Dual-functional radar-communication (DFRC) has attracted considerable attention. This paper considers the frequency-selective multipath fading environment and proposes DFRC waveform design strategies based on multiple-input and multiple-output (MIMO) and orthogonal frequency division multiplexing (OFDM) techniques. In the proposed waveform design strategies, the Cramer-Rao bound (CRB) of the radar system, the inter-stream interference (ISI) and the achievable rate of the communication system, are respectively considered as the performance metrics. In this paper, we focus on the performance trade-off between the radar system and the communication system, and the optimization problems are formulated. In the ISI minimization based waveform design strategy, the optimization problem is convex and can be easily solved. In the achievable rate maximization based waveform design strategy, we propose a water-filling (WF) and sequential quadratic programming (SQP) based algorithm to derive the covariance matrix and the precoding matrix. Simulation results validate the proposed DFRC waveform designs and show that the achievable rate maximization based strategy has a better performance than the ISI minimization based strategy.

翻译：双功能雷达通信（DFRC）技术已引起广泛关注。本文针对频率选择性多径衰落环境，提出基于多输入多输出（MIMO）与正交频分复用（OFDM）技术的DFRC波形设计策略。在所提出的波形设计策略中，分别以雷达系统的克拉美-罗界（CRB）、通信系统的流间干扰（ISI）及可达速率作为性能指标。本文聚焦于雷达系统与通信系统间的性能权衡问题，并构建了相应的优化模型。在基于流间干扰最小化的波形设计策略中，优化问题为凸优化问题，可简便求解。在基于可达速率最大化的波形设计策略中，提出一种结合注水算法（WF）与序列二次规划（SQP）的求解方法，用以推导协方差矩阵和预编码矩阵。仿真结果验证了所提DFRC波形设计方案的有效性，并表明基于可达速率最大化的策略优于基于流间干扰最小化的策略。