Method of and apparatus for determining position of mobile object and mobile radio communication system using the same

Claim 1

A method of determining a position of a mobile object, comprising the steps of: transmitting a radio wave of a constant frequency from said mobile object; receiving the radio wave transmitted from said mobile object and detecting the frequency of the received radio wave at each of a plurality of spaced positions in an area where said mobile object is movable; determining a plurality of Doppler shift signals observed at the respective spaced positions, each Doppler shift signal being indicative of a Doppler shift value dependent on a movement of the mobile object, on the basis of frequencies of the received radio wave detected at the respective positions, respectively; selecting at least two Doppler shift signals which satisfy predetermined two different conditions, respectively, among the plurality of Doppler shift signals; obtaining the position of said mobile object from position data indicating the positions corresponding to the selected Doppler shift signals; and wherein the selected Doppler shift signals comprise a first Doppler shift signal which provides a maximum value of upward Doppler shift values, a second Doppler shift signal which provides a maximum value of downward Doppler shift values and a third Doppler shift signal which provides a minimum value of the upward and downward Doppler shift values which are represented by the respective Doppler shift signals.

Claim 2

A method of determining a position of a mobile object, comprising the steps of: transmitting a radio wave of a constant frequency from said mobile object; receiving the radio wave transmitted from said mobile object and detecting the frequency of the received radio wave at each of a plurality of spaced positions in an area where said mobile object is movable; determining a plurality of Doppler shift signals observed at the respective spaced positions, each Doppler shift signal being indicative of a Doppler shift value dependent on a movement of the mobile object, on the basis of frequencies of the received radio wave detected at the respective positions, respectively; selecting at least two Doppler shift signals which satisfy predetermined two different conditions, respectively, among the plurality of Doppler shift signals; obtaining the position of said mobile object from position data indicating the positions corresponding to the selected Doppler shift signals; and wherein the selected Doppler shift signals comprise a first Doppler shift signal which provides a maximum value of upward Doppler shift values, a second Doppler shift signal which provides a maximum value of downward Doppler shift values and a third Doppler shift signal which provides a minimum value of the upward and downward Doppler shift values which are represented by the respective Doppler shift signals.

Claim 4

A method of determining a position of a mobile object, comprising the steps of: transmitting a radio wave of a constant frequency from said mobile object; receiving the radio wave transmitted from said mobile object and detecting the frequency of the received radio wave at each of a plurality of spaced positions in an area where said mobile object is movable; determining a plurality of Doppler shift signals observed at the respective spaced positions, each Doppler shift signal being indicative of a Doppler shift value dependent on a movement of the mobile object, on the basis of frequencies of the received radio wave detected at the positions, respectively; selecting at least two Doppler shift signals which satisfy predetermined two different conditions, respectively, among the plurality of Doppler shift signals; obtaining the position of said mobile object from position data indicating the positions corresponding to the selected Doppler shift signals; and wherein the selected Doppler shift signals comprise a first Doppler shift signal which provides a maximum value of upward Doppler shift values, a second Doppler shift signal which provides a maximum value of downward Doppler shift values and a third and a fourth Doppler shift signals which provide substantially equal upward and downward shift values, respectively, among the upward and downward shift values represented by the respective Doppler shift signals.

Claim 5

A method of determining a position of a mobile object, comprising the steps of: transmitting a radio wave of a constant frequency from said mobile object; receiving the radio wave transmitted from said mobile object and detecting the frequency of the received radio wave at each of a plurality of spaced positions in an area where said mobile object is movable; determining a plurality of Doppler shift signals observed at the respective spaced positions, each Doppler shift signal being indicative of a Doppler shift value dependent on a movement of the mobile object, on the basis of frequencies of the received radio wave detected at the positions, respectively; selecting at least two Doppler shift signals which satisfy predetermined two different conditions, respectively, among the plurality of Doppler shift signals; obtaining the position of said mobile object from position data indicating the positions corresponding to the selected Doppler shift signals; and wherein the selected Doppler shift signals comprise a first Doppler shift signal which provides a maximum value of upward Doppler shift values, a second Doppler shift signal which provides a maximum value of downward Doppler shift values and a third and a fourth Doppler shift signals which provide substantially equal upward and downward shift values, respectively, among the upward and downward shift values represented by the respective Doppler shift signals.

Claim 7

An apparatus for determining a position of a mobile object, comprising: means provided at each of a plurality of spaced positions for receiving a radio wave of a constant frequency transmitted from the mobile object and detecting a frequency of the radio wave; means for generating a plurality of Doppler shift signals observed at the respective spaced positions, each Doppler shift signal being indicative of a Doppler shift value dependent on a movement of the mobile object, on the basis of frequencies of the received radio wave detected at the respective positions; means for selecting at least two Doppler shift signals which satisfy predetermined two different conditions among the plurality of Doppler shift signals; means for determining the position of the mobile object from position data indicating the positions corresponding to the selected Doppler shift signals; and wherein the selected Doppler shift signals comprise a first Doppler shift signal which provides a maximum value of upward Doppler shift values, a second Doppler shift signal which provides a maximum value of downward Doppler shift values and a third Doppler shift signal which provides a minimum value of the upward and downward Doppler shift values which are represented by the plurality of Doppler shift signals, respectively.

Claim 8

An apparatus for determining a position of a mobile object, comprising: means provided at each of a plurality of spaced positions for receiving a radio wave of a constant frequency transmitted from the mobile object and detecting a frequency of the radio wave; means for generating a plurality of Doppler shift signals observed at the respective spaced positions, each Doppler shift signal being indicative of a Doppler shift value dependent on a movement of the mobile object, on the basis of frequencies of the received radio wave detected at the respective positions; means for selecting at least two Doppler shift signals which satisfy predetermined two different conditions among the plurality of Doppler shift signals; means for determining the position of the mobile object from position data indicating the positions corresponding to the selected Doppler shift signals; and wherein the selected Doppler shift signals comprise a first Doppler shift signal which provides a maximum value of upward Doppler shift values, a second Doppler shift signal which provides a maximum value of downward Doppler shift values and a third Doppler shift signal which provides a minimum value of the upward and downward Doppler shift values which are represented by the plurality of Doppler shift signals, respectively.

Claim 10

An apparatus for determining a position of a mobile object, comprising: means provided at each of a plurality of spaced positions for receiving a radio wave of a constant frequency transmitted from the mobile object and detecting a frequency of the radio wave; means for generating a plurality of Doppler shift signals observed at the respective spaced positions, each Doppler shift signal being indicative of a Doppler shift value dependent on a movement of the mobile object, on the basis of frequencies of the received radio wave detected at the respective positions; means for selecting at least two Doppler shift signals which satisfy predetermined two different conditions among the plurality of Doppler shift signals; means for determining the position of the mobile object from position data indicating the positions corresponding to the selected Doppler shift signals; and wherein the selected Doppler shift signals comprise a first Doppler shift signal which provides a maximum value of upward Doppler shift values, a second Doppler shift signal which provides a maximum value of downward Doppler shift values and third and fourth Doppler shift signals which provide substantially equal upward and downward shift values, respectively.

Claim 11

An apparatus for determining a position of a mobile object, comprising: means provided at each of a plurality of spaced positions for receiving a radio wave of a constant frequency transmitted from the mobile object and detecting a frequency of the radio wave; means for generating a plurality of Doppler shift signals observed at the respective spaced positions, each Doppler shift signal being indicative of a Doppler shift value dependent on a movement of the mobile object, on the basis of frequencies of the received radio wave detected at the respective positions; means for selecting at least two Doppler shift signals which satisfy predetermined two different conditions among the plurality of Doppler shift signals; means for determining the position of the mobile object from position data indicating the positions corresponding to the selected Doppler shift signals; and wherein the selected Doppler shift signals comprise a first Doppler shift signal which provides a maximum value of upward Doppler shift values, a second Doppler shift signal which provides a maximum value of downward Doppler shift values and third and fourth Doppler shift signals which provide substantially equal upward and downward shift values, respectively.

Claim 17

An apparatus for determining a position of a mobile object, comprising: a plurality of radio stations disposed in a region where a mobile object which transmits a radio wave, is movable to make radio communication with the mobile object; frequency detecting means provided in each of said radio stations for detecting a predetermined frequency of a radio wave transmitted from the mobile object and received at the radio station; mobile object detecting means for detecting the position of the mobile object on the basis of respective positions of said radio stations and frequency differences between the detected frequencies detected by said frequency detecting means of the respective radio stations and the predetermined frequency of the radio wave transmitted from the mobile object; and wherein said mobile object detecting means comprises means for determining the position of the mobile object as a point where a first straight line and a second straight line intersect with each other, the first straight line passing through at least one of the radio stations which detects a substantially maximum upward Doppler shift value or its vicinity and at least one of the radio stations which detects a substantially maximum downward Doppler shift value or its vicinity, the second straight line intersecting with the first straight line substantially at a right angle and passing through at least one of the radio stations which detects a substantially zero or minimum Doppler shift value or its vicinity.

Claim 18

An apparatus for determining a position of a mobile object, comprising: a plurality of radio stations disposed in a region where a mobile object which transmits a radio wave, is movable to make radio communication with the mobile object; frequency detecting means provided in each of said radio stations for detecting a predetermined frequency of a radio wave transmitted from the mobile object and received at the radio station; mobile object detecting means for detecting the position of the mobile object on the basis of respective positions of said radio stations and frequency differences between the detected frequencies detected by said frequency detecting means of the respective radio stations and the predetermined frequency of the radio wave transmitted from the mobile object; and wherein said mobile object detecting means comprises means for determining the position of the mobile object as a point where a first straight line and a second straight line intersect with each other, the first straight line passing through at least one of the radio stations which detects a substantially maximum upward Doppler shift value or its vicinity and at least one of the radio stations which detects a substantially maximum downward Doppler shift value or its vicinity, the second straight line intersecting with the first straight line substantially at a right angle and passing through at least one of the radio stations which detects a substantially zero or minimum Doppler shift value or its vicinity.

Claim 19

An apparatus for determining a position of a mobile object, comprising: a plurality of radio stations disposed in a region where a mobile object which transmits a radio wave, is movable to make radio communication with the mobile object; frequency detecting means provided in each of said radio stations for detecting a predetermined frequency of the radio wave transmitted from the mobile object and received at the radio station; mobile object detecting means for detecting the position of the mobile object on the basis of respective positions of said radio stations and frequency differences between the detected frequencies detected by said frequency detecting means of the respective radio stations and the predetermined frequency of the radio wave transmitted from the mobile object; and wherein said mobile object detecting means comprises means for determining the position of the mobile object as a point where a first straight line and a second straight line intersect with each other, the first straight line passing through at least one of the radio stations which detects a substantially maximum upward Doppler shift values or its vicinity and at least one of the radio stations which detects a substantially maximum downward Doppler shift value or its vicinity, the second straight line passing through at least two of the radio stations which obtained the detected values including substantially equal up and down shift values or their vicinities.

Claim 20

An apparatus for determining a position of a mobile object, comprising: a plurality of radio stations disposed in a region where a mobile object which transmits a radio wave, is movable to make radio communication with the mobile object; frequency detecting means provided in each of said radio stations for detecting a predetermined frequency of the radio wave transmitted from the mobile object and received at the radio station; mobile object detecting means for detecting the position of the mobile object on the basis of respective positions of said radio stations and frequency differences between the detected frequencies detected by said frequency detecting means of the respective radio stations and the predetermined frequency of the radio wave transmitted from the mobile object; and wherein said mobile object detecting means comprises means for determining the position of the mobile object as a point where a first straight line and a second straight line intersect with each other, the first straight line passing through at least one of the radio stations which detects a substantially maximum upward Doppler shift values or its vicinity and at least one of the radio stations which detects a substantially maximum downward Doppler shift value or its vicinity, the second straight line passing through at least two of the radio stations which obtained the detected values including substantially equal up and down shift values or their vicinities.

Claim 21

An apparatus for determining a position of a mobile object, comprising: a plurality of spaced receiving means disposed in a space where a mobile object which transmits a radio wave signal of a given frequency is movable for receiving the radio wave signal from the mobile object; frequency deviation measuring means for measuring a frequency deviation in the radio wave signal received by each of said plurality of receiving means; position detecting means for detecting the position of the mobile object on the basis of the frequency deviation associated with each of said plurality of receiving means and the respective positions of said receiving means; and wherein said position detecting means comprises means for determining the position of the mobile object as a point where a first straight line and a second straight line intersect with each other, the first straight line passing through at least one of the receiving means which detects a substantially maximum upward Doppler shift value or its vicinity and at least one of the receiving means which detects a substantially maximum downward Doppler shift value or its vicinity, the second straight line intersecting with the first straight line substantially at a right angle and passing through at least one of the receiving means which detects a substantially zero or minimum Doppler shift value or a vicinity.

Claim 22

An apparatus for determining a position of a mobile object, comprising: a plurality of spaced receiving means disposed in a space where a mobile object which transmits a radio wave signal of a given frequency is movable for receiving the radio wave signal from the mobile object; frequency deviation measuring means for measuring a frequency deviation in the radio wave signal received by each of said plurality of receiving means; position detecting means for detecting the position of the mobile object on the basis of the frequency deviation associated with each of said plurality of receiving means and the respective positions of said receiving means; and wherein said position detecting means comprises means for determining the position of the mobile object as a point where a first straight line and a second straight line intersect with each other, the first straight line passing through at least one of the receiving means which detects a substantially maximum upward Doppler shift value or its vicinity and at least one of the receiving means which detects a substantially maximum downward Doppler shift value or its vicinity, the second straight line intersecting with the first straight line substantially at a right angle and passing through at least one of the receiving means which detects a substantially zero or minimum Doppler shift value or a vicinity.

Claim 23

An apparatus for determining a position of a mobile object, comprising: a plurality of spaced receiving means disposed in a space where a mobile object which transmits a radio wave signal of a given frequency is movable for receiving the radio wave signal from the mobile object; frequency deviation measuring means for measuring a frequency deviation in the radio wave signal received by each of said plurality of receiving means; position detecting means for detecting the position of the mobile object on the basis of the frequency deviation associated with each of said plurality of receiving means and the respective positions of said receiving means; and wherein said position detecting means comprises means for determining the position of the mobile object as a point where a first straight line and a second straight line intersect with each other, the first straight line passing through at least one of the receiving means which detects a substantially maximum upward Doppler shift value or its vicinity and at least one of the receiving means which detects a substantially maximum downward Doppler shift value or its vicinity, the second straight line passing through at least two of the receiving means which detect substantially equal up and down Doppler shift values or their vicinities.

Claim 24

An apparatus for determining a position of a mobile object, comprising: a plurality of spaced receiving means disposed in a space where a mobile object which transmits a radio wave signal of a given frequency is movable for receiving the radio wave signal from the mobile object; frequency deviation measuring means for measuring a frequency deviation in the radio wave signal received by each of said plurality of receiving means; position detecting means for detecting the position of the mobile object on the basis of the frequency deviation associated with each of said plurality of receiving means and the respective positions of said receiving means; and wherein said position detecting means comprises means for determining the position of the mobile object as a point where a first straight line and a second straight line intersect with each other, the first straight line passing through at least one of the receiving means which detects a substantially maximum upward Doppler shift value or its vicinity and at least one of the receiving means which detects a substantially maximum downward Doppler shift value or its vicinity, the second straight line passing through at least two of the receiving means which detect substantially equal up and down Doppler shift values or their vicinities.

Claim 25

A method of determining a current position of a mobile object which has moved from a known position, said method comprising the steps of: transmitting a radio wave of a constant frequency from the mobile object; receiving the radio wave transmitted from said mobile object and detecting a frequency of the received radio wave at each of a plurality of spaced fixed positions in an area where said mobile object is movable; determining a plurality of Doppler shift signals observed at the respective fixed positions, each Doppler shift signal being indicative of a Doppler shift value dependent on a movement of the mobile object, on the basis of frequencies of the received radio wave detected at the fixed positions, respectively; selecting at least two of said Doppler shift signals which satisfy a predetermined condition among the plurality of Doppler shift signals; determining the current position of said mobile object on the basis of position data indicating the fixed positions corresponding to said selected at least two Doppler signals; and wherein said selected at least two Doppler signals include maximum and minimum Doppler shift signals which provide maximum and minimum Doppler shift values, respectively, among upward or downward Doppler shift values given by said plurality of Doppler shift signals.

Claim 26

A method of determining a current position of a mobile object which has moved from a known position, said method comprising the steps of: transmitting a radio wave of a constant frequency from the mobile object; receiving the radio wave transmitted from said mobile object and detecting a frequency of the received radio wave at each of a plurality of spaced fixed positions in an area where said mobile object is movable; determining a plurality of Doppler shift signals observed at the respective fixed positions, each Doppler shift signal being indicative of a Doppler shift value dependent on a movement of the mobile object, on the basis of frequencies of the received radio wave detected at the fixed positions, respectively; selecting at least two of said Doppler shift signals which satisfy a predetermined condition among the plurality of Doppler shift signals; determining the current position of said mobile object on the basis of position data indicating the fixed positions corresponding to said selected at least two Doppler signals; and wherein said selected at least two Doppler signals include maximum and minimum Doppler shift signals which provide maximum and minimum Doppler shift values, respectively, among upward or downward Doppler shift values given by said plurality of Doppler shift signals.