基于凸优化提高MIMO-STAP检测性能的波形设计

Waveform Design to Improve the Detection Performance of MIMO-STAP Via Convex Optimization

考虑了复杂环境下改善基于多输入多输出正交频分复用(MIMO-OFDM)雷达的空时自适应处理(STAP)检测性能的波形优化问题。基于最大化输出信干噪比(SINR)准则,推导了改善STAP检测性能,且具有恒模约束的波形优化问题。为求解所得复杂非线性优化问题,将非凸约束-恒模约束,松弛为凸约束-低峰均比(PAR)约束,以降低运算复杂度从而利于工程应用。提出一种基于对角加载(DL)的新方法,以将此问题转化为半定规划问题(SDP),因而可获得高效求解,从而便于硬件实现。仿真表明:相较于不相关波形以及MIMO-STAP方法,所提方法可显著提高STAP检测性能。

The waveform optimization issue to improve the detection performance of MIMO-OFDM radar based STAP in the complex environment is considered in this paper.With maximizing the output signal-to-interference-and-noise-ratio(SINR)criterion,the waveform optimization issue to enhance the detection probability of STAP is derived,which is subjected to the constant modulus constraint.To tackle the resultant nonlinear and complicated optimization issue,the non-convex constraint,i.e.,the constant modulus constraint can be firstly relaxed as a convex one,that is,the low peak-to-averageratio(PAR)constraint,by which the computational complexity can be reduced for benefitting the application.In what follows,a novel diagonal loading(DL)based method is proposed to reformulate it as a semidefinite programming(SDP)one,thereby this problem can be solved very efficiently so that the implementation on hardware can be simplified.The simulation results show that the proposed method can improve the output SINR detection performance considerably,as compared to that of uncorrelated waveforms and the MIMO-STAP method.