is analyzed,and a symbol rate estimation algorithm based on the modified L-DFT and cyclic statistics is proposed.Simulation results show that the L-DFT based method can suppress impulse noise efficiently and it has a superior parametric estimation performance under heavier impulse noise.
出处
《振动与冲击》
EI
CSCD
北大核心
2015年第17期38-43,共6页
Journal of Vibration and Shock
基金
国家自然科学基金(61201286)
陕西省自然科学基金(2014JM8304)
