A novel frequency estimation algorithm for wideband signal with sub-Nyquist sampling is proposed in this paper. With the aid of information provided by the auxiliary delayed sampling channel and the aliased frequency ...A novel frequency estimation algorithm for wideband signal with sub-Nyquist sampling is proposed in this paper. With the aid of information provided by the auxiliary delayed sampling channel and the aliased frequency estimation for wideband signal with sub-Nyquist sampling, the frequency aliasing due to sub-Nyquist sampling can be solved. This method can reduce the complexity of the overall hardware at the cost of an auxiliary sampling channel. Furthermore, in order to alleviate the computation burden for its practicability, a more simplified algorithm is put forward and its validity is proved by our numerical simulation results. The Cramer-Rao Lower Bound (CRLB) of the frequency estimation is also derived at the end of this paper.展开更多
This paper addresses an algebraic approach for wideband frequency estimation with sub-Nyquist temporal sampling. Firstly, an algorithm based on double polynomial root finding procedure to estimate aliasing frequencies...This paper addresses an algebraic approach for wideband frequency estimation with sub-Nyquist temporal sampling. Firstly, an algorithm based on double polynomial root finding procedure to estimate aliasing frequencies and joint aliasing frequencies-time delay phases in multi-signal situation is presentcd. Since the sum of time delay phases determined from the least squares estimation shows the characteristics of the corre- sponding parameters pairs, then the pairmatching method is conducted by combining it with estimated parameters mentioned above. Although the proposed method is computationally simpler than the conventional schemes, simulation results show that it can approach optimum estimation performance.展开更多
采用线性正则域模糊函数的二次调频(quadratic frequency modulated,QFM)信号参数估计算法简单易解,估计精度较高,误差传递小,在实际应用中有较好的前景。本文对输出信噪比进行了较为深入而详细的分析,推导了输出信噪比与输入信噪比及...采用线性正则域模糊函数的二次调频(quadratic frequency modulated,QFM)信号参数估计算法简单易解,估计精度较高,误差传递小,在实际应用中有较好的前景。本文对输出信噪比进行了较为深入而详细的分析,推导了输出信噪比与输入信噪比及信号采样点数之间的关系表达式;通过仿真实验比较了在同等条件下和积分广义模糊函数算法(integrated generalized ambiguity function,IGAF)以及多项式相位变换(polynomial-phase trans-form,PPT)算法的输出信噪比大小,以及达到相同大小输出信噪比所需采样点数。发现该算法的输出信噪比要大于IGAF算法和PPT算法,且达到相同大小的输出信噪比所需采样点数分别是IGAF算法和PPT算法的1/4和1/9,即得到相同大小的输出信噪比时该算法所需的采样点数更少。展开更多
针对空间欠采样情况下的角度估计模糊问题,本文提出了一种基于多载频的分布式目标波达方向(Direction of Arrival,DOA)估计方法。该方法首先把阵列接收的空时二维回波数据重新组成新的空时频三维数据,然后利用多载频技术来构造空时最优...针对空间欠采样情况下的角度估计模糊问题,本文提出了一种基于多载频的分布式目标波达方向(Direction of Arrival,DOA)估计方法。该方法首先把阵列接收的空时二维回波数据重新组成新的空时频三维数据,然后利用多载频技术来构造空时最优处理器滤除地杂波并匹配目标信号,最后利用最优处理器的输出结果对目标DOA进行估计,能够在空间欠采样情况下获得分布式目标中心DOA的准确估计。仿真结果表明了该方法的有效性。展开更多
Coherent Jamming is one of the Important trends in modern radar electronic warfare. High-speed sampling of wldeband radio frequency （RF） signals and high isolatlon of two receive-transmit antennas are key technologi...Coherent Jamming is one of the Important trends in modern radar electronic warfare. High-speed sampling of wldeband radio frequency （RF） signals and high isolatlon of two receive-transmit antennas are key technologies for the realization of coherent jamming. However, these technologies present significant challenges to enginserlng application. In this paper, a novel repeater Jamming based on interrupted sampling technique is presented. For a Jammer with a receive-transmit time-sharing antenna, a radar signal is sampled with a low rate by the jammer. Then, a train of false targets will be achieved after the Jamming signal feed the matched flltar of a pulse compression radar. For the case of the Ilnser frequency modulated （LFM） pulse compression radars, mathematic principles of the interrupted.sampiing repeater jamming Is developed, and then the efficiency of the jamming is described and stated as expressions of key parameters which are also beneficial to the Jamming design for other coherent radars.展开更多
文摘A novel frequency estimation algorithm for wideband signal with sub-Nyquist sampling is proposed in this paper. With the aid of information provided by the auxiliary delayed sampling channel and the aliased frequency estimation for wideband signal with sub-Nyquist sampling, the frequency aliasing due to sub-Nyquist sampling can be solved. This method can reduce the complexity of the overall hardware at the cost of an auxiliary sampling channel. Furthermore, in order to alleviate the computation burden for its practicability, a more simplified algorithm is put forward and its validity is proved by our numerical simulation results. The Cramer-Rao Lower Bound (CRLB) of the frequency estimation is also derived at the end of this paper.
文摘This paper addresses an algebraic approach for wideband frequency estimation with sub-Nyquist temporal sampling. Firstly, an algorithm based on double polynomial root finding procedure to estimate aliasing frequencies and joint aliasing frequencies-time delay phases in multi-signal situation is presentcd. Since the sum of time delay phases determined from the least squares estimation shows the characteristics of the corre- sponding parameters pairs, then the pairmatching method is conducted by combining it with estimated parameters mentioned above. Although the proposed method is computationally simpler than the conventional schemes, simulation results show that it can approach optimum estimation performance.
文摘针对空间欠采样情况下的角度估计模糊问题,本文提出了一种基于多载频的分布式目标波达方向(Direction of Arrival,DOA)估计方法。该方法首先把阵列接收的空时二维回波数据重新组成新的空时频三维数据,然后利用多载频技术来构造空时最优处理器滤除地杂波并匹配目标信号,最后利用最优处理器的输出结果对目标DOA进行估计,能够在空间欠采样情况下获得分布式目标中心DOA的准确估计。仿真结果表明了该方法的有效性。
文摘Coherent Jamming is one of the Important trends in modern radar electronic warfare. High-speed sampling of wldeband radio frequency （RF） signals and high isolatlon of two receive-transmit antennas are key technologies for the realization of coherent jamming. However, these technologies present significant challenges to enginserlng application. In this paper, a novel repeater Jamming based on interrupted sampling technique is presented. For a Jammer with a receive-transmit time-sharing antenna, a radar signal is sampled with a low rate by the jammer. Then, a train of false targets will be achieved after the Jamming signal feed the matched flltar of a pulse compression radar. For the case of the Ilnser frequency modulated （LFM） pulse compression radars, mathematic principles of the interrupted.sampiing repeater jamming Is developed, and then the efficiency of the jamming is described and stated as expressions of key parameters which are also beneficial to the Jamming design for other coherent radars.
