Analog VS Digital Question

"All of the power has to go into this
narrow pulse. This pulsing several hundred times per second is what
causes the interference with speakers and other equipment."

CDMA phones from what I understand transmit at the lowest power
possible to keep down noise and save battery life. Why don't TDMA/GSM
phones do the same? Wouldn't this help cut down on interference? I'm
not sure why TDMA phones sent out so much power when they send out
these pulses??

M.


--
ChaosThyre81

Joseph wrote:
> On Thu, 17 Mar 2005 22:38:34 +0000, ChaosThyre81
> <ChaosThyre81.1m2g2r@news.cellbanter.com> wrote:
>
>>CDMA phones from what I understand transmit at the lowest power
>>possible to keep down noise and save battery life. Why don't TDMA/GSM
>>phones do the same? Wouldn't this help cut down on interference? I'm
>>not sure why TDMA phones sent out so much power when they send out
>>these pulses??
>
> CDMA handsets have much poorer battery life than either TDMA or GSM.
> The equivalent CDMA model might have three days maximum standby where
> the equivalent GSM or TDMA model will have over a week. CDMA is more
> power hungry than GSM and TDMA.

Don't know if they put smaller batteries on CDMA phones, but one point
I've often heard is that it's not the radio transmitter, but rather that
CDMA is much more computationally intensive than TDMA protocols like
GSM. A TDMA phone (such as GSM) just has to know when to turn on to
listen for its bits. A CDMA phone is doing some very fancy signal
processing to pull the desired signal out of all the other "noise" on
the same frequency band (its noise from its perspective, anyway; it is
actually the other users). It likewise has to do complex calculations to
compute the signal to be transmitted. Newer generation CDMA (1xRTT) has
about twice the standby time as the first generation CDMA protocol.