标题： 非相干MIMO通信：理论基础、设计方法与未来挑战 显示英文标题

标题： Noncoherent MIMO Communications: Theoretical Foundation, Design Approaches, and Future Challenges

摘要： 非相干通信是一种有前景的未来无线系统范式，在这些系统中获取精确的信道状态信息（CSI）具有挑战性或不可行。它提供了一种方法，可以在高移动性网络、大规模分布式天线阵列、能量受限的物联网设备以及非结构化传播环境等实际场景中绕过显式信道估计的需求。本文综述了多输入多输出（MIMO）系统中的非相干通信策略，重点关注自2000年代初以来的最新进展。我们将非相干通信方案分为三大类，分别基于子空间检测（即Grassmannian信号传输）、差分检测和能量检测的无信道信息恢复方法。对于每种方法，我们回顾了其理论基础和设计方法。我们还提供了关于它们在不同信道模型和系统约束下的适用性的比较见解，强调了非相干方法在性能和可扩展性方面优于传统相干通信的应用场景。此外，我们讨论了非相干通信的实际考虑因素，包括与正交频分复用（OFDM）的兼容性、对硬件损伤的鲁棒性和用户数量增加时的可扩展性。最后，我们对未来设计用于下一代无线网络的稳健且高效的非相干系统的挑战和研究方向进行了展望。 显示英文摘要

摘要： Noncoherent communication is a promising paradigm for future wireless systems where acquiring accurate channel state information (CSI) is challenging or infeasible. It provides methods to bypass the need for explicit channel estimation in practical scenarios such as high-mobility networks, massive distributed antenna arrays, energy-constrained Internet-of-Things devices, and unstructured propagation environments. This survey provides a comprehensive overview of noncoherent communication strategies in multiple-input multiple-output (MIMO) systems, focusing on recent advances since the early 2000s. We classify noncoherent communication schemes into three main approaches where CSI-free signal recovery is based on subspace detection (i.e., Grassmannian signaling), differential detection, and energy detection, respectively. For each approach, we review the theoretical foundation and design methodologies. We also provide comparative insights into their suitability across different channel models and system constraints, highlighting application scenarios where noncoherent methods offer performance and scalability advantages over traditional coherent communication. Furthermore, we discuss practical considerations of noncoherent communication, including compatibility with orthogonal frequency division multiplexing (OFDM), resilience to hardware impairments, and scalability with the number of users. Finally, we provide an outlook on future challenges and research directions in designing robust and efficient noncoherent systems for next-generation wireless networks.