Hi Hamid,
Some points to check, Sorry to write in English, i'm on the work's PC
1. Remove the connection between PIC and the mobile, trurn on the mobile and make sure that it's stays ON, make a call and check once more
2. If it shuts down or restarts, then the supply is not sufficient, use another power supply ( 2A will be good)
3. Make sure that you added a large capacitor ( 1000uf or more) across the battery connection in the mobile, or in the circuit board over the GND and VCC sent to mobile
4. if it shuts down only when connecting with the PIC, then make sure that the voltage levels is not high, mobiles doesn't work with 5V TTL signals
make sure that you use the resistors (R10, R11)
Let me know the result
