Iterative modified threshold method based on EMD for interference suppression in FMCW radars

The mutual interference between frequency-modulated continuous-wave (FMCW) automotive radars increases the noise floor, even submerges the information of targets, and creates ghost targets. To reduce the impact of the mutual interference between automotive radars and improve the detection performance, this study proposes an iterative modified threshold method based on empirical mode decomposition (IMT-EMD) for interference suppression in FMCW automotive radars. The IMT-EMD uses the consecutive mean square error algorithm to determine the interference-dominated components after decomposing, which are adjusted according to the modified threshold. The proposed method can mitigate the interference effectively while keeping the signals continuous and reducing the loss of useful signals as much as possible. To further improve the detection performance, the authors used the proposed algorithm iteratively. The improvement of the signal-to-noise ratio of targets will converge to an optimal value when the number of iterations reaches a certain value after using the IMT-EMD. The results of simulation and field experiments showed that the proposed algorithm has a satisfactory effect on interference suppression and improves detection performance.