Signal Detection and Jammer Localization in Multipath Channels for Frequency Hopping Communications

摘要

Frequency hopping (FH) is the prevailing spread spectrum method in military communications, largely due to its low probability of detection and interception. In this project we developed a novel signal processing scheme for code-blind reception of multiple frequency hopped transmissions over multipath channels. This technique is based on the principle of dynamic programming and/or expectation-maximization, coupled with multidimensional harmonic and low- rank analysis. It is able to jointly estimate hop timing, hop frequency, and direction-of-arrival (DOA) of multiple FH signals in the presence of frequency collisions, without the knowledge of signal hop patterns. The method can also be used to obtain locate information and operation characteristics of active FH jammers. The associated identifiability of 2-D and multidimensional frequency estimation is also investigated.