Comparison Energy Efficiency and Spectral Efficiency in Beamspace MIMO and Beamspace MIMO-NOMA System Model

Abstract

There are ongoing research interests in the past decade to develop wireless communication systems and advance information rate limits. Therefore, to achieve future requirements and increase network capacity, the first method is to use millimeter wave (mmWave), which is essential for the upcoming 5G wireless communication technology. However, some challenges are encountered when using both mmWave and Massive MIMO in the spectrum and power efficiency to achieve optimal performance. Beamspace (BS) MIMO is a discovery in Massive MIMO, which is essential for making an exchange between energy efficiency (EE) and spectral efficiency (SE) in BS-MIMO. Therefore, BS-MIMO can increase network capacity and reduce energy consumption by significantly reducing the required number of radio frequency (RF) chains. The problem with the traditional method is that the beam can only support one user, not more at the same time and frequency resources. In this paper, we propose to use multiple users (MU) with non-orthogonal multiple access (NOMA) in the beamspace Massive MIMO. The method is integrating the NOMA with BS-MIMO to create a new configuration called BS-MIMO-NOMA. In this paper, we present simulation performance among three methods as fully digital MIMO, BS-MIMO, and BS-MIMO-NOMA. Simulation results show that the fully digital MIMO system shows the worst EE performance compared to other methods. In addition, the BS-MIMO-NOMA method can achieve better spectrum efficiency performance compared to the beamspace-specific MIMO method. This paper aims to make the trade-off between the EE and SE in terms of best performances. In the future, we propose the use of power optimization iterative method with minimal complexity to realize the best EE performance.