Signal processing system and signal processing method

A signal processing system comprising:

• a digital unit connected to a core system and configured to process a radio digital signal;
• and
• a plurality of radio units physically separated from the digital unit, configured to convert and amplify a digital signal received from the digital unit and transmit the amplified signal to a terminal based on a multi-input multi-output (MIMO) using two antennas, and receive a signal transmitted from a terminal based on MIMO using the two antennas and deliver the received signal to the digital unit,
• wherein two radio units, among the plurality of radio units, transmit data signals by using a cell-specific reference signal to a terminal located within a cell, rather than being located in a cell boundary area, under the control of the digital unit, and with respect to a terminal located in the cell boundary area, the two radio units transmit the same data signal by using a user-specific reference signal.

A method in which a digital unit, which processes a radio signal digital, processes signals from a plurality of radio units, which are installed in a service area to process radio signals and which transmit and receive signals to and from a terminal based on multi-input multi-output (MIMO) using two antennas, the method comprising:

• determining whether the terminal is adjacent to a cell within a boundary area between cells to which two radio units belong and whether the terminal is located in an overlap area within the boundary area, on the basis of signal strength values received from the two radio units, among the plurality of radio units;
• when the terminal is adjacent to a cell within the boundary area, controlling a radio unit of the adjacent cell to transmit a data signal by using a user-specific reference signal;
• and
• when the terminal is located in the overlap area within the boundary area, controlling the two radio units to transmit the same data signal by using a user-specific reference signal.