Detection of In-band Hidden Interference Based on Subtractive Signal Cancellation
Guoqing Xu · Journal of Spacecraft TT&C Technology · 2012
An in-band hidden interference detection technology is proposed for on-line monitoring of communication signals.The desired signal is reconstructed with demodulated data and it is kept correlated with the received signal in time,amplitude and phase through delay estimation and adaptive filtering.Finally,the estimated signal is removed from the received signal to get the in-band signal based on subtractive signal cancellation.The method can detect the hidden interference and noise without interruption of the desired carrier.Simulation results show that the similarity coefficient between the expected signal and its original one and that between the detected interference and its original one are both higher than 0.9 when the signal to interference ratio is no less than 6 dB and the signal to noise ratio is no less than 3 dB.As a result,the inference is accurately extracted.Meanwhile,the constellation diagram of the mixed signal converges obviously when the detected interference is removed.