I am trying to implement ofdm using grc blocks. I am getting an error in insert preamble block saying
TypeError: in method 'ofdm_insert_preamble', argument 2 of type 'std::vector< std::vector< gr_complex,std::allocator< gr_complex > >,std::allocator< std::vector< gr_complex,std::allocator< gr_complex > > > > const &
I have attached the grc file. what should i give as input to flag input of insert preamble block and also how to connect the output flag of insert preamble block. How does that flag work in the block.
ofdm1.grc