The 5G single-path frequency-shift MIMO DAS system consists of three components: the main unit (newly built), the coverage unit (replacing the original antennas), and the power divider coupler (replacing the original coupler). The main unit downshifts one 2.6G signal and combines it with the bypass signal (non-frequency-shifted 2.6G and the original 2/3/4G signals) into a single-path DAS. The frequency-shifted signal is processed by the coverage unit, restored to the 2.6G signal, and then combined with the bypass signal for unified coverage.