Evaluation of Cooperative Diversity Techniques Using STC for Future S-DMB Services

This paper presents an evaluation of various cooperative diversity techniques applied to future satellite digital multimedia broadcasting (S-DMB) systems. The increasing importance of hybrid and/or integrated satellite and terrestrial networks is associated with the utilization of spatial diversity techniques such as antenna diversity using space-time coding. The space-time coding schemes can be expected to result in more diversity gain as the number of transmit antennas are increased. However, we cannot design a rate-1 scheme that achieves full diversity for more than two transmit antennas. To overcome this limitation, quasi-orthogonal schemes were proposed, at the expense of the decoder complexity and diversity gain. In this paper, we introduce an efficient quasi-orthogonal space time coding scheme, and evaluate various aspects associated with the application of the proposed scheme to satellite systems. The proposed scheme in this paper provides the full rate as well as maximum-likelihood decoding via simple linear detection.