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To: Quincy who wrote (13393)	8/6/1998 3:18:00 AM
From: Clarksterh	Respond to of 152472

Qunicy - <I think IS95 CDMA required sectorization and rake receivers from the start.> Just some clarification: 1) CDMAOne does not actually require sectorization, but it is much easier and more productive to do it for CDMA than it is in a system with frequecy reuse problems (i.e GSM, AMPS, IS-136). 2) Although the technology behind cell sectorization and AAA are very very different, you are correct that it has some of the same functions. Both allow a user to get a more dedicated 'link', and that in turn allows more links. However, just to make it clear, in AAA each user would get their own personal high gain beam, whereas in sectorization several people are still sharing a relatively lower gain beam (unless you made hundreds of sectors). 3) You are right that CDMA rake receivers perform, in a completely different technical fashion, some of the same functions as AAA. For GSM or other non CDMA signals one of the biggest problems is multipath (signal ricochets). They come in from other directions and with a little delay and interfere with your main signal. CDMA can figure this out and actually undo the delay so that they actually add instead of interfere. AAA allows GSM to really boost the main signal and ignore the interfering signals. In sum, it is possible that the combination of CDMA sectorization and rake receivers is actually better than AAA, but it isn't something to know without a good model or possibly some experiments. Clark PS Good catch on the rake receiver.