Systems and methods for noise floor optimization in distributed antenna system with direct digital interface to base station

A signal interface unit for a distributed antenna system includes a channelized radio carrier interface configured to communicate an uplink channelized radio carrier for a radio frequency carrier to a channelized radio carrier base station interface; an antenna side interface configured to receive an uplink digitized radio frequency signal from the distributed antenna system communicatively coupled to the antenna side interface, wherein the uplink digitized radio frequency signal includes baseband data having bits; and a signal conversion module communicatively coupled between the channelized radio carrier interface and the antenna side interface and configured to convert between the uplink digitized radio frequency signal and the uplink channelized radio carrier at least in part by performing an adjustment of the bits included in the baseband data for the uplink digitized radio frequency signal received from the distributed antenna system to comply with requirements of the channelized radio carrier base station interface.