Re: [Economist] Ultrawideband

Gregory Alan Bolcer (
Wed, 10 Nov 1999 08:43:30 -0800

I wish I had one of those unscrambling on the same frequency radios
at the beginning of this last week.

Starting last Saturday, one of the more less-than world famous, famous
new rock stations 91 X. 91X is broadcast out of Tijuana and 91.1FM is the
kissing cousin of 106.7 KROQ. The signal was drowned out by
a local religious broadcast. Although the government doesn't make mistakes,
a check of the stat sheet seems to reveal that they somehow granted several
new 91.1 FM licenses including one that started recently broadcasting in
what's called the Mexican border zone, even though it's 314km to the border
in Las Vegas, NV. Somebody finally pulled the plug on Thursday after 3-4 days.
After a day or two, I thought maybe it was a pirate broadcast as I never
heard any commercials, but it turns out maybe it was official. I wonder
how much ad revenue 91 X lost because of the mixup.



Rohit Khare wrote:

> Don't all talk at once. Actually, do
> Turn the dial (or press a button) on a radio, and you determine which
> station's signal is played through the speaker. Now imagine that
> several radio stations are transmitting on exactly the same
> frequency, so that their signals interfere with one another. Is it
> possible to build a new kind of radio, capable of separating the
> signals, so that just one of them can be heard clearly? The
> conventional answer is no. Once radio signals have been mixed
> together, trying to separate them is like trying to unscramble an
> egg. In 1996, however, Gerard Foschini of Bell Labs (the research arm
> of Lucent Technologies, based in Murray Hill, New Jersey) suggested
> that multiple transmissions on a single frequency could be separated
> after all-by using more than one receiving antenna and clever signal
> processing. The result was a technology called Bell Labs Layered
> Space-Time, or BLAST.