Massive MIMO: Enhancement of Spectral and Energy Efficiency for 5G Perspective

Abstract

Massive Multi-Input and Multi-Output (MIMO) antenna system is considered as the key technology to improve both spectral efficiency (SE) and energy efficiency (EE) for 5G wireless systems. This paper evaluates the impact of perfect and imperfect channel state information (CSI) on the SE. The maximum SE of 200 bits/s/Hz achieved in a multi-cell scenario and its limiting factors were explored. We mainly demonstrated linear precoding algorithms such as zero-forcing (ZF), maximum ratio combing (MRC), and minimum mean square error (MMSE) for SE analysis. The explicit SE and EE expressions were derived from Shannon capacity calculations for single and multi-cell scenario. The proposed ZF and MRC precoding schemes were observed with SEs of 185 bit/s/Hz, and 180 bits/s/Hz respectively with pilot reuse factor with λ=7. The simulation results were validated by comparing the SE versus the number of base station (BS) antennas with receiving schemes by using MATLAB 2018a.

Performance Evaluation of Precoding Schemes for Multi User Massive MIMO System Over Nakagami-m Fading Channel

“…To improve overall performance, users that generate excessive interference in surrounding cells were first identified, followed by shared channel processing. The performance of the suggested technique was compared to that of single-cell MMSE channel estimation and multi-cell MMSE channel estimation.The authors proposed a research in which they demonstrated the impact of perfect CSI and imperfect CSI on the SE in [14]. Zero-forcing precoding and maximum ratio combing precoding were used to investigate spectral efficiency.…”

Achievable Capacity with Spatial Channel Correlation in Massive MIMO Multi-Cell Systems

“…This Shannon capacity demonstrates the maximum achievable data rate of a channel with given bandwidth and desired signal to noise ratio. Future wireless networks demands high speed transmission and serve large number of user terminal(UT)s. Massive Multi-Input and Multi-Output (MIMO) is considered as a suitable candidate to obtain higher Spectral efficiency(SE) by spatial multiplexing of massive number of UTs in multi-cell scenario [1][2][3][4][5]. This is achieved by deploying massive number of antennas at the base station (BS).…”