21-08-2014, 03:54 PM
Cognitive radio is a paradigm for wireless communication in which either a network or a wireless node changes its transmission or reception parameters to communicate efficiently avoiding interference with licensed or unlicensed users. It refers to wireless architectures in which a communication system does not operate in a fixed assigned band, but rather searches and finds an appropriate band in which to operate. The demand for wireless connectivity and crowding of unlicensed spectra has pushed the regulatory agencies to be ever more aggressive in providing new ways to use spectra. Use of spectrum efficiently is one of the major aims of the growing technology. Cognitive radio aims at satisfying this aim by automatically sensing the spectrum and helps in sharing the spectrum for efficient use of the resource. This paper gives an overview of the implementation issues during sensing the spectrum , a brief description of the causes of interference in cognitive radio network and ways of measuring interference temperature and its various types, dynamic selection of operating frequency and research agenda in implementation of cognitive radio . Measurement of the capacity and frequency selection in cognitive radio network are also being discussed in this paper.