Reduced complexity space-time coding in single-frequency networks

Mobile broadcasting MIMO systems differ in several essential ways from conventional MIMO applications, especially when they are operating in single-frequency networks. There are certain channel features, like the imbalance of received average powers, which should be taken into account in system design. In this paper, space-time coding that allows reduced complexity maximum likelihood decoding of the received signal in a single-frequency network is introduced. A novel optimization criterion for fast-decodable 4×2 structures is proposed and the performance in single-frequency networks is studied in different scenarios through simulations. It is noticed that the reduced complexity codes suffer only a fraction of a decibel performance loss compared to an earlier proposed alternative for digital video broadcasting while achieving significant savings in computational complexity when maximum likelihood decoding is applied.