Lattice code decoder for space-time codes

TLDR

The paper investigates lattice sphere‑packing representations of multi‑antenna systems and algebraic space‑time codes. The authors model the system as a lattice code and apply sphere decoding to detect transmitted symbols. Sphere decoding outperforms V‑BLAST, fully exploits the diversity of algebraic ST codes, and delivers high spectral efficiency, maximum‑likelihood performance, and low decoding complexity.

Abstract

We explore the lattice sphere packing representation of a multi-antenna system and the algebraic space-time (ST) codes. We apply the sphere decoding (SD) algorithm to the resulted lattice code. For the uncoded system, SD yields, with small increase in complexity, a huge improvement over the well-known V-BLAST detection algorithm. SD of algebraic ST codes exploits the full diversity of the coded multi-antenna system, and makes the proposed scheme very appealing to take advantage of the richness of the multi-antenna environment. The fact that the SD does not depend on the constellation size, gives rise to systems with very high spectral efficiency, maximum-likelihood performance, and low decoding complexity.