Method and apparatus for determining a deviation between clock pulse devices

• US 7,594,133 B2
• Filed: 03/30/2005
• Issued: 09/22/2009
• Est. Priority Date: 04/07/2004
• Status: Active Grant

• Current Assignee: Symeo GmbH (indie Semiconductor, Inc.)
• Original Assignee: Symeo GmbH (indie Semiconductor, Inc.)
• Inventors: Vossiek, Martin
• Primary Examiner(s): ELAMIN, ABDELMONIEM I
• Application Number:
  US11/578,094
• Publication Number:
  US 20080292039A1
• Time in Patent Office: 1,637 Days
• Field of Search: 713/400, 713/401, 370/252, 370/332, 370/335, 370/336, 370/342, 370/345, 370/350, 455/436, 455/440
• US Class Current: 713/401
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/06 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/12 takes precedence

Abstract

The invention relates to a method for synchronizing clock pulse devices. According to this method, an emission unit emits at least one narrow-band distant signal; clock pulse devices of receiving units are pre-synchronized by coupling the same to the source of one such distant signal; the emission unit emits a wide-band measured signal after a defined waiting time, and the receiving units receive said signal; and the receiving units correlate the wide-band measuring signal with a homogeneously modulated comparison signal, the receiving time of the wide-band measuring signal and the deviation in the synchronization of the clock pulse devices being determined and compensated on the basis of the correlation result.

Claims

1. A method for determining a deviation between clock pulse devices, comprising:

emitting, by a transmitter unit, at least one narrow-band pre-signal using a clock pulse device;

pre-synchronizing clock pulse devices of receiver units to a source of the pre-signal via a coupling to such a pre-signal;

emitting, by the transmitter unit, a broadband measurement signal after a specific wait time and receiving, by the receiver units, this broadband measurement signal; and

correlating, by the receiver units, the broadband measurement signal with a similarly modulated comparison signal and, based on a correlation result, determining a reception point in time of the broadband measurement signal and determining a deviation of the synchronization of the clock pulse devices.

2. The method according to claim 1, farther comprising:

waiting for a specific wait time, and then emitting a further narrowband pre-signal that follows after the emission of a first pre-signal to increase detection assurance, to which narrowband pre-signal the clock pulse devices couple.

3. The method according to claim 2, wherein a time span between the first pre-signal and the further pre-signal corresponds to half of a modulation duration of the first pre-signal.

4. The method according to claim 2, wherein the at least one pre-signal comprises specifications about the wait time until the emission of the broadband measurement signal.

5. The method according to claim 1, wherein the pre-signal comprises specifications about a wait time until the emission of the further pre-signal.

6. The method according to claim 1, wherein the transmitter unit is realized as a transponder and the receiver units are realized as base stations.

7. The method according to claim 1, further comprising:

providing an identification number of the transmitter unit within the at least one pre-signal.

8. The method according to claim 1, further comprising:

providing the transmitter unit and receiver units in a radio-based positioning system.

9. The method according to claim 1, further comprising:

utilizing the method for determining a deviation between clock pulses in a system for determining a position of a transmitter unit;

calculating an arrival point in time of the broadband measurement signal based on the correlation result and the position of the transmitter unit that can be determined via a comparison of the delays of the measurement signal received by the receiver units and transmitted by the transmitter unit.

10. The method according to claim 9, wherein the comparison of the delays is executed using a TDOA method.

11. The method according to claim 9, further comprising:

emitting a reference signal with a reference station provided with its own clock source, the position of which reference station is known;

receiving this reference signal by the receiver units; and

synchronizing the clock pulse devices of the receiver units on this reference signal.

12. The method according to claim 1, further comprising:

receiving, by the reference station, the pre-signals of the transmitter unit;

synchronizing, by the reference station, these pre-signals;

emitting, by the transmitter unit, the broadband measurement signal after the specific wait time;

emitting, by the reference station, a similarly modulated broadband reference measurement signal offset by a slight time shift relative to the determined wait time,

selecting the time offset such that it is distinctly smaller than a length of the broadband measurement signals;

mixing both the broadband measurement signal and the broadband reference measurement signal with a similarly modulated comparison signal into a mix signal in the receiver units the arrival points in time of the measurement signals; and

b) the time difference between the measurement signals using the signal components of the transmitter unit and of the reference station comprised in the correlated mix signal; and

determining a position of the transmitter unit based on at least one of arrival points in time and time difference.

13. The method according to claim 8, wherein the transmitter unit is suited for reception of signals, flirt her comprising:

after the synchronization of the receiver units via the pre-signals and via the measurement signal;

generating, by the receiver units a response signal based on the arrival point in time of the measurement signal;

transmitting this response signal to the transmitter unit after a stipulated wait time;

receiving this signal, and calculating an arrival point in time of the response signal is calculated there; and

calculating, based on the stipulated wait time, the signal delay and thus the separation between the transmitter unit and the receiver.

14. The method according to claim 9, farther comprising:

after the synchronization of the receiver units via the pre-signals and via the measurement signal;

generating, by the receiver units a response signal based on the arrival point in time of the measurement signal;

transmitting this response signal to the transmitter unit after a stipulated wait time;

receiving this signal, and calculating an arrival point in time of the response signal is calculated there; and

calculating, based on the stipulated wait time, the signal delay and thus the separation between the transmitter unit and the receiver.

15. The method according to claim 9, further comprising:

utilizing the transmitter unit and receiver unit for position determination of a transmitter unit in a radio-based positioning system.

16. The method according to claim 1, further comprising:

determining and compensating the deviation of the synchronization of the clock pulse devices.

17. A system for determining a deviation of clock pulse devices, the system comprising:

a transmitter unit configured to emit at least one narrow-band pre-signal, and then to emit a broadband measurement signal after a specific wait time, the transmitter unit configured to use a clock pulse device;

a plurality of receiver units, each receiver unit comprising;

pre-synchronization means for pre-synchronizing the clock pulse devices to the source of the pre-signal via a coupling to the pre-signal;

receiving means for receiving the broadband measurement signal;

correlation means for correlating the broadband measurement signal with a similarly modulated comparison signal; and

determination means for determining, based on the correlation result, the reception point in time of the broadband measurement signal and the deviation of the synchronization of the clock pulse devices.

18. A method at a receiver unit for determining a deviation between clock pulse device, the method comprising:

receiving at least one narrow-band pre-signal transmitted by a transmitter unit, the transmitter unit using a clock pulse device;

pre-synchronizing a clock pulse device of the receiver unit to the source of the pre-signal via a coupling to the pre-signal;

receiving a broadband measurement signal transmitted by the transmitter unit after a specific wait time; and

correlating the broadband measurement signal with a similarly modulated comparison signal and, based on the correlation result, determining the reception point in time of the broadband measurement signal and the deviation of the synchronization of the clock pulse devices.

19. A receiver device for determining a deviation of clock pulse devices, the receiver device comprising:

receiving means for receiving at least one narrow-band pre-signal transmitted by a transmitter unit, and for receiving a broadband measurement signal that has been transmitted by the transmitter unit after a specific wait time, wherein the transmitter unit uses a clock pulse device;

pre-synchronization means for pre-synchronizing the clock pulse devices of the receiver device to the source of the pre-signal via a coupling to the pre-signal;

correlation means for correlating the broadband measurement signal with a similarly modulated comparison signal; and

determination means for determining, based on the correlation result, the reception point in time of the broadband measurement signal and the deviation of the synchronization of the clock pulse devices.