Re: [Discuss-gnuradio] About DPSK mod and demod

[Henry Jin]

I tried again replacing the DPSK module with PSK module. Still cannot get the correct data. The parameter for Error Rate "Bits per Symbol" is changed to 8 since every bit carries information in my flow. The sizes of the files from the two file sinks are exactly the same, except with different data.

On Tue, Dec 3, 2013 at 10:11 PM, Nick Foster <address@hidden> wrote:

Can you try using the PSK mod/demod blocks with differential=Yes instead of the DPSK mod/demod blocks? I found an issue today with the DPSK mod/demod blocks which results in them not actually using differential encoding.

--n

On Tue, Dec 3, 2013 at 9:00 PM, Henry Jin <address@hidden> wrote:

Hi, 

I tried to build a simple flow graph of DPSK modulation and demodulation. The result is verified using the Error Rate module. The link shows the flow I'm using.

https://www.dropbox.com/s/jwmmttyi4es4alf/Screenshot%20from%202013-12-03%2021%3A50%3A58.png

I know that the output of demod module is unpacked bytes, so an "unpacked to packed" module is attached after demodulation. However, the BER is close to 50%, which surely indicates something wrong. I further analyzed the two inputs of the Error Rate module by writing info to the file sink. It clearly shows the discrepancy. So I just wonder what is wrong with this flow graph. Could someone please help me?

Also, as I noticed, in the output file generated after "unpacked to packed" module, there are many consecutive 0s at the start of the file. Does that indicate something?

Suggestions are greatly appreciated!

Henry

_______________________________________________
Discuss-gnuradio mailing list
address@hidden
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio