In conventional dual-function radar-communication (DFRC) systems, the radar and communication channels are routinely estimated at fixed time intervals based on their worst-case operation scenarios. Such situation-agnostic repeated estimations cause significant training overhead and dramatically degrade the system performance, especially for applications with dynamic sensing/communication demands and limited radio resources. In this paper, we leverage the channel aging characteristics to reduce training overhead and to design a situation-dependent channel re-estimation interval optimization-based resource allocation for performance improvement in a multi-target tracking DFRC system. Specifically, we exploit the channel temporal correlation to predict radar and communication channels for reducing the need of training preamble retransmission. Then, we characterize the channel aging effects on the Cramer-Rao lower bounds (CRLBs) for radar tracking performance analysis and achievable rates with maximum ratio transmission (MRT) and zero-forcing (ZF) transmit beamforming for communication performance analysis. In particular, the aged CRLBs and achievable rates are derived as closed-form expressions with respect to the channel aging time, bandwidth, and power. Based on the analyzed results, we optimize these factors to maximize the average total aged achievable rate subject to individual target tracking precision demand, communication rate requirement, and other practical constraints. Since the formulated problem belongs to a non-convex problem, we develop an efficient one-dimensional search based optimization algorithm to obtain its suboptimal solutions. Finally, simulation results are presented to validate the correctness of the derived theoretical results and the effectiveness of the proposed allocation scheme.

翻译：在传统双功能雷达通信（DFRC）系统中，雷达和通信信道通常基于最差运行场景以固定时间间隔进行常规估计。这种与场景无关的重复估计会造成显著训练开销，并严重降低系统性能，尤其对于具有动态感知/通信需求且无线资源受限的应用场景。本文利用信道老化特性减少训练开销，并设计一种基于情境感知的信道重估计间隔优化资源分配方案，以提升多目标跟踪DFRC系统的性能。具体而言，我们利用信道时间相关性预测雷达和通信信道，从而减少训练前导重传需求。随后，我们刻画信道老化对用于雷达跟踪性能分析的克拉美罗下界（CRLBs）以及采用最大比传输（MRT）和迫零（ZF）发射波束成形的通信性能分析可达速率的影响。特别地，推导出老化CRLBs和可达速率关于信道老化时间、带宽和功率的闭合表达式。基于分析结果，我们优化这些因子以最大化平均总老化可达速率，同时满足目标跟踪精度需求、通信速率要求及其他实际约束。由于该优化问题属于非凸问题，我们开发了一种基于一维搜索的高效优化算法以获得次优解。最后，仿真结果验证了所推导理论结果的正确性以及所提分配方案的有效性。