Firmware

I have been assigned a project (software part) - wireless presentation mouse.
It consists of
1. Transmitter.
2. Receiver.
Major Parts:
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Transmitter
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(Infrared Emitter, Encoder Microcontroller(PIC 16F627), Laser Pointer, Battery)
Receiver
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(Infrared receiver, Decoder Microcontroller(PIC 16C745), USB connector)

What are neccessary to be coded (driver or firmware) regarding this project?.

I think, I have to code firmware in the transmitter and the receiver part. Firmware in the transmitter part encode the signals and transmit through the IR transmitter. Firmware in the receiver part receive the siganls and decode the signals. Am I correct?.

Please give some suggestions on this.