Hi, You don't need to convert it at all. Simply take a proper TSOP IR detector and connect the output to a RF radio module data input. On the receiving side simply take the RF data output and use a NE555 to generate a squarewave at 38KHz which you switch on and off with your RF data output from the RF module. The NE555 can than control an MOSFET to control a IR LED with your data on/off.
I do that, but it didn't work,I think I have a problem in my receiver that distort the signal.
so is anyone know how to build RF digital data receiver 433 Mhz low noise.