Energy Efficiency in Multiple Antenna Machine-Type Communications With Reconfigurable RF Transceivers

Abstract

In machine-type communication (MTC) networks, each node is equipped with a set of radiofrequency (RF) transceivers, antennas and power source. Besides, wireless nodes are typically batterypowered, whose recharging or replacement is often not viable or even impossible. Therefore, in such systems where energy is at a premium, minimizing power consumption improves energy efficiency and increases battery lifetime. In this paper, a novel energy-saving approach includes in the communication system model the use of reconfigurable RF transceivers. More specifically, the components involved in our power minimization framework are the power amplifier (PA) at the transmitter and the low noise amplifier (LNA) at the receiver, which are the blocks responsible for RF amplification and are on top of power consuming blocks in RF transceivers. Our goal is to show that RF circuits based on multimode operation can significantly improve the energy efficiency. We perform a joint selection of the best operating modes for PA and LNA circuits in different communication scenarios. Results show that by combining PA and LNA operating modes, an improvement of more than 75% in energy efficiency is obtained for multiple antenna communications, when compared to the state-of-the-art literature of non-reconfigurable amplifiers. Besides, we show that adapting spectral efficiency contributes towards improving energy efficiency. In this case, we consider different spectral efficiency values, including the effect that the PA operates at different backed-off power levels. In addition, when comparing single-input single-output (SISO) and multiple-input multiple-output (MIMO) transmission schemes, antenna selection (AS) outperforms the others schemes in terms of energy efficiency for short and moderate distances, but singular value decomposition (SVD) allows for longer communication distances. INDEX TERMS Energy efficiency, reconfigurable RF transceivers, machine-type communications, multiple antennas.

Energy Analysis in Cooperative Machine-Type Communications with Reconfigurable RF Transceivers

“…This section demonstrates the energy analysis of our proposed optimization approach. Following the system parameters used in [15], we consider B = 10 kHz, M L = 30 dB, f c = 2.4 GHz, G A = 5 dBi, α = 2.5, O = 10 −3 , N 0 = −174 dBm/Hz and ξ = 2 bps/Hz. Moreover, 97.9 mW and 92.2 mW are the power consumption of non-reconfigurable RF circuits in the transmitter and receiver chain, respectively.…”

“…In this work, we employ state-of-the-art multimode RF amplifiers, using real data from the PA proposed by [18] and the LNA in [19]. The main characteristics of these reconfigurable circuits are shown in Table I, following [15]. Let us remark that the PA admits 7 operating modes, whereas the LNA features 3 operating modes.…”

“…Results also show that the relay position between the source and destination nodes contributes differently to improve the energy efficiency. Furthermore, it is worth noting that this paper is an extension of our work presented in [15], which addresses reconfigurable RF transceivers for non-cooperative multiple antenna nodes.…”

Energy Efficient Probabilistic Switching ON–OFF Operation in Multiantenna Cooperative Wireless Sensor Networks

“…where η is the power amplifier efficiency and P ct is the power consumed by each transmission circuit chain [3].…”

Energy Efficiency Analysis of MIMO Wideband RF Front-End Receivers

“…In that sense, antenna selection (AS) is an important technique [ 4 ], yielding the same diversity gains as MIMO, but with lower power consumption due to the reduced number of active RF chains. For instance, the EE optimization of some MIMO techniques, when considering the effect of reconfigurable RF transceivers, is discussed in [ 5 ]. Along with AS, singular value decomposition (SVD) beamforming and single antenna (SISO) are considered.…”