Target recognition and discrimination based on multiple-frequencies LFM signal with subcarrier hopping

An anti-deception jamming technique is proposed for moving target indication in a pulse-Doppler (PD) radar. The deceive targets are produced by digital radio frequency memory, which tries to pull off the range and velocity gates of real targets. Similar to orthogonal frequency division multiplexing, we use different sets of orthogonal sub-carriers in consecutive coherent pulse intervals (CPIs). By changing sub-carriers in different CPIs, we show that the deceive targets appear as interference in receiving signals. The generalized likelihood ratio test is used for detection and discrimination of real targets. The performance of the proposed method is achieved analytically and by simulations. Furthermore, we implement a hardware block using a TMS6416-DSK DSP for a PD radar prototype exploiting the proposed algorithm to deception discrimination. The presented results demonstrate the good accordance with theoretical predictions.