Sorry, I do not have schematics. What type of remote control are you interested in? The old model airplane controls used a AM digital pulse stream on a carrier. A timing pulse longer than the others, then each channel in sequence with the analog information being the width of the pulses.The receiver had a decoder that routed each pulse to the servos. The servo compared the pulse width with the internal pulse generated from a feedback potentiometer.
The newer sets use FM. I do not know if they changed the basic priciples. I heard of "digital" sets but do not know which part is actually digital. It does not make sense for htem to be completely digital as the resolution would decrease without at least a 16 bit word length.
The control pulses used to be 1ms nominal, +/- 0.5ms variation for full range.
Original frequencies were in the 27 MHz band, then came 54MHz and then 72 MHz (between TV channels 3&4). Later they narrowed the 72 MHz band so more pagers and remote telephones could be accomodated. Frequency tolerance is tight and splatter will get you a visit from the FCC.