Title
Soft Pilot Reuse and Multi-Cell Block Diagonalization Precoding for Massive MIMO Systems
Abstract
The users at cell edge of a massive multiple-input multiple-output (MIMO) system suffer from severe pilot contamination, which leads to poor quality of service (QoS). In order to enhance the QoS for these edge users, soft pilot reuse (SPR) combined with multi-cell block diagonalization (MBD) precoding are proposed. Specifically, the users are divided into two groups according to their large-scale fading coefficients, referred to as the center users, who only suffer from modest pilot contamination and the edge users, who suffer from severe pilot contamination. Based on this distinction, the SPR scheme is proposed for improving the QoS for the edge users, whereby a cell-center pilot group is reused for all cell-center users in all cells, while a cell-edge pilot group is applied for the edge users in the adjacent cells. By extending the classical block diagonalization precoding to a multi-cell scenario, the MBD precoding scheme projects the downlink transmit signal onto the null space of the subspace spanned by the inter-cell channels of the edge users in adjacent cells. Thus, the inter-cell interference contaminating the edge users’ signals in the adjacent cells can be efficiently mitigated and hence the QoS of these edge users can be further enhanced. Our theoretical analysis and simulation results demonstrate that both the uplink and downlink rates of the edge users are significantly improved, albeit at the cost of the slightly decreased rate of center users.
Year
DOI
Venue
2015
10.1109/TVT.2015.2445795
Vehicular Technology, IEEE Transactions
Keywords
Field
DocType
Intercell interference (ICI), massive multiple-input-multiple-output (MIMO) system, multicell block diagonalization (MBD) precoding, pilot contamination (PC), quality of service (QoS), soft pilot reuse (SPR)
Computer science,Fading,Signal-to-noise ratio,Quality of service,Computer network,MIMO,Communication channel,Electronic engineering,Interference (wave propagation),Precoding,Telecommunications link
Journal
Volume
Issue
ISSN
PP
99
0018-9545
Citations 
PageRank 
References 
22
0.82
18
Authors
4
Name
Order
Citations
PageRank
Xudong Zhu1876.51
Zhaocheng Wang22359147.30
Chen Qian3716.13
Linglong Dai42713135.60