Energy-Efficient Resource Allocation for OFDMA Heterogeneous Networks

Abstract

We proposed several energy-efficient resource allocation algorithms for the downlink of an orthogonal frequencydivision-multiple-access (OFDMA) based femtocell heterogeneous networks (HetNets). Heterogeneous QoS and fairness in rate are investigated in the proposed resource allocation problem. A dense deployment of femtocells in the coverage area of a central macrocell is considered and energy usage of both femtocell and macrocell users are optimized simultaneously. We aim to maximize the weighted sum of the individual energy efficiencies (WSEEMax) and the network energy efficiency (NEEMax) while satisfying the following: (1) minimum throughput for delaysensitive (DS) users, (2) fairness constraint for delay-tolerant (DT) users, (3) required constraints of OFDMA systems. The problem is formulated in three different forms: mixed 0-1 integer programming formulation, time-sharing formulation and sparsity-inducing formulation. The proposed resource block (RB) and power optimization problems are combinatorial and highly non-convex due to the fractional form of the objective function, the integer constraint of OFDMA RBs and non-affine fairness. We adopt the successive convex approximation (SCA) approach and transform the problems into a sequence of convex subproblems. With the proposed algorithms, we show that the overall joint RB and power allocation schemes converge to suboptimal solutions. Numerical examples confirm the merits of the proposed algorithms.

Resource Allocation for Hybrid Visible Light Communications (VLC)-WiFi Networks

“…A reasonable scheduling algorithm will provide users with better QoS, and improve the efficiency of the BSs. Resource management technologies of the heterogeneous network are discussed in [24][25][26][27], including collaborative radio resource allocation management, multi-access distributed radio resource allocation management, and joint radio resource allocation management. Three kinds of common scheduling algorithms were analyzed in [28], including Round-robin (RR) algorithm, the maximum C / I algorithm, and the proportional fair (PF) algorithm.…”

“…The distributed joint resource management architecture is more flexible than the centralized joint resource management architecture and is easy to expand. Even if some nodes in the network fail, it will not cause a destructive impact on other nodes [27]. In each radio resource management entity, although the extra signaling will cause some cost, it reduces the calculation amount of each network node and increases the reliability of the communication system.…”

Fair Energy-Efficient Resource Allocation for Downlink NOMA Heterogeneous Networks

“…The power consumption parameters model is executed based on [45], by considering the power consumption from the transmission side of the BSs, as well as from the users' receiver side. The power consumption of the femtocell is given by (9).…”

Energy-Efficient Buffer-Aided Relaying Systems With Opportunistic Spectrum Access

“…As a result, energy efficiency, which is measured by bits-per-joule, has emerged as a key figure of merit and become the most widely adopted design metric for green IoT systems. In fact, extensive research efforts have been made to improve the energy efficiency for various kinds of wireless communication applications, such as orthogonal frequency division multiplexing access (OFDMA) [6]- [9], multiple-input multiple-output (MIMO) [10]- [13], millimeter-wave (mmWave) communications [14], [15], cognitive radio [16], [17], small cell [18], [19], and wireless powered communications [20], [21], etc. However, most of the previous research works mainly focus on energy-efficient designs for physical layer transmission.…”