Threshold Improvement of Low-Density Lattice Codes via Spatial Coupling

Spatially-coupled low-density lattice codes (LDLC) are constructed using protographs. Using Monte Carlo density evolution using single-Gaussian messages, we observe that the threshold of the spatially-coupled LDLC is within 0.22 dB of capacity of the unconstrained power channel. This is in contrast with a 0.5 dB noise threshold for the conventional LDLC lattice construction.