FPGA Design On The Interface Of Radio Remote Unit In NodeB Of WCDMA Based On CPRI

The common framework of a UMTS wireless network includes core network(CN), radio network controller(RNC), basestation(NodeB), and mobile terminal(UE). A NodeB consists of two subsystems, radio equipment control(REC) and radio equipment(RE). RRU is frequently used to add the cover ability or solve the problem when the basestation place is so bad that the transmitting is influenced.3GPP have defined and specified the Iu interface between CN and RNC, the Iur interface between two RNCs, the Iub interface between RNC and NodeB, the Uu interface between NodeB and UE. They haven't specified the interface between baseband processing unit and radio unit inside a NodeB.CPRI is a protocol of the interface between REC and RE. It was initiated by some famous multinational telecom product manufacturers. Later it is accepted as a common specification by most telecom operators and product manufacturers. CPRI defines the interface no mater radio unit departs or not from the baseband processing unit. As for a NodeB with RRUs, radio unit is connected with baseband unit through fiber or cable.In this thesis, we consider the role of interface circuit in system synthetically, and consider the constraints of time sequence, speed, take memory, etc. to design the interface synthetically. Interface design focuses on data transmission, the line bit rate, frame structure, line coding, synchronization and timing, bit error correction/diction, link delay accuracy and cable delay calibration was all finished in FPGA chip. In this thesis we analysed the CPRI specification and set down the RRU interface criterion according to CPRI specification, and elaborated the detail design of the FPGA circuit. The author's work is focus on downlink IQ processing module, uplink IQ processing module, and signal transmitting module.