Hello Cinaed, Thank you for the response,
I have detailed your Flowgraph, and I placed a "QT GUI Constellation Sink" after the chunks to symbols block, and what I found is that the modulation part only modulates in B-PSK, and this is beacuse you set it in the "Chunks to symbol block" with a dimension of "1", once I placed different "Symbol Table" and a "dimension" of 2 in the "Chunk to symbol block" the correct modulation appeared, but the BER gave really high values (even if in the "Constellation Decoder" is set to QPSK or DQPSK). I believe you only modulated in BPSK and in the decoder it matched the constellation points for -1 and 1, but not for any other constellation points, I would appreciate if you correct me if i am wrong. Kind regards. On Mon, Jan 28, 2019 at 5:12 AM Cinaed Simson <cinaed.sim...@gmail.com> wrote: > On 1/27/19 7:03 PM, Luis Felipe Albarracin Sanchez wrote: > > Hello Cinaed, > > > > Thank you so much for all the work in the BER, i tested both of the > > flowgraphs and they are very accurate regarding the BER measurements, i > > have a couple of questions if you don´t mind: > > > > 1- In the latest flowgraph you sent (my-ber-test.grc from Jan 25th) how > > do you change the modulations in the chunks to symbols block, in the > > flowgraph you sent me the flowgraph table was fixed with the values of > > "-1, 1", what line of commands should be place there to switch to other > > modulations? > > Correct - I already explain why. > > > > 2- The BER measurements you sent me seem so accurate, > > As I already indicated, you still need to add a complex gaussian noise > source. > > I wonder if you > > could take a look at the flowgraph i sent you > > No, use the last flowgraph I sent you. > > > > (my_ber_simulation_LFA.grc), what i did there was connecting a QT GUI > > Chooser to the functions i thougth would change the constellation > > selected, do you have any ideas why my change is not working, when i > > change in the QT GUI Chooser?, i would appreciate your help regarding > this. > > > > 3- Attached is a flowgraph i have devloped for doing modulations up to > > 64 QAM, please take a look at it, and if you have any ideas on how i > > would make a good BER measurement of higher modulations (32 -QAM and > > 64-QAM) please let me know. To select the modulatios, the easiest way is > > to define in the default value of the QT GUI chooser the value of 3 (for > > 32-QAM) and the value of 4 (for 64 QAM). > > I not going to look your flowgraph - you should be able to add the QAM > constellations to the last flowgraph I sent you. > > And to be clear, I don't believe can change the modulation of the > flowgraph with QT. Since you're the believer, the burden of proof is on > you. > > You need to first demonstrate you can add the 64QAM, and 32QAM to the > last flowgraph I sent you with DER 0. > > Then add whatever QT modifications you need to make QT change the > modulation and demonstrate the BER is 0. > > Or just demonstrate you can add QT code which changes the modulation to > last flowgraph I set you. If can't make the changes so it has BER of 0, > adding different of more modulations isn't going to help. > > -- Cinaed > > > > > > > > Once again thanks a lot for all the help. > > > > Kind regards. > > > > On Fri, Jan 25, 2019 at 3:20 PM Cinaed Simson <cinaed.sim...@gmail.com > > <mailto:cinaed.sim...@gmail.com>> wrote: > > > > It bothered me that the random source wasn't working. > > > > So I took at it again last night and discovered I needed to unpack a > bit > > from the random source stream. > > > > Using the random source, the following work: > > > > BPSK > > QPSK > > 8PSK > > 16QAM > > > > using the pull down menu. > > > > There is, however, one caveat: for 8PSK you have to enable the > complex > > Multiply Const by -1 block after the Chunks to Symbols block. > > > > Alternatively, you could change Chunks to Symbols from -1,1 to 1,-1 - > > but that's many more key strokes then just enabling and disabling the > > Multiply Const block. > > > > They all work with the GLFSR source too and with the same caveat. > > > > And you were right you don't need the PSK symbol table - you can use > > Chunks to Symbols -1,1 (except for 8PKS.) > > > > Also, I had to add a unpack k=1 block after the decoder - otherwise > for > > DPSK, 8PSK and 16QAM there was a vertical offset and BER sky rockets. > > > > The unpack k=1 is not needed for BPSK and QPSK - but it doesn't > create > > any problems so I left it enabled. > > > > You just need to add the complex noise source > > > > Have fun with QT. > > > > Actually, there is already a QT menu - the properties of > Constellation > > Object. You might want to look at the source - just figure what you > need > > to do to keep it open. > > > > -- Cinaed > > > > > > > > -- > > Eng. Luis Felipe Albarracin > > Msc. Telematics / MBA > > PMP > > CCNA/CCDA/CCNP/CCDP/CCIP > > ITIL v3 Foundation > > "Die Grenzen meiner Sprache bedeuten die Grenzen meiner Welt" > > -- Eng. Luis Felipe Albarracin Msc. Telematics / MBA PMP CCNA/CCDA/CCNP/CCDP/CCIP ITIL v3 Foundation "Die Grenzen meiner Sprache bedeuten die Grenzen meiner Welt"
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