With the rapid advancement of the Internet of Things (IoT) and mobile communication technologies, a multitude of devices are becoming interconnected, marking the onset of an era where all things are connected. While this growth opens opportunities for novel products and applications, it also leads to increased energy demand and battery reliance in IoT devices, creating a significant bottleneck that hinders sustainable progress. Traditional energy harvesting (EH) techniques, although promising, face limitations such as insufficient efficiency, high costs, and practical constraints that impede widespread adoption. Backscatter communication (BackCom), a low-power and passive method, emerges as a promising solution to these challenges, directly addressing stranded energy impasse by reducing manufacturing costs and energy consumption in IoT devices. We perform an in-depth analysis of three primary BackCom architectures: Monostatic, Bistatic, and Ambient BackComs. In our exploration, we identify fundamental challenges, such as complex interference environments (including the direct-link interference and the mutual interference among tags) and double-path fading, which contribute to suboptimal performance in BackCom systems. This review aims to furnish a comprehensive examination of existing solutions designed to combat complex interference environments and double-path fading, offering insightful analysis and comparison to select effective strategies to address these challenges. We also delve into emerging trends and challenges in BackCom, forecasting potential paths for technological advancement and providing insights into navigating the intricate landscape of future communication needs. Our work provides researchers and engineers with a clear and comprehensive perspective, enabling them to better understand and creatively tackle the ongoing challenges in BackCom systems.

翻译：随着物联网（IoT）与移动通信技术的快速发展，大量设备正实现互联，标志着万物互联时代的开启。这种增长在催生新型产品与应用的同时，也导致物联网设备能源需求与电池依赖度的增加，构成阻碍可持续发展的重大瓶颈。传统能量收集（EH）技术虽具潜力，却面临效率不足、成本高昂及实际应用限制等障碍，难以实现广泛部署。反向散射通信（BackCom）作为一种低功耗无源技术，通过降低物联网设备制造成本与能耗，直接破解能源困境，成为应对上述挑战的前景解决方案。我们深入分析了三种主要反向散射通信架构：单站式、双站式与环境反向散射通信。在探索中，我们识别出根本性挑战，包括复杂干扰环境（如直射链路干扰与标签间互干扰）以及双路径衰落，这些因素导致反向散射通信系统性能欠佳。本文旨在全面梳理现有应对复杂干扰环境与双路径衰落的解决方案，通过深刻分析与对比，遴选应对这些挑战的有效策略。我们亦探讨反向散射通信领域的新兴趋势与挑战，预测技术演进的可能路径，为应对未来通信需求的复杂格局提供见解。本工作为研究人员与工程师提供清晰全面的视角，助其更好地理解并创造性地解决反向散射通信系统中的持续挑战。