基于发射方向图合成的低PAPR宽带MIMO雷达波形设计

本文研究了单向和宽角度的宽带MIMO雷达发射方向图合成.首先构造了单一范数优化准则下单向发射方向图合成的统一框架,使得已有的一些方法可视为其特例.在此基础上,提出了一种基于单向发射方向图合成的波形设计方法,并考虑了设计的波形具有单模或低的峰均比(PAPR)特性;进而提出了一种混合范数的宽角度的发射方向图合成方法.本文将上述的方向图合成和波形设计问题转化成凸优化问题,然后利用公开的模型系统CVX求解.仿真结果表明,本文方法设计的单向方向图能有效地逼近了期望的方向图,也验证了合成波形满足期望的单模或PAPR约束;另外,仿真显示设计的宽角度的方向图在主瓣区域内逼近了期望主瓣响应,而将旁瓣峰值比控制在-40 dB以下.

Low PAPR waveform design based on transmit beam-pattern synthesis for wideband MIMO radar

Transmit beam-pattern synthesis is discussed regarding unidirectional and wide-beam signals for wideband multi-input multi-output radars. First, a unified optimal framework, which generalizes some existing criteria, is proposed to match a given unidirectional transmit beam-pattern. A new method, which satisfies the unit-modulus or low peak-to-average power ratio （PAPR） constraints, is proposed to synthesize transmit waveforms that match the above beam-pattern design. Finally, another approach is proposed to generate power spectral density matrices using mixed norms that match a given wider main-beam beam-pattern. The designed transmit beam-pattern not only matches the desired wideband transmit beam-pattern in the mainlobe region but also maintains the sidelobes below a specified threshold value. The two approaches to beam-pattern synthesis and waveform design are converted into convex optimization problems and solved using the modeling system Concurrent Versions System. Simulations show that the designed transmit beam-pattern with unidirectional signal approximates the given transmit beam-pattern and the signals obtained also satisfy the PAPR constraint. Similarly, we demonstrate that the designed wide-beam transmit beam-pattern approximates the desired beam- pattern in the mainlobe region and maintains sidelobes-to-peak ratio below -40 dB.