Lattice Codes and Generalized Minimum-Distance Decoding for OFDM Systems

Abstract

Lattice coding of orthogonal frequency division multiplexing (OFDM) systems is considered.Mapping of multilevel construction lattices to OFDM blocks is shown, and a methodology for probabilistic analysis of multistage generalized minimum distance (GMD) decoding of the received OFDM blocks is derived. As a case study transmission of points from a 128-dimensional Barnes-Wall lattice is considered. Tight approximations to the system error rate are obtained and verified by simulation. It appears that GMD decoding of lattice encoded OFDM provides high coding gain at low complexity.2