The ever-growing demand for high data rate and more user capacity increases the need to use the available spectrum more efficiently. Multi-user MIMO (MU-MIMO) improves in the spectrum efficiency by allowing a base station (BS) transmitter to communicate instantaneously with multiple mobile stations (MS) receivers using the same time-frequency resources. Massive MIMO allows the number of BS antenna elements to be on the order of tens or hundreds, thereby also increasing the number of data streams in a cell to a large value.
The next generation, 5G, wireless systems use millimeter wave (mm Wave) bands to take advantage of their wider bandwidth. The 5G systems also deploy large scale antenna arrays to mitigate severe propagation loss in the mm Wave band.
Compared to current wireless systems, the wavelength in the mm Wave band is much smaller. Although this allows an array to contain more elements within the same physical dimension, it becomes much more expensive to provide one transmit-receive (TR) module, or an RF chain, for each antenna element. Hybrid transceivers are a practical solution as they use a combination of analog beamformers in the RF and digital beamformers in the baseband domains, with fewer RF chains than the number of transmit elements.
In this thesis uses a multi-user MIMO Antenna Utilizing Antenna Culster system to highlight the partitioning of the required precoding into its digital baseband and RF analog components at the transmitter end. Building on the system highlighted in , this example Shows the formulation of the transmit-end precoding matrices and their application to a MIMO-OFDM system.