Raymond,
First, you haven't explained at all how being backward compatible with a 2G technology limits the scope or performance of a 3G technology. Here is what you said:
<If you have to think about that in all the parameters you choose for a new system it's pretty obvious that you will not get the most optimal system.You don't have to look further than the TV-standard in US NTSC.Because they had to keep the compability US has a much worse TV-picture then for example Europe./R.>
It's pretty obvious? How? In what way? Please be specific to the topic..W-CDMA/CDMA-2000. Show us why it's obvious.
As for the rest, Raymond, since you claim to know the technology than I'm puzzled. You've read the proposals right? You know that in them they answer specific questions put forth by the ITU right? For example: you know that the ITU asks what the cell capacity is right? You know that the ITU question specifies certain criteria so ITU will be able to assess the viability of the proposal right? You've read where W-CDMA proposal has less capacity than CDMA-2000 proposal right? That's what I read...it's right there if you read the proposals.
Since, you're up on the technology... you know that the W-CDMA proposal specifies concatenated Reed-Solomon/convolutional coding right? You also know that CDMA-2000 specifies the use of turbo codes. Now, we both know that turbo codes offer performance much closer to the Shannon limit than concatenated Reed-Solomon/convolutional coding is capable of right? I found the explanation of this fact in the ETSI UTRA W-CDMA proposal rather illuminating, didn't you? We both know that this goes right to system capacity right? No rocket science there huh? In fact, when you read in the W-CDMA proposal that they were looking at using turbo codes and that it could give a 2dB improvement in bit error rates you were kind of surprised that they were aware of this yet had not included this state of the art coding scheme in their proposal. I'll bet you were surprised that companies like Ericsson were calling W-CDMA 3rd generation technology when they were using something like Reed-Solomon/convolutional coding and not state of the art turbo codes, in their proposal. Yes, I too was surprised.
It's very interesting when you read the proposals and start digging into this stuff isn't it Raymond? This is why I find your remarks puzzling. You see Raymond, if you really did understand the technology and if you really did read and understand the proposals you wouldn't need to wait to see which proposal represents superior technology in the field. It should be obvious to you. And you would know that one company has the keys to the CDMA highway and the other is engaging in FUD.
Raymond, if you did understand you could give proper answers instead of "well it's obvious because blah blah". You're answers are non answers that don't square with the facts.
So Raymond, if I'm wrong, explain it to me. Don't look at NTSC or the Ericsson website etc. I read the proposals..... you read the proposals.. I understand the technology... you understand the technology....explain it to me. Don't say "well it's obvious because the sky is blue and NTSC blah blah".
Best Regards
Walt
P.S. If I have to explain to you the impact of concatenated Reed-Solomon/convolutional codes vs turbo codes to the system capacity...I will, but you must promise not to make any more unfounded claims until you understand the issues involved. :) |
