Path: utzoo!attcan!uunet!samsung!munnari.oz.au!bruce!trlluna!rhea.trl.oz.au!aurie
From: aurie@rhea.trl.oz.au (Alistair Urie - Radio and Satellite Networks)
Newsgroups: comp.dsp
Subject: Re: 1 Bit D to A Revisited
Message-ID: <826@trlluna.trl.oz>
Date: 21 Nov 89 00:46:56 GMT
References: <8911201702.AA03844@en.ecn.purdue.edu>
Sender: root@trlluna.trl.oz
Reply-To: aurie@rhea.trl.oz.au.trl.oz (Alistair Urie - Radio and Satellite Networks)
Organization: Telecom Research Labs.
Lines: 24

In article <8911201702.AA03844@en.ecn.purdue.edu> zawada@EN.ECN.PURDUE.EDU (Paul J Zawada) writes:
>
>A day or two ago, I heard another one bit D-to-A algorithm from a
>strictly unreliable source.  (A musician friend of mine.)  Since
>1 bit D-to-A was a recent topic, I thought I'd share this one with 
>with the net.  He claims this new revolutionary algorithm uses one
>bit to tell whether the output voltage should be incremented or
>decremented from its current state.  i.e. Voltages are not quantisized

But this is good old delta modulation, one of the very first digital modulation
systems invented.  

It works quite well provided you choose a bit rate that is high enough to 
handle the highest expected slope in the input signal.

By the way I understand that NASA used it back in the Apollo days as the last
ditch communications system - the last few minutes before complete comms
blackout during re-entry.


Alistair URIE                                     Radio and Satellite Networks
Phone:   +61 3 541 6370                           Telecom Research Laboratories
Fax:     +61 3 543 3339                           770 Blackburn Rd. Clayton Vic
Internet: aurie@rhea.trl.oz.au                                        AUSTRALIA