Abstract
Device-to-device (D2D) underlay massive multipleinput multiple-output (MIMO) is a notable technology to improve spectrum efficiency by using the same frequency among both cellular user equipments (CUEs) and D2D user equipments (DUEs). In terms of communication resources, it is required to avoid assigning orthogonal pilot sequences to all CUEs and DUEs. Although sharing the same pilot sequences among user equipments (UEs) can save the communication resources, interference arises among the same pilot sequences, which is known as pilot contamination. Because the impact of this interference is still large in the conventional pilot reuse, it is highly demanded to mitigate the effect of pilot contamination. In this paper, we propose a novel pilot reuse scheme based on a graph coloring technique to mitigate the effect of pilot contamination. By leveraging the fact that the interference is alleviated when the number of antennas is large and the angle of arrivals (AOAs) of the same pilot sequences does not overlap, our method assigns the same pilot sequences so that they are not overlapped. Furthermore, to improve the channel estimation accuracy between D2D pairs, our scheme restricts reusable pilot sequences by constructing an interference graph based on graph coloring. In this graph, the nodes near to each other are connected and assigned orthogonal pilot sequences. Simulation results show that the proposed scheme outperforms the conventional one in terms of channel estimation accuracy for UEs and spectral efficiency of the system.
| Original language | English |
|---|---|
| Title of host publication | 2018 IEEE 87th Vehicular Technology Conference, VTC Spring 2018 - Proceedings |
| Publisher | Institute of Electrical and Electronics Engineers Inc. |
| Pages | 1-6 |
| Number of pages | 6 |
| Volume | 2018-June |
| ISBN (Electronic) | 9781538663554 |
| DOIs | |
| Publication status | Published - 2018 Jul 20 |
| Event | 87th IEEE Vehicular Technology Conference, VTC Spring 2018 - Porto, Portugal Duration: 2018 Jun 3 → 2018 Jun 6 |
Other
| Other | 87th IEEE Vehicular Technology Conference, VTC Spring 2018 |
|---|---|
| Country | Portugal |
| City | Porto |
| Period | 18/6/3 → 18/6/6 |
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ASJC Scopus subject areas
- Computer Science Applications
- Electrical and Electronic Engineering
- Applied Mathematics
Cite this
Graph Coloring-Based Pilot Reuse with AOA and Distance in D2D Underlay Massive MIMO. / Echigo, Haruhi; Ohtsuki, Tomoaki.
2018 IEEE 87th Vehicular Technology Conference, VTC Spring 2018 - Proceedings. Vol. 2018-June Institute of Electrical and Electronics Engineers Inc., 2018. p. 1-6.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Graph Coloring-Based Pilot Reuse with AOA and Distance in D2D Underlay Massive MIMO
AU - Echigo, Haruhi
AU - Ohtsuki, Tomoaki
PY - 2018/7/20
Y1 - 2018/7/20
N2 - Device-to-device (D2D) underlay massive multipleinput multiple-output (MIMO) is a notable technology to improve spectrum efficiency by using the same frequency among both cellular user equipments (CUEs) and D2D user equipments (DUEs). In terms of communication resources, it is required to avoid assigning orthogonal pilot sequences to all CUEs and DUEs. Although sharing the same pilot sequences among user equipments (UEs) can save the communication resources, interference arises among the same pilot sequences, which is known as pilot contamination. Because the impact of this interference is still large in the conventional pilot reuse, it is highly demanded to mitigate the effect of pilot contamination. In this paper, we propose a novel pilot reuse scheme based on a graph coloring technique to mitigate the effect of pilot contamination. By leveraging the fact that the interference is alleviated when the number of antennas is large and the angle of arrivals (AOAs) of the same pilot sequences does not overlap, our method assigns the same pilot sequences so that they are not overlapped. Furthermore, to improve the channel estimation accuracy between D2D pairs, our scheme restricts reusable pilot sequences by constructing an interference graph based on graph coloring. In this graph, the nodes near to each other are connected and assigned orthogonal pilot sequences. Simulation results show that the proposed scheme outperforms the conventional one in terms of channel estimation accuracy for UEs and spectral efficiency of the system.
AB - Device-to-device (D2D) underlay massive multipleinput multiple-output (MIMO) is a notable technology to improve spectrum efficiency by using the same frequency among both cellular user equipments (CUEs) and D2D user equipments (DUEs). In terms of communication resources, it is required to avoid assigning orthogonal pilot sequences to all CUEs and DUEs. Although sharing the same pilot sequences among user equipments (UEs) can save the communication resources, interference arises among the same pilot sequences, which is known as pilot contamination. Because the impact of this interference is still large in the conventional pilot reuse, it is highly demanded to mitigate the effect of pilot contamination. In this paper, we propose a novel pilot reuse scheme based on a graph coloring technique to mitigate the effect of pilot contamination. By leveraging the fact that the interference is alleviated when the number of antennas is large and the angle of arrivals (AOAs) of the same pilot sequences does not overlap, our method assigns the same pilot sequences so that they are not overlapped. Furthermore, to improve the channel estimation accuracy between D2D pairs, our scheme restricts reusable pilot sequences by constructing an interference graph based on graph coloring. In this graph, the nodes near to each other are connected and assigned orthogonal pilot sequences. Simulation results show that the proposed scheme outperforms the conventional one in terms of channel estimation accuracy for UEs and spectral efficiency of the system.
UR - http://www.scopus.com/inward/record.url?scp=85050989352&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85050989352&partnerID=8YFLogxK
U2 - 10.1109/VTCSpring.2018.8417577
DO - 10.1109/VTCSpring.2018.8417577
M3 - Conference contribution
AN - SCOPUS:85050989352
VL - 2018-June
SP - 1
EP - 6
BT - 2018 IEEE 87th Vehicular Technology Conference, VTC Spring 2018 - Proceedings
PB - Institute of Electrical and Electronics Engineers Inc.
ER -