OFDM: CIS-112 signal

CIS-112

Br~22.22, Sh~25.6, Ch-112 + 1 Pilot, pi/4 DQPSK

The record of this signal, which has been made by lakisan2008

The record of this signal, which has been made by RadioKoteg

Author: SergUA6

Band Width ~3000-3100 Hz

Low Range ~340-320 Hz, shift is possible, recieveing in SSB

Baud Rate ~22.22 Hz

n-Ary (PSK/MPSK) pi/4 DQPSK

Count of Carriers 56, 112

Step between carriers ~25.6 Hz

Pilot tone(s) one pilot ~3305 Hz, shift is possible, recieveing in SSB

RX mode SSB

Sonograms:

pic.1 General view

pic.2 Spectrum's detalization

Diagrams:

pic.3 Preamble 1, detalization.

pic.4 Detalization of the signal's part with 56 channeles

pic.5 The signal itself, 112 channeles.

CIS-112 is the very interesting signal. We classify it to CIS, because CIS signals have the upper pilot with frequency 3300 Hertz. It is hard to identify this signal and it's parameters by classical methods. Other tools are necessary, SA OFDM module allows to define parameters of the signal precisely enough and fast, to define signal key parametres. The signal has been sent by lakisan2008, this signal has an interesting preamble 1, where all tones are modulated. In the whole signal pi/4 DPSK is used, which is standardly enough for OFDM. In the signal , which has been sent by RadioKoteg, PSK-2 is used in all channels, within the limits of the main manipulation pi/4 DQPSK ofcourse. Besides in this record, there are single symbols with 56 channels, about each 72 symbol