RF is truly the best way to remotely control a robot. But RF communications are not for beginners who often stumble on various problems. For example the way you design your boards has a great impact on your signal. Doing it wrong could mean signal deviance. That’s why it’s recommended to use RF boards that come in pair, already assembled. They’re not too expensive and you can avoid allot of trouble.
RF Modem Robotics Project: [Link]