> On Wednesday, June 17, 2015 at 1:07:23 AM UTC+12, randeepk wrote:
>> Hi,
>>
>> I am trying to design an analog transfer function in digital domain. I
>> tried using various methods like impulse invariance and bilinear
>> transform. But when I used bilinear transform I am getting error of around
>> 1db at nyquist frequency.
>> Are there any other better methods???
>>
>> Thanks
>>
>>
>> ---------------------------------------
>> Posted through http://www.DSPRelated.com
>
> make sure you sample 10 to 20 times the max frequency of interest.
On Wednesday, June 17, 2015 at 1:07:23 AM UTC+12, randeepk wrote:
> Hi,
>
> I am trying to design an analog transfer function in digital domain. I
> tried using various methods like impulse invariance and bilinear
> transform. But when I used bilinear transform I am getting error of around
> 1db at nyquist frequency.
> Are there any other better methods???
>
> Thanks
>
>
> ---------------------------------------
> Posted through http://www.DSPRelated.com
make sure you sample 10 to 20 times the max frequency of interest.
>I am obligated to inform that the document referenced there is copyright
>material. I am not the copyright holder; I am the author. The rights
>belong to IEEE.
Greg -- thanks for pointing this out.
The website for this URL states the licensing as "CC Attribution-Share
Alike 2.0 Unported except where otherwise noted". (I do not know
if this is binding; IANAL etc.)
Steve
Reply by Greg Berchin●June 17, 20152015-06-17
On Wed, 17 Jun 2015 07:16:58 -0500, "alpha1" <103600@DSPRelated> wrote:
>Right now I am going through Greg's FDLS method
[URL omitted]
I am obligated to inform that the document referenced there is copyright
material. I am not the copyright holder; I am the author. The rights
belong to IEEE.
Reply by alpha1●June 17, 20152015-06-17
>>
>>As Eric said -- tell us what you're really trying to do.
>>
>>--
>>
>>Tim Wescott
>>Wescott Design Services
>>http://www.wescottdesign.com
>
>I am trying to realise a deemphasis filter on the CDDA output. In CDDA
the
>sampling rate is 44.1Khz.
>De emphasis transfer function is (10^6 + 15s)/(10^6 + 50s).
>
>I have seen discussions regarding this before here. I feel that this has
>to be discussed in general scenario where one is trying realise an
analog
>transfer function in digital domain.
>
>
>---------------------------------------
>Posted through http://www.DSPRelated.com
>
>As Eric said -- tell us what you're really trying to do.
>
>--
>
>Tim Wescott
>Wescott Design Services
>http://www.wescottdesign.com
I am trying to realise a deemphasis filter on the CDDA output. In CDDA the
sampling rate is 44.1Khz.
De emphasis transfer function is (10^6 + 15s)/(10^6 + 50s).
I have seen discussions regarding this before here. I feel that this has
to be discussed in general scenario where one is trying realise an analog
transfer function in digital domain.
---------------------------------------
Posted through http://www.DSPRelated.com
Reply by Tim Wescott●June 16, 20152015-06-16
On Tue, 16 Jun 2015 08:07:19 -0500, randeepk wrote:
> Hi,
>
> I am trying to design an analog transfer function in digital domain. I
> tried using various methods like impulse invariance and bilinear
> transform. But when I used bilinear transform I am getting error of
> around 1db at nyquist frequency.
> Are there any other better methods???
It sounds like you really mean that you're trying to replicate the
effects of an already-specified analog transfer function in the digital
domain. Unless the sampling rate is considerably higher than your
highest frequency of interest, this is fraught with inaccuracies.
You best bet would be to increase your sampling rate so that you have no
frequencies of interest at Nyquist -- if you don't have tons of
attenuation at Nyquist then there's a good chance that you're not going
to care what your filter is doing because aliasing will be driving you up
the wall.
As Eric said -- tell us what you're really trying to do.
--
Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
Reply by Eric Jacobsen●June 16, 20152015-06-16
On Tue, 16 Jun 2015 08:07:19 -0500, "randeepk" <106589@DSPRelated>
wrote:
>Hi,
>
>I am trying to design an analog transfer function in digital domain. I
>tried using various methods like impulse invariance and bilinear
>transform. But when I used bilinear transform I am getting error of around
>1db at nyquist frequency.
>Are there any other better methods???
>
>Thanks
What sort of transfer function are you trying to convert?
Eric Jacobsen
Anchor Hill Communications
http://www.anchorhill.com
Reply by randeepk●June 16, 20152015-06-16
Hi,
I am trying to design an analog transfer function in digital domain. I
tried using various methods like impulse invariance and bilinear
transform. But when I used bilinear transform I am getting error of around
1db at nyquist frequency.
Are there any other better methods???
Thanks
---------------------------------------
Posted through http://www.DSPRelated.com