Is-95 cdma forward and reverse channel pdf

The is 95 forward link and the is95 reverse link are different in their construction in view of the fact that there are different requirements for each. Also walsh codes need to be synchronised if they are to remain orthogonal. The is95 air interface is based around the use of cdma within a 1. Signaling voicedata signaling voicedata application na 1200 9600 960014,400 4800 960014,400 bitss walsh code 0 walsh code 32 walsh codes 17 walsh 831,3363 access channel long code. Pilot channel is a reference channel which the mobile station uses for acquisition, timing and as a phase reference for coherent demodulation. Access channel is used by mobile stations to establish a communication with the base station or to answer paging channel messages. Pn code offsets are used for the identifi cation of the reverse channels. Reverse link 824 to 849 mhz each channel is 45 mhz away from the forward counterpart access channel 4800 bps initiate communication respond to paging channel message reverse voice traffic channel 9600, 4800, 2400, 1200 bps very similar to forward link, but there are important differences. Modulation and coding details for the forward and reverse channels differ. Example of a forward cdma channel transmitted by a base st ation. Basic spreading procedure on the forward channels in is95. Is95 cdma channels types of channels forward channels pilot synchronization paging traffic reverse channels access traffic channels system mon.

Design and system operation of globalstartm versus is95 cdma. The is95 standard describes a code division multiple access cdma. The cdma reverse channel is fundamentally different from the forward channel. The reverse channel is the mobiletocell direction of communication or the uplink path. The modulation and coding features of the is95 cdma system are listed in table 11. Cdma channels can be broadly categorized as forward channel and. Ramanikumar animations telecom and wireless 941 views. Performance characteristics of the is95 standard for cdma spread. The reverse link supports up to 32 access channels and up to.

In cdma 2000, there are two types of channels dedicated and common. The is95 cdma system operates in the same frequency band as the amps using frequency division. Is95 air interface forward and reverse links basics of the is95, is95a and is95b, cdmaone air interface looking at the cdma spreading, forward and reverse links and basic channel. The is95 channels differ between the forward and reverse links as a result of the. Programming, pricing and offers are subject to change and may vary. The reverse link supports up to 32 access channels and up to 62 traffic channels. The forward and reverse link cdma waveform design in globalstar is described in section 3. Cdma forward and reverse channels forward channels the forward cdma channel is the celltomobile direction of communication or the downlink path. Forward dedicated channels carry information between the base station and a specific mobile. A complete video lecture course with animations on telecom technology and wireless technology. The is95 channels differ between the forward and reverse links as a result of the different requirements and the different way in which the links operate. The cdma reverse channel employs oqpsk rather than the qpsk digital modulation scheme used in the forward channel. The access channel is used for short signaling message exchanges such as callups, responses to pages and registrations.