Energy Efficiency Optimization With SWIPT in MIMO Broadcast Channels for Internet of Things

Abstract

Abstract-Simultaneous wireless information and power transfer (SWIPT) is anticipated to have great applications in fifthgeneration (5G) communication systems and the Internet-ofThings (IoT). In this paper, we address the energy efficiency (EE) optimization problem for SWIPT multiple-input multiple-output broadcast channel (MIMO-BC) with time-switching (TS) receiver design. Our aim is to maximize the EE of the system whilst satisfying certain constraints in terms of maximum transmit power and minimum harvested energy per user. The coupling of the optimization variables, namely, transmit covariance matrices and TS ratios, leads to an EE problem which is non-convex, and hence very difficult to solve directly. Hence, we transform the original maximization problem with multiple constraints into a suboptimal min-max problem with a single constraint and multiple auxiliary variables. We propose a dual inner/outer layer resource allocation framework to tackle the problem. For the inner-layer, we invoke an extended SWIPT-based BC-multiple access channel (MAC) duality approach and provide two iterative resource allocation schemes under fixed auxiliary variables for solving the dual MAC problem. A sub-gradient searching scheme is then proposed for the outer-layer in order to obtain the optimal auxiliary variables. Numerical results confirm the effectiveness of the proposed algorithms and illustrate that significant performance gain in terms of EE can be achieved by adopting the proposed extended BC-MAC duality-based algorithm.Index Terms-Simultaneous wireless information and power transfer (SWIPT), energy efficiency (EE), multiple-input multiple-output (MIMO), Internet-of-Things (IoT).

Energy Efficiency Optimization for NOMA With SWIPT

“…Most research works on SWIPT systems focused on maximizing sum rate or harvested energy. However, EE optimization for SWIPT systems has also been investigated recently [2], [28]. The work in [2] studied the optimal resource allocation for maximizing the EE of the OFDMA-based SWIPT system.…”

“…The work in [2] studied the optimal resource allocation for maximizing the EE of the OFDMA-based SWIPT system. Energy efficiency optimization with SWIPT in MIMO broadcast channels for internet of things (IoT) was studied in [28], where a practical linear power model taking into account the entire transmitreceive chain was proposed.…”

Coverage Analysis for Energy-Harvesting UAV-Assisted mmWave Cellular Networks

“…As an emerging technology, the Internet of Things (IoT) is expected to offer promising solutions to transform the operation and role of many existing industrial systems such as transportation systems and manufacturing systems [1]. Expected to be commercially available in early 2020s, the fifth generation (5G) enabled IoT will connect massive number of IoT devices [2] [3]. In certain applications, IoT sensors are low-power devices.…”

Energy Efficiency Optimization for CoMP-SWIPT Heterogeneous Networks

“…However, given that the receivers sensitivity for information and energy are fundamentally different, this approach was not practically feasible [25]. Motivated by this, two new receiver structures are developed where ID and EH are separated through time domain and power domain [26], [27]. In addition, rather than splitting the data and energy through time or power domain, a new approach named spatial switching (SS) was developed for a MIMO-SWIPT system where the eigen-channels are either assigned to ID or EH [28].…”