A General Perfect Cyclic Interference Alignment by Propagation Delay for Arbitrary X Channels with Two Receivers

Conggai LI
Feng LIU
Shuchao JIANG
Yanli XU

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E102-A    No.11    pp.1580-1585
Publication Date: 2019/11/01
Online ISSN: 1745-1337
DOI: 10.1587/transfun.E102.A.1580
Type of Manuscript: LETTER
Category: Digital Signal Processing
K×2 X channel,  propagation delay,  cyclic interference alignment,  degree of freedom,  feasibility,  

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Interference alignment (IA) in temporal domain is important in the case of single-antenna vehicle communications. In this paper, perfect cyclic IA based on propagation delay is extended to the K×2 X channels with two receivers and arbitrary transmitters K≥2, which achieves the maximal multiplexing gain by obtaining the theoretical degree of freedom of 2K/(K+1). We deduce the alignment and separability conditions, and propose a general scheme which is flexible in setting the index of time-slot for IA at the receiver side. Furthermore, the feasibility of the proposed scheme in the two-/three- Euclidean space is analyzed and demonstrated.