由于诱饵的存在使反辐射武器天线接收的信号时序不一致,已经无法通过传统多重信号分类(multiple signal classification,MUSIC)和旋转不变子空间(rotational invariance techniques,ESPRIT)算法对其脉冲进行前沿、后沿或中间脉冲取样来...由于诱饵的存在使反辐射武器天线接收的信号时序不一致,已经无法通过传统多重信号分类(multiple signal classification,MUSIC)和旋转不变子空间(rotational invariance techniques,ESPRIT)算法对其脉冲进行前沿、后沿或中间脉冲取样来准确跟踪目标雷达。针对此问题提出两种适用于估计时序不一致信号波达方向(direction of arrival,DOA)的算法。第一种基于ESPRIT算法,适用于信号相互独立的情况,第二种基于MUSIC算法,适用于相干信号的情况。计算机仿真试验表明,与同类算法相比,两种新方法具有更好的估计性能。展开更多
The influence of array element’s consistency on the hydrophone array’s signal-to-noise ratio (SNR) is studied. The consistency of array elements means the outputs of all the array’s elements are the same, that is t...The influence of array element’s consistency on the hydrophone array’s signal-to-noise ratio (SNR) is studied. The consistency of array elements means the outputs of all the array’s elements are the same, that is to say, the outputs have the same phase and amplitude when their inputs are the same. The relationship between the SNR and the correlation coefficient of signal and the relationship between the SNR and the correlation coefficient of noise are given. Hydrophone array’s gain with the output of elements’ inconsistent phase and amplitude is analyzed theoretically. When the signal is single-frequency, the gain expression of two-elements array is deduced. Then the gain is calculated when the phase difference is 10° and the amplitude difference is 3 dB. The theoretical analysis is verified through simulation. The simulation results show the variation rule of array’s SNR when the consistency changes: the array SNR gain is greatly affected by the consistency of the elements’ output and the gain decreases as the consistency decreases and the gain may be negative when the amplitude response becomes worse.展开更多
Simple authenticated key agrcement algorithm is one of the Diffie-Hellman key agreement variations. It prevents man-inthe-middle attack with only two more packets required to agree on the secret session key, but it ha...Simple authenticated key agrcement algorithm is one of the Diffie-Hellman key agreement variations. It prevents man-inthe-middle attack with only two more packets required to agree on the secret session key, but it has some weaknesses. In this paper, a new enhanced simple authenticated key agreement algorithm is proposed to overcome these weaknesses on the basis of analyzing the weaknesses of the related protocols. The new enhanced simple authenticated key agreement algorithm can get over replay attack and password guessing attack, provide perfect forward secrecy, and hold the merits of the simple authenticated key agreement algorithm.展开更多
文摘由于诱饵的存在使反辐射武器天线接收的信号时序不一致,已经无法通过传统多重信号分类(multiple signal classification,MUSIC)和旋转不变子空间(rotational invariance techniques,ESPRIT)算法对其脉冲进行前沿、后沿或中间脉冲取样来准确跟踪目标雷达。针对此问题提出两种适用于估计时序不一致信号波达方向(direction of arrival,DOA)的算法。第一种基于ESPRIT算法,适用于信号相互独立的情况,第二种基于MUSIC算法,适用于相干信号的情况。计算机仿真试验表明,与同类算法相比,两种新方法具有更好的估计性能。
基金Major State Basic Research Development Program of China(No.2016YFC0101900)Applied Basic Research Project of Shanxi Province(Nos.201601D011035,201701D121067)
文摘The influence of array element’s consistency on the hydrophone array’s signal-to-noise ratio (SNR) is studied. The consistency of array elements means the outputs of all the array’s elements are the same, that is to say, the outputs have the same phase and amplitude when their inputs are the same. The relationship between the SNR and the correlation coefficient of signal and the relationship between the SNR and the correlation coefficient of noise are given. Hydrophone array’s gain with the output of elements’ inconsistent phase and amplitude is analyzed theoretically. When the signal is single-frequency, the gain expression of two-elements array is deduced. Then the gain is calculated when the phase difference is 10° and the amplitude difference is 3 dB. The theoretical analysis is verified through simulation. The simulation results show the variation rule of array’s SNR when the consistency changes: the array SNR gain is greatly affected by the consistency of the elements’ output and the gain decreases as the consistency decreases and the gain may be negative when the amplitude response becomes worse.
基金This work was supported by National"863"High Technology Research and Development Programof China under grant 2002AA145090
文摘Simple authenticated key agrcement algorithm is one of the Diffie-Hellman key agreement variations. It prevents man-inthe-middle attack with only two more packets required to agree on the secret session key, but it has some weaknesses. In this paper, a new enhanced simple authenticated key agreement algorithm is proposed to overcome these weaknesses on the basis of analyzing the weaknesses of the related protocols. The new enhanced simple authenticated key agreement algorithm can get over replay attack and password guessing attack, provide perfect forward secrecy, and hold the merits of the simple authenticated key agreement algorithm.
