In a centralized radio access network, a system in a remote radio unit combines signals from multiple radios and independently attenuates uplink and downlink signals for multiple antennas connected to the multiple radios. The system includes two Or more antennas; a radio set including a first analog front end configured for a first channel of a first frequency band and a second analog front end configured for a second channel of a second frequency band; and a signal combining and conditioning (SCC) unit coupled in series between the radio set and the two or more antennas. The SCC unit includes downlink passive attenuators for downlink signals from the radio set to each of the two or more antennas and uplink passive attenuators for uplink signals from each of the two or more antennas to the radio set.