Effect of jammer signal on stepped frequency PAM4 radar waveforms

摘要

In a RADAR system, the introduction of a jamming signal in the received signal path makes the distinguishing of targets a challenging task. The most frequently used signals in radar are of the continuous and pulsed wave types. When using pulsed radar signals, modification of the waveform is required in the radar operations for improved target sensitivity and range resolution. In addition, for the monostatic radar case, two antennas are used, one each at the transmitter and receiver sides. In the work discussed here, along with the monostatic model radar signals such as the stepped frequency waveform (SFW) and the 4-level pulse amplitude modulation (PAM4) waveform are considered, and they are observed to be powerful modulation techniques capable of avoiding jamming. SFW is used to obtain high range resolution, while PAM4 is used to obtain lower bandwidth. Combination of SFW and PAM4 provides a compound pulsed radar modulation technique which shows efficient results in target detection. To examine the performance of SFW and PAM4, simulation is done using a monostatic radar model under different conditions such as multipath propagation, fading and jamming. The compound pulsed radar modulation techniques are shown as being able to detect targets in the presence of a jamming signal. The results are analyzed in terms of the critical radar parameters such as range-speed response, burn-through range, cross-over range and signal-jammer noise ratio.