Abstract: Wireless technology has become the primary enabler of mobility and ubiquitous network access over the past decade. Multiuser- MIMO (MU-MIMO) has emerged as one of the prime technologies for achieving spectral efficiency (SE) in 4G LTE- A system. In addition to spectral-efficiency improvement, energy efficiency (EE) is becoming increasingly important for wireless communications because of the slow progress of battery technology and the growing requirements of anytime and anywhere multimedia applications. But this two design criteria (SE and EE) conflict with each other and a careful study of their trade-off is necessary for green network planning in future wireless communication systems. By considering the SE requirement, as a constrained optimization problem where constraints redefined to maximize EE using convex optimization technique and it is done for a 2×2 antenna configuration. It is proposed to use 4×4 MIMO antenna configuration and also an optimal beam forming design for both 2×2and 4×4 configuration is considered.

Keywords: MU-MIMO, LTE-A, Beam forming, Green Network, Energy Efficiency.