The focus of this study is on the spectrum sharing between multiple-input multiple-output (MIMO) communications and co-located MIMO radar systems in multi-path environments. The major challenge is to suppress the mutual interference between the two systems while combining the useful multi-path components received at each system. We tackle this challenge by jointly designing the communication precoder, radar transmit waveform and receive filter. Specifically, the signal-to-interference-plus-noise ratio (SINR) at the radar receiver is maximized subject to constraints on the radar waveform, communication rate and transmit power. The multi-path propagation complicates the expressions of the radar SINR and communication rate, leading to a non-convex problem. To solve it, a sub-optimal algorithm based on the alternating maximization is used to optimize the precoder, radar transmit waveform and receive filter iteratively. Simulation results are provided to demonstrate the effectiveness of the proposed design.

翻译：本研究聚焦于多路径环境中的多输入多输出（MIMO）通信系统与同址MIMO雷达系统之间的频谱共享问题。主要挑战在于抑制两系统间的相互干扰，同时有效整合各系统接收到的有用多路径分量。我们通过联合设计通信预编码器、雷达发射波形和接收滤波器来应对这一挑战。具体而言，在雷达波形、通信速率和发射功率的约束条件下，最大化雷达接收端的信号与干扰加噪声比（SINR）。多路径传播使得雷达SINR和通信速率的表达式复杂化，导致问题呈现非凸性。为解决该问题，采用基于交替最大化的次优算法，迭代优化预编码器、雷达发射波形和接收滤波器。仿真结果验证了所提设计方案的有效性。