Hi, Do you have a particular device in mind? Anything that is supported by Osmosdr can be tested, but I only have AD9364 and Lime Micro devices available.
73, Adrian On 9/18/17, Helmut Oeller <dc...@gmx.de> wrote: > Hi, > > IMO objective and severe comparison in presence of interference can only > succeed using appropriate SDR hardware. These USB sticks are not developed > for narrow bandwidths due to very low SFDR, phase noise of LO etc. > > 73, Helmut > > -----Ursprüngliche Nachricht----- > Von: Adrian Musceac [mailto:kanto...@gmail.com] > Gesendet: Montag, 18. September 2017 11:01 > An: freetel-codec2@lists.sourceforge.net > Betreff: Re: [Freetel-codec2] Comparison between digital voice and analog > narrowband FM on weak signals with interference > > Hi, > > Helmut, for me RTL-SDR support is required. I will not be testing with > another SDR hardware for reception as my application is meant to work with > the USB stick (small dynamic range or not). > > Glen, have a look at > http://www.etsi.org/deliver/etsi_etr/300_399/30001/01_60/etr_30001e01p.pdf > specifically section 6.2.2 and below. Faces exactly the same issues. > FM is also affected by fast Rayleigh fading.. > Anyway, Doppler shift will be a bigger issue than multipath. > > Cheers, > Adrian > > > On 9/18/17, glen english <g...@cortexrf.com.au> wrote: >> 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 >> > > ---------------------------------------------------------------------------- > -- > 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 > ------------------------------------------------------------------------------ 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
