понедельник, 8 марта 2010 г.

MFSK: Rosmodem


(Author): SergUA6
Band Width ~2250-2300 Hz
Low Range ~400 Hz, shift is possible
Baud Rate ~15.5, and very slow mode 1 Hz
Count of Carriers not less than 144
Step between carriers ~15.5 Hz
Pilot tone(s) Start tone ~1481 Hz, with duration ~ 4200 ms,shift is possible
ACF ~18662 ms
RX mode SSB

Sonograms:
pic.1 General view
pic.2 Manipulation speed
Diagrams:
pic.3 Allocation of frequencies and their quantity
pic.4 the signal's ACF and view in VMW
ROSMODEM - the new radio amateur protocol created by Spanish developer Alberto Nieto Ros, the technology of the extension of a spectrum is put in a basis. In this signal if to trust the description, base MFSK-16 extends by the pseudo-casual law at least to MFSK-144. High enough characteristics of this protocol are declared. ACF most likely connected with the period of pseudo-casual sequences of randomization, but this is only supposition. The real transfer speed is essentially lower then speed of manipulation, that can indirectly speak not only about the spectrum extension, but also about usage of serious noise-resistant coding. The mode with speed of manipulation 1 Hz is supported, here are used formerstep between frequencies and principle of creation former.