Extremely large-scale antenna arrays (ELAA) play a critical role in enabling the functionalities of next generation wireless communication systems. However, as the number of antennas increases, ELAA systems face significant bottlenecks, such as excessive interconnection costs and high computational complexity. Efficient distributed signal processing (SP) algorithms show great promise in overcoming these challenges. In this paper, we provide a comprehensive overview of distributed SP algorithms for ELAA systems, tailored to address these bottlenecks. We start by presenting three representative forms of ELAA systems: single-base station ELAA systems, coordinated distributed antenna systems, and ELAA systems integrated with emerging technologies. For each form, we review the associated distributed SP algorithms in the literature. Additionally, we outline several important future research directions that are essential for improving the performance and practicality of ELAA systems.

翻译：极大规模天线阵列（ELAA）在实现下一代无线通信系统功能方面发挥着关键作用。然而，随着天线数量的增加，ELAA系统面临着显著的瓶颈，例如过高的互连成本和巨大的计算复杂度。高效的分布式信号处理（SP）算法在克服这些挑战方面展现出巨大潜力。本文针对这些瓶颈，对面向ELAA系统的分布式SP算法进行了全面综述。我们首先介绍了三种具有代表性的ELAA系统形式：单基站ELAA系统、协调式分布式天线系统以及与新兴技术集成的ELAA系统。针对每种形式，我们回顾了文献中相关的分布式SP算法。此外，我们还概述了几个对未来提升ELAA系统性能和实用性至关重要的研究方向。