A sequential processing is presented aiming at optimizing the direction of arrival(DOA)tracking performance.Firstly,current positions and Doppler frequency are estimated and a mathematical model is derived in order to...A sequential processing is presented aiming at optimizing the direction of arrival(DOA)tracking performance.Firstly,current positions and Doppler frequency are estimated and a mathematical model is derived in order to clarify the effect of Doppler frequency on the estimation.The Doppler effect is employed within subspace concept in order to refine the estimation of the target position.Secondly,a renewed weight factor that depends on target maneuver is employed in order to realize more accurate association and smoothing processes.Simulation results show that the presented method has high accuracy in DOA tracking.展开更多
In wireless communication environment, the time-varying channel and angular spreads caused by multipath fading and the mobility of Mobile Stations (MS) degrade the performance of the conventional Direction-Of-Arrival ...In wireless communication environment, the time-varying channel and angular spreads caused by multipath fading and the mobility of Mobile Stations (MS) degrade the performance of the conventional Direction-Of-Arrival (DOA) tracking algorithms. On the other hand, although the DOA estimation methods based on the Maximum Likelihood (ML) principle have higher resolution than the beamforming and the subspace based methods, prohibitively heavy computation limits their practical applications. This letter first proposes a new suboptimal DOA estimation algorithm that combines the advantages of the lower complexity of subspace algorithm and the high accuracy of ML based algo- rithms, and then proposes a Kalman filtering based tracking algorithm to model the dynamic property of directional changes for mobile terminals in such a way that the association between the estimates made at different time points is maintained. At each stage during tracking process, the current suboptimal estimates of DOA are treated as measurements, predicted and updated via a Kalman state equation, hence adaptive tracking of moving MS can be carried out without the need to perform unduly heavy computations. Computer simulation results show that this proposed algorithm has better per- formance of DOA estimation and tracking of MS than the conventional ML or subspace based algo- rithms in terms of accuracy and robustness.展开更多
针对阵列信号处理中单快拍情况下的多源时变波达方向(direction of arrival,DOA)跟踪问题,提出了一种基于单快拍空间平滑的多伯努利DOA跟踪算法。首先,利用多伯努利随机有限集(random finite set,RFS)描述状态过程的随机性,并直接利用...针对阵列信号处理中单快拍情况下的多源时变波达方向(direction of arrival,DOA)跟踪问题,提出了一种基于单快拍空间平滑的多伯努利DOA跟踪算法。首先,利用多伯努利随机有限集(random finite set,RFS)描述状态过程的随机性,并直接利用从传感器阵列中获得单快拍量测。其次,采用空间平滑技术对单快拍量测进行处理,得到伪协方差矩阵,并进行奇异值分解。最后,用多重信号分类(multiple signal classification,MUSIC)谱函数作为伪似然函数进行多伯努利DOA跟踪。仿真结果表明,该算法能实时有效跟踪单快拍量测下的时变信源DOA状态,且能准确估计信源个数。展开更多
在跟踪和数据中继卫星系统反向链路中,多路频分复用信号通过高功率放大器时存在严重的交调干扰,导致输出的各路阵元信号严重失真.针对这一问题,该文通过幂级数模型分析高功率放大器调幅-调幅(AM-AM)变换对通道间幅度一致性的影响机理,...在跟踪和数据中继卫星系统反向链路中,多路频分复用信号通过高功率放大器时存在严重的交调干扰,导致输出的各路阵元信号严重失真.针对这一问题,该文通过幂级数模型分析高功率放大器调幅-调幅(AM-AM)变换对通道间幅度一致性的影响机理,建立幅度不一致性对波达方向(direction of arrival,DOA)估计影响的数学模型,并进行计算机仿真.理论分析和仿真结果表明:高功率放大器的AM-AM变换不会引起估计角度的偏移,但会导致空间角度范围内的谱峰值降低,同时使3 dB谱宽变宽.此外,AM-AM变换还会导致DOA估计性能恶化.展开更多
利用阵列天线波束指向空间相关性的特点,可以构建一个类似于传统锁相环结构的闭合环路以实现对导航信号来波方向(direction of arrival,DOA)的跟踪。DOA跟踪环路中鉴别器的实现方法主要有实部相减相干法、幅值相减归一化法、功率相减归...利用阵列天线波束指向空间相关性的特点,可以构建一个类似于传统锁相环结构的闭合环路以实现对导航信号来波方向(direction of arrival,DOA)的跟踪。DOA跟踪环路中鉴别器的实现方法主要有实部相减相干法、幅值相减归一化法、功率相减归一化法,首先基于波束形成技术建立了阵列天线导航接收机DOA跟踪模型,在此基础上从鉴别器增益、收敛范围和输出噪声方差3个方面对比分析了采用不同角度鉴别器算法的跟踪性能,最后对其进行了仿真验证。展开更多
研究了基于两分量简化电磁矢量传感器阵列的多个信号波达方向(Direction of arrival,DOA)跟踪问题,提出了一种基于四元数模型的数据投影(Quaternion data projection method,QDPM)跟踪算法。此算法对初始化条件引起的波动具有很强的鲁棒...研究了基于两分量简化电磁矢量传感器阵列的多个信号波达方向(Direction of arrival,DOA)跟踪问题,提出了一种基于四元数模型的数据投影(Quaternion data projection method,QDPM)跟踪算法。此算法对初始化条件引起的波动具有很强的鲁棒性,并且具有比常规DPM(Data projection method)算法更快的收敛速度,尤其在信号角度变化较剧烈时体现得更明显。此外,在低信噪比的情况下,QDPM算法比DPM算法具有更高的DOA跟踪精度。最后通过仿真实验验证了算法的有效性。展开更多
提出了一种新的多目标波达方向(direction of arrival,DOA)跟踪方法。首先利用可靠且低复杂度的快速数据投影法(fast data projection method,FDPM)自适应更新阵列接收信号的时变信号子空间,再采用高斯-牛顿法在更新后的信号子空间中,...提出了一种新的多目标波达方向(direction of arrival,DOA)跟踪方法。首先利用可靠且低复杂度的快速数据投影法(fast data projection method,FDPM)自适应更新阵列接收信号的时变信号子空间,再采用高斯-牛顿法在更新后的信号子空间中,估计多个目标实时变化的DOA观测值,最后采用卡尔曼滤波获得当前时刻多个目标的最优DOA估计值。仿真多个交叉运动目标的情况,验证了该方法具有跟踪速度快、精度高的特点,并且可以避免数据关联。展开更多
An antenna adjustment strategy is developed for the target tracking problem in the collocated multiple-input multipleoutput(MIMO)radar.The basic technique of this strategy is to optimally allocate antennas by the prio...An antenna adjustment strategy is developed for the target tracking problem in the collocated multiple-input multipleoutput(MIMO)radar.The basic technique of this strategy is to optimally allocate antennas by the prior information in the tracking recursive period,with the objective of enhancing the worst-case estimate precision of multiple targets.On account of the posterior Cramer-Rao lower bound(PCRLB)offering a quantitative measure for target tracking accuracy,the PCRLB of joint direction-of-arrival(DOA)and Doppler is derived and utilized as the optimization criterion.It is shown that the dynamic antenna selection problem is NP-hard,and an efficient technique which combines convex relaxation with local search is put forward as the solution.Simulation results demonstrate the outperformance of the proposed strategy to the fixed antenna configuration and heuristic search algorithm.Moreover,it is able to offer close-to performance of the exhaustive search method.展开更多
文摘A sequential processing is presented aiming at optimizing the direction of arrival(DOA)tracking performance.Firstly,current positions and Doppler frequency are estimated and a mathematical model is derived in order to clarify the effect of Doppler frequency on the estimation.The Doppler effect is employed within subspace concept in order to refine the estimation of the target position.Secondly,a renewed weight factor that depends on target maneuver is employed in order to realize more accurate association and smoothing processes.Simulation results show that the presented method has high accuracy in DOA tracking.
文摘In wireless communication environment, the time-varying channel and angular spreads caused by multipath fading and the mobility of Mobile Stations (MS) degrade the performance of the conventional Direction-Of-Arrival (DOA) tracking algorithms. On the other hand, although the DOA estimation methods based on the Maximum Likelihood (ML) principle have higher resolution than the beamforming and the subspace based methods, prohibitively heavy computation limits their practical applications. This letter first proposes a new suboptimal DOA estimation algorithm that combines the advantages of the lower complexity of subspace algorithm and the high accuracy of ML based algo- rithms, and then proposes a Kalman filtering based tracking algorithm to model the dynamic property of directional changes for mobile terminals in such a way that the association between the estimates made at different time points is maintained. At each stage during tracking process, the current suboptimal estimates of DOA are treated as measurements, predicted and updated via a Kalman state equation, hence adaptive tracking of moving MS can be carried out without the need to perform unduly heavy computations. Computer simulation results show that this proposed algorithm has better per- formance of DOA estimation and tracking of MS than the conventional ML or subspace based algo- rithms in terms of accuracy and robustness.
文摘针对阵列信号处理中单快拍情况下的多源时变波达方向(direction of arrival,DOA)跟踪问题,提出了一种基于单快拍空间平滑的多伯努利DOA跟踪算法。首先,利用多伯努利随机有限集(random finite set,RFS)描述状态过程的随机性,并直接利用从传感器阵列中获得单快拍量测。其次,采用空间平滑技术对单快拍量测进行处理,得到伪协方差矩阵,并进行奇异值分解。最后,用多重信号分类(multiple signal classification,MUSIC)谱函数作为伪似然函数进行多伯努利DOA跟踪。仿真结果表明,该算法能实时有效跟踪单快拍量测下的时变信源DOA状态,且能准确估计信源个数。
文摘在跟踪和数据中继卫星系统反向链路中,多路频分复用信号通过高功率放大器时存在严重的交调干扰,导致输出的各路阵元信号严重失真.针对这一问题,该文通过幂级数模型分析高功率放大器调幅-调幅(AM-AM)变换对通道间幅度一致性的影响机理,建立幅度不一致性对波达方向(direction of arrival,DOA)估计影响的数学模型,并进行计算机仿真.理论分析和仿真结果表明:高功率放大器的AM-AM变换不会引起估计角度的偏移,但会导致空间角度范围内的谱峰值降低,同时使3 dB谱宽变宽.此外,AM-AM变换还会导致DOA估计性能恶化.
文摘利用阵列天线波束指向空间相关性的特点,可以构建一个类似于传统锁相环结构的闭合环路以实现对导航信号来波方向(direction of arrival,DOA)的跟踪。DOA跟踪环路中鉴别器的实现方法主要有实部相减相干法、幅值相减归一化法、功率相减归一化法,首先基于波束形成技术建立了阵列天线导航接收机DOA跟踪模型,在此基础上从鉴别器增益、收敛范围和输出噪声方差3个方面对比分析了采用不同角度鉴别器算法的跟踪性能,最后对其进行了仿真验证。
文摘研究了基于两分量简化电磁矢量传感器阵列的多个信号波达方向(Direction of arrival,DOA)跟踪问题,提出了一种基于四元数模型的数据投影(Quaternion data projection method,QDPM)跟踪算法。此算法对初始化条件引起的波动具有很强的鲁棒性,并且具有比常规DPM(Data projection method)算法更快的收敛速度,尤其在信号角度变化较剧烈时体现得更明显。此外,在低信噪比的情况下,QDPM算法比DPM算法具有更高的DOA跟踪精度。最后通过仿真实验验证了算法的有效性。
文摘提出了一种新的多目标波达方向(direction of arrival,DOA)跟踪方法。首先利用可靠且低复杂度的快速数据投影法(fast data projection method,FDPM)自适应更新阵列接收信号的时变信号子空间,再采用高斯-牛顿法在更新后的信号子空间中,估计多个目标实时变化的DOA观测值,最后采用卡尔曼滤波获得当前时刻多个目标的最优DOA估计值。仿真多个交叉运动目标的情况,验证了该方法具有跟踪速度快、精度高的特点,并且可以避免数据关联。
基金supported by the National Natural Science Foundation of China(61601504)
文摘An antenna adjustment strategy is developed for the target tracking problem in the collocated multiple-input multipleoutput(MIMO)radar.The basic technique of this strategy is to optimally allocate antennas by the prior information in the tracking recursive period,with the objective of enhancing the worst-case estimate precision of multiple targets.On account of the posterior Cramer-Rao lower bound(PCRLB)offering a quantitative measure for target tracking accuracy,the PCRLB of joint direction-of-arrival(DOA)and Doppler is derived and utilized as the optimization criterion.It is shown that the dynamic antenna selection problem is NP-hard,and an efficient technique which combines convex relaxation with local search is put forward as the solution.Simulation results demonstrate the outperformance of the proposed strategy to the fixed antenna configuration and heuristic search algorithm.Moreover,it is able to offer close-to performance of the exhaustive search method.
