Due to the requirements and developments of personal mobile communications for the past several decades, all kinds of global and local wireless/wire and military/civil communications systems are developing flourishingly in accordance with the novelties and breakthrough of all related electronic and communication techniques. Nevertheless, there still exist mutual interference phenomena and problems among many communication systems even with many standards specified, especially when the jamming sources are intentional, which try to effect the private information convey of the whole communications system. Therefore, it’s of particular importance to mitigate or decrease the effects of jamming. Furthermore, it’s a very important research topic to evaluate the performance of anti-jamming (AJ). In this thesis, we will focus on the simulation and analysis of anti-jamming topic. Moreover, a satellite communications system is illustrated to study and evaluate its AJ performances.