I noticed that the hestimate matrix in the 2x1 ofdm alamouti communication has crazy values like:
sym: -0.0020 + j-0.0018 ks: -1.0000 + j+0.0000 eq: +282.3798 + j-254.7796 ==> -1.0000 + j+0.0000 sym: +0.0017 + j+0.0022 ks: +0.0000 + j+0.0000 eq: +811.7408 + j-449.4426 ==> +2.3752 + j+1.0470 sym: +0.0006 + j+0.0003 ks: +1.0000 + j+0.0000 eq: +1341.1019 + j-644.1057 ==> +1.0000 + j+0.0000 sym: +0.0001 + j+0.0005 ks: +0.0000 + j+0.0000 eq: +656.4164 + j-71.1795 ==> +0.0770 + j+0.3318 sym: -0.0001 + j-0.0020 ks: +1.0000 + j+0.0000 eq: -28.2691 + j+501.7466 ==> +1.0000 + j+0.0000 meanwhile when I use a 1x1 ofdm communication I have pretty regular values sym: -0.0254 + j-0.0084 ks: -1.0000 + j+0.0000 eq: +35.4218 + j-11.7727 ==> -1.0000 + j+0.0000 sym: +0.0004 + j+0.0049 ks: +0.0000 + j+0.0000 eq: +33.7460 + j-10.3629 ==> +0.0633 + j+0.1618 sym: +0.0289 + j+0.0081 ks: +1.0000 + j+0.0000 eq: +32.0702 + j-8.9531 ==> +1.0000 + j-0.0000 sym: -0.0011 + j+0.0022 ks: +0.0000 + j+0.0000 eq: +31.4286 + j-12.1152 ==> -0.0078 + j+0.0822 sym: +0.0261 + j+0.0129 ks: +1.0000 + j+0.0000 eq: +30.7870 + j-15.2773 ==> +1.0000 + j+0.0000 do you have any idea why this happens? Any help will be appreciated Vanessa On Wed, Nov 9, 2011 at 9:44 AM, Vanessa Gardellin <[email protected]> wrote: > 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 <[email protected]> wrote: >> On Tue, Nov 8, 2011 at 4:51 AM, Vanessa Gardellin >> <[email protected]> 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 >>> <[email protected]> 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: [email protected] >>> > 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: [email protected] >>> 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: [email protected] > 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: [email protected] WWW: http://www.iit.cnr.it/staff/vanessa.gardellin/ Skype: gardellin.vanessa _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
