A novel digital frequency de-hopper using bandpass sampling technique

In military and defense communication systems, frequency hopping technique is considered one of the most effective electronic protective measurements to avoid jamming. Frequency hopping is performed by rapidly changing carrier frequencies during the communication. With the rapid growth of frequency hopped wireless networks, frequency detection and jamming has become a challenging task. In this paper, we propose a novel algorithm for frequency detection in a frequency hopping system, by using bandpass sampling technique. Bandpass sampling downsamples the signal below the Nyquist frequency as a result of which, copies of signal are received at frequencies around carrier frequency which are integral multiple of the sampling frequency. The resulting copies are then used to detect the carrier frequency. The performance of the proposed algorithm is analyzed in Stanford University Interim (SUI) channel models. The proposed technique provides fast frequency detection with low probability of error and low computational complexity.