Ah, after re-reading the Header/Payload Demux docs, I noticed the trigger port is optional. The block will trigger on tags connected to the input stream.
What seems like the best strategy to me now is this: 1) Detect the header with a correlator and add a tag at the start 2) Feed the output of the correlator into the input port of the Header/Payload Demux block 3) Process the out header port and generate a message that feeds into the message port of the Header/Payload Demux block 4) The Header/Payload Demux block then releases the corresponding number of payload samples through the payload port. I haven't touched messages before so this should be interesting. I welcome any feedback or common pitfalls to avoid. Rich On Wed, Mar 4, 2015 at 10:54 AM, Richard Bell <[email protected]> wrote: > No I haven't. I was hoping to keep this a self contained grc radio, > because it makes my life easier. I will look at the benchmark scripts > though. > > Thanks, > Rich > > On Wed, Mar 4, 2015 at 9:58 AM, Marc Newlin <[email protected]> wrote: > >> Have you looked at the narrowband example scripts? The >> benchmark_[rx|tx].py scripts support packetized QPSK. >> >> On Wed, Mar 4, 2015 at 11:54 AM, Richard Bell <[email protected]> >> wrote: >> >>> Hi all, >>> >>> As the subject states, how have you detected packets in your packet >>> based gnu radio SDR? >>> >>> The only example I have come across is Tom's OFDM packet detect in the >>> digital examples folder. There, he uses an OFDM specific block to generate >>> the trigger signal for the Header/Payload demux. >>> >>> >>> My use case is very basic. I have a QPSK radio that I am using to >>> measure the performance of different source codes. What I want to do is >>> transmit a file (USRP N210) from the Tx and on the Rx dump the received >>> signal into a file only after detection of the start of the file. I don't >>> want a lot of garabage data before the file actually starts. To stop the >>> dump, I would be happy detecting an end of file condition or using a smart >>> preamble with the file length specified. Doesn't matter to me. >>> >>> If you have any advice for my case, I would appreciate that. >>> >>> v/r, >>> Rich >>> >>> _______________________________________________ >>> Discuss-gnuradio mailing list >>> [email protected] >>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >>> >>> >> >
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