I suspect that Qualcomm and all the thousands of people who have made
millions from their stock would strongly disagree with you.=20




On Fri, 12 Apr 2002 14:07:32 -0400, you wrote:

>Spread spectrum is much more hype than real benefit.  Frequency hopping
>is good to prevent eavesdropping.  Direct Sequence spreading helps you
>hide in the noise.  Both are useful for military applications, but have
>limited ligitimate civilian use.
>
>If you had four channels of space with a varying number of users,
>sometimes more than four, who couldn't agree on who should use what
>space when, then spread spectrum helps to arbitrate the use of bandwith.
> When too many users occupy the band everybody's signal to noise ratio
>degrades, and everybody suffers equally.
>
>I can stay on this soapbox for longer than anybody wants to read...
>
>Sherpa Doug
>
>> -----Original Message-----
>> From: Brandon Irwin [mailto:BrandonI@LEAKED.INFO]
>> Sent: Friday, April 12, 2002 1:30 PM
>> To: PICLIST@MITVMA.MIT.EDU
>> Subject: [OT]:Spread Spectrum Efficiency for Continuous signals
>>
>>
>>       I've been reading about spread spectrum and I don't see
>> how spread
>> spectrum techniques could be used for continuous transmissions.
>>
>>       Everyone seems to want to convert everything to spread spectrum
>> because of its greater efficiency. I don't see how it could
>> be any more
>> efficient when used on continuous transmissions such as a TV
>> video signal.
>> The following assumes that they would keep the signal in the
>> analog form.
>> If you have four available channels with four TV stations and
>> you implement
>> the freq hopping method, then all four channels will always
>> be full because
>> the TV stations would never have a pause to allow a fifth channel to
>> transmit. If you where to use a method similar to TDMA, then
>> you would see
>> little gaps in the picture.
>> It seems to me that the only way the "more efficient" spread spectrum
>> methods could be used would be to convert the signal to a
>> digital form so
>> it could be buffered on the TV side while the transmission ceased for
>> whatever amount of time.
>>
>>       Is there something I'm missing? Maybe the whole concept?
>>
>>
>>
>>
>> -Brandon Irwin
>>
>>
>>
>>
>>
>>
>> -------------------------------------
>> This message was written using the Dvorak keyboard layout.
>>
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>>

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