[sdiy] Sigma Delta DSP

[Dave Krooshof - dendriet.nl]

2006/3/1, ASSI <Stromeko at compuserve.de>:
>
> On Mittwoch, 1. März 2006 17:45, Dave Krooshof - dendriet.nl wrote:
> > The downside however, is that I would not even know how to
> > do gain properly in a bitstream, let alone filtering.
>
> There's a number of PhD thesis' in that question... :-)


I know, and google shows a lot of interesting pdfs that are
on the IEEE site, but I can't download those (or I'll have to pay a lot)


> Can anyone point us to information about bistream DSP?
>
> You may actually have more luck looking up publications on how
> binary/trinary pulsed neural networks process information.


Okee.  I see. And probably Cellulair Automata too.

Paramount to DSP directly with pulse trains is to chose an efficient
> (and likely redundant) number system for each operation at hand (for
> integration and thresholding). That implies frequent number system and
> sample rate conversions. Multiplication and addition may both be done
> by XOR gates in the right representation, while other operation may be
>
more efficiently implemented by splitting up the signal into several
> bitstreams that are processed in parallel before funneled together
> again.\




yes, and adding the same signal will not make any gain, unless it's
delayed a bit. But then the question is how much I should delay to
make a nice 6dB gain. Will the number of bits delay be my gain value
from +0 to +6 dB?



The second key ingredient IMHO is a number of mutually
> independent (white) noise sources with adjustable probability of the
> pulse density (the tricky part here is the seemingly innocent
> "independent" as you'd need lots of them). And now the best or worst
> part, depending on how you look at things: you gotta do this in an FPGA
> at least (ASIC would be even better), because the most common
> operations are wildly inefficient to do in software.


This is exactly what we were thinking of!

thanks

Dave
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