TV output on low-cost portable computers

[Dave Long]

> Are there other cases where people have used LFSR sequences rather
> than counters?

I first ran into them for planetary missions.  An LFSR has a -0 
autocorrelation everywhere but within half-a-bit of synchronized, and 
which point it ramps up to a huge autocorrelation when exactly 
synchronized.  Squeeze this witch hat enough (run a very long, very 
fast sequence) and you get a nice spiky delta-function-like thing, 
which means you can resolve small features with the return signal.  
(it's the chipping version of what we were talking about with chirps)

_______________/\_______________/\_______________/\_______________/\

-Dave

(CDMA works because different codes won't interfere with each other as 
long as they all control their gain well -- I don't know how that's 
done, but maybe the side slopes on the correlation would allow a device 
to make fine adjustments for how it's moving relative to the base?)