need for a wireless communication project

hi....
i'm doin a project which includes wireless communication....

i want to transmit digital data(32 bit) via a transmitter(directional antenna)
n the same should be received by a receiver(directional receiver)....the tx n rx should be mobile,i.e. it should be able to fix it on any vehicle......n each vehicle has a tx n rx but the rx should not detect its own tx's signal thats y i need directional antennas.......i need some help wid the circuit n antenna type.....jus c the pic also