The Dispersion of Nearest-Neighbor Decoding for Additive Non-Gaussian Channels

Abstract

We study the second-order asymptotics of informa- tion transmission using random Gaussian codebooks and nearest neighbor (NN) decoding over a power-limited additive stationary memoryless non-Gaussian channel. We show that the dispersion term depends on the non-Gaussian noise only through its second and fourth moments. We also characterize the second-order performance of point-to-point codes over Gaussian interference networks. Specifically, we assume that each user’s codebook is Gaussian and that NN decoding is employed, i.e., that interference from unintended users is treated as noise at each decoder