Main Features Of IS-95 (cdmaone) Modulation is performed using DSSS. Employs variable rate coders....
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Transcript of Main Features Of IS-95 (cdmaone) Modulation is performed using DSSS. Employs variable rate coders....
Main Features Of IS-95 (cdmaone)• Modulation is performed using DSSS.• Employs variable rate coders.• Powerful low rate forward error-correcting
codes.• Fast power control is employed to over come
the near-far problem.• Soft handoff is employed.• Qualcomm code excited linear predictive
(QCELP): 13.4 kbps
Frequency and Channel Spec• Reverse: 824-849MHz, forward: 869-894MHz; PCS version 1800-2000MHz• Data rate 9.6kb/s; chip rate 1.2288Mchips/s, spreading factor 128.• Power Control: Close-loop/open-loop• Rake receiver; • Soft handoff
Spec• Convolution code ½. Repetition circuit depending on speech• Block interleaver• Long PN sequence:
CT2• CT2 is a cordless
telephony standard that was used in the early nineties to provide short-range proto-mobile phone service in some countries in Europe. It is considered the precursor to the
popular DECT system.
DECT• Digital Enhanced (formerly European) Cordless Telecommunications is an
ETSI standard for digital portable phones, commonly used for domestic or corporate purposes. DECT can also be used for wireless data transfers. DECT is recognised by the ITU as fullfilling the IMT-2000 requirements and thus qualifies as a 3G system, as a part of the IMT-2000
group of technologies,
DECT functional concept• Portable handset• Radio fixed part• Cordless controller• Network-specific
interface unit• Supplementary
services