Собственно сам модулятор вопросов не вызывает,уже запущен в серию. А в импортных аналогах есть режим ввода предискажений сигнала и не совсем понятно как это делается.Вот цитата:
Digital Linear and Non-linear Pre-corrector option

This option is recommended in order to maximize the performance of the transmitter in which the modulator is installed.

--The Non-linear pre-corrector balances out gain and phase non-linearity in the transmitter RF power amplifier, thereby reducing significantly the in-band as well as out of band intermodulation generated by the amplifier. This optimization of the performance will extend the transmitters coverage area and ease the performance requirement from the transmitter output filter, used for suppressing the radiation in adjacent channels below the maximum allowed level.
--The Linear pre-corrector balances out level and group delay variations over the channel bandwidth caused by the transmitter antenna filter and/or channel combiner filters. The linear optimization of the signal radiated from the transmitter means that the channel equalizer of the DVB-T or DVB-H receiver may focus all its correction capacity on level and group delay errors originating from the actual transmission path.

Буду рад любым предположениям,ссылкам и т.д.