Weighted-Graph-Coloring- Based Pilot Decontamination for Multicell Massive MIMO Systems

作者：Zhu, Xudong^*; Dai, Linglong; Wang, Zhaocheng; Wang, Xiaodong

来源：IEEE Transactions on Vehicular Technology, 2017, 66(3): 2829-2834.

DOI：10.1109/TVT.2016.2572203

• Edge-weighted interference graph (EWIG)
• graph coloring problem
• massive multiple-input multiple-output (MIMO)
• pilot contamination (PC)

A multicell massive multiple-input multiple-output (MIMO) system, which utilizes a large number of base-station antennas to simultaneously serve a set of users, suffers from pilot contamination (PC) due to unavoidable reuse of pilots in adjacent cells. In this paper, a weighted-graph-coloring-based pilot decontamination (WGC-PD) scheme is proposed to mitigate PC for multicell massive MIMO systems. Specifically, based on limited cooperation among cells, an edge-weighted interference graph (EWIG) is first constructed to depict the potential PC relationship among users, whereby two users in different cells are connected by a weighted edge, indicating the strength of potential PC when they reuse the same pilot. Then, inspired by classical graph coloring algorithms, we develop the WGC-PD scheme by denoting each color as a pilot and each vertex as a user in the EWIG, which is able to mitigate PC by assigning different pilots to connected users with a large weight in a greedy way with insufficient pilot resource. Compared with exhaustive search among numerous pilot assignment solutions, the proposed WGC-PD scheme is able to mitigate PC with significantly reduced complexity, which is verified by numerical results.

• 出版日期2017-3
• 单位清华大学