> For the carrier itself absolute phase measurements cant be done. > Such phase measurements only have meaning when modulation is present.
Alternating modulation frequency may do it for instance. Choosing a set of modulation frequencies being relative prime to each other alows for several readings of alternating cycle ambiguity to be resolved using the Chinese Reminder theorem. Similar set of frequencies can be used, for instance multiple of 10 alows the phase of the lower frequency to determine which of the 10 cycles the next frequency is. However, this is not easilly extendable to carrier frequency cycles, since it would imply a very wide modulation, so for that a chinese reminder approach is of interest. A PRN sequence is just a multiple of these frequencies at the same time. Alternating PRN length could be used for similar purposes of course. Multiple simultaneous PRN sequences can be added upon each other. Using multiple carrier frequencies may also be an interesting option. Consider for instance COFDM which creates a dense set of carriers using IFFT modulation and FFT demodulation. Cheers, Magnus _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
