For a large-scale adaptive array, the heavy computational load and the high-rate data transmission are two challenges in the implementation of an adaptive digital beamforming system. An efficient parallel digital beam...For a large-scale adaptive array, the heavy computational load and the high-rate data transmission are two challenges in the implementation of an adaptive digital beamforming system. An efficient parallel digital beamforming （DBF） algorithm based on the least mean square algorithm （PLMS） is proposed. An appropriate method is found to partition the least mean square （LMS） algorithm into a number of operational modules, which can be easily executed in a distributed-parallel-processing fashion. As a result, the proposed PLMS algorithm provides an effective solution that can alleviate the bottleneck of high-rate data transmission and reduce the computational cost. PLMS requires less computational load than that of the conventional parallel algorithms based on the recursive least square （RLS） algorithm, as well as it is easier to be implemented to do real time adaptive array processing. Moreover, low sidelobe of the beam pattern is obtained by constraining the static steering vector with Tschebyscheff coefficients. Finally, a scheme of the PLMS algorithm using distributed-parallel-processing system is also proposed. The simulation results demonstrate that the PLMS algorithm has the same interference cancellation performance as that of the conventional LMS algorithm. Moreover, the PLMS algorithm can obtain the same good beamforming performance, regardless how the algorithm is partitioned. It is expected that the proposed algorithm will be used in a large-scale adaptive array system to deal with real time adaptive digital beamforming processing.展开更多
针对传统数字波束成形体制抗干扰容限受制于模拟数字转换器(Analog to Digital Converter,ADC)量化精度问题,提出一种用于压制式干扰抑制的模拟-数字混合自适应波束成形方法。通过在射频端引入模拟波束成形,实现对干扰信号的初步抑制,...针对传统数字波束成形体制抗干扰容限受制于模拟数字转换器(Analog to Digital Converter,ADC)量化精度问题,提出一种用于压制式干扰抑制的模拟-数字混合自适应波束成形方法。通过在射频端引入模拟波束成形,实现对干扰信号的初步抑制,有效避免信号采样饱和,进一步结合数字波束成形技术,实现对干扰信号的再次抑制。建立了模拟-数字混合自适应波束成形信号模型,分析了抗干扰性能影响因素。仿真结果表明所提方法能够有效减少ADC量化精度的影响,对不同强度干扰均表现出很好的干扰抑制效果,与传统数字波束成形方法相比,抗压制式干扰能力实现了突破。展开更多
单脉冲雷达往往工作在复杂的电磁环境下。为了解决强干扰信号,尤其是主瓣干扰信号造成的单脉冲角度估计不准确问题,提出了一种新的自适应单脉冲角度跟踪算法。该算法首先利用接收到的阵列数据,利用多级维纳滤波器(Multistage Wiener fil...单脉冲雷达往往工作在复杂的电磁环境下。为了解决强干扰信号,尤其是主瓣干扰信号造成的单脉冲角度估计不准确问题,提出了一种新的自适应单脉冲角度跟踪算法。该算法首先利用接收到的阵列数据,利用多级维纳滤波器(Multistage Wiener filter)的前向递推结构以及合适的信源估计技术,快速地估计出主瓣干扰的方向(Direction of arrival);之后利用该方向信息,构造阻塞矩阵来滤除主瓣干扰信号;最后,利用经过阻塞矩阵预处理之后的信号进行基于正交投影的快速自适应数字波束形成(Adaptive digital beamforming),形成单脉冲跟踪所需的和、差波束。理论分析和仿真结果验证了该算法的正确性和有效性。展开更多
该文分析了天波超视距雷达(Over The Horizon Radar,OTHR)多径扩展多普勒杂波(Spread Doppler Clutter,SDC)的产生机理。由于阵列存在幅相误差且期望信号的功率大于SDC功率,自适应数字波束形成(Adaptive Digital Beam Forming,ADBF)将降...该文分析了天波超视距雷达(Over The Horizon Radar,OTHR)多径扩展多普勒杂波(Spread Doppler Clutter,SDC)的产生机理。由于阵列存在幅相误差且期望信号的功率大于SDC功率,自适应数字波束形成(Adaptive Digital Beam Forming,ADBF)将降低SDC抑制能力,同时还会导致信号对消,严重降低信噪比。针对以上问题,该文提出一种自适应抑制SDC的方法。该方法首先采用改进噪声子空间拟合自校正法消除阵列幅相误差,得到期望信号和SDC准确的到达仰角,然后采用正交投影权矢量进行ADBF处理,避免了强期望信号条件下ADBF权矢量估计不准的问题。理论分析和仿真实验表明该方法能够较彻底地抑制多径SDC。展开更多
文摘For a large-scale adaptive array, the heavy computational load and the high-rate data transmission are two challenges in the implementation of an adaptive digital beamforming system. An efficient parallel digital beamforming （DBF） algorithm based on the least mean square algorithm （PLMS） is proposed. An appropriate method is found to partition the least mean square （LMS） algorithm into a number of operational modules, which can be easily executed in a distributed-parallel-processing fashion. As a result, the proposed PLMS algorithm provides an effective solution that can alleviate the bottleneck of high-rate data transmission and reduce the computational cost. PLMS requires less computational load than that of the conventional parallel algorithms based on the recursive least square （RLS） algorithm, as well as it is easier to be implemented to do real time adaptive array processing. Moreover, low sidelobe of the beam pattern is obtained by constraining the static steering vector with Tschebyscheff coefficients. Finally, a scheme of the PLMS algorithm using distributed-parallel-processing system is also proposed. The simulation results demonstrate that the PLMS algorithm has the same interference cancellation performance as that of the conventional LMS algorithm. Moreover, the PLMS algorithm can obtain the same good beamforming performance, regardless how the algorithm is partitioned. It is expected that the proposed algorithm will be used in a large-scale adaptive array system to deal with real time adaptive digital beamforming processing.
文摘针对传统数字波束成形体制抗干扰容限受制于模拟数字转换器(Analog to Digital Converter,ADC)量化精度问题,提出一种用于压制式干扰抑制的模拟-数字混合自适应波束成形方法。通过在射频端引入模拟波束成形,实现对干扰信号的初步抑制,有效避免信号采样饱和,进一步结合数字波束成形技术,实现对干扰信号的再次抑制。建立了模拟-数字混合自适应波束成形信号模型,分析了抗干扰性能影响因素。仿真结果表明所提方法能够有效减少ADC量化精度的影响,对不同强度干扰均表现出很好的干扰抑制效果,与传统数字波束成形方法相比,抗压制式干扰能力实现了突破。
文摘单脉冲雷达往往工作在复杂的电磁环境下。为了解决强干扰信号,尤其是主瓣干扰信号造成的单脉冲角度估计不准确问题,提出了一种新的自适应单脉冲角度跟踪算法。该算法首先利用接收到的阵列数据,利用多级维纳滤波器(Multistage Wiener filter)的前向递推结构以及合适的信源估计技术,快速地估计出主瓣干扰的方向(Direction of arrival);之后利用该方向信息,构造阻塞矩阵来滤除主瓣干扰信号;最后,利用经过阻塞矩阵预处理之后的信号进行基于正交投影的快速自适应数字波束形成(Adaptive digital beamforming),形成单脉冲跟踪所需的和、差波束。理论分析和仿真结果验证了该算法的正确性和有效性。
文摘该文分析了天波超视距雷达(Over The Horizon Radar,OTHR)多径扩展多普勒杂波(Spread Doppler Clutter,SDC)的产生机理。由于阵列存在幅相误差且期望信号的功率大于SDC功率,自适应数字波束形成(Adaptive Digital Beam Forming,ADBF)将降低SDC抑制能力,同时还会导致信号对消,严重降低信噪比。针对以上问题,该文提出一种自适应抑制SDC的方法。该方法首先采用改进噪声子空间拟合自校正法消除阵列幅相误差,得到期望信号和SDC准确的到达仰角,然后采用正交投影权矢量进行ADBF处理,避免了强期望信号条件下ADBF权矢量估计不准的问题。理论分析和仿真实验表明该方法能够较彻底地抑制多径SDC。
