# One Tap Equalizer in OFDM

Started by April 1, 2007
```hi all,

Generally i have coded my OFDM system, but i have some problem in
understanding about the one tap equalizer.

Actually i know how to generate a ZF equalizer , but i would like to know
how to generate MMSE equalizer, even i have the algorithm , but i dont
understand the symbol stand for,hence i cant code in matlab

&#1043;=E[||X||]^2

G= [&#1043;^0.5 * conj(H)] / &#1043;||H||^2+ &#1073;^2

The question i would like to ask is ,the E stand for what in the system.
is it the variance of the X or the mean of the X or the Standard
derivation of the X or neither it...

I am comfuse on it.

Thank you

_____________________________________
Do you know a company who employs DSP engineers?
Is it already listed at http://dsprelated.com/employers.php ?
```
```On Apr 1, 3:05 am, "ericknightX" <wil...@gmail.com> wrote:
> hi all,
>
> Generally i have coded my OFDM system, but i have some problem in
> understanding about the one tap equalizer.
>
> Actually i know how to generate a ZF equalizer , but i would like to know
> how to generate MMSE equalizer, even i have the algorithm , but i dont
> understand the symbol stand for,hence i cant code in matlab
>
> &#1043;=E[||X||]^2
>
> G= [&#1043;^0.5 * conj(H)] / &#1043;||H||^2+ &#1073;^2
>
> The question i would like to ask is ,the E stand for what in the system.
> is it the variance of the X or the mean of the X or the Standard
> derivation of the X or neither it...
>
> I am comfuse on it.
>
> Thank you
>
> _____________________________________
> Do you know a company who employs DSP engineers?
> Is it already listed athttp://dsprelated.com/employers.php?

so I can only guess that E[.] means Expectation (mean).
Note that you have E[ ||X||^2 ] which means Expectation
of the square norm of X.

```
```>On Apr 1, 3:05 am, "ericknightX" <wil...@gmail.com> wrote:
>> hi all,
>>
>> Generally i have coded my OFDM system, but i have some problem in
>> understanding about the one tap equalizer.
>>
>> Actually i know how to generate a ZF equalizer , but i would like to
know
>> how to generate MMSE equalizer, even i have the algorithm , but i dont
>> understand the symbol stand for,hence i cant code in matlab
>>
>> &#1043;=E[||X||]^2
>>
>> G= [&#1043;^0.5 * conj(H)] / &#1043;||H||^2+ &#1073;^2
>>
>> The question i would like to ask is ,the E stand for what in the
system.
>> is it the variance of the X or the mean of the X or the Standard
>> derivation of the X or neither it...
>>
>> I am comfuse on it.
>>
>> Thank you
>>
>> _____________________________________
>> Do you know a company who employs DSP engineers?
>> Is it already listed athttp://dsprelated.com/employers.php?
>
>
>so I can only guess that E[.] means Expectation (mean).
>Note that you have E[ ||X||^2 ] which means Expectation
>of the square norm of X.
>
>

erm...actually the main problem is come from r =E[||X||]^2 ,but as u say
E[||X||]^2 stand for the expectation of the square norm of x. so in matlab
is that show in this way : norm(abs(x).^2)

thank you

_____________________________________
Do you know a company who employs DSP engineers?
Is it already listed at http://dsprelated.com/employers.php ?
```
```Hi all
I don't understand your characters if you could write with normal
characters, to use MMSE the equation bellow describe the Equalizer
technique
W(n)=conj H(n)/|H(n)|^2+1/EbN0
where h is the channel gain.
If you have any other query do not hesitate to contact me, and if you need
a paper regarding this field i will send it to you.
Regards,
Z.

>On Apr 1, 3:05 am, "ericknightX" <wil...@gmail.com> wrote:
>>> hi all,
>>>
>>> Generally i have coded my OFDM system, but i have some problem in
>>> understanding about the one tap equalizer.
>>>
>>> Actually i know how to generate a ZF equalizer , but i would like to
>know
>>> how to generate MMSE equalizer, even i have the algorithm , but i
dont
>>> understand the symbol stand for,hence i cant code in matlab
>>>
>>> &#1043;=E[||X||]^2
>>>
>>> G= [&#1043;^0.5 * conj(H)] / &#1043;||H||^2+ &#1073;^2
>>>
>>> The question i would like to ask is ,the E stand for what in the
>system.
>>> is it the variance of the X or the mean of the X or the Standard
>>> derivation of the X or neither it...
>>>
>>> I am comfuse on it.
>>>
>>> Thank you
>>>
>>> _____________________________________
>>> Do you know a company who employs DSP engineers?
>>> Is it already listed athttp://dsprelated.com/employers.php?
>>
>>
>>so I can only guess that E[.] means Expectation (mean).
>>Note that you have E[ ||X||^2 ] which means Expectation
>>of the square norm of X.
>>
>>
>
>erm...actually the main problem is come from r =E[||X||]^2 ,but as u say
>E[||X||]^2 stand for the expectation of the square norm of x. so in
matlab
>is that show in this way : norm(abs(x).^2)
>
>thank you
>
>
>_____________________________________
>Do you know a company who employs DSP engineers?
>Is it already listed at http://dsprelated.com/employers.php ?
>

```