Apparatus and methods for position computation based on broadcast initialization data

• US 6,636,740 B1
• Filed: 06/16/1998
• Issued: 10/21/2003
• Est. Priority Date: 06/16/1998
• Status: Expired due to Term

• Current Assignee: Optis Wireless Technology, LLC (Brevet Capital)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Ramesh, Rajaram
• Primary Examiner(s): Nguyen, Lee
• Application Number:
  US09/098,049
• Time in Patent Office: 1,953 Days
• Field of Search: 455/456, 455/457, 455/466, 455/13.2, 342/357.15, 342/358, 342/457, 342/357.1, 342/357.02, 342/357.06, 714/700
• US Class Current: 455/456.1
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 19/41 Differential correction, e.g. DGPS [differential GPS]
• CPC Class Codes: G01S 2205/008 using a mobile telephone network
• CPC Class Codes: G01S 5/009 Transmission of differential positioning data to mobile

Abstract

The present invention provides apparatus and methods for position computation with high accuracy, low acquisition time and low power consumption. The position computation apparatus includes a radio communication receiver which monitors a radio communication network, such as a cellular network, covering the geographic region in which the position computation apparatus is located. The apparatus demodulates the signal from the radio communication network and obtains positioning data from the broadcast channel of the network for use in satellite acquisition operations prior to computing a position. The apparatus further includes a receiver for receiving positioning messages broadcast by a constellation of GPS satellites. A position computation circuit in the apparatus utilizes the positioning data obtained from the radio communication network in initial acquisition of one or more positioning satellites. Once the desired number of positioning satellites have been acquired, positioning messages are received from the acquired positioning satellites and used to calculate the position of the position computation apparatus.

Claims

1. A mobile position computation apparatus for use within a region serviced by a radio communication network comprising:

a first receiver for receiving a radio communication broadcast over the radio communication network on a broadcast control channel;

a second receiver for receiving positioning messages broadcast by a positioning satellite;

position computation circuit coupled to the second receiver; and

means coupled to said first receiver for obtaining positioning data from the radio communication broadcast and providing the positioning data to the position computation circuit for use in acquisition of the positioning satellite.

2. A position computation apparatus according to claim 1 wherein the positioning satellite is a global positioning system satellite.

3. A position computation apparatus according to claim 1 wherein the radio communication network is a cellular communication network.

4. A position computation apparatus according to claim 3 wherein the positioning data is selected from the group consisting of ephemeris data for the positioning satellite, includes a position of a base station transmitting the radio communication, clock correction information and a framing structure timestamp for the broadcast control channel.

5. A position computation apparatus according to claim 3 wherein the means coupled to the first receiver further comprises:

means for demodulating and decoding the radio communication;

means for obtaining the positioning data from the demodulated and decoded radio communication; and

means for providing the position computation circuit the positioning data obtained from the demodulated and decoded radio communication.

6. A position computation apparatus according to claim 3 wherein the position computation circuit includes means for warm starting acquisition of the positioning satellite based on the positioning data.

7. A position computation apparatus according to claim 6 wherein the position computation circuit further includes means for limiting the time window during which it searches for the positioning messages broadcast by the positioning satellite based on the positioning data.

8. A position computation apparatus to claim 6 wherein the position computation circuit further includes further means for limiting the window during which it searches for the positioning messages broadcast by the positioning satellite based on the positioning data.

9. A position computation apparatus according to claim 6 wherein the positioning data includes an identification of only ones of a plurality of positioning satellites within view of the base station, and wherein the position computation circuit further includes means for selecting only ones of the plurality of positioning satellites within view of the base station as the positioning satellite based on the included identifications.

10. A method for acquisition of a positioning satellite from within the coverage area of a radio communication network broadcasting positioning data, the method comprising the steps of:

receiving the positioning data over the radio communication network on a broadcast control channel; and

receiving a radio communication from the positioning satellite; and

acquiring the positioning satellite based on the received positioning data.

11. A method according to claim 10 wherein the step of receiving the positioning data comprises the steps of:

receiving a broadcast radio communication containing the positioning data over the radio communication network on the broadcast control channel;

demodulating the radio communication;

decoding the radio communication; and

obtaining the positioning data from the demodulated and decoded radio communication.

12. A method according to claim 10 wherein the positioning satellite is a global positioning system satellite.

13. A method according to claim 12 wherein the radio communication network is a cellular communication network.

14. A method according to claim 12 wherein the positioning data includes a position of a base station transmitting the radio communication.

15. A method according to claim 12 wherein the step of acquiring a positioning satellite includes the step of warm starting acquisition of the positioning satellite based on the positioning data.

16. A method according to claim 12 wherein the step of acquiring a positioning satellite includes the step of limiting the time window during which searches are made for the positioning messages broadcast by the positioning satellite based on the positioning data.

17. A method according to claim 12 wherein the step of acquiring a positioning satellite includes the step of limiting the Doppler frequency range over which searches are made for the positioning messages broadcast by the positioning satellite based on the positioning data.

18. A method according to claim 12 wherein the positioning data includes an identification of only ones of a plurality of positioning satellites within view of the base station, and wherein the step of acquiring a positioning satellite includes the step of selecting only ones of the plurality of positioning satellites within view of the base station as the positioning satellite based on the included identifications.

19. A method according to claim 10 further comprising the step following said receiving step of acquiring a positioning satellite without positioning data when outside the coverage area of a radio communication network broadcasting positioning data.

20. A method according to claim 10 further comprising the step following said acquiring step of receiving positioning messages from the acquired positioning satellite.

21. A method for acquisition of a positioning satellite from within the coverage area of a base station of a cellular radio communication network, the method comprising the steps of:

periodically broadcasting positioning data including a position of the base station from the base station on a broadcast control channel; and

wherein the following steps are performed by a mobile position computation apparatus;

receiving the positioning data from the base station on the broadcast control channel without registering with the base station;

demodulating the radio communication;

decoding the radio communication;

obtaining the positioning data from the demodulated and decoded radio communication, the obtained positioning data including a position of the base station; and

acquiring the positioning satellite based on the received positioning data including the position of the base station.

22. A method according to claim 21 wherein the positioning data includes an identification of only ones of a plurality of positioning satellites within view of the base station, and wherein the step of acquiring the positioning satellite further comprises the step of acquiring only ones of the plurality of positioning satellites within view of the base station as the positioning satellite based on the included identifications.

23. A method for acquisition of a positioning satellite from within the coverage area of a base station of a cellular radio communication network, the base station periodically broadcasting positioning data including a position of the base station from the base station on a broadcast control channel, the method comprising the steps of:

receiving the positioning data from the base station on the broadcast control channel without registering with the base station;

demodulating the radio communication;

decoding the radio communication;

obtaining the positioning data from the demodulated and decoded radio communication, the obtained positioning data including the position of the base station; and

acquiring the positioning satellite based on the received positioning data including the position of the base station.

24. A method according to claim 23 wherein the positioning data includes an identification of only ones of a plurality of positioning satellites within view of the base station, and wherein the step of acquiring the positioning satellite further comprises the step of acquiring only ones of the plurality of positioning satellites within view of the base station as the positioning satellite based on the included identifications.

25. A mobile position computation apparatus for use within a region serviced by a radio communication network comprising:

a first receiver that receives a radio communication broadcast from a base station of the radio communication network on a broadcast control channel, the radio communication including positioning data including a position of the base station;

a signal processing circuit that obtains the positioning data from the received radio communication;

a second receiver for receiving positioning messages broadcast by a positioning satellite; and

a position computation circuit coupled to the second receiver and the signal processing circuit that acquires the positioning satellite based on the positioning data including the position of the base station.

26. A position computation apparatus according to claim 25 wherein the positioning data includes an identification of only ones of a plurality of positioning satellites within view of the base station, and wherein the position computation circuit is further configured to acquire only ones of the plurality of positioning satellites within view of the base station as the positioning satellite based on the included identifications.