четверг, 17 декабря 2009 г.

WINDRM 51-Tone COFDM Modem

WINDRM 51-Tone COFDM Modem
Amateur mode, Br-37.5, Sh-46.875, Ch-51, QAM-64

Author: SergUA6
Band Width 2400 Hz
Low Range 300 Hz
Baud Rate 37.5 Hz
Count of Carriers 51
Step between carriers 46.875 Hz
Pilot tone(s) 3 pilot tones 750, 1500 and 1875 Hz
ACF 400 ms, brightly expressed period
RX mode SSB

pic.1 General view

pic.2 Graphical spectrum
pic.3 Allocation of channeles
pic.4 Constellation of the lower channel, start.
pic.5 Constellation of the lower channel
pic.6 Constellations in other channeles
pic.7 ACF

WINDRM 51-TONE - difficult enough sort of modulation mastered by hams, the "industrial" basis is certainly visible, many things are taken from standard DRM. 400 msec frames and the circuit of a rating/spacing of pilots-tones are made by analogy of "big DRM", all accessible frequency resource of 2400 Hz is completely used. SA possibilities allow to receive both signal parametres, and constellation in any channel. It is well visible that QAM-64 is with various service "design", there are also channels with "pure" QAM-64. Maximum technical speed is 10800 bps.