Algebraic hybrid satellite-terrestrial space-time codes for digital broadcasting in SFN

Lately, different methods for broadcasting future digital TV in a single frequency network (SFN) have been under an intensive study. To improve the transmission to also cover suburban and rural areas, a hybrid scheme may be used. In hybrid transmission, the signal is transmitted both from a satellite and from a terrestrial site. In 2008, Y. Nasser et al. proposed to use a double layer 3D space-time (ST) code in the hybrid 4×2 MIMO transmission of digital TV. In this paper, alternative codes with simpler structure are proposed for the 4×2 hybrid system, and new codes are constructed for the 3×2 system. The performance of the proposed codes is analyzed through computer simulations, showing a significant improvement over simple repetition schemes. The proposed codes prove in addition to be very robust in the presence of power imbalance between the two sites.