Tom Rondeau wrote: > Matt Ettus wrote: >> Eric A. Cottrell wrote: >> >>> Hello, >>> >>> The processing of pulses into data requires me to keep track of valid >>> pulses (following samples are above threshold) and leading edges (sample >>> is 6 dB or more than previous sample and following sample is 6 dB or >>> less than current sample). I also want to indicate preamble start and >>> pass timestamps along. I have thought of three methods to do this but >>> do not know which would be the best one. >>> >>> >> >> You can do this, or you may be able to break things up into chunks of >> samples and process them as vectors. See the ofdm_sync code for an >> example of how we do that. > > Also, off the top of my head, you might find the peak_detector and > sample_and_hold blocks useful for what you're doing. If these won't do > what you need, that at least the S/H block illustrates the use of > different streams where input stream 0 is some data type (float, > gr_complex, bytes, ints) and input stream 1 is a byte stream > (sizeof_char) as the control line. > > Tom Hello,
Thanks for the suggestions and observations. I will look at the OFDM code and other blocks. This is getting to be a big project. PPM is so simple but there are some interesting enhanced receiving techniques to squeeze the last drop of performance. I took a text description and turned it into code so no doubt there are other functions I can use to optimize the current code. I want to add capability to time stamp the frames and get signal levels so I am modifying the code again. I also want to comment it so others can figure out what is going on. Sorry it is taking some time to get the code ready but I want the code structure to be set before check-in. I am still figuring out GNURadio and Python so I looked at the cfile example and used it to improve my log program. I noticed that I may be able to use a higher sample rate if I go with the 4rx0tx USRP file. A future enhancement may be to put the AM detector in the USRP and just send shorts over the USB bus. I want to try 10 or 16 MSPS rate to see if performance improves. I want to try the OFDM code anyway and see if I get any data off the BPSK carriers of IBOC AM stations used for station information. 73 Eric _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
