Interference Mitigation in cognitive Radio Communication Systems Based on Wavelet Transform

One of the destructive factors in telecommunication and radar systems is intentional interference. Intentional interference is created by using jammer to destroy the enemy's communication and radar systems. If the intentional interference is not reduced well, the efficiency of the telecommunication system will be completely disrupted. Jammers purposefully interfere and affect the optimal performance of the system. The NLMS adaptive algorithm is one of the effective algorithms in eliminating intentional interference. In this paper, a new algorithm for eliminating intentional interference in cognitive radio systems using wavelet transform is presented. In the simulations, a 25-user cognitive radio system (as a victim network) is used in the vicinity of a network of primary users with Markov channel functionality. Considering eleven different scenarios, the performance of the proposed algorithm is investigated. To evaluate the performance of the proposed algorithm, the criterion of successful transmission of information in terms of signal to jammer ratio in each of the scenarios is discussed. According to the simulation results, the proposed algorithm, compared to the adaptive algorithm (NLMS), shows a significant improvement. According to the results, the proposed algorithm shows a 13% improvement in successful transmission at SJR=5dB compared to the NLMS adaptive algorithm