First, what tools are you using?
It looks like Keil - yes?

And it would help to provide a link to the GPS module's datasheet.



So the first thing you need to do is to demonstrate that you can receive serial characters at 4800, 8n1.
Forget about GPS for the moment - just concentrate on the serial characters.

You can use Hyperterminal to send the characters to your target (you'll need an RS232 transceiver, or USB-to-logic-level-UART).

Once you know you can receive the characters, then you can start to think about handling them...