| 摘要 |
PROBLEM TO BE SOLVED: To share a circuit for a portable telephone reception system and a GPS reception system by devising the GPS reception system because the digital portable telephone processes an orthogonal modulation signal and the GPS processes a BPSK modulation signal thereby causing the difference from each other in a demodulator and a signal level diagram. SOLUTION: In the digital portable telephone set provided with a GPS function, a phase shifter 30 that matches phases of I and Q signals obtained by demodulating a BPSk modulation signal and an adder 31 that synthesizes both the signals (I, Q signals) after phase matching are provided to a signal processing circuit 28 so as to share a reception IF stage 17 having usually been used for the portable telephone set in common with an IF stage of the GPS reception system. |
