Energy efficiency comparison between distributed and co‐located MIMO systems

Abstract

SUMMARYEnergy efficiency (EE) is becoming more and more important in future wireless communications because of limited battery power in mobile terminals. In this paper, we compare EE of the distributed MIMO (D‐MIMO) and co‐located MIMO (C‐MIMO) in uplink systems. Taking into account both circuit and transmit power, we derive an analytical expression for EE of D‐MIMO and C‐MIMO systems in a composite Rayleigh‐lognormal channel. What is more, an optimization algorithm is proposed to get the optimal EE values while satisfying given spectral efficiency requirement for both D‐MIMO and C‐MIMO systems. Simulation results show that D‐MIMO systems are more energy effective than C‐MIMO systems when considering the realistic systems, and the optimal EE can be obtained by the proposed algorithm while satisfying given spectral efficiency requirement. Copyright © 2012 John Wiley & Sons, Ltd.

Energy- and Spectral-Efficiency Tradeoff for Distributed Antenna Systems with Proportional Fairness

“…An energy-efficient link-adaptive transmission scheme for MIMO-OFDM systems has been proposed in [15] where the circuit power consumption is considered. The EE of the distributed MIMO (D-MIMO) and co-located MIMO (C-MIMO) in the uplink cellular systems have been compared in [16]. It has been demonstrated that D-MIMO systems are more energy-efficient than C-MIMO systems.…”

On the Energy Efficiency-Spectral Efficiency Trade-Off of Distributed MIMO Systems

“…On the one hand, results show that our novel low-SE approximation is as accurate as the approximation of [2], but it has the advantage of a simplified formulation. On the other hand, our novel high-SE approximation is very tight with the actual EE-SE trade-off results in both the mid as well as high SE regimes, and is far more accurate than the approximation in [24]. This is due to the fact that the derivation of the approximations in [24] is based on lower and upper bounds instead of an exact formulation.…”

“…On the other hand, our novel high-SE approximation is very tight with the actual EE-SE trade-off results in both the mid as well as high SE regimes, and is far more accurate than the approximation in [24]. This is due to the fact that the derivation of the approximations in [24] is based on lower and upper bounds instead of an exact formulation. As an application for our novel and accurate approximations, we study in Section V, both analytically and numerically, the effects of connecting additional RAUs to the user terminal (UT) on the system EE and how DMIMO compares with CMIMO in terms of EE, for both idealistic and realistic PCMs.…”

“…The channel capacity of DMIMO has been extensively studied and its asymptotic closed-form expression can be found in [21], [22] while its high signalto-noise ratio (SNR) approximation has been derived in [20], [23]. As far as the uplink of the DMIMO EE-SE trade-off is concerned, its lower and upper bounds at high SNR have been obtained in [24] by using the high SNR approximation of [20], but only for some limited antenna configurations. Furthermore, an energy-efficient resource allocation for the downlink of the DMIMO system has been recently proposed in [25].…”

“…In this paper, we propose a framework for comprehensively analyzing the DMIMO system from both an EE and SE perspective by means of a tight CFA of its EE-SE trade-off. Relying on our novel approach, we go beyond [24] and propose an accurate CFA of the DMIMO EE-SE trade-off for any SE regime and wider range of antenna configurations. Section II presents the system model for the DMIMO system and reviews its capacity expression which serves as a basis for our own derivation.…”