Update Channel coding toolbox to Gnuradio 3.7.0

GNU Radio
1

Deal all,

Does anyone update the Channel Coding
(https://www.cgran.org/wiki/chancoding)
toolbox so that it can work in Gnuradio 3.7.0?

I did try to install this toolbox. The installation was done but it do
not
appear in Gnuradio Companion interface.

Thanks,
Hoang

2

Hi Hoang,

GNU Radio 3.7 has the gr-fec framework, and recent updates brought more
performance and some features, so if that matches your use case, go
ahead and try it out!

Greetings,
Marcus

3

Thank you Marcus.

I’ve checked out gr-fec. The problem is that Decode CCSDS 27 block takes
float input while my data to feed it is in byte.

On Wed, Jun 25, 2014 at 3:23 PM, Marcus Müller
[email protected]

4

On Wed, Jun 25, 2014 at 5:27 AM, Hoang Ngo K. [email protected]
wrote:

Thank you Marcus.

I’ve checked out gr-fec. The problem is that Decode CCSDS 27 block takes
float input while my data to feed it is in byte.

If you’ve built the documentation of the latest version of GNU Radio,
look
at the Forward Error Correction page for a description of the new FEC
API.
It’s designed with exactly your issue in mind. You would write a new
deployment for the FEC of your choice to handle the data type
conversions.
In fact, the current CC decoder actually takes in bytes but the
deployment
takes in floats. The floats are intended to be soft symbols, and the
decoder deployment converts from the soft symbol floats to a quantized
soft
symbol byte that floats at a particular level.

Tom

5

Thank you Tom.
I’ve modified the Decode CCSDS 27. In particular, I changed the code in
implementation file (.cc):

Existing code:

unsigned char sym = (unsigned char)(floor(sample));
    // printf("%li\n", *(out-1), metric);
  }
}

d_count++;
  }

My code:

    byte = in[ni];
  }
}

ni ++;

d_count++;

}

I also modify the header file, xml file. Now the new block appear in
GRC.
I build a flow graph (see in attachment) to test this block. When I run
this flowgraph, I got this error:

init::console_sink_bb
Traceback (most recent call last):
File “/home/khachoang/GNU_Radio/Test GRC/top_block.py”, line 58, in

tb = top_block()
File “/home/khachoang/GNU_Radio/Test GRC/top_block.py”, line 43, in
init
self.connect((self.fec_encode_ccsds_27_bb_0, 0),
(self.fec_decode_ccsds_27_bb_0, 0))
File
“/usr/local/lib/python2.7/dist-packages/gnuradio/gr/top_block.py”,
line 130, in connect
self._connect(points[i-1], points[i])
File
“/usr/local/lib/python2.7/dist-packages/gnuradio/gr/top_block.py”,
line 142, in _connect
dst_block.to_basic_block(), dst_port)
File
“/usr/local/lib/python2.7/dist-packages/gnuradio/gr/runtime_swig.py”,
line
4100, in primitive_connect
return _runtime_swig.top_block_sptr_primitive_connect(self, *args)

ValueError: itemsize mismatch: encode_ccsds_27_bb0:0 using 1,
decode_ccsds_27_bb0:0 using 4
Is my code correct? How could I fix this bug?

Thanks
,
Hoang

6

On Fri, Jun 27, 2014 at 11:24 PM, Hoang Ngo K. [email protected]
wrote:

// Translate and clip [-1.0..1.0] to [28..228]
  viterbi_butterfly2(d_viterbi_in, d_mettab, d_state0, d_state1);
  }

    // long metric =

I also modify the header file, xml file. Now the new block appear in GRC.
self.connect((self.fec_encode_ccsds_27_bb_0, 0),
return _runtime_swig.top_block_sptr_primitive_connect(self, *args)

ValueError: itemsize mismatch: encode_ccsds_27_bb0:0 using 1,
decode_ccsds_27_bb0:0 using 4
Is my code correct? How could I fix this bug?

Thanks
,
Hoang

First, I’d say in the long run, you’re still better off looking into the
FEC API. Right now, you’ll have to build the new manual yourself as we
don’t have it published yet online, but the Forward Error Correction
section in the new manual explains how you could build a deployment to
use
the FEC codes you need. Then, you wouldn’t have to have a patch on an
existing block.

That having been said, the FEC API is brand new, so there’s not much
more
help or examples than what’s in the manual and in the code right now. So
we
should at least be able to get you going with where you are now.

Most likely, the problem is in the constructor of the block you’re
editing.
Look for the io_signature line. You’ll see a ‘sizeof(float)’ there.
Change
that to ‘sizeof(char)’ and that should work for you.

Tom