What is Zero-Forcing (ZF)?

What means Zero-Forcing (ZF)?

Thanks,
Luca

On Fri, 01 Aug 2003 13:19:06 GMT, Luca <luksaiyan@libero.it> wrote:

>What means Zero-Forcing (ZF)?

In what context?


Best Regards
John McCabe

To reply by email replace 'nospam' with 'assen'

Luca wrote:
> What means Zero-Forcing (ZF)?
>
> Thanks,
> Luca
Do you mean this?
(ZIF) A kind of socket for integrated circuits. A ZIF socket can be opened
and closed by means of a lever or screw. When open, there the chip may be
placed in the socket without any pressure at all, the socket is then closed,
causing its contacts to grip the pins of the chip. Such sockets are used
where chips must be inserted and removed frequently, such as in test
equipment. They are more expensive and usually take up more space than
conventional IC sockets.

ciao Ban

Luca wrote:

> What means Zero-Forcing (ZF)?

That is not a Jedi, yet.

bye,

-- 
   Piergiorgio Sartor

"Luca" <luksaiyan@libero.it> wrote in message
news:o4qkiv00q99vonbqqc5fnd2lneks2hhus2@4ax.com...
> What means Zero-Forcing (ZF)?
>
> Thanks,
> Luca

Are you referring to a zero-forcing equalizer (ZFE) or something else?

Cheers
Bhaskar

Excuse me ... :-)

I'm referring to the Zero-Forcing decoder or equalizer: what is the
algorithm, what is the idea ... what does he work??? :-)

Thanks,
Luca


Il Fri, 1 Aug 2003 09:16:46 -0700, "Bhaskar Thiagarajan"
<bhaskart@deja.com> ha scritto:

>"Luca" <luksaiyan@libero.it> wrote in message
>news:o4qkiv00q99vonbqqc5fnd2lneks2hhus2@4ax.com...
>> What means Zero-Forcing (ZF)?
>>
>> Thanks,
>> Luca
>
>Are you referring to a zero-forcing equalizer (ZFE) or something else?
>
>Cheers
>Bhaskar
>

Hello Luca,

If the channel has a response H(s), the zero forcing EQ is attempting to
match the response 1/H(s). So, the influence of the channel is
completely canceled ideally.

Obviously this is not the best algorithm, since it optimizes the
response. The optimal equalizer should optimize the SNR.

Vladimir Vassilevsky, Ph.D.

DSP and Mixed Signal Design Consultant

http://www.abvolt.com




Luca wrote:
> 
> Excuse me ... :-)
> 
> I'm referring to the Zero-Forcing decoder or equalizer: what is the
> algorithm, what is the idea ... what does he work??? :-)
> 
> Thanks,
> Luca
> 
> Il Fri, 1 Aug 2003 09:16:46 -0700, "Bhaskar Thiagarajan"
> <bhaskart@deja.com> ha scritto:
> 
> >"Luca" <luksaiyan@libero.it> wrote in message
> >news:o4qkiv00q99vonbqqc5fnd2lneks2hhus2@4ax.com...
> >> What means Zero-Forcing (ZF)?
> >>
> >> Thanks,
> >> Luca
> >
> >Are you referring to a zero-forcing equalizer (ZFE) or something else?
> >
> >Cheers
> >Bhaskar
> >

> If the channel has a response H(s), the zero forcing EQ is attempting to
> match the response 1/H(s). So, the influence of the channel is
> completely canceled ideally.
> Obviously this is not the best algorithm, since it optimizes the
> response. The optimal equalizer should optimize the SNR.

Buongiorno,
according to what I remember about this subject, ZF equalizers should never
be used since the noise power could become infinite.

E.

On Sat, 02 Aug 2003 09:32:54 -0500, Vladimir Vassilevsky
<vlv@abvolt.com> wrote:

>Hello Luca,
>
>If the channel has a response H(s), the zero forcing EQ is attempting to
>match the response 1/H(s). So, the influence of the channel is
>completely canceled ideally.
>
>Obviously this is not the best algorithm, since it optimizes the
>response. The optimal equalizer should optimize the SNR.
>
>Vladimir Vassilevsky, Ph.D.

"Best" should be evaluated in the context of the application.  If ISI
drives the performance of a system (as it often does) then a
Zero-Forcing equalizer can be a very good solution, I would even argue
that it is sometimes "best".


Eric Jacobsen
Minister of Algorithms, Intel Corp.
My opinions may not be Intel's opinions.
http://www.ericjacobsen.org

"Vladimir Vassilevsky" <vlv@abvolt.com> wrote in message
news:3F2BCB96.8CF92DB5@abvolt.com...
> Hello Luca,
>
> If the channel has a response H(s), the zero forcing EQ is attempting to
> match the response 1/H(s). So, the influence of the channel is
> completely canceled ideally.
>
> Obviously this is not the best algorithm, since it optimizes the
> response. The optimal equalizer should optimize the SNR.
>
> Vladimir Vassilevsky, Ph.D.
>
> DSP and Mixed Signal Design Consultant
>
> http://www.abvolt.com

Vladimir,

This sounds like an equalizer to get low intersymbol interference.  That's a
pretty typical application.

It appears you're assuming that the pulse waveform into the "system" has
zero intersymbol interference.  That may not be the case.  Then 1/H(s)
wouldn't be the solution.

Fred