The 5G single-channel frequency-shift MIMO DAS consists of three parts: the main unit (newly installed), the coverage unit (replacing the original antennas), and the DC coupler (replacing the original coupler).The main unit down-converts a 2.6G signal and multiplexes it with the through-path signals (including the non-converted 2.6G signal and existing 2G/3G/4G signals), feeding them into the single-channel DAS.The frequency-shifted signal is restored to a 2.6G signal by the coverage unit and then combined with the through-path signals for unified coverage