An Interference Elimination and Coherent Accumulation Method for Narrowband Aiming Jamming Based on FCM-IAA

Narrowband aiming jammer interferes with the normal work of the radar by transmitting high-power noise signals to realize the suppression of the target echo signal. Frequency agile signals with random inter-pulse carrier frequency hopping can reduce the coverage of narrowband aiming jamming on the target echo effectively, and exhibit strong anti-jamming capability. However, due to its inter-pulse carrier frequency hopping, the traditional phase reference accumulation method is difficult to apply. Aiming at the above problems, this paper proposes an interference elimination and coherent accumulation method for narrowband aiming jamming based on Fuzzy C-means and Iterative Adaptive Approach (FCM-IAA) algorithm. For the frequency agile signal interfered by narrowband aiming jamming, pulse compression is used at first and then extract the mean and variance characteristics based on the pulse compression results. Subsequently, the Fuzzy C-means (FCM) algorithm is employed to determine whether each pulse echo is affected by jamming and eliminate any jammed pulses accordingly. For frequency agile signals with frequency points missing, we use the Iterative Adaptive Approach (IAA) to realize super-resolution estimation of target range-velocity two-dimensional parameters, and solve the problem of coherent processing caused by inter-pulse carrier frequency agile. Finally, simulation results demonstrate that compared with traditional algorithms, the proposed algorithm offers a lower coherence processing floor which can achieve weak target detection and have a higher detection probability in the case of low Signal-to-Noise Ratio (SNR) and high Jamming Coverage Rate (JCR).