Challenges and Evaluation of Massive MIMO System Capacity Bounds for 5G Cellular Networks.

In the last decade, a lot of research has been done in the field for improving the Spectral Efficiency (SE) of the cellular wireless communicating channels. Multiple-Input and Multiple-Output (MIMO) technologies play a significant role in improving the overall efficiency of the system. The entire world is facing the major challenge of bandwidth crunch. Therefore, any work or contribution, which can improve the efficiency of the communication system, is a significant contribution to society. The paper presents a brief classification of the massive MIMO system designs, and the challenges are addressed. Initially, the MIMO system is introduced to increase SE by increasing the degree of freedom in space domain by multiple antennas. A large number of transmit-antennas provide more spectral and Energy Efficiency (EE) than conventional MIMO system. Then the massive MIMO system capacity bounds are evaluated considering the hardware impairment in the system. It is found that the performance of the channel estimation is essential for improving the overall efficiency of the massive MIMO system design. Mathematical modeling is given for evaluating the channel capacity; capacity is calculated and MIMO performance is evaluated. [ABSTRACT FROM AUTHOR]