detection of phase code modulated lpi radar signals using time-frequency distributions and comparing with roc of lpi radar receiver

nowadays, in the modern wars, radars have faced with many threats. therefore, low probability of interception (lpi) capability is considered as an important factor in military radars. on the other hand, research on the interception of their signals is started and so far several methods are presented for detection of these signals. by using of time-frequency techniques, we can estimate signal parameters such as carrier frequency, modulation bandwidth, and its period, in addition of detection of lpi signal. in this paper, the proposed detector architecture uses time-frequency techniques including wigner-ville and choi- williams distributions for detection of some lpi radar waveforms with phase shift keying (psk) modulation such as barker code, frank code and p1-p4 codes to compare an interception receiver and matched-filter detector in lpi radar receiver with assumption of additive white gaussian noise (awgn). then, power function graphs for proposed intercept receiver and lpi radar receiver are depicted and compared, which indicate that we obtain desirable results by using of this technique in the intercept receiver.