Can anyone explain about Reverse CDMA Channel of IS-95 in CDMA?
alaxander 12-May-2008 10:37:51 PM

Comments


It carries both signalling and traffic from MS to BSS.
Posted by waqqas1


 From MS to BSS
 It carries traffic and signaling information.
 FEC code rate is 1/3, the code symbol rate = 28,800 symbols/sec, 6 code symbols/modulation symbol, and the PN rate is 1.2288 MHz
 Modulation is 64-ary orthogonal Walsh functions, each period of the Walsh function is repeated for four chips of the PN code
 Walsh symbol rate is 1.2288 MHz/(4 chips per Walsh chip)/(64 Walsh chips per Walsh symbol) = 4,800 modulation symbols/ second
 Reverse CDMA Channel consists of 2 42-1 logical channels
 One of the logical channels is permanently and uniquely associated with each MS. The channel does not change upon handoff.
 Reverse link addressing is accomplished through manipulation of period 2 42-1 Long Code, which is part of the spreading process.
 The reverse CDMA Channel does not use strict orthogonality in any sense to separate logical channels. Rather, it uses a very long period spreading code, in distinct phases. The correlations between stations are not zero, but they are acceptably small
Posted by srini_murali


Fundamentally different from the forward channels
1.)Uses OQPSK for power efficiency
2.) QPSK demodulation is easy
3.) 869-894 MHz range.
4.) No spreading of the data using orthogonal codes
5.) Same orthogonal codes are used for WAVEFORM encoding
6.)Two types of logical channels: The access channels and the reverse traffic channels
Posted by sagitraz



Posted: 13-May-2008 09:33:46 AM By: sagitraz

Fundamentally different from the forward channels
1.)Uses OQPSK for power efficiency
2.) QPSK demodulation is easy
3.) 869-894 MHz range.
4.) No spreading of the data using orthogonal codes
5.) Same orthogonal codes are used for WAVEFORM encoding
6.)Two types of logical channels: The access channels and the reverse traffic channels

Posted: 13-May-2008 11:38:45 AM By: srini_murali

 From MS to BSS
 It carries traffic and signaling information.
 FEC code rate is 1/3, the code symbol rate = 28,800 symbols/sec, 6 code symbols/modulation symbol, and the PN rate is 1.2288 MHz
 Modulation is 64-ary orthogonal Walsh functions, each period of the Walsh function is repeated for four chips of the PN code
 Walsh symbol rate is 1.2288 MHz/(4 chips per Walsh chip)/(64 Walsh chips per Walsh symbol) = 4,800 modulation symbols/ second
 Reverse CDMA Channel consists of 2 42-1 logical channels
 One of the logical channels is permanently and uniquely associated with each MS. The channel does not change upon handoff.
 Reverse link addressing is accomplished through manipulation of period 2 42-1 Long Code, which is part of the spreading process.
 The reverse CDMA Channel does not use strict orthogonality in any sense to separate logical channels. Rather, it uses a very long period spreading code, in distinct phases. The correlations between stations are not zero, but they are acceptably small

Posted: 31-December-2008 12:01:01 AM By: waqqas1

It carries both signalling and traffic from MS to BSS.