Hybrid of Downlink and Uplink Transmission for Small Cell Networks with Interference Alignment

Feifei ZHAO  Wenping MA  Momiao ZHOU  Chengli ZHANG  

Publication
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E101-A   No.6   pp.988-991
Publication Date: 2018/06/01
Online ISSN: 1745-1337
DOI: 10.1587/transfun.E101.A.988
Type of Manuscript: LETTER
Category: Mobile Information Network and Personal Communications
Keyword: 
feasibility,  interference alignment,  two-way,  degrees of freedom,  

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Summary: 
Based on Bezout's theorem, the feasibility condition for interference alignment (IA) is established in a two-way small cell network where part of cells transmit in downlink while the others in uplink. Moreover, the sufficient and necessary condition for the two-way network to achieve as many degrees of freedom (DoFs) as the traditional one-way network is presented. We find that in certain cases every small cell can independently decide to work in either downlink mode or uplink mode as needed without causing performance degradation of IA.