Re: [Discuss-gnuradio] Offest Multiple Access Channel

[Nathan West]

On Thu, Apr 4, 2013 at 12:45 PM, Manu T S <address@hidden> wrote:

Hi Everyone,

I need help regarding a problem.

It's a Multiple Access Channel problem but one of the source is offset by half a symbol period.

########################################################

source1 ---> bytes_to_chunks(1) ----> chunks_to_symbol ---
                                                                                             |

                                                                                              ---> black_box --->

                                                                                             |

source2 ---> bytes_to_chunks(1) ----> chunks_to_symbol ---

########################################################

I want to add these to outputs such that the the symbol corresponding to souce2 falls between two symbols of source1.

There will be RRC waveform corresponding to every bit out of the source. The RRC waveform corresponding to a bit in source2 should fall between RRC waveform corresponding to 2 bits of source1 ( preferably at the midpoint ).

I guess I can not do a streams to stream converter, before RRC, because what that would give me a channel with twice the bandwidth of a single channel.

Should I work on a new RRC filter block with 2 inputs or is there any other way to do this?

New ideas to achieve this is also welcome.

--
Manu T S

Unless I'm misunderstanding it sounds like you want to interleave bytes.
http://gnuradio.org/doc/sphinx/gr/slicedice_blk.html?highlight=interleave#gnuradio.gr.interleave

Available in GRC Stream Conversions>Interleave

-nw