Although the name FSK 96Bd/500, the used shift of this sytem is 480 Hz. Speed is 96Bd and the two 5-bit data words are bit-interleaved according to the CIS-14 format; first two bits are the system bits: t_a and t_b: 0 = traffic, 1 = idle (or no traffic). As you can see in the demodulate stream, only channel b transports data (figure 1). It's probably a test transmission since data are in clear-text mode and consist of a "classic" Russian test sequence "GA VIL BY CITRUS? DA,NO FALX" (figure 2), something like "the brown fox jumps over the lazy dog".
Fig. 1
Fig. 2
Another example of a CIS-14 96Bd/500 bit-interleaved is shown in figure 3
No comments:
Post a Comment