System Level Evaluation of Space-Time Turbo Coded MIMO-OFDM for Wide Area Communications

It is foreseen that a single (wideband) air interface mode is not sufficient for achieving the high spectral efficiency targets set for next generation wireless system. A dual-bandwidth approach is adapted to simultaneously provide wide coverage and high capacity in a large range of different operating environments. In this paper, hybrid diversity-multiplexing scheme, where Space-time Turbo Coded Modulation (STTuCM) and layered space-time architectures are combined, is used as the air interface for the wide area communication to provide high spectral efficiency and robustness against spatial fading correlation. A system level performance study with different radio resource allocation functionalities applied to the proposed low bandwidth STTuCM orthogonal frequency division multiplexing air interface concept is conducted. The simulation results from the developed system level simulator indicate that the dynamic channel allocation (DCA) results in far better performance than the random allocation, especially in the case of frequency reuse factor one network. Moreover, the single frequency network with DCA performs equally well as the frequency reuse three network with DCA if the frequency resources are limited. Large system level gains can be achieved also if the suppression of structured inter-cell interference is utilized in all terminals. The results also show that transmission modes requiring large number of antennas at both sides of the communication link cannot be supported in the entire simulation scenario even if the frequency reuse of three is used.