ABSTRACT
The MIMO techniques are very promising for the design of future wireless communication systems. They are capable of providing high data rates without increasing the spectrum utilization and the transmit power. Diversity gain can also be gained in MIMO, which lay very important foundations for physical-layer standards like WiMAX (Worldwide Interoperability for Microwave Access) (Andrews et al., 2007) and LTE-A (Long Term Evolution-Advanced) (Ghosh et al., 2010). In MIMO systems, all TAs are active at any time instance, resulting in SE optimization. Yet, this does not naturally lead to Energy Efficiency (EE) optimization (Hellings and Utschick, 2013), which is key to future communication systems requiring low energy-consumption techniques.
