Subject: Re: Binary Sampler
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Date: Thu, 16 Jan 2003 06:38:37 GMT
NNTP-Posting-Date: Thu, 16 Jan 2003 01:38:37 EST
Organization: Cox Communications
"John Larkin" wrote in
> On Wed, 15 Jan 2003 06:33:14 GMT, "Mike" wrote:
> >> It would be interesting to see if they recognized the noise-rejection
> >> properties and how they analyzed it.
> >There's no other reason for it. This paper concerned itself with
> >characterization; noise analysis followed in later papers. It won't make
> >happy: it's a biased estimator when the signal is nonmonotonic, even if
> >noise is zero mean. In other words, it rejects noise, but gets the wrong
> >-- Mike --
> Right. The thing servoes on the signal median, not the mean.
Actually, even if it did servo on the mean and there was no noise, there
would still be errors.
Mike isn't sampling the recovered signal synchronously, so the noise
averaging has to happen over time. The averaging function can be modeled as
a window. Errors result from the convolution of the window and the sine
wave. The errors can be reduced by either narrowing the window or increasing
the sample rate. Narrowing the window increases the bandwidth, reducing the
noise cancellation and the usefulness of the circuit. The only way to reduce
the noise and the error is to increase the sample rate. The error can be
made to approach zero, but only at the cost of infinite sample rate. Given a
signal frequency and a finite sample rate, noise cancellation performance
trades off with error magnitude.
-- Mike --