Wall Clutter Suppression Method Based on Amplitude Coherence Factor for MIMO Through-the-Wall Radar

Multiple-input multiple-output (MIMO) through-the-wall radar (TWR) is utilized for target detection under indoor environments. However, target signals are often overshadowed by wall clutter. Existed clutter suppression methods predominantly work effectively for TWR under synthetic aperture mode, with limited approaches for MIMO TWR. Therefore, this letter introduces amplitude coherence factor (ACF) to suppress the wall clutter. In the proposed method, the ACF is denoted by using the variance across all transmit-receive channels, which directly reflects the correlation of echo amplitudes in each pixel. Then, weights based on the ACF are assigned to the image of raw TWR image. The performance of ACF is validated by simulation and experimental results.