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

[Tom Rondeau]

On Wed, Dec 4, 2013 at 12:52 PM, Henry Jin <address@hidden> wrote:
> 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.

Bits/symbol refers to the constellation. BPSK is 1 bit/sym, QPSK is 2
bit/sym, etc.

Tom


> 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
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>>>
>>
>
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