Abstract:
Wirelesscommunicationssystem, evolvingfromsimplevoicecommunicationtoadvanced cellular communication have grown at a rapid pace in last two decades. But we are still seeking solution for keeping pace with the ever increasing demand for higher data rates in a more connected world today or more tomorrow. In order to accommodate such demands,5Gmobilenetworkwithmm-Wavelargemulti-inputmulti-output(MIMO)system is expected to offer high data rate and reliable communication. The large number of antennas helps focus energy, which brings drastic improvements in data rate and efficiency. However, fully digital beamforming technique is not a viable solution due to the required number of RF chain per antenna element and processors require lots and lots of power. A viable solution to mitigate the challenge is to adopt hybrid beamforming techniques that perform precoding in the analog domain following digital processing. In this work we consider, hierarchical SVD based decomposition and two-stage iterative multiuserhybridbeamformingalgorithmtoalleviatethegenericoptimizationdifficultiesofthe analog and digital beamforming matrices. We evaluate the performance of the down-link large multi-user(MU)-MIMO hybrid beamforming techniques in mm-Wave scenario taking spectral efficiency, energy efficiency, and computational and hardware complexity as a performance metrics. Plotted result showed that fully-connected hybrid beamforming techniques provides approximately 0.57 b/s/Hz higher spectral efficiency performance than the partially-connected hybrid beamforming techniques when the transmit power varies with 5dB difference. The required power consumption for fully-connected hybrid beamforming technique is number of RF chain at the BS times higher than the partiallyconnected hybrid beamforming techniques.