Hi, > (Bipolar: a signal swings between +A volts (or amperes) and -A volts; > Ethernet, USB, Wi-Fi, ... are using bipolar signals, > Unipolar: a signal swings between +A volts and 0 volts)
There is no difference ... "0 volt" is just an arbitrary reference point. 0 <-> +A swing is the same as -A/2 <-> A/2 swing if you shift your reference ... Ethernet and USB are _differential_ but that's just to improve signal integrity / noise immunity and such. At the receiver end, the differential input buffer essentially compares both and see which one is higher. (a bit simplified, but that's the gist of it). > Is there anyone already implemented unipolar preamble detection > succesffully, or could anyone give me some hints on mathematical approach or > something? If 'A' is known, just remove -A/2 from your input signal. If it is unknown,you can use a very long time constant low pass to find it. (assuming your signal doesn't have long runs of 0 or 1). Cheers, Sylvain _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
