I just read the Pactor 3 specification. I am not sure that it is OFDM. It is multi-tone but the spacing of the tones seems wider than OFDM requires.
But I may be missing something in the technical definition OFDM of that differentiates it from MT. Rud Merriam K5RUD ARES AEC Montgomery County, TX http://TheHamNetwork.net Pactor has proven the worth (necessity?) of using full time FEC and a moderate baud rate OFDM signal using PSK. Otherwise, you wouldn't you need some kind of training pulse sequence as used on the 8PSK MIL-STD/FED-STD/STANAG modems? 73, Rick, KV9U
