Fast and accurate primary user detection with machine learning techniques for cognitive radio networks

Abstract

<p class="IJASEITAbtract"><span>Spectrum decision is an important and crucial task for the secondary user to avail the unlicensed spectrum for transmission. Managing the spectrum is an efficient one for spectrum sensing. Determining the primary user presence in the spectrum is an essential work for using the licensed spectrum of primary user. The information which lacks in managing the spectrum are the information about the primary user presence, accuracy in determining the existence of user in the spectrum, the cost for computation and difficult in finding the user in low signal-to noise ratio (SNR) values. The proposed system overcomes the above limitations. In the proposed system, the various techniques of machine learning like decision tree, support vector machines, naive bayes, ensemble based trees, nearest neighbour’s and logistic regression are used for testing the algorithm. As a first step, the spectrum sensing is done in two stages with Orthogonal Frequency Division Multiplexing and Energy Detection algorithm at the various values of SNR. The results generated from the above algorithm is used for database generation. Next, the different machine learning techniques are trained and compared for the results produced by different algorithms with the characteristics like speed, time taken for training and accuracy in prediction. The accuracy and finding the presence of the user in the spectrum at low SNR values are achieved by all the algorithms. The computation cost of the algorithm differs from each other. Among the tested techniques, k-nearest neighbour (KNN) algorithm produces the better performance in a minimized time.</span></p>

Free-space optical channel performance under atmospheric losses using orthogonal frequency division multiplexing

“…Various papers have examined the scintillation of the optical beam, which is the primary cause of pointing errors in FSO systems because of the line-of-sight nature. DL and artificial intelligence (AI) algorithms provide the most economical way to overcome this problem [17], [18], and these algorithms are applied in broad applications like self-driving cars, visual recognition, healthcare [19], [20]. Different deep learning models can be applied to different strengths of FSO turbulent channels to detect OOK modulated signals [21].…”