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Pastimes : The New Qualcomm - write what you like thread. -- Ignore unavailable to you. Want to Upgrade?

To: Maurice Winn who wrote (2047)	9/3/2000 5:37:49 PM
From: S100	Read Replies (1) \| Respond to of 12242

My Comments on HDR documents from the QCOM web site Seems like the recent HDR info from QCOM has driven the oak stake through the 5Mbps data rate(1XTREME?) Flailex. Or was it 15Mbps (per three sector cell)? Or maybe 150 per site with a stack of 10 antennas? Or was it three times more using 3xMC or WCDMA or what? Has anyone found ANY real data on EDGE? Seems to be very scarce. There is a little data on GPRS. FWIW I find it best to save the documents from any web site to my hard disk since they seem to disappear fairly soon. The movie at qualcomm.com does not appear to have any sound(58 seconds, file size of 1.5 Mb or so). I needed to load QuickTime V4 to play the movie on a computer running WIN2000 but QuickTime V3 seemed to work fine on a computer running W98. I saved the movie but seem to have trouble playing it with V3, V4 seems to work. Be sure you note the name of the movie file. Seems to tell where it was done. Also, what is this all this color stuff in the PRD files? It is getting so it is hard to tell what is what by reading a black and white copy. Guess I need to look at getting a HP color laser printer next. From the 1xHigh Data Rate Airlink overview. Snip We have chosen not to use higher modulation schemes such as 64-QAM in non line-of-sight environment. Using higher modulation schemes will increase the Access Terminals production cycle and increase its cost by adding the following inherited design constraints. More linear components are needed due to phase noise susceptibility, improved baseband receiver design to meet the required 18.5 dB SNR, improved A/D converter timing (chipx16 sampling resolution rather than chipx8), complexity of design parameters to avoid self interference, and more expensive devices by not leveraging of the high volume cost curves. snip And most interesting is the following: snip It is important to note that 9.5 dB SNR is readily attained by the Access Terminal in mobile scenarios using a single "whip" antenna. Using higher modulation (such as 64-QAM) requires 18.5 dB SNR. Simulation and field data shows that the required 18.5 dB C/I is not achievable under any conditions with current subscriber designs. The 18.5 dB SNR might be achieved using fixed panel antennas in line of sight applications. Also, minimum Base Station performance specifications for current 1xMC systems would not guarantee such SNR even if the Access Terminal is cabled to the Base Station. snip 1XTREME uses the following, 5 Mbps seems in doubt after the remarks in the QCOM HDR data. (QCOM quotes 3.6 Mbps per cell using dual antennas(receivers).) High Data Rate Carrier in 1.25MHz bandwidth 64 QAM provides ~5 Mbps peak 16 QAM provides ~3.4 Mbps peak 8 PSK provides ~ 2.6 Mbps peak ---- any comments ? am I misreading the documents? - Hint: Movie file name is hdr-china.mov