scholarly journals Optimal Energy-Efficient Sensing and Power Allocation in Cognitive Radio Networks

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Xia Wu ◽  
Jin-Ling Xu ◽  
Ming Chen ◽  
Junbo Wang
Keyword(s):  
Energy Efficiency ◽  
Cognitive Radio ◽  
Power Allocation ◽  
Energy Efficient ◽  
Primary User ◽  
Joint Optimization ◽  
Secondary Users ◽  
Function Of Two Variables ◽  
Sensing Time

We consider a joint optimization of sensing parameter and power allocation for an energy-efficient cognitive radio network (CRN) in which the primary user (PU) is protected. The optimization problem to maximize the energy efficiency of CRN is formulated as a function of two variables, which are sensing time and transmit power, subject to the average interference power to the PU and the target detection probability. During the optimizing process, the quality of service parameter (the minimum rate acceptable to secondary users (SUs)) has also been taken into consideration. The optimal solutions are analyzed and an algorithm combined with fractional programming that maximizes the energy efficiency for CRN is presented. Numerical results show that the performance improvement is achieved by the joint optimization of sensing time and power allocation.

scholarly journals Multiband Spectrum Sensing and Power Allocation for aCognitive Radio-Enabled Smart Grid

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8384
Author(s):  
Jun Wang ◽  
Weibin Jiang ◽  
Hongjun Wang ◽  
Yanwei Huang ◽  
Riqing Chen ◽  
...  
Keyword(s):  
Smart Grid ◽  
Power Allocation ◽  
Communication Technologies ◽  
Optimization Techniques ◽  
Secondary Users ◽  
Key Technology ◽  
Optimal Power ◽  
Detection Probabilities ◽  
Sensing Time

As part of an Internet of Things (IoT) framework, the Smart Grid (SG) relies on advanced communication technologies for efficient energy management and utilization. Cognitive Radio (CR), which allows Secondary Users (SUs) to opportunistically access and use the spectrum bands owned by Primary Users (PUs), is regarded as the key technology of the next-generation wireless communication. With the assistance of CR technology, the quality of communication in the SG could be improved. In this paper, based on a hybrid CR-enabled SG communication network, a new system architecture for multiband-CR-enabled SG communication is proposed. Then, some optimization mathematical models are also proposed to jointly find the optimal sensing time and the optimal power allocation strategy. By using convex optimization techniques, several optimal methods are proposed to maximize the data rate of multiband-CR-enabled SG while considering the minimum detection probabilities to the active PUs. Finally, simulations are presented to show the validity of the proposed methods.

scholarly journals Performance Analysis of Cooperative Spectrum Sensing under Guaranteed Throughput Constraints for Cognitive Radio Networks

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
H. F. Al-Doseri ◽  
M. A. Mangoud
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Cooperative Spectrum Sensing ◽  
Primary User ◽  
Radio Networks ◽  
Probability Of Detection ◽  
Cooperative Sensing ◽  
Soft Decision ◽  
Secondary Users ◽  
Sensing Time

One of the main challenges in cognitive radio networks is the ability of secondary users to detect the primary user presence with high probability of detection. In previous research, optimizing cooperative sensing in cognitive radio networks is performed for either a targeted probability of detection or a false alarm. After setting one of the probabilities as an optimization constraint, the other is optimized. In this paper, a guaranteed constant throughput at the secondary users is introduced as a target while optimizing probability of detection for cooperative sensing. Both sensing time values and number of cooperated cognitive radio secondary users are investigated to maximize the probability of detection of primary user. AND and OR hard decision schemes are considered and compared with soft decision scheme which is weighted modified deflection coefficient scheme (W-MDC). It is illustrated that cooperation of all users and utilizing full frames for sensing time will not provide maximum probability of detection. A tradeoff between performances of cognitive radio networks with and without optimization is presented. The effects of varying network sizes, normalized target throughput, maximum frame duration times, and received signal-to-noise ratio at the fusion center are investigated for different fusion rules.

scholarly journals An Energy-Efficient Unselfish Spectrum Leasing Scheme for Cognitive Radio Networks

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6161
Author(s):  
Denis Bilibashi ◽  
Enrico M. Vitucci ◽  
Vittorio Degli-Esposti ◽  
Andrea Giorgetti
Keyword(s):  
Energy Efficiency ◽  
Cognitive Radio ◽  
Energy Efficient ◽  
Cooperative Communications ◽  
Cooperative Behavior ◽  
Maximization Problem ◽  
Secondary Users ◽  
Bipartite Matching ◽  
Spectrum Leasing ◽  
Primary Users

Cooperative Communications in Cognitive Radio (CR) have been introduced as an essential and efficient technique to improve the transmission performance of primary users and offer transmission opportunities for secondary users. In a typical multiuser Cooperative Communication in CR, each primary user can choose one secondary user as a relay node. To encourage the cooperative behavior of the secondary users, primary users lease a fraction of their allocated spectrum to the relay secondary users to transmit their data packets. In this work, a novel unselfish spectrum leasing scheme in CR networks is proposed that offers an energy-efficient solution minimizing the environmental impact of our network. A network management architecture is introduced, and resource allocation is proposed as a constrained sum energy efficiency maximization problem. The optimization problem is formulated and solved using non-linear programming methods and based on a modified Kuhn-Munkres bipartite matching algorithm. System simulations demonstrate an increment in the energy efficiency of the primary users’ network compared with previously proposed algorithms.

scholarly journals Energy-Efficient Layered Video Multicast over OFDM-Based Cognitive Radio Systems

2015 ◽  
Vol 2015 ◽  
pp. 1-12
Author(s):  
Wenjun Xu ◽  
Shengyu Li ◽  
Yue Xu ◽  
Zhiyong Feng ◽  
Jiaru Lin
Keyword(s):  
Cognitive Radio ◽  
Power Allocation ◽  
Energy Efficient ◽  
Video Data ◽  
Spectrum Efficiency ◽  
Base Layer ◽  
Video Multicast ◽  
Layered Video ◽  
Subcarrier Assignment

An energy-efficient layered video multicast (LVM) scheme for “bandwidth-hungry” video services is studied in OFDM-based cognitive radio (CR) systems, where the video data is encoded into a base layer and several enhancement layers with the former intended for all subscribers to guarantee the basic quality of reconstructed video and the latter aiming at the quality improvement for the promising users with good channel conditions. Moreover, in order to balance user experience maximization and power consumption minimization, a novel performance metricenergy utility(EU) is proposed to measure the sum achieved quality of reconstructed video at all subscribers when unit transmit power is consumed. Our objective is to maximize the system EU by jointly optimizing the intersession/interlayer subcarrier assignment and subsequent power allocation. For this purpose, we first perform subcarrier assignment for base layer and enhancement layers using greedy algorithm and then present an optimal power allocation algorithm to maximize the achievable EU using fractional programming. Simulation results show that the proposed algorithms can adaptively capture the state variations of licensed spectrum and dynamically adjust the video transmission to exploit the scarce spectrum and energy resources adequately. Meanwhile, the system EU obtained in our algorithms is greatly improved over traditional spectrum efficiency (SE) and energy efficiency (EE) optimization models.

scholarly journals Energy-Efficient Cluster-Based Cooperative Spectrum Sensing in a Multiple Antenna Cognitive Radio Network

2021 ◽  
pp. 176-185
Author(s):  
Samson I. Ojo ◽  
◽  
Zachaeus K. Adeyemo ◽  
Damilare O. Akande ◽  
Ayobami O. Fawole
Keyword(s):  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Energy Efficient ◽  
Cooperative Spectrum Sensing ◽  
Cluster Head ◽  
Fusion Rule ◽  
Probability Of Detection ◽  
Multiple Antenna ◽  
Secondary Users ◽  
Sensing Time

Spectrum Hole Detection (SHD) is a major operation in a Cognitive Radio (CR) network to identify empty spectrum for maximum utilization. However, SHD is often affected by multipath effects resulting in interference. The existing techniques used to address these problems are faced by poor detection rate, long sensing time and bandwidth inefficiency. Hence, this paper proposes a cluster-based Energy-Efficient Multiple Antenna Cooperative Spectrum Sensing (EEMACSS) for SHD in CR networks using Energy Detector (ED) with a modified combiner. Multiple secondary users are used to carry out local sensing using ED in multiple antenna configurations. The local sensing results are combined at the cluster head using majority fusion rule to determine the sensing results at each cluster. The sensing results from individual cluster are combined to determine the global sensing result using OR fusion rule. The proposed EEMACSS is evaluated using Probability of Detection (PD), Sensing Time (ST) and Spectral Efficiency (SE) by comparing with existing techniques. The results reveal that the proposed technique shows better performance.

scholarly journals Transceiver Design and Power Allocation for SWIPT in MIMO Cognitive Radio Systems

Symmetry ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 647 ◽  
Author(s):  
Fahui Wu ◽  
Lin Xiao ◽  
Dingcheng Yang ◽  
Laurie Cuthbert ◽  
Xiaoping Liu
Keyword(s):  
Cognitive Radio ◽  
Power Allocation ◽  
Null Space ◽  
Energy Requirement ◽  
Multiple Input Multiple Output ◽  
Primary User ◽  
Power Splitting ◽  
Secondary Users ◽  
Wireless Communication Network ◽  
Input Multiple Output

In this paper, we consider a symmetric wireless communication network, i.e., each user is equipped with the same number of antennas. Specifically, this paper studies simultaneous wireless information and power transfer (SWIPT) in a K-user multiple-input multiple-output (MIMO) cognitive radio network where the secondary users (SUs) access the same frequency band as the pre-existing primary user (PU) without generating any interference. The transceivers and power splitting ratio are designed and power allocation is considered in our system model. To guarantee the signal-to-interference-plus-noise ratio (SINR) and harvested energy requirement of the PU, its optimal transceiver and minimal transmitted power are obtained by the technique of semi-definite relaxation (SDR). We design the beamformers of the SUs using the distance between the interference subspaces at the PU and the null space of PU’s desired signal to preserve the PU from the interference caused by the SUs. We aim to maximize the sum rate of all the SUs by jointly designing power splitting ratios and allocating transmission power. Furthermore, to consider the performance fairness of SUs, we propose another approach to maximize the minimum SINR of the SUs. Finally, numerical results are given to evaluate the performance of proposed approaches.

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