Concepts 3GPP_082307Concepts of W-CDMA(UMTS-FDD)Andy YehAgenda CDMA Concepts UMTS Network Architecture W-CDMA Protocol Structure W-CDMA Basic Physical Structure(Physical Channel) Down Link channel Transmit Diversity Up Link channel UMTS-FDD physical layer procedures How will UMTS evolve?Page 2Multiple Access ApproachesFrequency Division Multiple Access Time Division Multiple Access1 2N 3Spread Spectrum Multiple AccessCode Division Multiple AccessMultiple Transmitters User 2 User 1 User 3 and Multiple Data ChannelsFrequencyFrequencyti m eFrequencyEach User has a unique frequency (1 voice channel per user) All users transmit at the same time, but on different frequencies AMPS, NMT, TACSEach User has a unique time slot Each Data Channel has a unique position within the tim……
猜您喜欢
评论