This paper concentrates on MIMO (multiple-input multiple-output) radar waveform design to improve SINR (signal-to-interference-plus-noise ratio). Due to the constant modulus constraint, the problem is essentially an NP-hard and high dimensional problem. Many conventional methods generally transform the original problem to a convex optimization problem through relaxation. To address it more efficiently, we propose a new approach based on a Riemannian manifold, which is the product of complex circles and a Euclidean space. The original constraint problem in our proposed method is considered as unconstrained over a restricted search space. Then, the reformulated problem is solved by Riemannian conjugate gradient (RCG) algorithm efficiently. Numerical results reveal that the proposed algorithm can achieve higher SINR via different input SNR while consumes a lower computation time.

本文重点介绍 MIMO（多输入多输出）雷达波形设计，以提高 SINR（信干噪比）。由于恒模约束，该问题本质上是一个NP难的高维问题。许多常规方法一般通过松弛将原问题转化为凸优化问题。为了更有效地解决这个问题，我们提出了一种基于黎曼流形的新方法，黎曼流形是复圆和欧几里德空间的乘积。我们提出的方法中的原始约束问题被认为是在有限搜索空间上不受约束。然后，通过黎曼共轭梯度 (RCG) 算法有效地解决了重新制定的问题。