GLOBECOM'09 Proceedings of the 28th IEEE conference on Global telecommunications
Turbo packet combining for broadband space-time BICM hybrid-ARQ systems with co-channel interference
IEEE Transactions on Wireless Communications
| Hi-index | 35.68 |
In this paper, we develop some new automatic repeat request (ARQ) protocols for multiple-input multiple-out (MIMO) flat-fading channels which adapt the bit-to-symbol mapping of each ARQ retransmission. We begin by defining a model for distinctly mapped transmissions through flat-fading MIMO channels. We characterize the effect that such a mapping diversity has on an integrated receiver utilizing sphere decoding. Varying the symbol mapping complicates the sphere decoding process, particularly for the enumeration of candidate solutions within the sphere. A technique that enables quick candidate enumeration is presented, utilizing concepts from existing closest point search schemes. The advantage of mapping diversity, in reducing bit error rate and reducing computational complexity, is presented along with simulation examples.