Generalized Quadrature Beamspace Modulation for Millimeter-wave Communication Systems using Lens Antenna Array

Millimeter-wave technology is one of the key 5G technology, which provides broadband data transmission (Gbps). Millimeter-wave band often suffers from high attenuation due to blockages and atmospheric absorption. In order to increase the propagation distance instead of single antenna transmitter, large antenna arrays are employed. Employing large number of antennas requires the need for optimal beamforming techniques and improved spatial diversity techniques. Large antenna array requires high implementation cost in terms of number of RF chain required. Limited number of RF chain reduces system cost but reduces the spectral efficiency and multiplexing gain. So, for improving spectral efficiency, index modulation technique is a best alternate for beamspace millimeter wave MIMO communication. A novel Generalised Quadrature Beamspace Modulation, which uses index modulation technique to improve Spectral Efficiency in beamspace channel for millimeter wave communication is proposed and compared with the existing Generalised Beamspace Modulation and Quadrature Beamspace Modulation. Spectral efficiency is found to better than the conventional methods.