scholarly journals Optimum energy harvesting model for bidirectional cognitive radio networks

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Mohammad Kamrul Hasan ◽  
Md. Monwar J. Chowdhury ◽  
Shakil Ahmed ◽  
Saifur R. Sabuj ◽  
Jamel Nibhen ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Cognitive Radio ◽  
Energy Harvesting ◽  
Outage Probability ◽  
Primary User ◽  
Battery Life ◽  
Transmission Power ◽  
Wireless Devices ◽  
Harvesting Technique ◽  
Power And Energy

AbstractWireless devices’ energy efficiency and spectrum shortage problem has become a key concern worldwide as the number of wireless devices increases at an unparalleled speed. Wireless energy harvesting technique from traditional radio frequency signals is suitable for extending mobile devices’ battery life. This paper investigates a cognitive radio network model where primary users have their specific licensed band, and secondary users equipped with necessary hardware required for energy harvesting can use the licensed band of the primary user by smart sensing capability. Analytical expressions for considered network metrics, namely data rate, outage probability, and energy efficiency, are derived for uplink and downlink scenarios. In addition, optimal transmission power and energy harvesting power are derived for maximum energy efficiency in downlink and uplink scenarios. Numerical results show that outage probability improves high transmission power in the downlink scenario and high harvested power in the uplink scenario. Finally, the result shows that energy efficiency improves using optimum transmission power and energy harvesting power for downlink and uplink scenarios.

scholarly journals Design an Optimum Energy Harvesting Model for Bidirectional Cognitive Radio Networks

2021 ◽  
Author(s):  
Mohammad Kamrul Kamrul Hasan ◽  
Md. Monwar Jahan Chowdhury ◽  
Shakil Ahmed ◽  
Saifur Rahman Sabuj ◽  
Jamel Nibhen ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Cognitive Radio ◽  
Energy Harvesting ◽  
Outage Probability ◽  
Network Model ◽  
Cognitive Radio Network ◽  
Primary User ◽  
Battery Life ◽  
Radio Network ◽  
Wireless Devices

Abstract The energy efficiency and spectrum shortage problem of wireless devices has become a concern for researchers worldwide as the number of wireless devices increases at an unparalleled speed. Many new solutions have been proposed to extend mobile devices' battery life, such as wireless energy harvesting from traditional radio frequency signals to design new smart battery chips. This paper considers a cognitive radio network model where primary users have their specific licensed band, and secondary users equipped with necessary hardware required for energy harvesting can use the licensed band of the primary user by smart sensing capability. First, the expression of outage probability is theoretically derived for uplink and downlink scenarios. Moreover, maximum energy efficiency for both uplink and downlink in the cognitive radio network model subject to interference and noise is investigated here. The theoretical analysis is then evaluated. It has been observed that outage probability improves low harvested power in the downlink scenario and high harvested power in the uplink scenario. Finally, the result signifies that energy efficiency is improved using optimum power for uplink and downlink scenarios.

scholarly journals Secrecy Energy Efficiency Maximization in an Underlying Cognitive Radio–NOMA System with a Cooperative Relay and an Energy-Harvesting User

2020 ◽  
Vol 10 (10) ◽  
pp. 3630 ◽  
Author(s):  
Carla E. Garcia ◽  
Mario R. Camana ◽  
Insoo Koo
Keyword(s):  
Energy Efficiency ◽  
Cognitive Radio ◽  
Energy Harvesting ◽  
Multiple Access ◽  
Pso Algorithm ◽  
Critical Issue ◽  
Primary User ◽  
Secondary User ◽  
Cooperative Relay ◽  
Security Issue

Security is considered a critical issue in the deployment of 5G networks because of the vulnerability of information that can be intercepted by eavesdroppers in wireless transmission environments. Thus, physical layer security has emerged as an alternative for the secure enabling of 5G technologies and for tackling this security issue. In this paper, we study the secrecy energy efficiency (SEE) in a downlink underlying cognitive radio (CR)—non-orthogonal multiple access (NOMA) system with a cooperative relay. The system has an energy-harvesting (EH) user and an eavesdropper, where the transmitter provides direct communication with a close secondary user and a distant secondary user via the relay. Our objective is to maximize the SEE of the CR-NOMA system under the constraints of a minimum information rate for the secondary users, a minimum amount of energy harvested by the EH user, and maximum power availability at the transmitter and the relay that still prevents them from causing unacceptable interference with the primary user. The proposed solution to maximize the SEE is based on the low-computational—complexity particle swarm optimization (PSO) algorithm. For validation purposes, we compare the optimization outcomes obtained by the PSO algorithm with the optimal exhaustive search method. Furthermore, we compare the performance of our proposed CR-NOMA scheme with the conventional orthogonal multiple access (OMA) scheme.

Game Theory for Cognitive Radio Networks

Game Theory ◽  
2017 ◽  
pp. 487-502
Author(s):  
Sungwook Kim
Keyword(s):  
Cognitive Radio ◽  
Cognitive Abilities ◽  
Cognitive Radios ◽  
Primary User ◽  
Spectrum Management ◽  
Cognitive Networks ◽  
Wireless Devices ◽  
New Paradigm ◽  
Secondary Users ◽  
Dynamic Spectrum Management

A cognitive radio is an intelligent radio that can be programmed and configured dynamically. Its transceiver is designed to use the best wireless channels in its vicinity. Such a radio automatically detects available channels in the wireless spectrum, then accordingly changes its transmission or reception parameters to allow more concurrent wireless communications in a given spectrum band at one location. This process is a form of dynamic spectrum management. In recent years, the development of intelligent, adaptive wireless devices called cognitive radios, together with the introduction of secondary spectrum licensing, has led to a new paradigm in communications: cognitive networks. Cognitive networks are wireless networks that consist of several types of users: often a primary user and secondary users. These cognitive users employ their cognitive abilities to communicate without harming the primary users. The study of cognitive networks is relatively new and many questions are yet to be answered. This chapter furthers the study.

scholarly journals Power Control and Channel Allocation Algorithm for Energy Harvesting D2D Communications

Algorithms ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 93 ◽  
Author(s):  
Na Su ◽  
Qi Zhu
Keyword(s):  
Energy Harvesting ◽  
Power Control ◽  
Channel Allocation ◽  
Base Station ◽  
Transmission Power ◽  
D2d Communications ◽  
Harvesting Time ◽  
Allocation Algorithm ◽  
Total Capacity ◽  
Power And Energy

This paper assumes that multiple device-to-device (D2D) users can reuse the same uplink channel and base station (BS) supplies power to D2D transmitters by means of wireless energy transmission; the optimization problem aims at maximizing the total capacity of D2D users, and proposes a power control and channel allocation algorithm for the energy harvesting D2D communications underlaying the cellular network. This algorithm firstly uses a heuristic dynamic clustering method to cluster D2D users and those in the same cluster can share the same channel. Then, D2D users in the same cluster are modeled as a non-cooperative game, the expressions of D2D users’ transmission power and energy harvesting time are derived by using the Karush–Kuhn–Tucker (KKT) condition, and the optimal transmission power and energy harvesting time are allocated to D2D users by the joint iteration optimization method. Finally, we use the Kuhn–Munkres (KM) algorithm to achieve the optimal matching between D2D clusters and cellular channel to maximize the total capacity of D2D users. Simulation results show that the proposed algorithm can effectively improve the system performance.

scholarly journals Energy Efficiency Design for Secure MISO Cognitive Radio Network Based on a Nonlinear EH Model

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Lei Ni ◽  
Xinyu Da ◽  
Hang Hu ◽  
Miao Zhang
Keyword(s):  
Energy Efficiency ◽  
Cognitive Radio ◽  
Optimization Problem ◽  
Optimal Solution ◽  
Primary User ◽  
Open Architecture ◽  
Maximization Problem ◽  
Transmit Beamforming ◽  
Secrecy Rate ◽  
Single Output

In this work, we investigate the secrecy energy efficiency (SEE) optimization problem for a multiple-input single-output (MISO) cognitive radio (CR) network based on a practical nonlinear energy-harvesting (EH) model. In particular, the energy receiver (ER) is assumed to be a potential eavesdropper due to the open architecture of a CR network with simultaneous wireless information and power transfer (SWIPT), such that the confidential message is prone to be intercepted in wireless communications. The aim of this work is to provide a secure transmit beamforming design while satisfying the minimum secrecy rate target, the minimum EH requirement, and the maximum interference leakage power to primary user (PU). In addition, we consider that all the channel state information (CSI) is perfectly known at the secondary transmitter (ST). We formulate this beamforming design as a SEE maximization problem; however, the original optimization problem is not convex due to the nonlinear fractional objective function. To solve it, a novel iterative algorithm is proposed to obtain the globally optimal solution of the primal problem by using the nonlinear fractional programming and sequential programming. Finally, numerical simulation results are presented to validate the performance of the proposed scheme.

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