Capacity Analysis of Interference Alignment With Bounded CSI Uncertainty

Author

Guiazon, Raoul F. ; Kai-Kit Wong ; Wisely, Dave

Author_Institution

Dept. of Electron. & Electr. Eng., Univ. Coll. London, London, UK

Volume

3

Issue

5

fYear

2014

fDate

Oct. 2014

Firstpage

505

Lastpage

508

Abstract

Interference alignment (IA) has been demonstrated to achieve the degree-of-freedom (DoF) of an interference channel given perfect global channel state information (CSI). In this letter, we consider the case of imperfect CSI with bounded errors and derive a capacity lower bound of the channel using IA. We show that this lower bound is within 1 bps/Hz of the capacity of the perfect CSI case up to a certain signal-to-noise ratio (SNR) which we refer to it as the saturating SNR. Further, we introduce a new metric called modified DoF (mDoF) in order to characterize the multiplexing performance of IA with imperfect CSI at finite SNR. Simulation results for the 3-user case are provided to illustrate the region within which the actual capacity of IA falls.

Keywords

channel capacity; radiofrequency interference; wireless channels; bounded CSI uncertainty; bounded errors; capacity analysis; capacity lower bound; channel state information; degree-of-freedom; finite SNR; imperfect CSI; interference alignment; interference channel; modified DoF; multiplexing performance; saturating SNR; signal-to-noise ratio; Channel estimation; Heating; Interference channels; MIMO; Signal to noise ratio; Vectors; Beamforming; capacity bound; channel errors; interference alignment; interference channel;

fLanguage

English

Journal_Title

Wireless Communications Letters, IEEE

Publisher

ieee

ISSN

2162-2337

Type

jour

DOI

10.1109/LWC.2014.2344656

Filename

6868967