Re: [Discuss-gnuradio] Coarse Frequency and related stuff

[Vanessa Gardellin]

Thank you.
Unfortunately I am still trying to make the 2x1 working because I can
receive the preamble and compute the estimate matrix but the headers
are always wrong. Did someone solve this problem?

Thank you

Vanessa

On Wed, Nov 9, 2011 at 4:01 AM, Tom Rondeau <address@hidden> wrote:
> On Tue, Nov 8, 2011 at 4:51 AM, Vanessa Gardellin
> <address@hidden> wrote:
>>
>> Do you remember which parts you did not implement?
>>
>> Apparently make the alamouti work is harder than I though...
>>
>> Thanks
>> Vanessa
>
> I know that we got the 2x1 (2 TX and 1 RX) working, and we did 1x2 with
> maximum ratio and equal gain (obviously not Alamouti). I know we were close
> with the 2x2 Alamouti, but we ran out of time and didn't manage to track
> down one of the major bugs. Neither of use has had time since to finish it.
> Tom
>
>
>>
>> On Thu, Oct 27, 2011 at 9:33 AM, Vanessa Gardellin
>> <address@hidden> wrote:
>> >> Dear all,
>> >>>
>> >>> I am trying to use the alamouti code implemented by trondeau.
>> >>> Studying the gr_ofdm_frame_acquisition I found several concepts that
>> >>> are not clear to me:
>> >>
>> >>
>> >> Wow, this code is pretty old, and we never did finish it. I hope you
>> >> get it
>> >> working! I'd love to see the results.
>> >
>> > Yes I know... I am trying to implement alamouti and this is the only
>> > thing that I have found... do you know about newer code? and/or
>> > working one?
>> >
>> >>
>> >>>
>> >>> 1)  d_phase_count: what does it mean?
>> >>
>> >> We have a look up table for various phase rotations to use in the
>> >> calculations instead of recalculating them every time. This is the
>> >> index
>> >> into the LUT.
>> >
>> > In the code you never used "d_phase_lut"... so this explain a lot of
>> > things...
>> >
>> >>
>> >>>
>> >>> 2) coarse_freq_comp(int freq_delta, int count): which is the meaning
>> >>> of this function?
>> >>
>> >> If the frequency offset is larger than a subcarrier spacing, we want to
>> >> correct for that. Once the number of subcarrier offset is found, we use
>> >> this
>> >> function to recenter it. The fine frequency correct has already been
>> >> taken
>> >> care of to center the signals to the center of a subcarrier.
>> >>
>> >>>
>> >>> 3) what "-M_TWOPI*freq_delta*d_cplen/d_fft_length" represents?
>> >>
>> >> This is the integer number of subarriers (freq_delta) and the phase
>> >> correction per subcarrier.
>> >>
>> >>>
>> >>> Thank you
>> >>>
>> >>> Vanessa
>> >>
>> >> Tom
>> >>
>> >
>> > Thanks
>> >
>> > Vanessa
>> >
>> > --
>> > Vanessa GARDELLIN, Ph.D.
>> > Researcher
>> > Institute for Informatics and Telematics (IIT),
>> > Italian National Research Council (CNR)
>> > Via G. Moruzzi 1
>> > 56124 Pisa - ITALY
>> > Phone: +390503153267
>> > Room: B65/c
>> > E-mail: address@hidden
>> > WWW: http://www.iit.cnr.it/staff/vanessa.gardellin/
>> > Skype: gardellin.vanessa
>> >
>>
>>
>>
>> --
>> Vanessa GARDELLIN, Ph.D.
>> Researcher
>> Institute for Informatics and Telematics (IIT),
>> Italian National Research Council (CNR)
>> Via G. Moruzzi 1
>> 56124 Pisa - ITALY
>> Phone: +390503153267
>> Room: B65/c
>> E-mail: address@hidden
>> WWW: http://www.iit.cnr.it/staff/vanessa.gardellin/
>> Skype: gardellin.vanessa
>
>



-- 
Vanessa GARDELLIN, Ph.D.
Researcher
Institute for Informatics and Telematics (IIT),
Italian National Research Council (CNR)
Via G. Moruzzi 1
56124 Pisa - ITALY
Phone: +390503153267
Room: B65/c
E-mail: address@hidden
WWW: http://www.iit.cnr.it/staff/vanessa.gardellin/
Skype: gardellin.vanessa