A Search Space-Based Clutter Mitigation Algorithm for ISAC Systems

For integrated sensing and communication (ISAC) systems, clutter refers to the received echoes from stationary scatterers other than targets of interest. Clutter echoes are usually several orders of magnitude larger than target echoes due to their large radar cross-section. Therefore, the dim target peaks in the radar image might be overshadowed by the clutter return. This problem poses a critical challenge to moving target detection and leads to sensing degradation problems such as "missed detection" and "false alarm". This paper proposes a signal processing algorithm to mitigate clutter return in radar images. The main idea of the algorithm is to remove as much of the clutter return as possible from the received sensing signal by searching the magnitude and range for each clutter scatterer in a search space and subtracting the clutter components from the original sensing signal matrix before applying the fast Fourier transform (FFT) calculation. Simulation results demonstrate that the proposed algorithm can mitigate the clutter return 20 dB with acceptable computational complexity.