Opportunistic interference alignment in MIMO interference channels

Abstract—We present two interference alignment techniques such that an opportunistic point-to-point multiple input multiple output (MIMO) link can reuse, without generating any additional interference, the same frequency band of a similar pre-existing primary link. In this scenario, we exploit the fact that under power constraints, although each radio maximizes independently its rate by water-filling on their channel transfer matrix singular values, frequently, not all of them are used. Therefore, by aligning the interference of the opportunistic radio it is possible to transmit at a significant rate while insuring zero-interference on the pre-existing link. We propose a linear pre-coder for a perfect interference alignment and a power allocation scheme which maximizes the individual data rate of the secondary link. Our numerical results show that significant data rates are achieved even for a reduced number of antennas.

• Type: Conference
• Year: 2008
• Where: PIMRC
• Authors: Samir Medina Perlaza, Mérouane Debbah, Samson Lasaulce, Jean-Marie Chaufray
• Keywords: Communications, Interference Alignment, Interference Alignment Techniques, PIMRC 2008, Pre-existing Primary Link