Re: [Discuss-gnuradio] Verifying Turbo encoder output (was: Re: (no subject)

[Salija P]

Thank you very much.. I got it

With Regards,

Salija.P

On Tue, Jun 23, 2015 at 10:00 PM, Achilleas Anastasopoulos <address@hidden> wrote:

Salija,

the notation

interleaver(666)

is one way to generate a random interleaver with a given seed (666 in this case).

The pccc block requires two FSM (finite state machine) specifications (one for each of the constituent codes)

and an interleaver specification.

You can give the interleaver specification either through a file or by letting gnuradio generate a random one.

The interleaver class (pretty straighforward) has been implemented in the files:

gr-trellis/include/trellis/gnuaradio/interleaver.h
gr-trellis/lib/interleaver.cc

I am copying the class definition below:

------------------

/*!
     * \brief  INTERLEAVER class
     * \ingroup trellis_coding_blk
     */
    class TRELLIS_API interleaver
    {
    private:
      int d_K;
      std::vector<int> d_INTER;
      std::vector<int> d_DEINTER;

    public:
      interleaver();
      interleaver(const interleaver & INTERLEAVER);
      interleaver(int K, const std::vector<int> & INTER);
      interleaver(const char *name);
      interleaver(int K, int seed);
      int K () const { return d_K; }
      const std::vector<int> & INTER() const { return d_INTER; }
      const std::vector<int> & DEINTER() const { return d_DEINTER; }
      void write_interleaver_txt(std::string filename);
    };

--------------------

as you can see there are 5 possible constructors:

interleaver();
interleaver(const interleaver & INTERLEAVER);
interleaver(int K, const std::vector<int> & INTER);
interleaver(const char *name);
interleaver(int K, int seed);

the first 2 are trivial and copy constructor,
the third construct an interleaver from a vector with specified permutations and
the fourth one from a file with specified permutations.

The last one constructs it from a random permutation with a given seed (please see .cc code for details).

Let us know if you have any more questions.

Achilleas