Need help in designing a transmitter and receiver.

[kannihoe]

Hi,
my assignment was to build some thing like this.

[analog input]--->[ band limiting filter]--->[ PCM Encoder]--->[ASK modulator]--->[Wireless channel]--->[ASK demodulator]--->[PCM Decoder]--->[Lowpass filter]--->[analog output]

i really don't have a slight idea on how to start, can any one of you help me in designing the circuit? or any reference that i can go through?
thanks.