Hi all , I have some experience with PS/2 and PIC since I made interfacing between keyboard or barcode reader PS/2 and PIC microcontrollers, you may take these considrations in your work:

1) PS/2 have two signals to communicate with it , clock and data
2) clock generated and data sends at every falling edge of the clock
3) each character represented with 33 bits ( make code , break code , make code)
4) each 11 bits is consist of ( 1 start bit , 8 data bits , 1 parity bit , 1 stop bit)
5) low level of clock duration is about 50 microsecond

you can search on google for PS/2 keyboard interface for more specification

I don't know the way how you use optical wireless but if you attach the schematic will be better