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
L-ornithine is a metabolic product of L-arginine and is found in the liver and other tissues after the enzyme arginase in the urea cycle catalyses the reaction.The presence of L-ornithine has an influence on certain b...L-ornithine is a metabolic product of L-arginine and is found in the liver and other tissues after the enzyme arginase in the urea cycle catalyses the reaction.The presence of L-ornithine has an influence on certain biochemical activities such as the proliferation of collagen production and also has an effect on airway responsiveness.Therefore,it has a role to play in the availability of nitric oxide(NO).A brief reactivity study was carried out for various substituents at the α-C atom of this amino acid.Substituents such as chlorine and fluorine affect the reactivity of the entire molecule and may alter the properties of the amino acid.To understand the properties of molecule,a detailed study was done at the density functional theory(DFT) level and compared with ab initio calculations.Fukui functions were invoked to assess reactivity and stability.The descriptive properties were correlated to logP or pKa using available software to help build a model to quantitatively assess properties and reactivity.Results showed a random reactivity pattern upon halogen substitution and this indicates the need to exercise caution during docking and reactivity studies.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。
基金supported by the University Grants Commission,India
文摘L-ornithine is a metabolic product of L-arginine and is found in the liver and other tissues after the enzyme arginase in the urea cycle catalyses the reaction.The presence of L-ornithine has an influence on certain biochemical activities such as the proliferation of collagen production and also has an effect on airway responsiveness.Therefore,it has a role to play in the availability of nitric oxide(NO).A brief reactivity study was carried out for various substituents at the α-C atom of this amino acid.Substituents such as chlorine and fluorine affect the reactivity of the entire molecule and may alter the properties of the amino acid.To understand the properties of molecule,a detailed study was done at the density functional theory(DFT) level and compared with ab initio calculations.Fukui functions were invoked to assess reactivity and stability.The descriptive properties were correlated to logP or pKa using available software to help build a model to quantitatively assess properties and reactivity.Results showed a random reactivity pattern upon halogen substitution and this indicates the need to exercise caution during docking and reactivity studies.
