понедельник, 27 сентября 2010 г.

FSK: "Avaris" - domestic(Russia) system of special communication on VHF

"Avaris" - special-radio service(VHF), FM-GFSK, Br-9600.

Author: SergUA6
Band Width ~12000 Hz
Baud Rate 9600 Hz
RX mode Source I/Q record


pic.1 General view


pic.2 Signals demodulation


pic.3 General structure of the signal

"Avaris" - domestic(Russia) system of special communication. In a basis of this system, lies using of special repeaters under similar mark "Avaris". Repeaters provide expect the basic functions, also functions of recording coded/encrypted speech messages and their subsequent transfer to concrete addressees or group of users. In this system, and not only in this, speech is digitized by means of the delta modulation. The received digital stream is ciphered and transferred, in this case, GFSK modulation is used.