WINDRM 51-Tone COFDM Modem

WINDRM 51-Tone COFDM Modem

Amateur mode, Br-37.5, Sh-46.875, Ch-51, QAM-64

Here is the example of WINDRM signal

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

Sonograms:

pic.1 General view

pic.2 Graphical spectrum

pic.3 Allocation of channeles

Diagrams:

pic.4 Constellation of the lower channel, start.

pic.5 Constellation of the lower channel

pic.6 Constellations in other channeles

Pictures:

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.