Energy efficiency-based joint spectrum handoff and resource allocation algorithm for heterogeneous CRNs

Abstract

Cognitive radio networks (CRNs) are expected to improve spectrum utilization significantly by allowing secondary users (SUs) to opportunistically access the licensed spectrum of primary users (PUs). In an integrated network consisting of multiple heterogeneous CRNs, SUs with multiple interfaces may have to conduct inter-system or intra-system spectrum handoff due to the arrival of PUs or performance degradation on serving spectrum. In this case, designing an optimal spectrum handoff scheme which offers quality of service (QoS) guarantee and performance enhancement of the SUs is of particular importance. On the other hand, resource allocation strategy on target channel also plays an important role in affecting the transmission performance of handoff SUs. In this paper, we jointly design spectrum handoff and resource allocation strategy for handoff SUs in heterogeneously integrated CRNs. To achieve joint resource management among various CRNs, we propose a joint radio resource management architecture, based on which the proposed spectrum handoff and resource allocation scheme can be conducted. Jointly considering the transmission performance of the handoff SUs, we formulate the total energy efficiency of the SUs and design an optimization problem which maximizes the energy efficiency subject to spectrum handoff, QoS, and power constraints of the SUs. An iterative algorithm is proposed to solve the formulated nonlinear fractional optimization problem. Within each iteration, the optimization problem is transformed equivalently into two subproblems, i.e., power allocation subproblem of each SU-spectrum pair and spectrum handoff subproblem for all the SUs. The two subproblems are solved, respectively, through applying Lagrange dual method and the Kuhn-Munkres (K-M) algorithm. Numerical results demonstrate the efficiency of the proposed algorithm.

An Optimal Joint User Association and Power Allocation Algorithm for Secrecy Information Transmission in Heterogeneous Networks

“…In this paper, we jointly consider user association and power allocation problem in HetNets and design joint optimal strategies so that the overall performance of the networks can be maximized. (iii) While most of the previous works [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] consider secure communication environment in HetNets, it is highly possible that the information transmission from BSs to UE is eavesdropped on by eavesdroppers. In this paper, we study the problem of information transmission in HetNets where eavesdroppers tend to eavesdrop on user information.…”

“…In previous research works [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16], secure communication environment is considered where no information eavesdropping exists. However, as the network architecture of HetNets is more open and diverse compared to traditional cellular systems, information exchange in HetNets is more susceptible to eavesdropping; therefore, the problem of secure information transmission becomes extremely important in HetNets.…”

“…Reference [15] considers a downlink multiuser orthogonal frequency-division multiple access (OFDMA) system and proposes an optimal power and subcarrier allocation scheme to maximize the sum energy efficiency of users under the total transmit power constraint. The authors in [16] consider spectrum handoff and resource allocation problem of secondary users (SUs) in heterogeneous cognitive radio networks and propose an optimal joint handoff channel selection and transmit power allocation scheme which aims at maximizing the energy efficiency of all the SUs.…”

“…References [11][12][13][14][15][16] investigate the energy consumption issues in HetNets. In [11], the authors aim at minimizing the power consumption of an orthogonal frequency-division multiplexing (OFDM) based HetNet under the data rate constraints of the users.…”

Time triggered handoff schemes in cognitive radio networks: A survey

“…[42] [74][77][87][79] focus on designing energy efficient spectrum handoff algorithms. In addition, the survey presented in…”