A Next Generation Chaotic Time Hopping System for Anti-Jamming Communications

Abstract

Since the intentional electromagnetic disturbances are frequently performed for malicious purposes, the importance of anti-jamming(AJ) technology is increasing. In this thesis, we first proposed a next generation communication system for improvement of AJ performance. Furthermore, we proposed two more enhanced systems for improvement of data rate, and for improvement of bit error rate (BER) performance by machine learning based scheme. First, we propose a TH-NRDCSK system for AJ performance. Time hopping spread spectrum (THSS) system and chaotic system have been studied as candidates of the AJ systems with substantial advantages. However, THSS systems suffer from the strict time synchronization prerequisite. In order to overcome the shortcomings of the THSS system and utilize the profits of the non-coherent chaotic system, a novel TH-NRDCSK system is proposed to enhance the BER performance of the conventional non-coherent THSS system and relieve the strict synchronization issue of coherent THSS systems. Then, we analyze the performance of the proposed system under additive white Gaussian noise (AWGN) channel and four jamming environment. In addition, we implement the simulation to demonstrate the consistency of the analysis and the simulation results and to disclose the effects of the system parameters on system’s AJ performance. Moreover, the performance of the proposed system is compared to that of conventional counterparts to look at the benefits of integrating chaotic and THSS systems. The simulation results show that the proposed system significantly outperforms conventional counterparts in a practical environment. Secondly, we propose a novel E-TH-NRDCSK system to increase the data rate and reduce the complexity of the TH-NRDCSK system by applying time inversion operation. Moreover, we analyze the system performance under the Gaussian noise channel and derive the BER closed form expression. Furthermore, we show the consistency of the analysis and the simulation results and outstanding AJ performance under a sweep jamming environment compared to conventional counterparts. Finally, we also propose CNN-based TH-NRDCSK system to improve the BER performance. We define the TH-NRDCSK system model and CNN structure under the jamming environments. Moreover, overall CNN based TH-NRDCSK system and scenarios of the communication are illustrated. The simulation results demonstrate that the jamming classification help to improve the AJ performance by selecting the system parameters adaptively and appropriately according to the classified jamming type.