Capacity-Maximized Transmitter Antenna Selection for Multi-user Massive MIMO Systems with Linear Beamforming

The implementation of multi-user massive multiple input multiple output (MIMO) systems usually suffers from the increased complexity of system design. In such systems, the numbers of transmit antennas and radio frequency chains (RFC) increases extensively. In this paper, a capacity maximized transmit antenna selection (CM-TAS) algorithm is utilized to reduce the system complexity by reducing the number of RFC. In addition to CM-TAS, three different beamforming (BF) techniques, namely, maximum ratio transmission (MRT-BF), zero-forcing (ZF-BF) and minimum mean square error (MMSE-BF) techniques are considered. When CM-TAS is applied, the numerical analysis shows that the MRT-BF became sensitive to the amount of transmitted power and the number of RFC. On the other hand, the MMSE-BF and ZF-BF are proved to have better BER values than MRT-BF while becoming very sensitive to the number of served users in the system. The results illustrate that CM-TAS is effective in reducing the system complexity while maintaining an acceptable bit error rate (BER) performance.