scholarly journals Cognitive Radio RF: Overview and Challenges

VLSI Design ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Van Tam Nguyen ◽  
Frederic Villain ◽  
Yann Le Guillou
Keyword(s):  
Cognitive Radio ◽  
Software Defined Radio ◽  
Internal State ◽  
Disruptive Technology ◽  
Operational Parameters ◽  
Radio System ◽  
Analog To Digital ◽  
Implementation Challenges ◽  
The Status ◽  
High Spectral Efficiency

Cognitive radio system (CRS) is a radio system which is aware of its operational and geographical environment, established policies, and its internal state. It is able to dynamically and autonomously adapt its operational parameters and protocols and to learn from its previous experience. Based on software-defined radio (SDR), CRS provides additional flexibility and offers improved efficiency to overall spectrum use. CRS is a disruptive technology targeting very high spectral efficiency. This paper presents an overview and challenges of CRS with focus on radio frequency (RF) section. We summarize the status of the related regulation and standardization activities which are very important for the success of any emerging technology. We point out some key research challenges, especially implementation challenges of cognitive radio (CR). A particular focus is on RF front-end, transceiver, and analog-to-digital and digital-to-analog interfaces which are still a key bottleneck in CRS development.

DEVELOPMENT OF A SOFTWARE COMPLEX FOR INTELLIGENT TUNING OF OPERATING FREQUENCIES FOR COGNITIVE RADIO SYSTEMS

2021 ◽  
Author(s):  
Е.О. КАНДАУРОВА ◽  
Д.С. ЧИРОВ
Keyword(s):  
Cognitive Radio ◽  
Software Defined Radio ◽  
Experimental Studies ◽  
Spectrum Utilization ◽  
Radio System ◽  
Cognitive Radio System ◽  
Software Complex ◽  
Cognitive Radio Systems ◽  
Software Modules ◽  
Radio Systems

Представлено описание разработанных программных модулей интеллектуальной перестройки рабочих частот для системы когнитивного радио, в которых применяется ранее предложенный алгоритм анализа использования радиочастотного спектра. Также разработаны программные модули для взаимодействия с программно-определяемыми радиосистемами, такими как LimeSDR. Экспериментально показано, что использование алгоритма предсказания занятости частотных каналов позволяет сократить время оперативного сканирования спектра. A description of the developed software modules for intelligent tuning of operating frequencies for the cognitive radio system is presented. These software modules use the previously proposed algorithm of RF spectrum utilization analysis. Also, software modules have been developed for interacting with software-defined radio such as LimeSDR. Experimental studies have shown that the use of an algorithm for predicting the occupancy of frequency channels allows reducing the time of operational scanning of the spectrum.

scholarly journals Rényi Entropy-Based Spectrum Sensing in Mobile Cognitive Radio Networks Using Software Defined Radio

Entropy ◽  
2020 ◽  
Vol 22 (6) ◽  
pp. 626 ◽  
Author(s):  
Ernesto Cadena Muñoz ◽  
Luis Fernando Pedraza Martínez ◽  
Cesar Augusto Hernandez
Keyword(s):  
Cognitive Radio ◽  
Cognitive Radio Networks ◽  
Software Defined Radio ◽  
Orthogonal Frequency Division Multiplexing ◽  
Additive White Gaussian Noise ◽  
Radio Networks ◽  
Renyi Entropy ◽  
Rényi Entropy ◽  
Phone Call ◽  
Radio System

A very important task in Mobile Cognitive Radio Networks (MCRN) is to ensure that the system releases a given frequency when a Primary User (PU) is present, by maintaining the principle to not interfere with its activity within a cognitive radio system. Afterwards, a cognitive protocol must be set in order to change to another frequency channel that is available or shut down the service if there are no free channels to be found. The system must sense the frequency spectrum constantly through the energy detection method which is the most commonly used. However, this analysis takes place in the time domain and signals cannot be easily identified due to changes in modulation, power and distance from mobile users. The proposed system works with Gaussian Minimum Shift Keying (GMSK) and Orthogonal Frequency Division Multiplexing (OFDM) for systems from Global System for Mobile Communication (GSM) to 5G systems, the signals are analyzed in the frequency domain and the Rényi-Entropy method is used as a tool to distinguish the noise and the PU signal without prior knowledge of its features. The main contribution of this research is that uses a Software Defined Radio (SDR) system to implement a MCRN in order to measure the behavior of Primary and Secondary signals in both time and frequency using GNURadio and OpenBTS as software tools to allow a phone call service between two Secondary Users (SU). This allows to extract experimental results that are compared with simulations and theory using Rényi-entropy to detect signals from SU in GMSK and OFDM systems. It is concluded that the Rényi-Entropy detector has a higher performance than the conventional energy detector in the Additive White Gaussian Noise (AWGN) and Rayleigh channels. The system increases the detection probability (PD) to over 96% with a Signal to Noise Ratio (SNR) of 10dB and starting 5 dB below energy sensing levels.

Multiband OFDM for Cognitive Radio – A Way for Cyclostationary Detection and Interference Cancellation

2016 ◽  
Vol 6 (4) ◽  
pp. 1702
Author(s):  
Avila J ◽  
Thenmozhi K
Keyword(s):  
Cognitive Radio ◽  
Interference Cancellation ◽  
Software Defined Radio ◽  
Test Bed ◽  
Radio System ◽  
Labview Software ◽  
Free Spectrum ◽  
Wireless Environment ◽  
Cyclostationary Detection ◽  
Hardware Test

With the tremendous growth in wireless technology there has been a shortage in the spectrum utilized for certain applications while some spectrum remains idle. To overcome this problem and for the efficient utilization of the spectrum cognitive radio is the suitable solution.Multiband OFDM can be easily modeled as cognitive radio, a technology that is employed for utilizing the available spectrum in the most efficient way. Since sensing of the free spectrum for detecting the arrival of the primary users is the foremost job of cognitive, here cyclostationary based spectrum sensing is carried out. Its performance is investigated using universal software defined radio peripheral (USRP) kit which is the hardware test bed for the cognitive radio system. Results are shown using Labview software. Further to mitigate the interference between the primary and cognitive users a modified intrusion elimination (AIC) algorithm had been proposed which in turn ensures the coexistence of both the users in the same wireless environment.

scholarly journals Multiband OFDM for Cognitive Radio – A Way for Cyclostationary Detection and Interference Cancellation

2016 ◽  
Vol 6 (4) ◽  
pp. 1702
Author(s):  
Avila J ◽  
Thenmozhi K
Keyword(s):  
Cognitive Radio ◽  
Interference Cancellation ◽  
Software Defined Radio ◽  
Test Bed ◽  
Radio System ◽  
Labview Software ◽  
Free Spectrum ◽  
Wireless Environment ◽  
Cyclostationary Detection ◽  
Hardware Test

With the tremendous growth in wireless technology there has been a shortage in the spectrum utilized for certain applications while some spectrum remains idle. To overcome this problem and for the efficient utilization of the spectrum cognitive radio is the suitable solution.Multiband OFDM can be easily modeled as cognitive radio, a technology that is employed for utilizing the available spectrum in the most efficient way. Since sensing of the free spectrum for detecting the arrival of the primary users is the foremost job of cognitive, here cyclostationary based spectrum sensing is carried out. Its performance is investigated using universal software defined radio peripheral (USRP) kit which is the hardware test bed for the cognitive radio system. Results are shown using Labview software. Further to mitigate the interference between the primary and cognitive users a modified intrusion elimination (AIC) algorithm had been proposed which in turn ensures the coexistence of both the users in the same wireless environment.

Performance of Chaotic CDMA System implemented on Software-Defined Radio System

2014 ◽  
Vol 1 ◽  
pp. 662-665
Author(s):  
Hisashi Watanabe ◽  
Yuichi Omori ◽  
Mikio Hasegawa ◽  
Kazuyuki Aihara
Keyword(s):  
Software Defined Radio ◽  
Cdma System ◽  
Radio System

scholarly journals Secrecy Outage Analysis on Underlay Cognitive Radio System With Full-Duplex Secondary User

IEEE Access ◽  
2017 ◽  
Vol 5 ◽  
pp. 25696-25705 ◽  
Author(s):  
Chao Zhang ◽  
Danyang Wang ◽  
Jia Ye ◽  
Hongjiang Lei ◽  
Jiliang Zhang ◽  
...  
Keyword(s):  
Cognitive Radio ◽  
Secondary User ◽  
Full Duplex ◽  
Radio System ◽  
Cognitive Radio System ◽  
Underlay Cognitive Radio ◽  
Secrecy Outage ◽  
Outage Analysis
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