Spectrally Efficient Frequency Hopping System Design under Hostile Jamming

This paper considers spectrally efficient anti-jamming system design based on message-driven frequency hopping (MDFH). As a highly efficient frequency hopping scheme, MDFH is particularly robust under strong jamming. However, disguised jamming from sources of similar power strength can cause performance losses. To overcome this drawback, in this paper, we first propose an anti-jamming MDFH (AJ-MDFH) system. The main idea is to transmit an ID sequence along with the information stream. The ID sequence is generated through a cryptographic algorithm using the shared secret between the transmitter and the receiver. It is then exploited by the receiver for effective signal detection and extraction. It is shown that AJ-MDFH is not only robust under strong jamming, but can also effectively reduce the performance degradation caused by disguised jamming. Second, we extend AJ-MDFH to a multi-carrier scheme for higher spectral efficiency and more robust jamming resistance. Based on secure group generation, MC-AJ-MDFH can increase the system efficiency and jamming resistance significantly through jamming randomization and enriched frequency diversity. Moreover, by assigning different carriers to different users, MC-AJ-MDFH can readily be used as a collision-free multiple access system. Simulation examples are provided to illustrate the performance of the proposed approaches.