Dual-functional radar-communication (DFRC) has attracted considerable attention. This paper considers the frequency-selective multipath fading environment and proposes DFRC waveform design schemes based on multiple-input and multiple-output (MIMO) and orthogonal frequency division multiplexing (OFDM) techniques. In the proposed waveform design schemes, 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 scheme, the optimization problem is convex and can be easily solved. In the achievable rate maximization based waveform design scheme, 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 scheme has a better performance than the ISI minimization based scheme.

翻译：双功能雷达通信（DFRC）系统已引起广泛关注。本文考虑频率选择性多径衰落环境，提出了基于多输入多输出（MIMO）和正交频分复用（OFDM）技术的DFRC波形设计方案。在所提出的波形设计方案中，分别以雷达系统的克拉美-罗界（CRB）、通信系统的流间干扰（ISI）和可达速率作为性能度量指标。本文重点研究雷达系统与通信系统之间的性能权衡，并建立了相应的优化问题。在基于ISI最小化的波形设计方案中，优化问题是凸的，易于求解。在基于可达速率最大化的波形设计方案中，我们提出了一种结合注水（WF）算法和序列二次规划（SQP）的算法来推导协方差矩阵和预编码矩阵。仿真结果验证了所提出的DFRC波形设计方案，并表明基于可达速率最大化的方案比基于ISI最小化的方案具有更优的性能。