HI Adrian good stuff!
OK, now try the analog versus the digital, with a copy of the TX signal at 30uS delay and -10dB with respect to the wanted signal.... (a common multipath ) , and also 30uS delay and 0dB. Let me know... On 15/09/2017 9:10 PM, Adrian Musceac wrote: > Hi, > > I present a three way comparison between narrow band FM (5 kHz), QPSK > Codec2 1300 (2.4 kHz) and QPSK Opus 19 kbit/s (16 kHz): > > https://www.youtube.com/watch?v=vApRe6R1gnk > > The comparison is taking place in the ISM band of 433 MHz with > interference present from some temperature sensors in an adjacent > channel. > > Conditions: same antenna locations, same RX chain gain, varying > transmit gain (LCD like number on the top left of the screen) > > Results: both digital modes cope better with interference and are more > intelligible than FM. The numbers on top left of RX application are > expressed in dB of amplification in the SDR transmitter chain. > > Hardware: for transmit one USRP B200 with 433 MHz filter installed, > for RX one RTL-SDR filter with 433 filter installed. > Software: QRadioLink running on top of Gnuradio (GNU/Linux): > https://github.com/kantooon/qradiolink > > 73, > Adrian YO8RZZ > > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > > _______________________________________________ > Freetel-codec2 mailing list > Freetel-codec2@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Freetel-codec2 mailing list Freetel-codec2@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freetel-codec2
