O-RAN remote unit system for multi-carrier and multi-frequency band based on O-RAN standard

An open radio access network (O-RAN) radio unit (RU) (O-RU) system for multiple carriers and multiple frequency bands based on an O-RAN standard, the O-RAN RU system comprising an O-RU digital part and a plurality of smart antenna modules configured to support multiple frequency bands and multiple carriers,

• wherein
• the O-RU digital part comprises:
• a fronthaul transport layer configured to transmit and receive a signal to and from a distributed unit (DU);
• a low physical layer (Low PHY) configured to process a signal according to an O-RAN division standard received through the fronthaul transport layer;
• a digital front end (DFE) configured to perform digital-to-analog conversion on a signal transmitted by the low physical layer;
• and
• a first radio frequency (RF) interface configured to transmit and receive a signal to and from the smart antenna module,
• each of the plurality of smart antenna modules comprises:
• a second RF interface configured to transmit and receive a signal to and from the O-RU digital part;
• and
• a radio frequency front end (RF FE) connected between one or more antennas and the second RF interface and configured to process an RF signal, and
• the first RF interface and the second RF interface are connected by a transmission line,
• wherein the O-RU digital part comprises a first controller for controlling the fronthaul transport layer, the low physical layer, the DFE, and the first RF interface, and the smart antenna module comprises a second controller for controlling the second RF interface and the RF FE, and
• wherein the second controller of each of the plurality of smart antenna modules independently controls a signal output level of the respective smart antenna module and all information of the second controller is transmitted to the first controller such that the first controller controls the plurality of smart antenna modules and transmits information about each of the plurality of smart antenna modules to the first controller such that the first controller controls the plurality of smart antenna modules,
• wherein the second controller is configured to pre-set a percentage of signal power level for each multi-frequency band or multi-carrier received from the DU, and
• wherein the second controller controls the signal power level so that a signal of a specific carrier does not exceed the pre-set percentage.