gps ... help required

hi i am working on gps receiver interface to another unit.
can any one help me how to go about the design of gps receiver using VHDL.
I AM USING TSIP Protocol
IF ANY E BOOKS PLEASE HELP ME.

this a very complete resource about gps receiver here this guy build one without using any specialized hardaware, maybe you can find some useful info for you to make your vhdl description.

http://lea.hamradio.si/~s53mv/navsats/theory.html