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

on 2007-02-21 03:20