Method for measuring distance and position using spread spectrum signal, and an equipment using the method

• US 7,609,197 B2
• Filed: 02/17/2005
• Issued: 10/27/2009
• Est. Priority Date: 06/27/2000
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kuwahara, Mikio, Doi, Nobukazu, Tsunehara, Katsuhiko, Ishifuji, Tomoaki
• Primary Examiner(s): Gregory; Bernarr E
• Application Number:
  US11/059,407
• Publication Number:
  US 20050140543A1
• Time in Patent Office: 1,713 Days
• Field of Search: 375130-153, 342 42- 59, 342/118, 342125-127, 342/175, 342195-197, 342450-465, 370/310, 370328-338, 370203-211, 370/342, 701/200, 701/207, 701/213, 455/403, 455/422.1, 4554561-457
• US Class Current: 342/47
• CPC Class Codes: G01S 1/026 of associated receivers
• CPC Class Codes: G01S 1/045 Receivers
• CPC Class Codes: G01S 5/0218 Multipath in signal reception
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308
• CPC Class Codes: H04B 1/70755 Setting of lock conditions, e.g. threshold
• CPC Class Codes: H04B 2201/70715 with application-specific features

Abstract

By using the delay profile created by delay profile creating section 102 and the first threshold value 330 received from the first threshold value calculation 105, the first threshold value timing detection section 103 selects only the earliest receive timing exceeding the first threshold value, from all the timing that the correlation value in the delay profile becomes a maximum. By using the receive timing and the second threshold value 331 received from the second threshold value calculation section 107, reference timing calculation section 106 selects the reference timing required for calculating the receive timing for the incoming wave of the minimum propagation delay time. The timing delayed by previously set timing behind said reference timing is sent from receive timing calculation section 108 as the receive timing 113 of the incoming wave of the minimum propagation delay time.

Claims

1. A terminal positioning method using received timings of received signals as to particular incoming waves transmitted between a plurality of base stations and a terminal:

the method comprising steps of;

a first step of calculating a correlation value between each of said received signals and a predetermined code to create a delay profile representing a correlation between them;

a second step of determining said received timing of each of said incoming waves with reference to a rise timing where each of said delay profiles rises from a noise level;

a third step of calculating a position of said terminal by using said received timings relative to the plurality of the base stations;

setting a predetermined threshold value for determining said rise timing on the basis of measured noise power; and

setting said rise timing when the value of said delay profile is equal to said predetermined threshold value within a predetermined time before an incoming wave determining timing used to determine the presence of said incoming wave.

2. The terminal positioning method according to claim 1, wherein said each of received timings is delayed by predetermined time after said rise timing to be a reference timing.

3. Terminal equipment in a terminal positioning system for positioning the terminal equipment using received timings of received signals as to particular incoming waves transmitted from a plurality of base stations to the terminal equipment;

comprising;

a signal receiving part for receiving said signals from said base stations;

a delay profile calculating part for creating a delay profile representing a correlation between each of said received signals and a predetermined code by calculating a correlation value between them; and

a received timing calculating part for determining each of said received timings relative to the plurality of the base stations by using said delay profile;

wherein said received timing calculation part determines each of said received timings with reference to a rise timing where said delay profile rises from a noise level; and

said rise timing is set when the value of said delay profile is equal to a threshold value within a predetermined time before an incoming wave determining timing used to determine the presence of said incoming wave.

4. The terminal equipment according to claim 3, wherein said received timing is delayed by predetermined time behind said rise timing to be a reference timing.

5. The terminal equipment according to claim 3, further comprising a positioning part for calculating a position of the terminal equipment from said received timings of said received signals as to particular incoming waves transmitted from said base stations.

6. A terminal positioning apparatus which measures a position of terminal equipment by using received timings of received radio signals as to particular incoming waves transmitted between a plurality of base stations and said terminal equipment;

comprising;

a delay profile calculating part for creating a delay profile representing a correlation between each of said received signals and a predetermined code by calculating a correlation value between them; and

a received timing calculating part for determining each of said received timings relative to the plurality of the base stations by using said delay profile;

wherein said received timing calculation part determines each of said received timings with reference to a rise timing where said delay profile rises from a noise level; and

said rise timing is set when the value of said delay profile is equal to a threshold value within a predetermined time before an incoming wave determining timing used to determine the presence of said incoming wave.

7. The terminal positioning apparatus according to claim 6, wherein said received timing is delayed by predetermined time behind said rise timing to be a reference timing.

8. The terminal positioning apparatus according to claim 6, further comprising a positioning part for calculating a position of the terminal equipment from said received timings of received signals as to particular incoming waves transmitted from said base stations.

9. A terminal positioning method using received timings of received signals as to particular incoming waves transmitted between a plurality of base stations and a terminal, the method comprising steps of:

a first step of calculating a correlation value between each of said received signals and a predetermined code to create a delay profile representing a correlation between each of said received signals and the predetermined code;

a second step of determining said received timings of each of said incoming waves with reference to a rise timing where each of said delay profiles rises from a noise level;

a third step of calculating a position of said terminal by using said received timings relative to the plurality of the base stations,

a fourth step of setting one threshold value for determining said rise timing is set on the basis of measured noise power; and

a fifth step of setting another threshold value, which is larger than said one threshold value and is used to determine each of incoming waves, on the basis of a value obtained by multiplying measured noise power by coefficient C1, where C1 is set to 10≦

C1,

wherein a received timing of said each incoming wave is determined at a point in time where a value of said delay profile becomes equal to said another threshold value, and said rise timing is set when the value of said delay profile is equal to said one threshold value before the received timing of said incoming wave.

10. The terminal positioning method according to claim 9, wherein said each of received timings is delayed by predetermined time after said rise timing to be a reference timing.

11. Terminal equipment in a terminal positioning system for positioning the terminal equipment using received timings of received signals as to particular incoming waves transmitted from a plurality of base stations to the terminal equipment;

comprising;

a signal receiving part for receiving said signals from said base stations;

a delay profile calculating part for creating a delay profile representing a correlation between each of said received signals and a predetermined code by calculating a correlation value between each of said received signals and the predetermined code; and

a received timing calculating part for determining each of said received timings relative to the plurality of the base stations by using said delay profile,

wherein said received timing calculation part determines each of said received timings with reference to a rise timing where said delay profile rises from a noise level, and

wherein said rise timing is set when a value of said delay profile becomes equal to one threshold value, which is set on the basis of measured noise power, before an incoming wave determination timing which is used to determine a reception of each of said incoming waves and that is a timing where the value of said delay profile becomes equal to another threshold which is larger than said one threshold value and is set on the basis of a value obtained by multiplying the measured noise power by coefficient C1, where C1 is set to 10≦

C1.

12. The terminal equipment according to claim 11, wherein said received timing is delayed by a predetermined time behind said rise timing to be a reference timing.

13. The terminal equipment according to claim 11, further comprising a positioning part for calculating a position of the terminal equipment from said received timings of said received signals as to particular incoming waves transmitted from said base stations.

14. A terminal positioning apparatus which measures a position of terminal equipment by using received timings of received radio signals as to particular incoming waves transmitted between a plurality of base stations and said terminal equipment;

comprising;

a delay profile calculating part for creating a delay profile representing a correlation between each of said received signals and a predetermined code by calculating a correlation value between each of said received signals and the predetermined code; and

a received timing calculating part for determining each of said received timings relative to the plurality of the base stations by using said delay profile, wherein said received timing calculation part determines each of said received timings with reference to a rise timing where said delay profile rises from a noise level, and

wherein said rise timing is set when a value of said delay profile becomes equal to one threshold value, which is set on the basis of measured noise power, before an incoming wave determination timing which is used to determine a reception of each of said incoming waves and that is a timing where the value of said delay profile becomes equal to another threshold which is larger than said one threshold value and is set on the basis of a value obtained by multiplying the measured noise power by coefficient C1, where C1 is set to 10≦

C1.

15. The terminal positioning apparatus according to claim 14, wherein said received timing is delayed by a predetermined time behind said rise timing to be a reference timing.

16. The terminal positioning apparatus according to claim 14, further comprising a positioning part for calculating a position of the terminal equipment from said received timings of received signals as to particular incoming waves transmitted from said base stations.