Performance Prediction of OFDM Based Cognitive Radio for Next Generation Networking Capabilities

Abstract

As a pioneering technology, next generation of mobile networks would overcome many problems of daily life activities. This new technology has many challenges that are tried to be destroyed. In this regard, to optimize the utilization of the allowed spectrum, an essential tool such as cognitive radio (CR) must be employed. It provides opportunity to use spectrum in strategic manner to both licensed and unlicensed users in such a way that the available spectrum is exploited in an efficient strategy. Meanwhile, the orthogonal frequency division multiplexing (OFDM) multicarrier transmission mechanism represents one of the more familiar techniques that are widely applied in free space systems of communication. Since this algorithm has the capability of satisfying the prime aspect of CR, which is associated with locally exploiting the unused spectrum autonomously, OFDM procedure is investigated as a CR system’s candidate. In other words, it is of interest to study its behavior when it is combined with CR technology. Here, our goal is to treat the problem of spectrum sensing techniques in conjunction with OFDM signal. Simulation results show that OFDM spectral correlation can be enhanced via varying the number of samples. Also, OFDM pilot is mandatory and acts as a flag for OFDM frames. So, it is of importance to boost it for better detection. Additionally, the probability of detection (Pd) is estimated for different values of signal strength when the false alarm probability (Pf) is fixed. Moreover, receiver operating characteristic, which is the variation of Pd as a function of Pf for a fixed SNR, is drawn for two cases; theoretical and simulated. It is found that the two cases are of high degree of coincidence.