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Old July 14th 10, 07:29 PM posted to rec.radio.amateur.antenna
Jim Lux Jim Lux is offline
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First recorded activity by RadioBanter: Mar 2007
Posts: 801
Default Design Flaw in iPhone 4, Testers Say

JIMMIE wrote:

The rumor I heard was that they tried to put in a "better" antenna to
cure problems with dropouts. While it does have more gain it is
sensitive to the way it's held. Basically they traded one problem for
another.
Any confirmation or rebutal would be appreciated

Jimmie


There's a whole raft of issues..

One is that cellphones aren't analog FM anymore, so they suffer from the
"digital cliff" problem.. If the Eb/No is good enough that the FEC
works, then it works great, but a dB or so worse, and it doesn't work at
all.

This is so different from most people's practical experience with
communications that it is disconcerting. E.g. if you walk away from me
while talking, your voice gets fainter and the SNR gradually drops, but
it's not like you've walked out of the "cone of silence" where it goes
from fully intelligible to not at all intelligible in milliseconds.

And, the fact that this happens on a packet by packet basis means that
at the threshold, it "stutters", which is also non-intuitive and
non-physical.


And then, the cellphone companies have managed to convince us that
really crummy sound is ok, even at the full bit rate of 8kpbs. The
voice codecs are impressive, but face it, it still doesn't sound like
56kbps u-law or 25 kHz NBFM, what used to be called "toll-quality"