An Efficient Blind Spectrum Sensing Scheme for OFDM Based CR in Multipath Environment

Cognitive radio technology is an emerging solution to avoid spectrum underutilization. Cognitive radio obtains and adjusts its parameters according to its surrounding environment. Cognitive radio involves the task of spectrum sensing, spectrum sharing, spectrum management etc. Spectrum sensing is first and most important task in case of cognitive radio. Due to major challenge of detecting signals in low signal to noise ratio environment, spectrum sensing is important task. In this paper an algorithm based on the property of OFDM signals i.e. cyclic prefix correlation coefficient (CPCC) is given. This algorithm performs well for environment without multipath. So, by taking multipath environment into consideration, multipath based GLRT algorithm is also obtained. Further performance improvement is achieved by combining both these algorithms.