As is to be expected, ordinary digital transmission is nowhere near robust enough to cope with the problems experienced by a mobilereceiver, which can suffer from all sorts of doppler-shift effects and multipath radio interference as it moves around the place.
Then there is the antenna needed for Bluetooth, and Wi-Fi if it is built in, and one for the GPS receiver, and if you have mobile TV capabilities built in there will be another antenna to receive, say the MediaFLO TV signals on 700 MHz.