Abstract:
Point-to-point wireless communications can benefit from massive multiple-input multiple-output systems (mMIMO) to attain higher data rates. But even with mMIMO systems the joint optimization of spectra land energy efficiencies can be only achieved by multilevel modulations with an efficient power amplification. Also,wireless channels are prone to be intercepted which compromises security. These constrains can be overpass a transmitter using several amplification branches that result from the decomposition of a multilevel constellation as a sum of quasi constant envelope signal components that are sent independently. Under these conditions, the better power amplification efficiency comes together with a physical security due to the constellation shaping according to the direction in which the antenna arrangement is optimized. Besides, this multi-amplifier structure when inserted in a multi-layered structure where the antenna arrays connected to several multi branch structures in parallel could achieve the high data rates attainable by mMIMO with spatial multiplexing, assuring at same time similar performances to conventionalize systems
