Hello! About frequencies pay attention that there are more than a single (406.025 MHz) frequency. In my direct experience there's also 406.028 / 406.039 MHZ in use. So also tuning has to be on the right frequency.
Take a look also at https://www.ntia.doc.gov/files/ntia/publications/compendium/0406.00-0406.10_01MAR14.pdf , but I suppose that also this document isn't up-to-date... 2017-04-23 17:07 GMT+02:00 Marcus Müller <marcus.muel...@ettus.com>: > Had to google that; for the others: http://www.epirb.com/ > > Emergency Position Indicating Radio Beacon ; 406 MHz, bursty, wikipedia > says: > > > The digital distress message generated by the beacon varies according > to the above factors and is encoded in 30 hexadecimal characters. The > unique 15-character digital identity (the 15-hex ID) is hard-coded in > the firmware of the beacon. The 406.025 MHz carrier signal is modulated > plus or minus 1.1 radians with the data encoded using Manchester > encoding, which ensures a net zero phase shift aiding Doppler location > > So, a PSK that can only take values of +1.1 and -1.1, relative to the > "idle" carrier. Bit rate is 400b/s, so that makes it a 800 S/s PSK > symbol rate (manchester-encoding happening in between). > > Cheers, > Marcus > > [1] > http://www.cospas-sarsat.int/images/stories/SystemDocs/ > Current/cs_t.001_oct_2013.pdf > > On 04/23/2017 04:48 PM, Vicfield Medici wrote: > > Hi, > > > > When trying to decode the signal, I always use the PLL Carrier Tracking > to > > solve the error > > about phase shifting, and it’s always doing a good job. > > > > But I start trying to decode the EPIRB signal, I just got a sample with > only > > one burst, > > and PLL seems not work anymore even I tuned the parameter in many ways. > > > > Does the PLL Carrier Tracking can’t handle the discontinuous signal > somehow? > > Or it’s my misunderstanding? > > > > I really want to know how to take that, thanks for any help. > > > > Regards, > > > > Vicfield > > > > > > > > > > -- > > View this message in context: http://gnuradio.4.n7.nabble. > com/The-PLL-for-the-burst-signal-tp63604.html > > Sent from the GnuRadio mailing list archive at Nabble.com. > > > > _______________________________________________ > > Discuss-gnuradio mailing list > > Discuss-gnuradio@gnu.org > > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >
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