A portable phone device comprises a telephone unit for base band processing of a receiving signal and audio conversion processing, as well as a global positioning system (GPS) receiving unit for receiving signals from at least one GPS satellite, each signal including a spread code. A crystal oscillator generates a first oscillation signal having a predetermined frequency, and a temperature controlled oscillator generates a second oscillation signal having a predetermined frequency different from that of the first oscillation signal. A synchronization capture portion performs synchronization capture of the spread code, and a synchronization hold portion performs synchronization holding and demodulation of the signals received from the at least one GPS satellite. A central processing unit calculates position and speed of the portable phone device.