Multiantenna Spectrum Sensing in the Presence of Multiple Primary Users over Fading and Nonfading Channels

Dayan Adionel Guimarães,Rausley Adriano Amaral De Souza,Guilherme Pedro Aquino

doi:10.1155/2015/165935

Dayan Adionel Guimarães, Rausley Adriano Amaral De Souza + Show 1 more

Open Access

https://doi.org/10.1155/2015/165935

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Abstract

The basis of this paper is Wei and Tirkkonen, 2012, in which expressions for the key performance metrics of the sphericity test applied to the multiantenna cooperative spectrum sensing of multiple primary transmitters in cognitive radio networks over nonfading channels are provided. The false alarm and the detection probabilities were derived in Wei and Tirkkonen, 2012, based on approximations obtained by matching the moments of the test statistics to the Beta distribution. In this paper we show that the model adopted in Wei and Tirkkonen, 2012, does not apply directly to fading channels, yet being considerably inaccurate for some system parameters and channel conditions. Nevertheless, we show that the original expressions from Wei and Tirkkonen, 2012, can be simply and accurately applied to a modified model that considers fixed or time-varying channels with any fading statistic. We also analyze the performance of the sphericity test and other competing detectors with a varying number of primary transmitters, considering different situations in terms of the channel gains and channel dynamics. Based on our results, we correct several interpretations from Wei and Tirkkonen, 2012, in what concerns the performance of the detectors, both over a fixed-gain additive white Gaussian noise channel and over a time-varying Rayleigh fading channel.

Highlights

The cognitive radio (CR) [1] concept has come as a promising solution for alleviating the problem of spectrum scarcity in wireless communication systems and is one of the key enabling technologies of the fifth-generation (5G) of these systems [2]
We have analyzed the performance of the sphericity test and other competing detectors with a varying number of primary transmitters, considering different situations in terms of the channel gains and channel dynamics
Based on a bunch of new results, we have corrected several interpretations from [4] in what concerns the performance of the detectors, over a fixed-gain additive white Gaussian noise channel, and over a time-varying Rayleigh fading channel

Summary

Introduction

The cognitive radio (CR) [1] concept has come as a promising solution for alleviating the problem of spectrum scarcity in wireless communication systems and is one of the key enabling technologies of the fifth-generation (5G) of these systems [2]. In this subsection we provide some counterexamples in which the theoretical results obtained from the expressions in [4] do not match empirical results, due to some inaccuracy of the Beta approximation under H1 This is an evidence that the Beta approximation under the hypothesis H1 is not accurate for all system parameters, whereas it is always accurate under H0.

Effect of the Channel Normalization and the Channel Dynamics

Performance of the ST Detector and Other Competing Detectors

Conclusions