Diversidad en transmisión con selección escalonada de código espacio temporal

in this paper, an adaptive transmision technique for multiple transmitter antennas systems is proposed. the proposed technique, refered as space-time step selection, uses predetermined time intervals to transmit with different numbers of antennas, using space-time codes when more than one transmitter antenna is selected. the time intervals using for transmission are found offline through simulations, as a function of the maximum doppler frequency. simulation results show that the proposed technique achieves a gain of around 2db w.r.t. one single antenna selection system, and around 1db w.r.t. a two antennas selection system using alamouti coding. computation complexity is limited to a channel ranking at the receiver and feedback information requeriments are very low.