Re: [Discuss-gnuradio] packed_to_unpacked--->chunks_to_symbols

[Vincenzo Pellegrini]

that'd be fantastic Achilleas..!

I was just wondering how I could do all that stuff besore qpsk and
ofdm..!

I'm so thankful.. :)

I modified the way i create the array and used the endianness constant
as you said.

I'm trying to do what you suggested to check this first bit of work..
the point is that I don't know how to set up the array of bytes that I
should write to the file for the single symbol received.

I think my problem is how to build up the "constellation_bytes" array in
the code below:


        Nfft=2048
        
        
        file_source_bytewise=gr.file_source(gr.sizeof_char,
"/mnt/root/gnuradio_datastreams/a.txt")
        file_sink=gr.file_sink(gr.sizeof_char,
"/mnt/root/gnuradio_datastreams/aa.txt")
        file_chunker=gr.packed_to_unpacked_bb(2,gr.GR_LSB_FIRST) #second
argument is endianness
       
        constellation=(1+1j,1-1j,-1-1j,-1+1j)
        constellation_bytes=(0x0,0x01,0x11,0x10)
        print constellation
        symbol_mapper=gr.chunks_to_symbols_bc(constellation, 1) #second
argument is dimension of the output symbol within the constllation
matrix


symbols_to_bytes=gr.constellation_decoder_cb(constellation,constellation_bytes)

        series_to_parallel=gr.stream_to_vector(8,Nfft)
        parallel_to_series=gr.vector_to_stream(8,Nfft)

        series_to_parallel_2=gr.stream_to_vector(8,Nfft)
        parallel_to_series_2=gr.vector_to_stream(8,Nfft)

        window=Numeric.ones(Nfft,Numeric.Float64)
        inverse_fft=gr.fft_vcc(Nfft,False,window )
        direct_fft=gr.fft_vcc(Nfft,True,window )

        gain=gr.multiply_const_cc(200)
 
        

        self.connect(file_source_bytewise,file_chunker,symbol_mapper)

self.connect(symbol_mapper,series_to_parallel,inverse_fft,parallel_to_series,gain)
 

self.connect(gain,series_to_parallel_2,direct_fft,parallel_to_series_2,symbols
_to_bytes,file_sink)


really what I don't understand is how can I manage to write pairs of
bits instead of bytes to my file (I'm using qpsk....) do I need a
unpacked to packed block?

thanks a lot for help
vincenzo