两种自适应方向图峰值副瓣控制方法比较

自适应阵列（或称自适应波束形成）目前已广泛应用到雷达、声纳和通信领域中用来抑制各种干扰（有意的干扰，杂波干扰和多用户干扰等）。在雷达应用中，为了减轻脉冲欺骗式干扰或旁瓣目标并利用单脉冲雷达来准确测量目标波达方向．要求自适应方向图具有低副瓣和稳定的主瓣形状。在实际应用中，各种失配误差将降低自适应阵列的性能．这些误差包括由于目标的波达方向不精确引起的信号指向误差，由通道失配和位置扰动引起的阵列校准误差和由小样本教引起的协方差矩阵估计误差。在此情况下，自适应波束形成的性能大大下降（干扰抑制性能变差。主瓣失真和高的副瓣）。已提出了一种基于二次约束的集成峰值副瓣控制（integrated peak sidelobe control，简称IPSC）方法。该方法可以精确地控制峰值副瓣电平并产生具有稳定的主瓣形状的自适应方向图。研究IPSC中目标信号的影响和信号消除方案以进一步提高IPSC的性能。并将IPSC方法和最新提出的基于二阶锥规划（second-order cone programming，简称SOCP）的分布式峰值副瓣控制（distfibuted peak sidelobe control，简称为DPSC）新方法在性能上进行了比较。仿真结果表明。在干扰抑制性能和方向图控制质量方面IPSC比DPSC性能优越。此外IPSC比DPSC计算高效。

Comparison Between Two Kinds of Peak Sidelobe Control in Adaptive Beampatterns

Adaptive arrays(or adaptive beamformers) are now widely used in radar,sonar,and communications to suppress various kinds of interference(jammers,clutter,multi-user interference,etc.).In radar applications,adaptive beampatterns with low sidelobes and stable mainlobe shapes are designed so as to mitigate pulsed deceptive jammers or sidelobe targets and to accurately measure the direction-of-arrival(DOA) of a target using monopulse techniques.In practice,there are many kinds of data modeling errors that would degrade the performance of adaptive arrays,including signal pointing errors due to imprecise knowledge about the DOA of a target,array calibration errors due to channel mismatch and position perturbation,and covariance matrix estimation errors due to small sample size.In this case,adaptive beamformers tend to suffer too much performance degradation(poor interference rejection,distorted mainlobes and high sidelobes).We have previously proposed a quadratical constraint based method,referred to as integrated peak sidelobe control(IPSC),which can precisely control the peak sidelobes and produce stable mainlobe shapes of adaptive beampatterns.In this paper,the effects of target signals on IPSC are investigated and a signal removal scheme is given to further improve its performance.The performance of IPSC is compared with the more recently devised second-order cone programming(SOCP) based new approach,referred to as distributed peak sidelobe control(DPSC).Numerical results indicate that IPSC outperforms DPSC in both the interference rejection performance and the beampattern control quality.Moreover,the former is computationally far more efficient than the latter.