Indirect Optical Free-Space Communications System and Method for the Broadband Transmission of Hight-Speed Data

• US 20080219671A1
• Filed: 06/28/2005
• Published: 09/11/2008
• Est. Priority Date: 09/23/2004
• Status: Active Grant

• Current Assignee: Airbus Operations GmbH (Airbus SE)
• Original Assignee: Airbus Deutschland GmbH (Airbus SE)
• Inventors: Schmitt, Nikolaus-Peter
• Granted Patent: US 8,548,332 B2
• Time in Patent Office: Days
• US Class Current: 398/130
• CPC Class Codes: H04B 10/1149 Arrangements for indoor wireless networking of information

Abstract

An indirect optical free-space communications system provides broadband transmission of high-speed data in in transportation vehicles such as aircraft. The system includes a transmitter with a light source that can be modulated and a receiver with a photo detector, adapted to receive light that is emitted from the transmitter and to convert it into an electric signal. The transmitter and the receiver are directed onto at least one common surface, which reflects the light emitted from the transmitter before it reaches the receiver. The free space communications system is cellular and includes several cells, each of which has a transmitter and at least one corresponding receiver. The cells are configured in such a way that crosstalk with a respective adjoining cell is prevented. The cells are thus independent of one another.

Claims

1-17. -17. (canceled)

18. An indirect optical free-space communication system for broadband transmission of high-speed data, comprising:

a transmitter that has a modulable light source, and

a receiver that has a photodetector to receive light emitted by the transmitter that is converted into an electric signal,

wherein the transmitter and the receiver are directed at at least one shared surface, which reflects the light emitted by the transmitter before it reaches the receiver,

wherein said transmitter is one of a plurality of transmitters and said receiver is one of a plurality of receivers,

wherein the free-space communication system is designed as a cellular system and has multiple cells, each of which comprises one of said transmitters and at least one respective receiver, and

wherein the cells are designed to prevent crosstalk with a neighboring cell so that the cells are independent of one another.

19. The indirect optical free-space communication system as claimed in claim 18, further comprising at least one of means for beam shaping of a respective transmitter and means for limiting a reception beam angle of a respective receiver to prevent crosstalk.

20. The indirect optical free-space communication system as claimed in claim 18, further comprising at least one shading element for shading the light reflected by the shared surface of a cell with respect to a receiver belonging to another cell.

21. The indirect optical free-space communication system as claimed in claim 18, wherein light sources of neighboring cells have different wavelengths.

22. The indirect optical free-space communication system as claimed in claim 18, wherein the at least one shared surface defines reflecting surfaces of the cells arranged in an interior of a transportation device in which the data transmission takes place.

23. The indirect optical free-space communication system as claimed in claim 22, wherein the transportation device is a motor vehicle, airplane, ship or satellite.

24. The indirect optical free-space communication system as claimed in claim 18, wherein reflection or scattering areas of the at least one shared surface does or do not overlap mutually within neighboring cells.

25. The indirect optical free-space communication system as claimed in claim 18, wherein the cells are arranged in a row, and wherein wavelengths of the light alternate in neighboring cells.

26. The indirect optical free-space communication system as claimed in claim 18, wherein the cells are spatially separated from one another.

27. The indirect optical free-space communication system as claimed in claim 18, wherein the surface of at least one of the cells is a surface of a wall or an object in the interior of a space in which data is transmitted.

28. The indirect optical free-space communication system as claimed in claim 18, wherein the light source comprises at least one LED, laser diode, edge-emitting laser diode, or VCSEL laser.

29. The indirect optical free-space communication system as claimed in claim 18, wherein the receiver comprises a light source and the transmitter comprises a photodetector to perform bidirectional communication.

30. The indirect optical free-space communication system as claimed in claim 18, wherein, during operation, a single transmitter of a cell supplies the data simultaneously to a plurality of receivers.

31. A method for indirect optical transmission of high-speed data, comprising:

generating light by means of a light source that is modulated at the frequency of the data to be transmitted;

transmitting the modulated light onto a surface that reflects, scatters, or reflects and scatters the light;

receiving the light scattered, reflected, or scattered and reflected by the surface so that it goes by an indirect route from the light source to a receiver; and

converting the modulated light into an electric signal;

wherein transmitting and receiving of the light take place in several independent cells, each comprising at least one transmitter and at least one receiver, so that crosstalk with a neighboring cell is actively prevented.

32. The method as claimed in claim 31, wherein the light emitted by the transmitter of a cell is limited in its beam angle such that it does not reach the receivers of other cells.

33. The method as claimed in claim 31, wherein a reception beam angle of a respective receiver of a cell is limited so that the light of the cells adjacent to the light sources does not reach the receiver.

34. The method as claimed in claim 31, wherein the light reflected by the surface of a cell is shaded with respect to a receiver belonging to another cell.

35. The method as claimed in claim 31, wherein light of different wavelengths is used in neighboring cells.