Loading [a11y]/accessibility-menu.js
Cyclostationarity-based versus eigenvalues-based algorithms for spectrum sensing in cognitive radio systems: Experimental evaluation using GNU radio and USRP | IEEE Conference Publication | IEEE Xplore

Cyclostationarity-based versus eigenvalues-based algorithms for spectrum sensing in cognitive radio systems: Experimental evaluation using GNU radio and USRP


Abstract:

Spectrum sensing is a fundamental problem in cognitive radio systems. Its main objective is to reliably detect signals from licensed primary users to avoid harmful interf...Show More

Abstract:

Spectrum sensing is a fundamental problem in cognitive radio systems. Its main objective is to reliably detect signals from licensed primary users to avoid harmful interference. As a first step toward building a large-scale cognitive radio network testbed, we propose to investigate experimentally the performance of three blind spectrum sensing algorithms. Using random matrix theory to the covariance matrix of signals received at the secondary users, the first two sensing algorithms base their decision statistics on the maximum to minimum eigenvalue ratio and the sum of the eigenvalues to minimum eigenvalue ratio, respectively. However, the third algorithm is based on cyclostationary feature detection and it uses the symmetry property of cyclic autocorrelation function as a decision policy. These spectrum sensing algorithms are blind in the sense that no knowledge of the received signals is available. Moreover, they are robust against noise uncertainty. In this paper, we implement spectrum sensing in real environment and the performance of these three algorithms is conducted using the GNU-Radio framework and the universal software radio peripheral (USRP) platforms. The results of the evaluation reveal that cyclostationary feature detector is effective in finite sample-size settings, and the gain in terms of the SNR with respect to eigenvalues-based detectors to achieve Pfa (probability of false alarm) = 0.08 is at least 4 dB.
Date of Conference: 19-21 October 2015
Date Added to IEEE Xplore: 07 December 2015
ISBN Information:
Conference Location: Abu Dhabi, United Arab Emirates

I. Introduction

Spectrum sensing to detect the presence of primary user transmissions is a crucial task for a cognitive radio system, which opportunistically accesses the spectrum once an empty subband is detected. Two basic approaches to spectrum sharing have been considered [1]: spectrum overlay and spectrum underlay. According to the spectrum overlay approach, the secondary users sense and identify unused frequency bands and use them for communication purposes. Thus, the secondary users (SU) are responsible for detecting the unused bands and they should vacate the spectrum as soon as the primary user begins its activities [2]. The underlay approach imposes constraints on the secondary users' transmission power level so that it can operates below the noise floor of primary users. In this paper we focus on the experimental evaluation of the overlay spectrum sharing.

References

References is not available for this document.