Opportunistic Interference Alignment in MIMO Interference Channels

Samir M. Perlaza (1) , Merouane Debbah (2) , Samson Lasaulce (3) , Jean-Marie Chauffray (1)

1 FT R&D - France Télécom Recherche & Développement
2 Chaire Radio Flexible - Chaire Radio Flexible Alcatel-Lucent/Supélec
3 L2S - Laboratoire des signaux et systèmes

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.

Domaines: Réseaux et télécommunications [cs.NI]

Samir M. Perlaza, Merouane Debbah, Samson Lasaulce, Jean-Marie Chauffray. Opportunistic Interference Alignment in MIMO Interference Channels. PIRMC 2008, Sep 2008, Cannes, France. 5 p., ⟨10.1109/PIMRC.2008.4699872⟩. ⟨hal-00335246⟩