Spectral occupation measurements and blind standard recognition sensor for cognitive radio networks

Abstract

Cognitive radio has been claimed to be a hopeful solution to the existing conflicts between spectrum demand growth and spectrum underutilization. The basic underlying idea of cognitive radio is to allow unlicensed users to access in an opportunistic and non-interfering manner some licensed bands temporarily unoccupied by licensed users. The cognitive radio concept relies on two basic premises: the current spectrum underutilization, which has been demonstrated in some spectrum measurements campaigns, and the ability of unlicensed users to effectively detect and identify the presence of different licensed technologies in order not to cause harmful interference. In this context, this paper reports the joint work on these two areas that is currently being carried out in the framework of the FP7 Network of Excellence in Wireless COMmunications (NEWCOM++). Concretely, this paper presents spectrum occupancy measurements conducted in the frequency range from 75 MHz to 7075 MHz that demonstrate the low degree to which spectrum is currently used in an urban outdoor environment and also describes the blind standard recognition sensor concept, a sensor embedded in a cognitive radio equipment to enable the identification of many commercial wireless standards without the need to connect to any network. The joint research in both areas is a key step in promoting and validating the idea of dynamic spectrum usage. © 2009 IEEE

Spectrum occupancy investigation: Measurements in South Africa

“…The first root is assumed to represent the peak value P N of the noise component and the second root, the peak value P S of the signal component of (7). The sample at the first root is used to estimate the mean µ N of the noise distribution and the sample at the second root to estimate the mean µ S of the signal distribution.…”

A Radio Spectrum Measurement Platform for Spectrum Surveying in Cognitive Radio

“…As mentioned in Section 1, the developed platform has successfully been employed to conduct extensive spectrum occupancy measurement campaigns [8,9,21] and empirical studies [22] in the context of DSA/CR. This section presents, as an illustrative example of operational measurements, results of a recent measurement campaign.…”

“…Spectrum measurements are essential for a proper understanding of real spectrum usage and can support regulatory organisms in taking actions to improve the use of the precious spectral resources. A good example of this is the important number of recent spectrum measurement campaigns that have been carried out all over the world in order to determine the degree to which allocated spectrum bands are used in real wireless communication systems [2][3][4][5][6][7][8][9][10][11][12][13][14]. Measurement results have demonstrated that spectrum is currently underutilized as a result of the owned spectrum allocation policy in use since the early days of modern radio communications.…”

“…This detector averages the power levels observed within one frequency bin in order to provide a representative power level for each frequency bin. As mentioned in section 4, the internal pre-amplifier is deactivated for measurements below 3 GHz since this region of the spectrum is highly populated [8,9], often by high-power transmitters that may cause overloading problems. For spectrum bands above 3 GHz, spectrum is used more sparsely and the more intense signal attenuation caused by these higher frequencies results in the reception of lower power levels.…”

“…The developed platform constitutes a very flexible measurement tool combining a powerful Radio Frequency (RF) measurement system with intelligent computer control and data processing. This platform has successfully been employed to conduct extensive spectrum occupancy measurement campaigns [8,9,21] and empirical studies [22] in the context of DSA/CR. While some previous works have been based on similar measurement designs, the focus of such works has been on measurement results rather on the description of the employed measurement configuration.…”