Negative Group Delay ... again!

On Mar 7, 11:18&#4294967295;pm, Andor <andor.bari...@gmail.com> wrote:
> From a recent discussion here:
>
> > >if i could generate some coefficents that had a 'negative' group delay for
> > >a period of time, would you think that 'phase cloning' was new and
> > >intersting??
>
> > A time machine would be pretty revolutionary, yes.
>
> > Negative group delay means that the output appears before the input
> > arrives.
>
> Fascinating concept, isn't it? I was curious enough to dig into the
> topic for a while and write up what I found out. You can read about it
> here:
>
> http://www.dsprelated.com/showarticle/54.php

Interesting piece. Just a couple of questions:

- Why not use the BLT to transfor to discrete-time domain?
  I don't know Greg's stuff, I am familiar with the properties
  of the BLT.
- Why analyze in discrete-time domain at all? Your results
  would have been seriously interesting if you could demonstrate
  similar effects in continuos-time domain; here they are amusing.
- Why not use the impulse as test signal? You refer to 'some' who
  'claim' that system with negative group delays are noncausal, as
  if you contest (or at least not support) such a view. I have
  made such claims.

Your way of phrasing opens a whole new can of worms of semantic wars
etc - why not demonstarte once and for all that systems with negative
group delays exist and can be implemented in CT? (If that indeed is
your claim, of course; I could not find out from the article what
your stand on the issue is.)

I would suggest the following:

1) Make a clear statement of the 'usual' views on the issue,
   your own opinions, and exactly what this article aims
   to demonstrate.
2) Compute the phase response of the CT system function and
   demonstrate that there is a negative group delay there.
   If you have the tools, I would also suggest you simulate
   the impulse response of that circuit in CT domain.
3) Use standard techniques in DT domain (BLT, Kronecker delta)
   and repeat your analysis.

If all the results persist (system functions show negative
group delays, anticausal behaviour) after such a re-work, I
will consider to spend some time looking into your article
in more detail.

As the article stands, it only cretates confusion. A less
benevolent reviewer than me might sugest that the instability
caused by the truncated signal is caused by poles located
outside the unit circle, and thus suggest that there is a
fundamental flaw in the argument. As you know, if you can
repeat the results using standard analysis tools and from
multiple angles of attack, it will stop those sorts of
argument at the outset.

Rune

On Mar 7, 11:18&#4294967295;pm, Andor <andor.bari...@gmail.com> wrote:
> From a recent discussion here:
>
> > >if i could generate some coefficents that had a 'negative' group delay for
> > >a period of time, would you think that 'phase cloning' was new and
> > >intersting??
>
> > A time machine would be pretty revolutionary, yes.
>
> > Negative group delay means that the output appears before the input
> > arrives.
>
> Fascinating concept, isn't it? I was curious enough to dig into the
> topic for a while and write up what I found out. You can read about it
> here:
>
> http://www.dsprelated.com/showarticle/54.php

Interesting piece. Just a couple of questions:

- Why not use the BLT to transfor to discrete-time domain?
  I don't know Greg's stuff, I am familiar with the properties
  of the BLT.
- Why analyze in discrete-time domain at all? Your results
  would have been seriously interesting if you could demonstrate
  similar effects in continuos-time domain; here they are amusing.
- Why not use the impulse as test signal? You refer to 'some' who
  'claim' that system with negative group delays are noncausal, as
  if you contest (or at least not support) such a view. I have
  made such claims.

Your way of phrasing opens a whole new can of worms of semantic wars
etc - why not demonstarte once and for all that systems with negative
group delays exist and can be implemented in CT? (If that indeed is
your claim, of course; I could not find out from the article what
your stand on the issue is.)

I would suggest the following:

1) Make a clear statement of the 'usual' views on the issue,
   your own opinions, and exactly what this article aims
   to demonstrate.
2) Compute the phase response of the CT system function and
   demonstrate that there is a negative group delay there.
   If you have the tools, I would also suggest you simulate
   the impulse response of that circuit in CT domain.
3) Use standard techniques in DT domain (BLT, Kronecker delta)
   and repeat your analysis.

If all the results persist (system functions show negative
group delays, anticausal behaviour) after such a re-work, I
will consider to spend some time looking into your article
in more detail.

As the article stands, it only cretates confusion. A less
benevolent reviewer than me might sugest that the instability
caused by the truncated signal is caused by poles located
outside the unit circle, and thus suggest that there is a
fundamental flaw in the argument. As you know, if you can
repeat the results using standard analysis tools and from
multiple angles of attack, it will stop those sorts of
argument at the outset.

Rune

On Mar 7, 11:18=A0pm, Andor <andor.bari...@gmail.com> wrote:
> From a recent discussion here:
>
> > >if i could generate some coefficents that had a 'negative' group delay =
for
> > >a period of time, would you think that 'phase cloning' was new and
> > >intersting??
>
> > A time machine would be pretty revolutionary, yes.
>
> > Negative group delay means that the output appears before the input
> > arrives.
>
> Fascinating concept, isn't it? I was curious enough to dig into the
> topic for a while and write up what I found out. You can read about it
> here:
>
> http://www.dsprelated.com/showarticle/54.php

Interesting piece. Just a couple of questions:

- Why not use the BLT to transfor to discrete-time domain?
  I don't know Greg's stuff, I am familiar with the properties
  of the BLT.
- Why analyze in discrete-time domain at all? Your results
  would have been seriously interesting if you could demonstrate
  similar effects in continuos-time domain; here they are amusing.
- Why not use the impulse as test signal? You refer to 'some' who
  'claim' that system with negative group delays are noncausal, as
  if you contest (or at least not support) such a view. I have
  made such claims.

Your way of phrasing opens a whole new can of worms of semantic wars
etc - why not demonstarte once and for all that systems with negative
group delays exist and can be implemented in CT? (If that indeed is
your claim, of course; I could not find out from the article what
your stand on the issue is.)

I would suggest the following:

1) Make a clear statement of the 'usual' views on the issue,
   your own opinions, and exactly what this article aims
   to demonstrate.
2) Compute the phase response of the CT system function and
   demonstrate that there is a negative group delay there.
   If you have the tools, I would also suggest you simulate
   the impulse response of that circuit in CT domain.
3) Use standard techniques in DT domain (BLT, Kronecker delta)
   and repeat your analysis.

If all the results persist (system functions show negative
group delays, anticausal behaviour) after such a re-work, I
will consider to spend some time looking into your article
in more detail.

As the article stands, it only cretates confusion. A less
benevolent reviewer than me might sugest that the instability
caused by the truncated signal is caused by poles located
outside the unit circle, and thus suggest that there is a
fundamental flaw in the argument. As you know, if you can
repeat the results using standard analysis tools and from
multiple angles of attack, it will stop those sorts of
argument at the outset.

Rune

On Mar 7, 11:18=A0pm, Andor <andor.bari...@gmail.com> wrote:
> From a recent discussion here:
>
> > >if i could generate some coefficents that had a 'negative' group delay =
for
> > >a period of time, would you think that 'phase cloning' was new and
> > >intersting??
>
> > A time machine would be pretty revolutionary, yes.
>
> > Negative group delay means that the output appears before the input
> > arrives.
>
> Fascinating concept, isn't it? I was curious enough to dig into the
> topic for a while and write up what I found out. You can read about it
> here:
>
> http://www.dsprelated.com/showarticle/54.php

Interesting piece. Just a couple of questions:

- Why not use the BLT to transfor to discrete-time domain?
  I don't know Greg's stuff, I am familiar with the properties
  of the BLT.
- Why analyze in discrete-time domain at all? Your results
  would have been seriously interesting if you could demonstrate
  similar effects in continuos-time domain; here they are amusing.
- Why not use the impulse as test signal? You refer to 'some' who
  'claim' that system with negative group delays are noncausal, as
  if you contest (or at least not support) such a view. I have
  made such claims.

Your way of phrasing opens a whole new can of worms of semantic wars
etc - why not demonstarte once and for all that systems with negative
group delays exist and can be implemented in CT? (If that indeed is
your claim, of course; I could not find out from the article what
your stand on the issue is.)

I would suggest the following:

1) Make a clear statement of the 'usual' views on the issue,
   your own opinions, and exactly what this article aims
   to demonstrate.
2) Compute the phase response of the CT system function and
   demonstrate that there is a negative group delay there.
   If you have the tools, I would also suggest you simulate
   the impulse response of that circuit in CT domain.
3) Use standard techniques in DT domain (BLT, Kronecker delta)
   and repeat your analysis.

If all the results persist (system functions show negative
group delays, anticausal behaviour) after such a re-work, I
will consider to spend some time looking into your article
in more detail.

As the article stands, it only cretates confusion. A less
benevolent reviewer than me might sugest that the instability
caused by the truncated signal is caused by poles located
outside the unit circle, and thus suggest that there is a
fundamental flaw in the argument. As you know, if you can
repeat the results using standard analysis tools and from
multiple angles of attack, it will stop those sorts of
argument at the outset.

Rune

On Mar 7, 11:18=A0pm, Andor <andor.bari...@gmail.com> wrote:
> From a recent discussion here:
>
> > >if i could generate some coefficents that had a 'negative' group delay =
for
> > >a period of time, would you think that 'phase cloning' was new and
> > >intersting??
>
> > A time machine would be pretty revolutionary, yes.
>
> > Negative group delay means that the output appears before the input
> > arrives.
>
> Fascinating concept, isn't it? I was curious enough to dig into the
> topic for a while and write up what I found out. You can read about it
> here:
>
> http://www.dsprelated.com/showarticle/54.php

Interesting piece. Just a couple of questions:

- Why not use the BLT to transfor to discrete-time domain?
  I don't know Greg's stuff, I am familiar with the properties
  of the BLT.
- Why analyze in discrete-time domain at all? Your results
  would have been seriously interesting if you could demonstrate
  similar effects in continuos-time domain; here they are amusing.
- Why not use the impulse as test signal? You refer to 'some' who
  'claim' that system with negative group delays are noncausal, as
  if you contest (or at least not support) such a view. I have
  made such claims.

Your way of phrasing opens a whole new can of worms of semantic wars
etc - why not demonstarte once and for all that systems with negative
group delays exist and can be implemented in CT? (If that indeed is
your claim, of course; I could not find out from the article what
your stand on the issue is.)

I would suggest the following:

1) Make a clear statement of the 'usual' views on the issue,
   your own opinions, and exactly what this article aims
   to demonstrate.
2) Compute the phase response of the CT system function and
   demonstrate that there is a negative group delay there.
   If you have the tools, I would also suggest you simulate
   the impulse response of that circuit in CT domain.
3) Use standard techniques in DT domain (BLT, Kronecker delta)
   and repeat your analysis.

If all the results persist (system functions show negative
group delays, anticausal behaviour) after such a re-work, I
will consider to spend some time looking into your article
in more detail.

As the article stands, it only cretates confusion. A less
benevolent reviewer than me might sugest that the instability
caused by the truncated signal is caused by poles located
outside the unit circle, and thus suggest that there is a
fundamental flaw in the argument. As you know, if you can
repeat the results using standard analysis tools and from
multiple angles of attack, it will stop those sorts of
argument at the outset.

Rune

On Mar 7, 11:18&#4294967295;pm, Andor <andor.bari...@gmail.com> wrote:
> From a recent discussion here:
>
> > >if i could generate some coefficents that had a 'negative' group delay for
> > >a period of time, would you think that 'phase cloning' was new and
> > >intersting??
>
> > A time machine would be pretty revolutionary, yes.
>
> > Negative group delay means that the output appears before the input
> > arrives.
>
> Fascinating concept, isn't it? I was curious enough to dig into the
> topic for a while and write up what I found out. You can read about it
> here:
>
> http://www.dsprelated.com/showarticle/54.php

Interesting piece. Just a couple of questions:

- Why not use the BLT to transfor to discrete-time domain?
  I don't know Greg's stuff, I am familiar with the properties
  of the BLT.
- Why analyze in discrete-time domain at all? Your results
  would have been seriously interesting if you could demonstrate
  similar effects in continuos-time domain; here they are amusing.
- Why not use the impulse as test signal? You refer to 'some' who
  'claim' that system with negative group delays are noncausal, as
  if you contest (or at least not support) such a view. I have
  made such claims.

Your way of phrasing opens a whole new can of worms of semantic wars
etc - why not demonstarte once and for all that systems with negative
group delays exist and can be implemented in CT? (If that indeed is
your claim, of course; I could not find out from the article what
your stand on the issue is.)

I would suggest the following:

1) Make a clear statement of the 'usual' views on the issue,
   your own opinions, and exactly what this article aims
   to demonstrate.
2) Compute the phase response of the CT system function and
   demonstrate that there is a negative group delay there.
   If you have the tools, I would also suggest you simulate
   the impulse response of that circuit in CT domain.
3) Use standard techniques in DT domain (BLT, Kronecker delta)
   and repeat your analysis.

If all the results persist (system functions show negative
group delays, anticausal behaviour) after such a re-work, I
will consider to spend some time looking into your article
in more detail.

As the article stands, it only cretates confusion. A less
benevolent reviewer than me might sugest that the instability
caused by the truncated signal is caused by poles located
outside the unit circle, and thus suggest that there is a
fundamental flaw in the argument. As you know, if you can
repeat the results using standard analysis tools and from
multiple angles of attack, it will stop those sorts of
argument at the outset.

Rune

On Mar 7, 11:18=A0pm, Andor <andor.bari...@gmail.com> wrote:
> From a recent discussion here:
>
> > >if i could generate some coefficents that had a 'negative' group delay =
for
> > >a period of time, would you think that 'phase cloning' was new and
> > >intersting??
>
> > A time machine would be pretty revolutionary, yes.
>
> > Negative group delay means that the output appears before the input
> > arrives.
>
> Fascinating concept, isn't it? I was curious enough to dig into the
> topic for a while and write up what I found out. You can read about it
> here:
>
> http://www.dsprelated.com/showarticle/54.php

Interesting piece. Just a couple of questions:

- Why not use the BLT to transfor to discrete-time domain?
  I don't know Greg's stuff, I am familiar with the properties
  of the BLT.
- Why analyze in discrete-time domain at all? Your results
  would have been seriously interesting if you could demonstrate
  similar effects in continuos-time domain; here they are amusing.
- Why not use the impulse as test signal? You refer to 'some' who
  'claim' that system with negative group delays are noncausal, as
  if you contest (or at least not support) such a view. I have
  made such claims.

Your way of phrasing opens a whole new can of worms of semantic wars
etc - why not demonstarte once and for all that systems with negative
group delays exist and can be implemented in CT? (If that indeed is
your claim, of course; I could not find out from the article what
your stand on the issue is.)

I would suggest the following:

1) Make a clear statement of the 'usual' views on the issue,
   your own opinions, and exactly what this article aims
   to demonstrate.
2) Compute the phase response of the CT system function and
   demonstrate that there is a negative group delay there.
   If you have the tools, I would also suggest you simulate
   the impulse response of that circuit in CT domain.
3) Use standard techniques in DT domain (BLT, Kronecker delta)
   and repeat your analysis.

If all the results persist (system functions show negative
group delays, anticausal behaviour) after such a re-work, I
will consider to spend some time looking into your article
in more detail.

As the article stands, it only cretates confusion. A less
benevolent reviewer than me might sugest that the instability
caused by the truncated signal is caused by poles located
outside the unit circle, and thus suggest that there is a
fundamental flaw in the argument. As you know, if you can
repeat the results using standard analysis tools and from
multiple angles of attack, it will stop those sorts of
argument at the outset.

Rune

On Mar 7, 11:18=A0pm, Andor <andor.bari...@gmail.com> wrote:
> From a recent discussion here:
>
> > >if i could generate some coefficents that had a 'negative' group delay =
for
> > >a period of time, would you think that 'phase cloning' was new and
> > >intersting??
>
> > A time machine would be pretty revolutionary, yes.
>
> > Negative group delay means that the output appears before the input
> > arrives.
>
> Fascinating concept, isn't it? I was curious enough to dig into the
> topic for a while and write up what I found out. You can read about it
> here:
>
> http://www.dsprelated.com/showarticle/54.php

Interesting piece. Just a couple of questions:

- Why not use the BLT to transfor to discrete-time domain?
  I don't know Greg's stuff, I am familiar with the properties
  of the BLT.
- Why analyze in discrete-time domain at all? Your results
  would have been seriously interesting if you could demonstrate
  similar effects in continuos-time domain; here they are amusing.
- Why not use the impulse as test signal? You refer to 'some' who
  'claim' that system with negative group delays are noncausal, as
  if you contest (or at least not support) such a view. I have
  made such claims.

Your way of phrasing opens a whole new can of worms of semantic wars
etc - why not demonstarte once and for all that systems with negative
group delays exist and can be implemented in CT? (If that indeed is
your claim, of course; I could not find out from the article what
your stand on the issue is.)

I would suggest the following:

1) Make a clear statement of the 'usual' views on the issue,
   your own opinions, and exactly what this article aims
   to demonstrate.
2) Compute the phase response of the CT system function and
   demonstrate that there is a negative group delay there.
   If you have the tools, I would also suggest you simulate
   the impulse response of that circuit in CT domain.
3) Use standard techniques in DT domain (BLT, Kronecker delta)
   and repeat your analysis.

If all the results persist (system functions show negative
group delays, anticausal behaviour) after such a re-work, I
will consider to spend some time looking into your article
in more detail.

As the article stands, it only cretates confusion. A less
benevolent reviewer than me might sugest that the instability
caused by the truncated signal is caused by poles located
outside the unit circle, and thus suggest that there is a
fundamental flaw in the argument. As you know, if you can
repeat the results using standard analysis tools and from
multiple angles of attack, it will stop those sorts of
argument at the outset.

Rune

On Mar 7, 11:18&#4294967295;pm, Andor <andor.bari...@gmail.com> wrote:
> From a recent discussion here:
>
> > >if i could generate some coefficents that had a 'negative' group delay for
> > >a period of time, would you think that 'phase cloning' was new and
> > >intersting??
>
> > A time machine would be pretty revolutionary, yes.
>
> > Negative group delay means that the output appears before the input
> > arrives.
>
> Fascinating concept, isn't it? I was curious enough to dig into the
> topic for a while and write up what I found out. You can read about it
> here:
>
> http://www.dsprelated.com/showarticle/54.php

Interesting piece. Just a couple of questions:

- Why not use the BLT to transfor to discrete-time domain?
  I don't know Greg's stuff, I am familiar with the properties
  of the BLT.
- Why analyze in discrete-time domain at all? Your results
  would have been seriously interesting if you could demonstrate
  similar effects in continuos-time domain; here they are amusing.
- Why not use the impulse as test signal? You refer to 'some' who
  'claim' that system with negative group delays are noncausal, as
  if you contest (or at least not support) such a view. I have
  made such claims.

Your way of phrasing opens a whole new can of worms of semantic wars
etc - why not demonstarte once and for all that systems with negative
group delays exist and can be implemented in CT? (If that indeed is
your claim, of course; I could not find out from the article what
your stand on the issue is.)

I would suggest the following:

1) Make a clear statement of the 'usual' views on the issue,
   your own opinions, and exactly what this article aims
   to demonstrate.
2) Compute the phase response of the CT system function and
   demonstrate that there is a negative group delay there.
   If you have the tools, I would also suggest you simulate
   the impulse response of that circuit in CT domain.
3) Use standard techniques in DT domain (BLT, Kronecker delta)
   and repeat your analysis.

If all the results persist (system functions show negative
group delays, anticausal behaviour) after such a re-work, I
will consider to spend some time looking into your article
in more detail.

As the article stands, it only cretates confusion. A less
benevolent reviewer than me might sugest that the instability
caused by the truncated signal is caused by poles located
outside the unit circle, and thus suggest that there is a
fundamental flaw in the argument. As you know, if you can
repeat the results using standard analysis tools and from
multiple angles of attack, it will stop those sorts of
argument at the outset.

Rune

On Mar 7, 11:18=A0pm, Andor <andor.bari...@gmail.com> wrote:
> From a recent discussion here:
>
> > >if i could generate some coefficents that had a 'negative' group delay =
for
> > >a period of time, would you think that 'phase cloning' was new and
> > >intersting??
>
> > A time machine would be pretty revolutionary, yes.
>
> > Negative group delay means that the output appears before the input
> > arrives.
>
> Fascinating concept, isn't it? I was curious enough to dig into the
> topic for a while and write up what I found out. You can read about it
> here:
>
> http://www.dsprelated.com/showarticle/54.php

Interesting piece. Just a couple of questions:

- Why not use the BLT to transfor to discrete-time domain?
  I don't know Greg's stuff, I am familiar with the properties
  of the BLT.
- Why analyze in discrete-time domain at all? Your results
  would have been seriously interesting if you could demonstrate
  similar effects in continuos-time domain; here they are amusing.
- Why not use the impulse as test signal? You refer to 'some' who
  'claim' that system with negative group delays are noncausal, as
  if you contest (or at least not support) such a view. I have
  made such claims.

Your way of phrasing opens a whole new can of worms of semantic wars
etc - why not demonstarte once and for all that systems with negative
group delays exist and can be implemented in CT? (If that indeed is
your claim, of course; I could not find out from the article what
your stand on the issue is.)

I would suggest the following:

1) Make a clear statement of the 'usual' views on the issue,
   your own opinions, and exactly what this article aims
   to demonstrate.
2) Compute the phase response of the CT system function and
   demonstrate that there is a negative group delay there.
   If you have the tools, I would also suggest you simulate
   the impulse response of that circuit in CT domain.
3) Use standard techniques in DT domain (BLT, Kronecker delta)
   and repeat your analysis.

If all the results persist (system functions show negative
group delays, anticausal behaviour) after such a re-work, I
will consider to spend some time looking into your article
in more detail.

As the article stands, it only cretates confusion. A less
benevolent reviewer than me might sugest that the instability
caused by the truncated signal is caused by poles located
outside the unit circle, and thus suggest that there is a
fundamental flaw in the argument. As you know, if you can
repeat the results using standard analysis tools and from
multiple angles of attack, it will stop those sorts of
argument at the outset.

Rune