IOSR Journal of Engineering
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. The OFDM based cognitive radio system is used for detection of signals. But in OFDM systems the performance of the signal is greatly affected by narrowband interference signals. In the proposed method, expectation maximization algorithm is used to detect signal even in the uncertainty condition. The literature survey discusses all the existing interference cancellation techniques.