New Researches in Electronic Defense Systems

New Researches in Electronic Defense Systems

Blind Separation of Multiple Asynchronous FH Signals with Frequency Interference Based on MWC and STF Distributions

Document Type : Original Article

Authors
Morteza Babaei 1
Mohsen Rezaee Kheirabadi 2
Mohammadreza Motedayen 3
1 Electronic Warfare Department, Faculty of Electrical Engineering, Communications and Electronic Warfare, Imam Hossein University, Tehran, Iran
2 ICT Research Institute, Tehran, Iran
3 Imam Hossein Comprehensive University,Tehran, Iran
10.22034/joeds.2025.498619.1078
Abstract
In most methods of Multiple signal separation, the time and frequency information of the signal are considered unique to an environmental source. However, in the actual environment, there is time and frequency interference between the signals received from several environmental sources at the same time. This article investigates the problem of separating and estimating the parameters of multiple frequency hopping (FH) wideband signals, non-synchronous, with the same hopping rate and having time-frequency interference using narrow-band receivers .The proposed method consists of two steps: in the first step, after receiving several FH signals by band-limited receivers, the number of ambient FH signals, with two estimators with good accuracy and signal-to-noise ratio (SNR) is estimated, and in the second step, the parameters of each signal are deduced in the space-time-frequency (STF) domain using the difference of STF distributions and the joint diagonal (JD) method. By carefully choosing the number of elements in uniform linear arrays (ULA), the number of sources werecorrectly estimated under conditions of SNR higher than -4dB. The simulation results indicate that the proposed algorithm, as the sampling rate of the modulated wideband converter (MWC), has lower computational complexity than existing algorithms.
Keywords
Array processing
blind
time-frequency space distribution
frequency hopping
frequency interference