The significant increase in BER occurs because the static scatterers provide beneficial multipath contributions that improve the effective channel gain. In the original example, these static reflections add diversity and can constructively interfere with the direct path, which enhances the overall SNR. When you set their reflection coefficients to zero, you remove these helpful multipath components, leaving only the less favorable dynamic paths. This results in a much weaker effective channel and, consequently, a dramatic increase in the BER.
Follow me so you can message me anytime with future MATLAB questions. If this helps, please accept the answer as well.
