Patent ID: 7127273

Claim:
A radio communications system, comprising: a radio access unit; a digital exchange; and a transmission system connecting said radio access unit and said digital exchange; said digital exchange comprising a radio controller; baseband processing means for providing a modulated multiplexed digital baseband signal from signals of several logical channels; and means for sending the modulated multiplexed digital baseband signal to said radio access unit; and protocol layer for handling access to a radio interface, whereby said protocol layer is not needed in the radio access unit; said radio access unit comprising means for receiving a modulated multiplexed digital baseband signal from said exchange; means for D/A converting said received signal; and an RF transmitter section for upconverting the D/A converted signal to an RF signal and transmitting said RF signal, wherein the transmitter is a transmitter linearized by a straight feedback loop from said exchange to said radio access unit.