wcdma 诺西内部培训资料.ppt

WCDMA Overview Contents System Architecture Protocol Structure of Interface Physical Channel Subsystems of Nokia 3G Network WCDMA Network Architecture UTRAN Interfaces Territorial Interface Protocol Structure Iub Interface Iur Interface Iu-CS and Iu-PS Air Interface Protocol architecture Air Interface Protocol RRC : Radio Resource Control RLC : Radio Link Control Protocol MAC: Medium Access Control Procedures in Layer 2 Procedures in Layer 1 Procedures in Layer 1(Exp.) Function of physical channel Physical Channel A physical channel is defined by a specific carrier frequency, code (scrambling code, spreading code) and relative phase In UMTS system, the different code (scrambling code or spreading code) can distinguish the channels Most channels consist of radio frames and time slots, and each radio frame consists of 15 time slots Two types of physical channel:UL and DL FDD-Downlink: Frame Structure TFCI: Transport Format Combination Identifier TPC: Transmitter Power Control FDD-Uplink: Frame Structure TFCI: Transport Format Combination Identifier FBI: Feedback Information TPC: Transmitter Power Control Spreading Technology Spreading consists of 2 steps： Channelization operation, which transforms data symbols into chips. Thus increasing the bandwidth of the signal, The number of chips per data symbol is called the Spreading Factor（SF）.The operation is done by multiplying with OVSF code. Scrambling operation is applied to the spreading signal . Channelization Code OVSF code is used as channelization code The channelization codes are uniquely described as Cch,SF,k, where SF is the spreading factor of the code and k is the code number, 0 ? k ? SF-1 Scrambling Code Scrambling code: GOLD sequence. Scrambling code period: 10ms ,or 38400 chips. The code used for scrambling of the uplink DPCCH/DPDCH may be of either long or short type, There are 2^24 long and 2^24 short uplink scrambling codes. Uplink scrambling codes are assigned by higher layers For downlink phys