Precoding incorporated MUI-PAPR reduction scheme in large-scale multi-user MIMO-OFDM downlink systems

Conservation of energy is gaining momentum day by day. Environmental concerns, hike in energy costs and limited energy resources are forcing us to reduce energy consumption in each and every field. This paper investigates the scope of large-scale Multi-User Multiple-Input Multiple-Output-Orthogonal Frequency- Division Multiplexing (MIMO-OFDM) as an energy efficient wireless communication technique. Despite being a key technology for future wireless communications, it faces two main problems, namely, Multi-User Interference (MUI) and high Peak-to-Average Power Ratio (PAPR). The high PAPR in turn results in higher power consumption and hence lower efficiency. In this paper, a large-scale Multi-User MIMO-OFDM based downlink system is studied. The problems of high PAPR and MUI are effectively solved by introducing a linear precoder based on a weighted Minimum Mean- Squared Error (MMSE) criterion. A convex optimization problem is formulated and is solved by using the Fast Iterative TRuncation Algorithm (FITRA). The simulation results prove the efficiency of the proposed method. The reduction in PAPR will reduce the power consumption and thus improve the energy efficiency.