Structured lattice codes for 2×2×2 MIMO interference channel
Song-Nam Hong, Giuseppe Caire · 2013
We consider the 2 × 2 × 2 multiple-input multiple-output interference channel where two source-destination pairs wish to communicate with the aid of two intermediate relays. In this paper we present a novel lattice strategy called Precoded Compute-and-Forward (PCoF) with Channel Integer Alignment (CIA). This scheme consists of two phases: 1) Using the CoF framework based on CIA we convert the Gaussian network into a deterministic finite-field network. 2) Using linear precoding (over finite-field) we eliminate the end-to-end interference in the finite-field domain. Further, we exploit the algebraic structure of lattices to enhance the performance at finite SNR, such that beyond a degree of freedom result (also achievable by other means). We can also show that PCoF with CIA outperforms timesharing in a range of reasonably moderate SNR, with increasing gain as SNR increases.