Title
Achievable Degrees of Freedom of the Four-User MIMO Y Channel
Abstract
In this letter, we investigate the achievable degrees of freedom (DoF) of four-user MIMO Y channel where four users each with M antennas intend to exchange messages via a relay of N antennas. By adopting the signal space alignment and a new transmission scheme which jointly align the subspace of unpaired signals from three different users among all the four users, we derive that the DoF per user of max{min(M,3/8N), min(6/7M, N/2)} can be achieved for this channel. Since signal space alignment relies on the dimensions of intersection space of two users, we show that the signal space is utilized efficiently without the restriction of two-user intersection space in the proposed scheme.
Year
DOI
Venue
2014
10.1109/LCOMM.2013.112613.131444
IEEE Communications Letters
Keywords
Field
DocType
Relays,MIMO,Vectors,Array signal processing,Receiving antennas,Transmitting antennas
Topology,Signal processing,Multi-user MIMO,Telecommunications,3G MIMO,Subspace topology,Computer science,MIMO,Communication channel,Real-time computing,Mimo communication,Relay
Journal
Volume
Issue
ISSN
18
1
1089-7798
Citations 
PageRank 
References 
9
0.55
4
Authors
4
Name
Order
Citations
PageRank
Yuan Bo153247.01
Xuewen Liao28815.95
Feifei Gao33093212.03
Xinmin Luo4223.55