CONTEXTUAL DATA COMPRESSION FOR GEO-TRACKING APPLICATIONS

• US 20130238573A1
• Filed: 03/01/2013
• Published: 09/12/2013
• Est. Priority Date: 03/07/2012
• Status: Active Grant

• Current Assignee: Titan Intelligence Technology Limited
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: LE PIFRE, Pierre
• Granted Patent: US 9,235,591 B2
• Time in Patent Office: Days
• US Class Current: 707/693
• CPC Class Codes: G01S 19/03 Cooperating elements; Interaction or communication between different cooperating elements or between cooperating elements and receivers
• CPC Class Codes: G01S 5/0018 Transmission from mobile station to base station
• CPC Class Codes: G06F 16/1744 using compression, e.g. sparse files

Abstract

Various exemplary embodiments relate to a method of compressing location data. The method may include: receiving original location data; selecting a contextual profile based at least in part on the original location data; selecting a compression method based on the contextual profile; and converting the original location data to a compressed format based on the compression method. Various exemplary embodiments relate to a system for compressing location data. The system may include: a location receiver configured to generate original location data based at least on signals from global navigation satellite system (GNSS) satellites; a location engine configured to select a contextual profile based at least in part on the original location data; and a contextual compression filter configured to generate compressed location data in a compressed format based on the selected contextual profile.

Claims

1. A method comprising:

receiving original location data;

selecting a contextual profile based at least in part on the original location data;

selecting a compression method based on the contextual profile; and

converting the original location data to a compressed format based on the compression method.

2. The method of claim 1, further comprising:

receiving second location data;

determining that the contextual profile no longer applies;

selecting a second contextual profile;

selecting a second compression method based on the second contextual profile; and

converting the second location data to a second compressed format using fewer bits than the second location data according to the second compression method.

3. The method of claim 1, wherein the original location data includes a plurality of component values including a longitude value and a latitude value and the step of selecting a contextual profile comprises:

comparing the longitude value and the latitude value of the original location data to a geographical area defined for a contextual profile; and

selecting the contextual profile if the longitude and latitude are within the geographical area.

4. The method of claim 1, wherein the contextual profile includes for each component of the original location data:

a base value, a precision value, and a number of bits, wherein each component of the original location data is stored using the corresponding number of bits.

5. The method of claim 1, further comprising storing an indication of the selected contextual profile.

6. The method of claim 1, wherein the original location data includes a plurality of component values including a speed value and the step of selecting a contextual profile comprises:

using the speed value to determine a mode of transportation; and

selecting a contextual profile based on the mode of transportation.

7. The method of claim 1, wherein the step of converting the original location data to a compressed format comprises scaling a component of the original location data.

8. The method of claim 1, wherein the step of converting the original location data to a compressed format comprises converting a component of the original location data to a relative measurement.

9. A system for compressing location data, the system comprising:

a location receiver configured to generate original location data based at least on signals from a global navigation satellite system satellites;

a location engine configured to select a contextual profile based at least in part on the original location data; and

a contextual compression filter configured to generate compressed location data in a compressed format based on the selected contextual profile.

10. The system of claim 9, wherein the original location data includes a plurality of component values including a longitude value and a latitude value and the location engine is configured to:

compare the longitude value and the latitude value of the original location data to a geographical area defined for a contextual profile; and

select the contextual profile if the longitude and latitude are within the geographical area.

11. The system of claim 9, wherein the contextual profile includes for each component of the original location data:

a base value, a precision value, and a number of bits, wherein each component of the original location data is stored in the compressed format using the corresponding number of bits.

12. The system of claim 9, wherein the contextual compression filter is configured to, for each original component value:

generate an intermediate value by subtracting the base value from the original component value;

generate a compressed value by dividing the intermediate value by the precision value; and

store the compressed value in the compressed format.

13. The system of claim 9, further comprising a processor configured to:

determine, based on a contextual profile, compression parameters including a number of bits, a precision value, and a base value;

read the number of bits from a stored compressed value;

generate an intermediate value by multiplying the read bits by the precision value; and

generate a location data component by adding the base value to the intermediate value.

14. The system of claim 9, wherein the contextual compression filter is configured to scale a component of the original location data based on a parameter defined in the contextual profile.

15. The system of claim 9, wherein the original location data includes a plurality of component values including a speed value and the location engine is configured to select a contextual profile based on the speed value.