Journal of Xidian University

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Interference alignment for MIMO downlink heterogeneous networks

LI Chuan   

  1. (School of Computer and Technology, Xi'an Univ. of Posts and Telecommunications, Xi'an 710061, China)
  • Received:2017-10-10 Online:2018-04-20 Published:2018-06-06

Abstract:

We propose a null space based interference alignment (IA) scheme for the downlink of a heterogeneous network. By jointly designing the transmit beamforming matrix at pico base stations and the receive beamforming matrix at macro users, the proposed null space based IA scheme can effectively cancel the interference from pico base stations to macro users. Furthermore, the proposed scheme supports an arbitrary number of macro users and provides one closed form solution. Moreover, the proposed null space based IA scheme is valid for the region where the traditional IA schemes are infeasible. Finally, simulation results are provided to demonstrate the achievable degrees of freedom (DoF) by the proposed null space based IA scheme.