wireless distance measuring circuit with arduino

what I want is to create similar to this circuit [login to view URL] but I want to be able to do it with the Arduino, here in the attachment you can see the internal circuit, what I think it does: the transmitter sends pulses and the receiver measure the pulses and the closes the transmitter is, the wider the pulses are. so what I need in the project is the same features as you see in that product plus for the arduino to display the distance on the serial monitor, the arduino only needs to be in the receiver in the transmitter you can put any chip you want. please dont bid on this project if you dont have the arduino.