Slow antenna selection and fast link adaptation MIMO systems

In this paper we propose joint antenna selection MIMO and adaptive modulation scheme for high spectral efficiency and power efficiency wireless transceiver design. In our proposed scheme the number of active receive antennas for spatial multiplexing MIMO detection is determined at the rate of the large scale channel variation which is a function of the path loss and shadowing parameters, while the link adaptation is updated as fast as the coherence time. Hence, in our proposed scheme, the rate of antenna selection is slower than the link adaptation, which is motivated by the fact that the portion of the power consumption is dominated by RF chains during the initial period of the switched-on terminal and some wireless service does not require the large scale mobility. From our analysis we determine the number of the active receive antennas to achieve a certain target ergodic capacity as well as a target link performance and evaluate bit error rate, average spectral efficiency and the outage probability for two MIMO detection schemes such as maximum likelihood and zero-forcing. Some selected numerical examples are finally presented and discussed to illustrate the tradeoff offered by this scheme.