Lattice code decoder for space-time codes

We explore in this letter the lattice sphere packing representation of a mu lti-antenna system and the algebraic space-time (ST) codes. We apply the sp here decoding (SD) algorithm to the resulted lattice code. For the uncoded system, SD yields, with small increase in complexity, a huge improvement ov er the well-known V-BLAST detection algorithm. SD of algebraic ST codes exp loits the full diversity of the coded multi-antenna system, and makes the p roposed scheme very appealing to take advantage of the richness of the mult i-antenna environment. The fact that the SD does not depend on the constell ation size, gives rise to systems with very high spectral efficiency, maxim um-likelihood performance, and low decoding complexity.