Hi, I was able to perform some field measurements on Sunday to compare the performance of the 4FSK modem and the QPSK modem in the 433 MHz ISM band.
My transmitter was set to 1 mW output power into a 2 dBi gain antenna located at approx. 21 meters above ground on one of the buildings in my city. I walked around a perimeter of about 600 meters in diameter, recording the RSSI of the data channel and the percentage of the data frames lost. For the QPSK modem, the performance was as expected: 5% lost frames at ~7 dB SNR. However the 4FSK modem as specified in 2400A performed about 3 dB worse, with the same percentage of dropped frames at ~11 dB SNR. For comparison, the analog FM signal was readable at 14 dB SNR. My question is: is this performance expected of the 2400A modem, or should I go back to the drawing board? Thanks, Adrian ------------------------------------------------------------------------------ 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
