Sensing techniques for Cognitive Radio - State of the art and trends
This document was initiated in the framework of the IEEE Standards Coordinating Committee 411
(Dynamic Spectrum Access Networks) within the 1900.6 Working group (Spectrum Sensing
Interfaces and Data Structures for Dynamic Spectrum Access and other Advanced Radio
This documents aims at identifying the spectrum sensing techniques being used of researched and that
may be considered for the 1900.6 standardization activities. Although it gathers State of the Art
material, this document does not aim at being a scientific paper in that regard that the equations are
not always justified or demonstrated. However, it provides sufficient information to have a good
perspective on the problems to solve, the techniques that have been proposed and the one that may
emerge in the next few years. Links to a wide bibliography section is systematically provided to
enable the reader to get more technical details.
Since 1900.6 deals with Spectrum Sensing, the focus is put on this issue in this paper.
Section 3 deals with single sensor spectrum sensing. In this section, the level of a priori knowledge
about the signal to detect is discussed and different techniques are presented according to this
Section 4 is somehow an extension of section 3 in which the problem is extended to the identification
of systems in presence through the estimation of key specific parameters. The example of OFDM
signal is highlighted for which sub-carrier spacing one of the parameters considered to differentiate
Section 5 extends the scope of section 3 by considering several sensors. Cooperative sensing and
collaborative sensing are discussed in this section.
Section 6 briefly discussed the estimation of the load of a system. This information may be a
determining parameter to decide on the network to get connected to.
Section 7 provides application examples of the spectrum sensing techniques described previously in
scenarios involving standardized wireless systems. Performance of the techniques is discussed.
Section 8 reminds that a cognitive radio often has to sense information that is not captured by
spectrum sensing. For instance, battery lifetime may be relevant for decision making in battery
multi-sensor spectrum sensing