System and method for providing time to a satellite positioning system (SPS) receiver from a networked time server

• US 20050078032A1
• Filed: 05/13/2004
• Published: 04/14/2005
• Est. Priority Date: 12/19/2002
• Status: Active Grant

• Current Assignee: Alan Martin Gilkes
• Original Assignee: Alan Martin Gilkes
• Inventors: Gilkes, Alan Martin
• Granted Patent: US 7,142,156 B2
• Time in Patent Office: Days
• US Class Current: 342/357.520
• CPC Class Codes: G01S 19/256 relating to timing, e.g. time of week, code phase, timing offset
• CPC Class Codes: G04G 7/00 Synchronisation radio-controlled time-pieces G04R

Abstract

System and method for enabling signal acquisition in a satellite positioning system (SPS) when signals from SPS satellites are attenuated by the operating environment of a SPS receiver. A preferred embodiment comprises a communications server (for example, communications server 220) coupled to a SPS receiver (for example, SPS receiver 210) at one end and a time server (for example, time server 225) by a public network (for example, the Internet 230). Preferably, the communications server 220 is coupled to the Internet 230 via a wireless network to facilitate maximum mobility and flexibility. The communications server 220 queries the time server 225 for the current time and then provides the current time to the SPS receiver 210. The SPS receiver 210 makes use of the current time to assist it in signal acquisition.

Claims

1-47. -47. (canceled)

48. An electronic apparatus, comprising:

a receiver containing circuitry to receive transmissions from a plurality of satellites in a satellite positioning system (SPS);

a communications processor coupled to the receiver and containing circuitry to obtain time-of-day information, generated by an external source other than the plurality of satellites, and to further provide the time information to the receiver, the receiver utilizing the time information to facilitate acquisition of signals transmitted from the plurality of satellites.

49. The electronic apparatus of claim 48, wherein the time-of-day information utilized by the receiver excludes time information received from any other source.

50. The electronic apparatus of claim 48, wherein the time-of-day information utilized by the receiver is unaltered from the form it is in when received from the external source.

51. An electronic apparatus, comprising:

a receiver containing circuitry to receive transmissions from a plurality of satellites in a satellite positioning system (SPS);

a communications processor coupled to the receiver and containing circuitry to obtain time information from an external source other than satellites in the satellite position system (SPS) and to provide the time information to the receiver, the receiver utilizing the time information in unaltered form to facilitate acquisition of signals transmitted from the plurality of satellites.

52. The electronic apparatus of claim 51, where the time information is time-of-day information.

53. A system for aiding signal acquisition in a satellite positioning system (SPS) comprising:

an SPS receiver, the SPS receiver containing circuitry to receive transmissions from a plurality of SPS satellites and compute, from the received transmissions, its current position and the current SPS Time;

a communications processor coupled to the SPS receiver, the communications processor containing circuitry to obtain time information from an external source and to provide the time information to the SPS receiver;

a first communications network coupled to the communications processor; and

a time server coupled to the first communications network, the time server containing circuitry to maintain accurate time and to response to time queries.

54. The system of claim 53, wherein the communications processor comprises:

a time server client coupled to the first communications network, the time server client containing circuitry to interface with the time server;

a real-time clock coupled to the time server client, the real-time clock to maintain a time as provided by the time server; and

a pulse and message generator (PMG) coupled to the real-time clock, the PMG containing circuitry to provide time information taken from the real-time clock to the SPS receiver.

55. The system of claim 54, wherein the real-time clock periodically provides the time to the PMG, and the system further comprises an additional clock coupled to the real-time clock, the additional clock to provide one of a series of periodic beacon pulses and a series of time messages that are used by the PMG to ensure the accuracy of the given period.

56. The system of claim 55, wherein the additional clock is a clock built into the SPS receiver that supplies one periodic beacon pulse at the beginning of each second of SPS Time, as computed by the SPS receiver.

57. The system of claim 54, wherein the additional clock is a clock built into the SPS receiver that supplies, after each pulse sent by the PMG to the SPS receiver, a set of time messages.

58. The system of claim 57, wherein the time messages specify:

the SPS receiver'"'"'s local clock time at which it received the PMG pulse,

the latest SPS Time computed by the SPS receiver, and

the SPS receiver local clock time exactly matching that SPS time.

59. A position measuring device comprising:

a satellite positioning system (SPS) receiver comprising

an analog processing unit containing circuitry to filter and amplify an analog SPS signal received via an antenna;

a digital processing unit coupled to the analog processing unit, the digital processing unit containing circuitry to perform signal acquisition, correlation, decode, and calculation of position and SPS Time;

a communications processor comprising

a pulse and message generator (PMG) unit containing circuitry to produce a timing beacon and a timing message;

a real-time clock coupled to the PMG unit, the real-time clock containing circuitry to keep track of time and to generate signals to indicate timing events; and

a network client coupled to the real-time clock, the network client containing circuitry to receive timing information from a time server coupled to the communications processor via a network and to provide time adjustments to the real-time clock.

60. The position measuring device of claim 59, wherein the PMG unit further comprises a second clock input, and wherein the second clock input provides at least one of timing signals and messages from another clock.

61. The position measuring device of claim 60 further comprising a second clock coupled to the second clock input, the second clock to provide at least one of a continuous stream of periodic beacons and a stream of time messages.

62. The position measuring device of claim 61, wherein the second clock is part of the SPS receiver and supplies one periodic beacon pulse at the beginning of each second of SPS Time, as computed by the SPS receiver.

63. The position measuring device of claim 62, wherein the second clock is part of the SPS receiver and supplies, after each pulse sent by the PMG to the SPS receiver, a set of time messages specifying:

the SPS receiver'"'"'s local clock time at which it received the PMG pulse,

the latest SPS Time computed by the SPS receiver, and

the SPS receiver local clock time exactly matching that SPS time.