Performance of the CODIT Radio Interface

Although the radio interface concept of the CDMA-based UMTS developed in the RACE project CODIT aims at providing service flexibility and ease of system deployment, every effort has been made to improve the performance of the radio interface. Variable-rate speech encoding, powerful channel coding schemes, coherent demodulation on the uplink, robust channel estimation, and closed-loop power control have been employed to increase spectral efficiency. The CODIT radio interface for speech and data traffic channels and for a dedicated control channel is described. Simulation results for uplink traffic channels used to assess spectral efficiency are presented.