DME system with broadcasting function

• US 6,366,233 B1
• Filed: 10/05/1999
• Issued: 04/02/2002
• Est. Priority Date: 10/07/1998
• Status: Expired due to Term

• Current Assignee: NEC Corporation, Texas Instruments, Inc.
• Original Assignee: NEC Corporation
• Inventors: Oshida, Naohito
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US09/412,911
• Time in Patent Office: 910 Days
• Field of Search: 342/46, 342/47, 342/50, 342/52, 342/57, 342/58, 342/59
• US Class Current: 342/47
• CPC Class Codes: G01S 13/765 with exchange of information between interrogator and responder
• CPC Class Codes: G01S 13/785 Distance Measuring Equipment [DME] systems
• CPC Class Codes: G01S 13/788 Coders or decoders therefor; Special detection circuits

Abstract

Frequency resources of a DME/TACAN band specified for the aircraft band are effectively utilized, and a GPS reinforcing data is overlapped onto distance information to be broadcast. A header is added to a DGPS reinforcing data, and the transmitting pulse level of a conventional ground DME system is modulated, and the data is broadcast to an airborne system. In the airborne system, a threshold value of “1” and “0” is generated by a level detecting device (5), and the start point of the data is detected by a header detecting device (6), and the reinforcing data is supplied to the airborne system. Consequently, the function of broadcasting a data by overlapping the data onto the distance information of the DME is achieved. Since the DME uses the L band, the radio interference with the existing ILS, VOR, aircraft radio transmission, and broadcasting station can be avoided.

Claims

1. A DME system including a ground unit which provides distance information by using paired pulses and an airborne unit which receives said distance information, wherein

said ground unit has changing means for changing a peak level of the paired pulses according to augmentation data to transmit said augmentation data with said distance information to said airborne unit;

and

said airborne unit has detecting means for detecting a pulse peak level of received paired pulses to receive said augmentation data.

2. A DME system as claimed in claim 1, wherein said augmentation data has header data having a predetermined pattern and said ground unit has decoding means for decoding said header data.

3. A DME system as claimed in claim 2, wherein said header data comprise a training sequence which has a reference value corresponding to data “

1” and

“

0”

.

4. A DME system as claimed in claim 2, wherein said header data comprise a training sequence which has a unique word for clearly expressing a start point of said augmentation data.

5. A DME system as claimed in claim 1, wherein said augmentation data are reinforcing data of GPS.

6. In a DME unit to provide distance information from a ground unit to an airborne unit, a DME system with a broadcasting function, comprising:

changing means which changes a peak level of paired pulse stimulation sent from a ground DME unit according to a signal including “

1” and

“

0” and

having a header added, according to a transmit data;

detecting means which detects a pulse peak level of a receiving video output of an airborne DME unit as “

1” and

“

0”

; and

decoding means which decodes said header,

wherein the DME system broadcasts information to an aircraft which is providing DME information.

7. In a DME unit to provide distance information from a ground unit to an airborne unit, a DME system with a broadcasting function, comprising:

modulating means which uses a pulse on one side of paired pulse stimulation sent from a ground DME unit according to a transmit data including “

1” and

“

0”

as a reference pulse, and which modulates a pulse on the other side by said transmit data;

adding means which adds said paired pulse stimulation modulated so that a start of said transmit data may be discriminated before said transmit data as a header;

detecting means which detects paired pulse stimulation showing said header from a receiving video output of an airborne DME unit; and

reading out means which reads out said transmit data from said pulse on the other side by using said pulse on one side of the paired pulse stimulation following said pair pulse stimulation showing the header as a reference, wherein the DME system broadcasts information to an aircraft which is providing DME information.

8. The DME system with a broadcasting function as claimed in claim 7, wherein in said paired pulse stimulation to transmit a data, a first pulse thereof is a pulse of level “

1”

showing a reference and a second pulse thereof is a data pulse shown by either “

1”

or “

0,” and

in said paired pulse stimulation to show a header, a first pulse thereof is a pulse of level “

0” and

a second pulse thereof is a pulse of level “

1”

.

9. A ground unit for a DME system with a broadcasting function, comprising header adding means which adds a header to a transmit data from data generating means and level modulating means into which the header and the transmit data outputted from said header adding means are inputted and which modulates paired pulse stimulation outputted from a ground DME transmitter by amplitude modulation by using said header and said transmit data.

10. An airborne unit for a DME system with a broadcasting function, comprising level detecting means which receives paired pulse stimulation transmitted from a ground DME transmitter and which judges whether a data signal overlapped onto said paired pulse stimulation is “

1”

or “

0”

by comparing a level of said received paired pulse stimulation with a reference level, and header detecting means which discriminates a header added to a transmit data transmitted from said ground DME transmitter on the basis of results judged by said level detecting means and which extracts the transmit data.

11. A DME system including a ground unit which provides distance information by using paired pulses and an airborne unit which receives said distance information, wherein

said ground unit has a changing device that changes a peak level of the paired pulses according to augmentation data to transmit said augmentation data with said distance information to said airborne unit;

and

said airborne unit has a detector that detects a pulse peak level of the received paired pulses to receive said augmentation data.

12. A DME system as claimed in claim 11, wherein said augmentation data is comprised of a header having a predetermined pattern and said ground unit includes a decoder that decodes said header.

13. A DME system as claimed in claim 12, wherein said header is comprised of a training sequence which has a reference value corresponding to data “

1” and

“

0”

.

14. A DME system as claimed in claim 12, wherein said header is comprised of a training sequence which has a unique word for clearly expressing a start point of said augmentation data.

15. A DME system as claimed in claim 11, wherein said augmentation data are reinforcing data of GPS.

16. A ground unit for a DME system with a broadcasting function, comprising an adder which adds a header to transmission data from data generating means and a level modulator into which the header and transmission data outputted from said adder are inputted and which modulates a paired pulse stimulation outputted from a ground DME transmitter by amplitude modulation by using said header and said transmission data.

17. An airborne unit for a DME system with a broadcasting function, comprising a level detector which receives a paired pulse stimulation transmitted from a ground DME transmitter and which judges whether a data signal overlapped onto said paired pulse stimulation is “

1”

or “

0”

by comparing a level of said received paired pulse stimulation with a reference level, and a detector which discriminates a header added to data transmitted from said ground DME transmitter on the basis of results judged by said level detector and which extracts the transmission data.