SI
SI
discoversearch

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor.  We ask that you disable ad blocking while on Silicon Investor in the best interests of our community.  If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.
Technology Stocks : The New Qualcomm - a S&P500 company
QCOM 173.20-3.3%3:59 PM EST
 Public ReplyPrvt ReplyMark as Last ReadFilePrevious 10Next 10PreviousNext  
To: Clarksterh who wrote (2780)10/27/1999 11:23:00 PM
From: wonk   of 13582
 
...Another mystery is why HDR boasts of 2.4Mbps peak only. Why is the average lower?

This help?


CDMA/HDR:
A Bandwidth Efficient High Speed
Wireless Data Service for Nomadic Users
Paul Bender, Peter Black, Matthew Grob,
Roberto Padovani,Nagabhushana Sindhushayana and Andrew Viterbi
QUALCOMM, Incorporated


TABLE I
Data Rate    Pckt Lgth          FEC rate            Modulation
(bps)		(Bytes)		(Bits/symbol)
76.8		128			_		QPSK
102.6		128			_		QPSK
153.6		128			_		QPSK
204.8		128			_		QPSK
307.2		128			_		QPSK
614.4		128			_		QPSK
921.6		192			3/8		QPSK
1228.8          256			_		QPSK
1843.2          384			_		8PSK
2457.6          512			_		16QAM

Figure 4 shows the bit-exact simulated performance of some of the
modes from Table I on an AWGN channel and Table III
summarizes the SNR  required to achieve a 1% packet error rate.

TABLE III
Data Rate [kbps]     Ec/Nt [dB]
76.8			-9.5
102.6			-8.5
153.6			-6.5
204.8			-5.7
307.2			-4.0
614.4			-1.0
921.6			1.3
1228.8			3.0
1843.2			7.2
2457.6			9.5


Slight problem for the system designer with the varying Ec/Nt, though.

ww
Report TOU ViolationShare This Post
 Public ReplyPrvt ReplyMark as Last ReadFilePrevious 10Next 10PreviousNext  

HomeMailHotSubjectMarksPeopleMarksKeepersSettings
Terms Of UseContact UsCopyright/IP PolicyPrivacy PolicyAbout UsFAQAdvertise on SI
© 2025 Knight Sac Media.  Data provided by Twelve Data, Alpha Vantage, and CityFALCON News