Apparatus and method for transmitting an image signal modulated with a spreading code

• US 6,456,607 B2
• Filed: 10/10/1997
• Issued: 09/24/2002
• Est. Priority Date: 10/16/1996
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Arai, Hideyuki, Suda, Hirofumi
• Primary Examiner(s): Yao, Kwang Bin
• Application Number:
  US08/948,970
• Publication Number:
  US 20010040913A1
• Time in Patent Office: 1,810 Days
• Field of Search: 370/319, 370/320, 370/328, 370/329, 370/335, 370/342, 370/441, 370/479, 375/130, 375/132, 375/133, 375/134, 375/135, 375/136, 375/137, 375/146, 375/147
• US Class Current: 370/335
• CPC Class Codes: H04J 13/0077 Multicode, e.g. multiple codes assigned to one user
• CPC Class Codes: H04J 13/10 Code generation
• CPC Class Codes: H04J 13/16 Code allocation
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0017 where the mode-switching is based on Quality of Service requirement
• CPC Class Codes: H04N 19/37 with arrangements for assigning different transmission priorities to video input data or to video coded data
• CPC Class Codes: H04N 21/238 Interfacing the downstream path of the transmission network, e.g. adapting the transmission rate of a video stream to network bandwidth; Processing of multiplex streams hybrid fiber coaxial [HFC] networks for downstream channel allocation for video distribution H04L12/2801; flow control in packet networks H04L47/10; real-time communication protocols in data switching networks H04L65/00; scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04N 21/2383 Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/6377 directed to server one-way streaming services wherein the source is controlled by the destination H04L65/613
• CPC Class Codes: H04N 21/6379 directed to encoder , e.g. for requesting a lower encoding rate
• CPC Class Codes: H04N 21/658 Transmission by the client directed to the server
• CPC Class Codes: H04N 23/66 Remote control of cameras or camera parts, e.g. by remote control devices

Abstract

An information signal processing apparatus discriminates a significance factor of an input information signal. A modulation process of the information signal is determined in accordance with the discriminated significance factor. The modulated information signal is transmitted to an external apparatus. Since the modulation process of an information signal to be transmitted is controlled basing upon the significance factor of the information signal, both the transmission error rate and transmission rate can be optimized.

Claims

1. An apparatus for transmitting an image signal and a control signal about the image signal, said apparatus comprising:

a modulator which modulates the image signal and the control signal with one or more spreading codes, with a number of spreading codes to modulate the image signal being larger than a number of spreading codes to modulate the control signal; and

a transmitter which transmits the modulated image signal and the modulated control signal.

2. An apparatus according to claim 1, wherein said modulator modulates the image signal generated by an image pickup unit.

3. An apparatus according to claim 1, wherein said modulator divides the image signal into a plurality of image signal portions, modulates the plurality of image signal portions with a plurality of spreading codes, and multiplexes a plurality of modulated image signal portions.

4. An apparatus according to claim 1, wherein said modulator modulates an audio signal with spreading codes, with a number of spreading codes to modulate the audio signal being larger than a number of spreading codes to modulate the control signal.

5. An apparatus according to claim 4, wherein the number of spreading codes to modulate the image signal is larger than the number of spreading codes to modulate the audio signal.

6. An apparatus according to claim 1, wherein said transmitter transmits the image signal and the control signal by radio waves.

7. An apparatus for transmitting an image signal, said apparatus comprising:

a converter which converts the image signal into a first image data and a second image data, the first image data including a lower frequency component than the second image data;

a modulator which modulates the first image data and the second image data with one or more spreading codes, with a number of spreading codes to modulate the first image data being smaller than a number of spreading codes to modulate the second image data; and

a transmitter which transmits the modulated first image data and the modulated second image data.

8. An apparatus according to claim 7, wherein said converter converts an image signal generated by an image pickup unit.

9. An apparatus according to claim 7, wherein said modulator divides the second image data into a plurality of second image data portions, modulates the plurality of second image data portions with a plurality of spreading codes, and multiplexes a plurality of modulated second image data portions.

10. An apparatus according to claim 7, wherein said modulator modulates an additional data of the image signal with spreading codes, with a number of spreading codes to modulate the additional data being smaller than the number of spreading codes to modulate the second image data.

11. An apparatus according to claim 7, wherein said transmitter transmits the first image data and the second image data by radio waves.

12. An apparatus for transmitting an image signal, said apparatus comprising:

an encoder which encodes the image signal to generate a first image data or a second image data using a first coding method or a second coding method different from the first coding method;

a modulator which modulates the first image data and the second image data with one or more spreading codes, with a number of spreading codes to modulate the first image data being smaller than a number of spreading codes to modulate the second image data; and

a transmitter which transmits the modulated first image data and the modulated second image data.

13. An apparatus according to claim 12, wherein the first coding method is an intraframe coding method and the second coding method is an interframe coding method.

14. An apparatus according to claim 12, wherein said encoder encodes an image signal generated by an image pickup unit.

15. An apparatus according to claim 12, wherein said modulator divides the second image data into a plurality of second image data portions, modulates the plurality of second image data portions with a plurality of spreading codes, and multiplexes a plurality of modulated second image data portions.

16. An apparatus according to claim 12, wherein said modulator modulates an additional data of the image signal with spreading codes, with a number of spreading codes to modulate the additional data being smaller than the number of spreading codes to modulate the second image data.

17. An apparatus according to claim 12, wherein said transmitter transmits the first image data and the second image data by radio waves.

18. A method for transmitting an image signal and a control signal about the image signal, the method comprising the steps of:

modulating the image signal and the control signal with one or more spreading codes, with a number of spreading codes to modulate the image signal being larger than a number of spreading codes to modulate the control signal; and

transmitting the modulated image signal and the modulated control signal.

19. A method according to claim 18, wherein said modulating step divides the image signal into a plurality of image signal portions, modulates the plurality of image signal portions with a plurality of spreading codes, and multiplexes a plurality of modulated image signal portions.

20. A method according to claim 18, wherein said modulating step modulates an audio signal with spreading codes, with a number of spreading codes to modulate the audio signal being larger than the number of spreading codes to modulate the control signal.

21. A method according to claim 20, wherein the number of spreading codes to modulate the image signal is larger than the number of spreading codes to modulate the audio signal.

22. A method according to claim 18, wherein said transmitting steps transmits the image signal and the control signal by radio waves.

23. A method according to claim 18, wherein said modulating step modulates an image signal generated by an image pickup unit.

24. A method for transmitting an image signal, the method comprising the steps of:

converting the image signal into a first image data and a second image data, the first image data including a lower frequency component than the second image data;

modulating the first image data and the second image data with one or more spreading codes, with a number of spreading codes to modulate the first image data being smaller than a number of spreading codes to modulate the second image data; and

transmitting the modulated first image and the modulated second image data.

25. A method according to claim 24, wherein said modulating step divides the second image data into a plurality of second image data portions, modulates the plurality of second image data portions with a plurality of spreading codes, and multiplexes a plurality of modulated second image data portions.

26. A method according to claim 24, wherein said modulating step modulates an additional data of the image signal with spreading codes, with a number of spreading codes to modulate the additional data being smaller than the number of spreading codes to modulate the second image data.

27. A method according to claim 24, wherein said transmitting step transmits the first image data and the second image data by radio waves.

28. A method according to claim 24, wherein said modulating step modulates an image signal generated by an image pickup unit.

29. A method for transmitting an image signal, the method comprising the steps of:

encoding the image signal to generate a first image data or a second image data using a first coding method or a second coding method different from the first coding method;

modulating the first image data and the second image data with one or more spreading codes, with a number of spreading codes to modulate the first image data being smaller than a number of spreading codes to modulate the second image data; and

transmitting the modulated first image data and the modulated second image data.

30. A method according to claim 29, wherein said modulating step divides the second image data into a plurality of second image data portions, modulates the plurality of second image data portions with a plurality of spreading codes, and multiplexes a plurality of modulated second image data portions.

31. A method according to claim 29, wherein said modulating step modulates an additional data of the image signal with spreading codes, with a number of spreading codes to modulate the additional data being smaller than the number of spreading codes to modulate the second image data.

32. A method according to claim 29, wherein the first coding method is an intraframe coding method and the second coding method is an interframe coding method.

33. A method according to claim 29, wherein said transmitting step transmits the first image data and the second image data by radio waves.

34. A method according to claim 29, wherein said modulating step modulates an image signal generated by an image pickup unit.