AI 中文总结
针对MU-MIMO ISAC发射机中天线互耦导致的感知与通信性能下降问题，提出鲁棒MC补偿波束成形设计，通过凸半定规划优化，可在残留MC误差下同时提升感知精度与通信SINR，且优势随误差增大而扩大。
AI 中文摘要
集成感知与通信（Integrated Sensing and Communications, ISAC）是下一代无线网络的关键技术，可在共享频谱和硬件资源上实现通信与雷达感知功能。然而，在实际多用户多输入多输出（Multi-User Multiple-Input Multiple-Output, MU-MIMO）ISAC发射机中，天线单元间的互耦（Mutual Coupling, MC）会使阵列导向矢量和每个通信用户（Communication User, CU）的信道发生畸变，导致感知波束方向图偏离期望状态，且与各用户的通信链路性能下降。为解决这一局限，本文提出一种鲁棒的MC补偿型波束成形设计，以保障MU-MIMO ISAC发射机在存在残留MC误差时的感知与通信性能。我们在MC矩阵中引入范数有界的残留误差，该误差会同时引发感知波束方向图不确定性和通信信道不确定性。随后，针对每种不确定性的最坏情况优化发射协方差矩阵，以最小化感知的最坏情况波束方向图匹配均方误差（Mean-Squared Error, MSE），同时保障每个CU的信干噪比（Signal-to-Interference-Plus-Noise Ratio, SINR）。将每个最坏情况约束转化为线性矩阵不等式，该问题成为凸半定规划（Semidefinite Program, SDP）问题。数值结果表明，所提鲁棒设计相比传统设计，能同时获得更低的感知波束方向图匹配MSE和更高的通信SINR，且优势随残留误差增大而扩大。
英文摘要
Integrated sensing and communications (ISAC) is a key technology for next-generation wireless networks, enabling communication and radar sensing over shared spectral and hardware resources. In practical multi-user multiple-input multiple-output (MU-MIMO) ISAC transmitters, however, mutual coupling (MC) between antenna elements distorts the array steering vector and each communication user (CU) channel, so that the sensing beampattern deviates from the desired one and the communication link to each user degrades. To address this limitation, we propose a robust MC-compensated beamforming design that guarantees both the sensing and communication performance of MU-MIMO ISAC transmitters against the residual MC error. We introduce a residual error on the MC matrix, so that a norm-bounded residual error induces both the sensing beampattern uncertainty and the communication channel uncertainty. The transmit covariance is then optimized against the worst-case of each uncertainty, minimizing the worst-case beampattern matching mean-squared error (MSE) for sensing while guaranteeing the signal-to-interference-plus-noise ratio (SINR) for each CU. Each worst-case constraint is converted into a linear matrix inequality, and the problem becomes a convex semidefinite program (SDP). Numerical results show that the proposed robust design attains both a lower sensing beampattern matching MSE and a higher communication SINR than those of the conventional designs, with an advantage that widens as the residual error grows.
Comments5 pages, 5 figures, submitted to IEEE Wireless Communication Letters, 2026
