School of Microelectronics and Communication Engineering, Chongqing University, Chongqing 400044, China.
Beijing Smart-Chip Microelectronics Technology Co., Ltd., Beijing 100192, China.
Sensors (Basel). 2023 May 23;23(11):5014. doi: 10.3390/s23115014.
Pilot contamination due to pilot reuse seriously mitigates the performance of the cell-free massive multiple-input multiple-output (MIMO) systems. In this paper, we propose a joint pilot assignment scheme that employs user clustering and graph coloring (UC-GC) to reduce pilot contamination. The proposed method consists of two steps: firstly, we utilize AP selection to classify all users; secondly, we assign pilots to users with more severe pilot contamination using the graph coloring algorithm and then assign pilots to the remaining users. The numerical simulation results show that the proposed scheme outperforms existing pilot assignment schemes and significantly improves throughout with low complexity.
由于导频重用导致的导频污染严重降低了无蜂窝大规模多输入多输出 (MIMO) 系统的性能。在本文中，我们提出了一种联合导频分配方案，该方案采用用户聚类和图着色（UC-GC）来减少导频污染。所提出的方法包括两个步骤：首先，我们利用 AP 选择对所有用户进行分类；其次，我们使用图着色算法为具有更严重导频污染的用户分配导频，然后为其余用户分配导频。数值仿真结果表明，所提出的方案优于现有导频分配方案，在低复杂度的情况下显著提高了吞吐量。
