English

Two-Hop Interference Channels: Impact of Linear Time-Varying Schemes

Information Theory 2013-05-20 v1 math.IT

Abstract

We consider the two-hop interference channel (IC) with constant real channel coefficients, which consists of two source-destination pairs, separated by two relays. We analyze the achievable degrees of freedom (DoF) of such network when relays are restricted to perform scalar amplify-forward (AF) operations, with possibly time-varying coefficients. We show that, somewhat surprisingly, by providing the flexibility of choosing time-varying AF coefficients at the relays, it is possible to achieve 4/3 sum-DoF. We also develop a novel outer bound that matches our achievability, hence characterizing the sum-DoF of two-hop interference channels with time-varying AF relaying strategies.

Keywords

Cite

@article{arxiv.1305.3969,
  title  = {Two-Hop Interference Channels: Impact of Linear Time-Varying Schemes},
  author = {Ibrahim Issa and Silas L. Fong and A. Salman Avestimehr},
  journal= {arXiv preprint arXiv:1305.3969},
  year   = {2013}
}

Comments

To appear in Proc. of ISIT 2013 (proof of lemma added)