Fwd: Question Concerning Custom Modulator Block

Forgot to hit reply all.

On Wed, Feb 19, 2014 at 3:30 AM, Martin B.
[email protected]wrote:

800 items (samples).

Do I make sure noutput_items is equal to number of samples I wish to
I am going to feed directly to the USRP sink, so a vector output is not
shaping filter.

M


Discuss-gnuradio mailing list
[email protected]
Discuss-gnuradio Info Page

Both sampling rate and symbol rate is variable, at least I intend it to
be.
The figurative “N” is calculated at runtime inside general_work()
because
it is related to the sampling rate. N is representative of the
number samples that the modulator produces. Any code I have written
takes
place inside the general_work() routine.

The 800 samples that make up the waveform is just an arbitrary number I
came up with as an example to explain how many samples I have to get
out.
In my modulator code, my basis functions will generate the same amount
of
samples as the samples of the bit stream. For prototyping purposes in
MATLAB, I had a 100 samples per each bit of the input. So an input of 8
bits after processing was going to give out 800 samples. In my block
code
this will be controlled by a variable argument.

I know the I/O signature would control that part. So noutput_items is
set
in the IO signature, the size of it increases when a vector output is
set.
So if I call set_output_multiple in my constructor and have it set the
size
of my modulated waveform sample size, will it handle my problem? Is
there
any block I should look at that has it?

On 02/20/2014 01:49 PM, Jonathan F. wrote:

I know the I/O signature would control that part. So noutput_items is
set in the IO signature, the size of it increases when a vector output
is set. So if I call set_output_multiple in my constructor and have it
set the size of my modulated waveform sample size, will it handle my
problem? Is there any block I should look at that has it?

Perhaps my reply to “Activecat” just know will help. Other than that, I
say you just start hacking and see where you end up :slight_smile:

M

On Thu, Feb 20, 2014 at 2:33 PM, Martin B.
[email protected]wrote:

M


Discuss-gnuradio mailing list
[email protected]
Discuss-gnuradio Info Page

Alright, I will take this as my cue to get back to work. I will find
that
email and take a look. Thanks for the help, I got a lot out of it.

Jon