Hi Clark:
I do not agree with several of the points you make
in your post:
a) If UWB radio employs truly a very large BW
(say of the order of a GHz), its interference
effect on narrowband channels, such as TV channels,
will be minimal, even with many users.
b) It is true that theoretically, impulse radio
with time hopping multiple access leads to the same
processing gains as standard CDMA over a channel with
the same BW. However, QCOM would find it impossible to
make its CDMA work with a BW of one or more Ghz, while
impulse radio has already been demonstrated to work
(admittedly not commercially) in such situations.
c) Impulse radio has a very good chance of being successful
for indoor local area networks, i.e. for short ranges.
I encourage all technically oriented readers to read
the papers coming out of Robert Scholtz's research group at
USC over the last few years. Most of the key issues
associated to the systems design of UWB local area
networks have been worked out. The key hurdle at this
stage is regulatory, i.e., getting the FCC to agree with
its deployment. The next hurdle will of course be financial
and commercial, i.e., technically sound systems do not
always find success in the market place.
I find it rather ironic that the most strident critics of
impulse radio should come out of the QCOM camp, given that
QCOM was almost strangled by regulatory and standards setting
opposition while it was in its infancy.
Best regards,
Bernard Levy |
