I'm investigating...something...involving the alignment of the digital systems of Icom iDas digital radios.
I have test equipment that is fully capable of answering every question I could possibly ask with regard to the digital transmisssion's characteristics, (Rohde & Schwarz FSEA 30 spectrum analyzer with FSE-07 vector analysis/flexible digital demodulation option) But there is some data that I need to find regarding the
iDas signal that I have not yet been able to locate.
I need to know the data pattern for any repetitive frame sync data in the iDas signal format. With that
data pattern, I can program my analyzer to sync up to the signal and allow me to analyze the signal parameters. Without that data, I can't sync up to the signal and thus it makes getting useful information
really hard.
If anyone here should know what the bit patterns are (hex or binary) that are repeated from frame to frame in the iDas signal, I'd sure like to get that information.
The signal format is 4800 symbols per seconds on a 4FSK carrier, very similar in many respects to APCO P25 C4FM, I'm not quite clear yet on the deviation from carrier of each of the 4 frequency shifts, but should be able to deduce that information if nobody happens to have it handy.
The hex values of each of the four 4FSK modulation states are 0, 5, 15, and 10, from low to high as demodulated on the analyzer. (I'm able to generate a simulated signal with my Agilent ESG signal generator, although I'm using a user-defined sync sequence as I don't have the "correct" one.)
Elroy
I have test equipment that is fully capable of answering every question I could possibly ask with regard to the digital transmisssion's characteristics, (Rohde & Schwarz FSEA 30 spectrum analyzer with FSE-07 vector analysis/flexible digital demodulation option) But there is some data that I need to find regarding the
iDas signal that I have not yet been able to locate.
I need to know the data pattern for any repetitive frame sync data in the iDas signal format. With that
data pattern, I can program my analyzer to sync up to the signal and allow me to analyze the signal parameters. Without that data, I can't sync up to the signal and thus it makes getting useful information
really hard.
If anyone here should know what the bit patterns are (hex or binary) that are repeated from frame to frame in the iDas signal, I'd sure like to get that information.
The signal format is 4800 symbols per seconds on a 4FSK carrier, very similar in many respects to APCO P25 C4FM, I'm not quite clear yet on the deviation from carrier of each of the 4 frequency shifts, but should be able to deduce that information if nobody happens to have it handy.
The hex values of each of the four 4FSK modulation states are 0, 5, 15, and 10, from low to high as demodulated on the analyzer. (I'm able to generate a simulated signal with my Agilent ESG signal generator, although I'm using a user-defined sync sequence as I don't have the "correct" one.)
Elroy