spread spectrum tranceiver

please help me in designing a tranceiver which utilises spread spectrum technique and is suitable for position location of the tags from which it gets echoes.
wat sgud be the range snr and threshold etc and what pseudorandom code it ustilises for its posityion detection .
it is like radar which uses spread spectrum the frequncy should be any of the suitable from 13.56 or 400 or 800-900 MHZ

please help me design this sort of position location system