Title
Graph Coloring Based Pilot Assignment for Cell-Free Massive MIMO Systems
Abstract
An efficient pilot assignment scheme based on graph coloring is proposed to mitigate the severe pilot contamination effect in cell-free massive multiple-input multiple-output systems. By exploiting the large-scale fading coefficients between the access points (APs) and the user equipments, we first utilize an AP selection algorithm to construct an interference graph. Then, the optimal pilot assignment can be achieved by updating the interference graph. In addition, we consider a fair policy for pilot reuse to improve the system performance. Numerical results verify that, compared with conventional pilot assignment schemes, the proposed graph coloring based pilot assignment scheme can significantly increase the 95%-likely per-user throughput and reduce the complexity of assigning pilot sequences.
Year
DOI
Venue
2020
10.1109/TVT.2020.3000496
IEEE Transactions on Vehicular Technology
Keywords
DocType
Volume
AP selection,cell-free massive multiple-input multiple-output,graph coloring,pilot contamination
Journal
69
Issue
ISSN
Citations 
8
0018-9545
9
PageRank 
References 
Authors
0.46
0
4
Name
Order
Citations
PageRank
Heng Liu115327.10
Jiayi Zhang291174.44
Shi Jin3100.82
Bo Ai41581185.94