Apparatus and method for coupling data to a position determination device

• US 6,307,505 B1
• Filed: 02/24/1999
• Issued: 10/23/2001
• Est. Priority Date: 07/22/1998
• Status: Expired due to Term

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: Green, James C.
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US09/256,159
• Time in Patent Office: 972 Days
• Field of Search: 342/357.09, 342/357.1
• US Class Current: 342/357.4
• CPC Class Codes: G01S 19/07 providing data for correcting measured positioning data, e.g. DGPS [differential GPS] or ionosphere corrections
• CPC Class Codes: G01S 5/009 Transmission of differential positioning data to mobile

Abstract

A method and apparatus for coupling data from an external data device to a position determination device. An Auxiliary Data Transmission Unit (ADTU) that includes a radio transmitter couples to the external data device. The ADTU receives serial data from the external data device and encodes the received serial data into a format suitable for receipt by the position determination device. The encoded data is then modulated to produce a radio signal that is transmitted to the position determination device in a scheme that permits multiple devices to communicate with the position determination device without interference.

Claims

1. A data transmission device comprising:

a.) a controller adapted to control the operation of said data transmission device;

b.) a data storage device coupled to said controller and adapted to store data;

c.) a connection mechanism coupled to said controller and adapted to couple to an external data device for receiving serial data;

d.) an encoder for encoding serial data into encoded data, said encoded data having a format adapted to be received by a position determination device, said encoder including a signal interference algorithm for preventing data loss from signal interference;

e.) a radio transmitter coupled to said controller for transmitting said data from said encoded data to a position determination device; and

f.) a housing, said controller, said data storage device, said encoder, and said radio transmitter disposed in said housing.

2. The data transmission device of claim 1 wherein said connection mechanism includes a connector that conforms to the RS232 standard.

4. The data transmission device of claim 1 wherein said signal interference algorithm generates duplicate data that is transmitted at predetermined intervals for preventing data loss from signal interference.

3. A data transmission device comprising:

a.) a controller adapted to control the operation of said data transmission device;

b.) a data storage device coupled to said controller and adapted to store data;

c.) a connection mechanism coupled to said controller and adapted to couple to an external data device for receiving serial data;

d.) an encoder for encoding serial data into encoded data, said encoded data having a format adapted to be received by a position determination device, said encoder is an algorithm for converting 8-bit data words into 12-bit data words that include forward error correction bits;

e.) a radio transmitter coupled to said controller for transmitting said encoded data to a position determination device; and

f.) a housing, said controller, said data storage device, said encoder, and said radio transmitter disposed in said housing.

5. A method for coupling data from an external data device to a position determination device comprising:

a.) providing a radio transmitter adapted to couple to an external data device;

b.) coupling said radio transmitter to an external data device;

c.) receiving serial data from said external data device;

d.) encoding said serial data so as to obtain encoded data, said encoded data formatted using Time Division Multiple Access (TDMA) formatting methods to prevent data loss from signal interference;

e.) modulating said encoded data so as to produce a radio signal; and

f.) transmitting said radio signal to a position determination device.

6. A method for coupling data from an external data device to a position determination device comprising:

a.) providing a radio transmitter adapted to couple to an external data device;

b.) coupling said radio transmitter to an external data device;

c.) receiving serial data from said external data device;

d.) encoding said serial data so as to obtain encoded data that is formatted into a format that includes a data packet and a duplicate data packet, said data packet and said duplicate data packet transmitted at different time intervals to prevent data loss from signal interference;

e.) modulating said encoded data so as to produce a radio signal; and

f.) transmitting said radio signal to a position determination device.

7. The method for coupling data from an external data device of claim 6 wherein step d.) further comprises:

encoding said serial data so as to convert said serial data into 12-bit words, said 12-bit words including forward error correction bits.

8. The method for coupling data from an external data device of claim 6 wherein step e.) further comprises:

e1.) modulating said encoded data to a frequency of 916 megaHertz so as to produce a radio signal.

9. The method for coupling data from an external data device of claim 6 wherein step e.) further comprises:

e1.) modulating said encoded data to a frequency of 868 megaHertz so as to produce a radio signal.

10. The method for coupling data from an external data device of claim 6 wherein step e.) further comprises:

e1.) modulating said encoded data to a frequency of 2.4 gigaHertz so as to produce a radio signal.

11. A network for determining position and receiving data from an external data device comprising:

a.) a signal conversion device including an antenna adapted to receive RTCM signals that include RTCM correction data, said signal conversion device including a radio receiver coupled to said antenna for demodulating said RTCM signals so as to obtain RTCM correction data, a modulator coupled to said radio receiver for modulating said RTCM correction data into a frequency adapted to be received by a position determination device so as to produce a converted correction signal, and a transmitter for transmitting said converted correction signal;

b.) a data transmission device including;

a controller adapted to control the operation of said data transmission device;

a data storage device adapted to store data;

a connection mechanism coupled to said controller and adapted to couple to an external data device for coupling serial data to said controller;

an encoder for encoding serial data into encoded data;

a radio transmitter coupled to said controller, said radio transmitter adapted to transmit said encoded data; and

c.) a position determination device that is adapted to receive said converted correction signal and said encoded data, said position determination device adapted to use said converted correction signal for accurately determining position.

12. The network of claim 11 wherein said encoder is a software program stored in said memory storage device and adapted to operate on said controller.

13. The network of claim 11 wherein said controller is an application specific integrated circuit device and said encoder is an algorithm programmed into said application specific integrated circuit device.