In modern active and passive sonar systems, broadband beamforming for acoustic arrays is widely used to suppress unwanted interference and to detect target signals of interest. A broadband low sidelobe beamforming sch...In modern active and passive sonar systems, broadband beamforming for acoustic arrays is widely used to suppress unwanted interference and to detect target signals of interest. A broadband low sidelobe beamforming scheme in time domain is proposed in this paper. The first step of this scheme is to delay the outputs of each element in the acoustic array by a tapped-delay-line (TDL) to accomplish the integer part of the time delay need to form a beam. Then, finite impulse response (FIR) digital filters are used to implement the fractional part of the time delay. The weighting coefficients for all array elements at different frequencies to realize the low sidelobe beams are also implemented with the FIR digital filters. Finally, the outputs of the digital filters are summed up to yield the time domain beam output. The design of low sidelobe beam pattern and that of the FIR digital filters are two crucial technical issues in this beamforming procedure. The low sidelobe beams of each sub-band are designed using the optimized beam synthesis approach based on the principle of MVDR beamforming. An improved adaptive approach are used for the design of FIR digital filters, and the design requirements of these filters were specified by the weights of low sidelobe beams of each sub-band over the broad frequency band. Results of computer simulation for a twelve-element arc array show that the beamforming scheme is very effective in forming low sidelobe broadband beam.展开更多
针对有阵列孔径阵元总数和最小阵元间距约束的稀布同心圆环阵列综合问题,提出了一种基于修正遗传算法(Modified real Genetic Algorithm,MGA)的半径优化方法.通过约束同一圆环上阵元间距相等,利用MGA优化圆环的半径,获得最小的峰值旁瓣...针对有阵列孔径阵元总数和最小阵元间距约束的稀布同心圆环阵列综合问题,提出了一种基于修正遗传算法(Modified real Genetic Algorithm,MGA)的半径优化方法.通过约束同一圆环上阵元间距相等,利用MGA优化圆环的半径,获得最小的峰值旁瓣电平.该方法不仅降低了优化的计算量和模型的复杂性,而且还有效地改善了阵列的旁瓣性能.仿真结果证明了该方法的有效性和鲁棒性.展开更多
文摘In modern active and passive sonar systems, broadband beamforming for acoustic arrays is widely used to suppress unwanted interference and to detect target signals of interest. A broadband low sidelobe beamforming scheme in time domain is proposed in this paper. The first step of this scheme is to delay the outputs of each element in the acoustic array by a tapped-delay-line (TDL) to accomplish the integer part of the time delay need to form a beam. Then, finite impulse response (FIR) digital filters are used to implement the fractional part of the time delay. The weighting coefficients for all array elements at different frequencies to realize the low sidelobe beams are also implemented with the FIR digital filters. Finally, the outputs of the digital filters are summed up to yield the time domain beam output. The design of low sidelobe beam pattern and that of the FIR digital filters are two crucial technical issues in this beamforming procedure. The low sidelobe beams of each sub-band are designed using the optimized beam synthesis approach based on the principle of MVDR beamforming. An improved adaptive approach are used for the design of FIR digital filters, and the design requirements of these filters were specified by the weights of low sidelobe beams of each sub-band over the broad frequency band. Results of computer simulation for a twelve-element arc array show that the beamforming scheme is very effective in forming low sidelobe broadband beam.
文摘针对有阵列孔径阵元总数和最小阵元间距约束的稀布同心圆环阵列综合问题,提出了一种基于修正遗传算法(Modified real Genetic Algorithm,MGA)的半径优化方法.通过约束同一圆环上阵元间距相等,利用MGA优化圆环的半径,获得最小的峰值旁瓣电平.该方法不仅降低了优化的计算量和模型的复杂性,而且还有效地改善了阵列的旁瓣性能.仿真结果证明了该方法的有效性和鲁棒性.
