Re: [Discuss-gnuradio] transmitting a bit stream

[Tom Rondeau]

Atita Shirwaikar wrote:
> Hi
>
> I am new to GNU radio.I was aiming to transmit a string of ones using
> BPSK modulation.
> I am not using benchmark_tx.py for this as i do not want to send any
> headers etc.
> I just need to transmit a continuous stream of all ones...
>
> I am using gr.vector_source_b to generate this bit stream.Then unpacking
> it using gr.packed_to_unpacked
> followed by chunks_to_symbols.
> Am writing the output from chunks_to_symbols to the usrp sink..
>
> I cannot seem to get this working..Is this the right way to do it?
>   

You'll likely need to interpolate it. Follow the example in 
gnuradio-core/src/python/gnuradio/blks2impl/dbpsk.py where we root raise 
cosine filter it and interpolate by some number of samples per symbol. 
You'll need to match this sampling rate and the interpolation value in 
the USRP to get to the 128 Msps DAC.

Transmitting a string of 1's is a bit of an odd application. What are 
you aiming to do with that?

Tom