PORTABLE WIRELESS TERMINAL AND MOVING VELOCITY DETECTING METHOD FOR PORTABLE WIRELESS TERMINAL

• US 20090075678A1
• Filed: 03/31/2006
• Published: 03/19/2009
• Est. Priority Date: 03/31/2005
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Ogoro, Kazuo
• Granted Patent: US 8,326,316 B2
• Time in Patent Office: Days
• US Class Current: 455/456.600
• CPC Class Codes: G01S 11/10 using Doppler effect
• CPC Class Codes: H04B 1/7113 Determination of path profile
• CPC Class Codes: H04B 2201/70715 with application-specific features
• CPC Class Codes: H04W 64/006 with additional information processing, e.g. for direction or speed determination

Abstract

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.

Claims

1-22. -22. (canceled)

23. A portable wireless terminal comprising means for obtaining a current moving velocity of the portable wireless terminal from base station position information indicating installation positions of a plurality of base stations, respectively, from initial position information indicating an initial position of the portable wireless terminal at start of a communication, and from information on relative velocities of the portable wireless terminal to the respective base stations.

24. The portable wireless terminal according to claim 23, comprising means for calculating current position information on the portable wireless terminal from the current moving velocity of the portable wireless terminal and the initial position information, for obtaining the current moving velocity of the portable wireless terminal from the base station information, from the information on the relative velocities, and from the calculated current position information in place of the initial position information, for newly calculating thereafter a current position whenever the current moving velocity is obtained, and for updating previous current position information to new current position information to use the updated current position information to calculate the moving velocity next time during the communication of the portable wireless terminal.

25. The portable wireless terminal according to claim 24, comprising means for, if the previous current position information is to be updated to the new current position information whenever the current moving velocity is obtained and the updated current position information is to be used to calculate the moving velocity the next time, recalculating the current position of the portable wireless terminal as the initial position information whenever predetermined time passes, whenever a moving distance from the initial position reaches a predetermined threshold value or at a predetermined frequency according to the calculated moving velocity or required calculation accuracy similarly to the start of the communication, and for calculating the current moving velocity of the portable wireless terminal from the recalculated initial position information in place of the updated current position information, from the base station information, and from the information on the relative velocities during the communication of the portable wireless terminal.

26. The portable wireless terminal according to claim 23, comprising means for calculating Doppler effects of down signals from the respective base stations using information obtained by a demodulator of a receiving unit included in the portable wireless terminal, and for obtaining the information on the relative velocities of the portable wireless terminal to the respective base stations as means for obtaining the information on the relative velocities of the portable wireless terminal to the respective base stations.

27. The portable wireless terminal according to claim 23, comprising means for using information on a phase rotation velocity of a phase modulation symbol point obtained by a demodulator of a receiving unit included in the portable wireless terminal as means for obtaining the information on the relative velocities of the portable wireless terminal to the respective base stations.

28. The portable wireless terminal according to claim 23, comprising means for causing a CDMA receiving unit included in the portable wireless terminal to demodulate down signals from the respective base stations, and for calculating the information on the relative velocities of the portable wireless terminal to the respective base stations from state changes of delay profiles of the down signals as means for obtaining the information on the relative velocities of the portable wireless terminal to the respective base stations.

29. The portable wireless terminal according to claim 23, comprising means for changing a parameter set to a wireless unit responsible for the communication based on the information indicating a current state of the portable wireless terminal obtained by the means for obtaining the current moving velocity of the portable wireless terminal.

30. The portable wireless terminal according to claim 23, comprising means for using base station characteristic information capable of uniquely identifying the respective base stations as means for obtaining the base station position information indicating the installation positions of the respective base stations.

31. The portable wireless terminal according to claim 23, comprising means for transmitting an inquiry signal to the base stations currently communicating with the portable wireless terminal as means for obtaining the base station position information indicating the installation positions of the respective base stations.

32. The portable wireless terminal according to claim 23, comprising means operating at a designated time as a time for obtaining the initial position, for receiving a GPS (Global Positioning System) signal as means for obtaining the initial position information on the portable wireless terminal.

33. The portable wireless terminal according to claim 23, comprising means operating at a designated time as a time for obtaining the initial position, for receiving position information on an access point from a wireless LAN system as means for obtaining the initial position information on the portable wireless terminal.

34. The portable wireless terminal according to claim 23, comprising means operating at a designated time as a time for obtaining the initial position, for receiving a wireless signal from an RFID (Radio Frequency Identification) system or a wireless IC card as means for obtaining the initial position information on the portable wireless terminal.

35. The portable wireless terminal according to claim 23, comprising means for using information input by a user of the portable wireless terminal as means for obtaining the initial position information on the portable wireless terminal.

36. A method of detecting a moving velocity of a portable wireless terminal, comprising obtaining a current moving velocity of the portable wireless terminal from base station position information indicating installation positions of a plurality of base stations, respectively, from initial position information indicating an initial position of the portable wireless terminal at start of a communication, and from information on relative velocities of the portable wireless terminal to the respective base stations.

37. The method of detecting a moving velocity of a portable wireless terminal according to claim 36, comprising means for calculating current position information on the portable wireless terminal from the current moving velocity of the portable wireless terminal and the initial position information, for obtaining the current moving velocity of the portable wireless terminal from the base station information, from the information on the relative velocities, and from the calculated current position information in place of the initial position information, for newly calculating thereafter a current position whenever the current moving velocity is obtained, and for updating previous current position information to new current position information to use the updated current position information to calculate the moving velocity next time during the communication of the portable wireless terminal.

38. The method of detecting a moving velocity of a portable wireless terminal according to claim 37, comprising, if the previous current position information is to be updated to the new current position information whenever the current moving velocity is obtained and the updated current position information is to be used to calculate the moving velocity the next time, recalculating the current position of the portable wireless terminal as the initial position information whenever predetermined time passes, whenever a moving distance from the initial position reaches a predetermined threshold value or at a predetermined frequency according to the calculated moving velocity or required calculation accuracy similarly to the start of the communication, and calculating the current moving velocity of the portable wireless terminal from the recalculated initial position information in place of the updated current position information, from the base station information, and from the information on the relative velocities during the communication of the portable wireless terminal.

39. The method of detecting a moving velocity of a portable wireless terminal according to claim 36, comprising calculating Doppler effects of down signals from the respective base stations using information obtained by a demodulator of a receiving unit included in the portable wireless terminal, and obtaining the information on the relative velocities of the portable wireless terminal to the respective base stations as means for obtaining the information on the relative velocities of the portable wireless terminal to the respective base stations.

40. The method of detecting a moving velocity of a portable wireless terminal according to claim 36, comprising obtaining the information on the relative velocities of the portable wireless terminal to the respective base stations using information on a phase rotation velocity of a phase modulation symbol point obtained by a demodulator of a receiving unit included in the portable wireless terminal.

41. The method of detecting a moving velocity of a portable wireless terminal according to claim 36, comprising causing a CDMA receiving unit included in the portable wireless terminal to demodulate down signals from the respective base stations, and calculating the information on the relative velocities of the portable wireless terminal to the respective base stations from state changes of delay profiles of the down signals.

42. The method of detecting a moving velocity of a portable wireless terminal according to claim 36, comprising changing a parameter set to a wireless unit responsible for the communication based on the information indicating a current state of the portable wireless terminal obtained.

43. The method of detecting a moving velocity of a portable wireless terminal according to claim 36, comprising obtaining position information indicating the installation positions of the respective base stations by using base station characteristic information capable of uniquely identifying the respective base stations or by transmitting an inquiry signal to the base stations currently communicating with the portable wireless terminal so as to obtain the position information indicating the installation positions of the respective base stations.

44. The method of detecting a moving velocity of a portable wireless terminal according to claim 36, comprising obtaining the initial position information by causing to operate at a designated time as a time for obtaining the initial position for receiving a GPS (Global Positioning System) signal to either receive position information on an access point from a wireless LAN system or receive a wireless signal from an RFID (Radio Frequency Identification) system or a wireless IC card and/or by using information input by a user of the portable wireless terminal so as to obtain the initial position information on the portable wireless terminal.