Energy and spectral efficiency trade‐off for the downlink OFDM‐distributed antenna systems

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SummarySpectral efficiency (SE) is an important metric in traditional wireless network design. However, as the development of high‐data rate services and rapidly increase of energy consumption, energy efficiency (EE) has received more and more attention. In this paper, we investigate the EE–SE tradeoff in downlink OFDMA network. Different from previous researches, we try to optimize EE and SE simultaneously. First, the problem is formulated as a multiobjective optimization problem (MOP), and its Pareto optimal set is characterized. Then, we convert the MOP to a single‐objective optimization problem (SOP) by the weighted linear sum method and show that it is neither quasi‐convex nor quasi‐concave. After that, a novel algorithm using particle swarm optimization is proposed to solve the SOP. Simulation results validate that the proposed algorithm can efficiently reduce total transmit power and improve EE, although the cost is sacrificing some SE, which could be used to design an flexible energy efficient network in the future.Copyright © 2014 John Wiley & Sons, Ltd.

Section: Related Workmentioning

confidence: 99%

Energy spectral efficiency tradeoff in downlink OFDMA network

Jiang

Pan

et al. 2014

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“…Furthermore in , the resource allocation is formulated to maximize EE for secure OFDMA systems as a mixed nonconvex and combinatorial optimization problem with negligible circuit power taking into consideration for single‐cell scenario. In , EE in OFDM distributed antenna systems in single cell scenario is also analyzed. EE comparison of the different types of MIMO systems is also present in .…”

Section: Introductionmentioning

confidence: 99%

Energy efficiency optimization for downlink OFDMA system in heterogeneous network with QoS constraints

Bastos

Huq

Mumtaz

et al. 2015

Summary Energy efficiency (EE) has currently turn into one of the major issues in heterogeneous networks (HetNet) paradigm of today's wireless communication industry. In this paper, we optimize EE for downlink OFDMA system in HetNet, taking into account realistic network power consumption model, that is, considering circuit power. This paper investigates the EE maximization using convex optimization theory where primary optimization criterion is data rate in a downlink multiuser HetNet. Given QoS (data rate) requirement, for maximizing EE, a constrained based optimization problem is devised. Because the optimization problem is non‐convex in nature, we reconstruct the optimization problem as a convex one and devise a pragmatically efficient novel resource assignment algorithm for maximizing achievable EE, with quick convergence. The considered optimization problem is transformed into a convex optimization problem by redefining the constraint using cubic inequality, which results in an efficient iterative resource allocation algorithm. In each iteration, the transformed problem is solved by using dual decomposition with a projected gradient method. Analytical insights and numerical results exhibit the potency of the devised scheme for the targeted complex wireless systems. Copyright © 2015 John Wiley & Sons, Ltd.

Novel schemes for interference‐resilient OFDM wireless communication

Imran

Loan

Mahmood

2015

This research work introduces some novel techniques for interference-resilient OFDM wireless communication. Firstly, novel schemes for spatial multiplexing and interference cancelation based on signal subspace estimation are proposed. Secondly, the OFDM system is designed such that it meets three main objectives simultaneously, namely, (i) interference-resiliency, (ii) throughput maximization, and (iii) energy consumption minimization. Interference-cancelation techniques in prior art mostly consider maximization of throughput without any focus on energy consumption. On the other hand, the literature in energy minimization is limited to interference-free environments. Most of the previous techniques also have a drawback that they cannot operate in smart or dynamically changing interference environments. The focus here is on interference-resilient communication with equal attention to both throughput and energy-efficiency maximization in dynamic hostile environments. The optimization problem is formulated, and then optimal policies and switching thresholds are found for throughput and energy-efficient interference-resilient communication. Methodologies for estimating the channel and jammer conditions and then adapting the transmission strategies accordingly are proposed. Moreover, to have an effective defense against smart jamming scenario, a constant-payoff scheme is also introduced. Simulation results are compared with previous techniques that demonstrate the efficacy of proposed research.