| 摘要 |
A portable wireless terminal and a moving velocity detecting method for the portable wireless terminal capable of detecting a moving velocity with high accuracy without increasing power consumption and terminal cost are provided. At the start of a communication, GPS reception-related circuits 32 and 33 are turned on, an initial position of a portable wireless terminal 10 is detected, a RAKE receiver 24 and a synchronous detector 25 measure Doppler shift amounts of down signals at a known frequency received from a plurality of base stations, respectively, and a CPU 41 calculates relative velocities of the portable wireless terminal 10 to the respective base stations and obtains a current moving velocity of the portable wireless terminal 10 from positions of the base stations, the initial position, and the relative velocities. The current position is calculated from the initial position and the current moving velocity, and sequentially updated to be used in place of the initial position at the time of calculating the moving velocity next time. The initial position at the start of the communication may be obtained by using a W-LAN, an RFID system, a wireless IC card or user input information instead of using a GPS.
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