Current research on multi-antenna architectures is trending towards increasing the amount of antennas in the base stations (BSs) so as to increase the spectral efficiency. As a result, the interconnection bandwidth and computational complexity required to process the data using centralized architectures is becoming prohibitively high. Decentralized architectures can reduce these requirements by pre-processing the data before it arrives at a central processing unit (CPU). However, performing decentralized processing introduces also cost in complexity/interconnection bandwidth at the antenna end which is in general being ignored. This paper aims at studying the interplay between level of decentralization and the associated complexity/interconnection bandwidth requirement at the antenna end. To do so, we propose a general framework for centralized/decentralized architectures that can explore said interplay by adjusting some system parameters, namely the number of connections to the CPU (level of decentralization), and the number of multiplications/outputs per antenna (complexity/interconnection bandwidth). We define a novel matrix decomposition, the WAX decomposition, that allows information-lossless processing within our proposed framework, and we use it to obtain the operational limits of the interplay under study. We also look into some of the limitations of the WAX decomposition.

中文翻译：

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分散式多天线架构的权衡：WAX 分解


当前多天线架构的研究趋势是增加基站（BS）中的天线数量，以提高频谱效率。因此，使用集中式架构处理数据所需的互连带宽和计算复杂性变得非常高。分散式架构可以通过在数据到达中央处理单元 (CPU) 之前对数据进行预处理来降低这些要求。然而，执行分散处理还引入了天线端的复杂性/互连带宽成本，这通常被忽略。本文旨在研究分散程度与天线端相关复杂性/互连带宽要求之间的相互作用。为此，我们提出了一个集中/分散架构的通用框架，可以通过调整一些系统参数来探索所述相互作用，即与 CPU 的连接数量（分散程度）以及每个天线的乘法/输出数量（复杂度） /互连带宽）。我们定义了一种新颖的矩阵分解，即 WAX 分解，它允许在我们提出的框架内进行信息无损处理，并使用它来获得所研究的相互作用的操作限制。我们还研究了 WAX 分解的一些局限性。