Code division multiplex communication apparatus

• US 6,128,309 A
• Filed: 12/16/1996
• Issued: 10/03/2000
• Est. Priority Date: 01/10/1996
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Tariki, Motoi
• Primary Examiner(s): Holloway, III, Edwin C.
• Application Number:
  US08/766,337
• Time in Patent Office: 1,387 Days
• Field of Search: 370/441, 370/342, 370/335, 370/347, 370/479, 375/206, 375/260, 375/200, 1/1, 340/825.69
• US Class Current: 370/441
• CPC Class Codes: H04J 13/16 Code allocation
• 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

Abstract

A communication apparatus is disclosed which allocates the respective bits indicating multilevel image data to different spread codes, and then spreads the bits by the use of the spread codes, thereby achieving code division multiplex communication. Image data consisting of 8 bits is transmitted and received at one time by the use of 8 or greater number of spreads codes. In the transmitting end, the amounts of the 8-bit luminance data and the 8-bit color difference data are halved along the time axis, and the resulting respective data are line-sequential multiplexed. Thus, among 12 fields, one field is transmitted according to the above-described code division multiplex method. In the receiving end, the receiving signal which has been code division multiplexed in the transmitting end is demodulated by de-spreading using a plurality of spread codes. The de-spread signal is stored in a memory and image data for one field is repeatedly read from the memory during 12 fields. Then, the luminance signal and the color difference signal are line-sequential separated from the read image data and are output.

Claims

1. A code division multiplex communication apparatus for communicating multilevel pixel data comprising a plurality of bits, the multilevel pixel data including luminance data and color difference data, said apparatus comprising:

allocating means for allocating each bit of the plurality of bits of the multilevel pixel data to a different spread code of a plurality of spread codes in such a manner that one of the plurality of spread codes is allocated to the luminance data at a first timing but allocated to the color difference data at a second timing; and

communication means for communicating the multilevel pixel data spread by the plurality of spread codes, wherein the plurality of bits of the multilevel pixel data are code-divided by the plurality of spread codes.

2. A code division multiplex communication apparatus according to claim 1, wherein said allocation means allocates each of the plurality of bits of the multilevel pixel data to a different one of the plurality of spread codes whose number is other than an integral multiple of the plurality of bits of the multilevel pixel data.

3. A code division multiplex communication apparatus according to claim 2, wherein said allocation means allocates each of the plurality of bits of the multilevel pixel data to a different one of the plurality of spread codes in such a manner that the multilevel pixel data which is unable to be communicated at one time by said communication means is communicated twice.

4. A code division multiplex communication apparatus according to claim 1, wherein said allocation means allocates each of a plurality of bits of luminance data of the multilevel pixel data to a different one of a first plurality of codes spreads, and allocates a plurality of bits of color difference data of the multilevel pixel data to a different one of a second plurality of spread codes.

5. A code division multiplex communication apparatus according to claim 1, further comprising:

means for providing a video signal;

digital video signal supplying means for converting the video signal into a digital data string;

first storage means for temporarily storing said digital data string output from said digital video signal supplying means;

first write-control signal generating means for generating a timing signal for writing said digital data string into said first storage means;

first read-control signal generating means for generating a timing signal for reading said digital data string from said first storage means at a predetermined timing;

transmission means for performing a code division multiplex operation, using a series of spread codes for n-number bits of data, on the respective bits of a parallel data string having a predetermined symbol number n which is read at the predetermined timing from said first storage means by said first read-control signal generating means, thereby transmitting the code division multiplexed signal to a transmission line;

receiving means for receiving the signal from the transmission line;

demodulation means for demodulating the n-symbol number of code division multiplexed data from the output of said receiving means and the series of spread codes for the n-number bits of data;

second storage means for temporarily storing the symbol number of data;

second write-control signal generating means for generating a timing signal for writing the digital data string which is output from said demodulation means into said second storage means;

second read-control signal generating means for generating a timing signal for reading the digital data string from said second storage means at a predetermined timing; and

encoding means for encoding the digital data string read from said second storage means into a predetermined video signal,

wherein said transmission means has conversion means for converting the digital data string in which a luminance signal and a color difference signal are line-sequential multiplexed, into a parallel data string having a predetermined symbol number of n.

6. A code division multiplex communication apparatus according to claim 5, wherein n is an even number.

7. A code division multiplex communication apparatus according to claim 5, wherein n is an odd number.

8. A code division multiplex communication apparatus according to claim 5, wherein said first write-control signal generating means generates the timing signal by scaling down the frequency of a vertical synchronizing signal of a video signal supplied from said digital video signal supplying means in such a manner that some of the digital data strings are removed.

9. A code division multiplex communication apparatus according to claim 5, wherein said second read-control signal generating means generates the timing signal in such a manner that the digital data string for one field is repeatedly read.

10. A code division multiplex communication method for communicating multilevel pixel data comprising a plurality of bits, the multilevel pixel data including luminance data and color difference data, said method comprising the steps of:

allocating each bit of the plurality of bits of the multilevel pixel data to a different spread code of a plurality of spread codes in such a manner that one of the plurality of spread codes is allocated to the luminance data at a first timing but allocated to the color difference data at a second timing; and

communicating the multilevel pixel data spread by the plurality of spread codes, wherein the plurality of bits of the multilevel pixel data are code-divided by the plurality of spread codes.

11. A code division multiplex communication method according to claim 10, wherein said allocating step allocates each of a plurality of bits of luminance data of the multilevel pixel data to a different one of a first plurality of spread codes, and allocates a plurality of bits of color difference data of the multilevel pixel data to a different one of a second Plurality of spread codes.

12. A code division multiplex communication method according to claim 10, wherein said allocation step allocates each of the plurality of bits of the multilevel pixel data to a different one of the plurality of spread codes whose number is other than an integral multiple of the plurality of bits of the multilevel pixel data.

13. A code division multiplex communication method according to claim 12, wherein said allocation step allocates each of the plurality of bits of the multilevel pixel data to a different one of the plurality of the spread codes in such a manner that the multilevel pixel data which is unable to be communicated at one time by said communication step is communicated twice.

14. A code division multiplex communication apparatus for communicating luminance data having a plurality of bits and color difference data also having a plurality of bits, said apparatus comprising:

allocation means for allocating each of the plurality of bits of the luminance data and each of the plurality of bits of the color difference data to a corresponding one of a first and a second plurality of spreading codes; and

communication means for communicating the luminance data and color difference data spread by the first and second plurality of spreading codes,

wherein said communication means communicates the luminance data spread by the first plurality of spread codes and the color difference data spread by the second plurality of spread codes at a first timing, and communicates the luminance data spread by the second plurality of spread codes and the color difference data spread by the first plurality of spread codes at a second timing.

15. A code division multiplex communication method for communicating luminance data having a plurality of bits and color difference data also having a plurality of bits, said method comprising the steps of:

allocating each of the plurality of bits of the luminance data and each of the plurality of bits of the color difference data to a corresponding one of a first and a second plurality of spreading codes; and

communicating the luminance data and the color difference data spread by the first and second plurality of spreading codes,

wherein in said communicating step the luminance data spread by the first plurality of spread codes and the color difference data spread by the second plurality of spread codes are communicated at a first timing, and the luminance data spread by the second plurality of spread codes and the color difference data spread by the first plurality of spread codes are communicated at a second timing.

16. A code division multiplex communication apparatus for communicating a plurality of image data representing an image, the plurality of image data including characteristic data obtained from the image in accordance with a characteristic of the image, said apparatus comprising:

allocating means for allocating the plurality of image data to a plurality of spreading codes in such a manner that one of the plurality of spreading codes is allocated to the characteristic data and to one of the plurality of image data other than the characteristic data at different timing; and

communicating means for communicating the image data code-divided by the plurality of spreading codes allocated by said allocating means.

17. An apparatus according to claim 16, wherein the characteristic data is obtained from the image in accordance with luminance of the image.

18. An apparatus according to claim 16, wherein the image data includes a color difference signal.

19. An apparatus according to claim 16, wherein said allocating means allocates the plurality of image data to the plurality of spreading codes in such a manner that the one of the plurality of spreading codes is allocated to the characteristic data at a predetermined interval.

20. An apparatus according to claim 16, wherein the image data includes luminance data and color difference data, and said allocating means allocates the plurality of image data to the plurality of spreading codes in such a manner that the one of the plurality of spreading code is allocated to the luminance data and the color difference data alternately.

21. An apparatus according to claim 16, wherein each of the plurality of image data consists of plural bits, and said allocating means allocates each bit of the plurality of image data to the plurality of spreading codes.

22. A code division multiplex communication method for communicating a plurality of image data representing an image, the plurality of image data including characteristic data obtained from the image in accordance with a characteristic of the image, said method comprising the steps of:

allocating the plurality of image data to a plurality of spreading codes in such a manner that one of the plurality of spreading codes is allocated to the characteristic data and to one of the plurality of image data other than the characteristic data at different timing; and

communicating the image data code-divided by the plurality of spreading codes allocated in said allocating step.

23. A method according to claim 22, wherein the characteristic data is obtained from the image in accordance with luminance of the image.

24. An apparatus according to claim 22, wherein said image data includes a color difference signal.

25. A method according to claim 22, wherein the plurality of image data is allocated in said allocating step to the plurality of spreading codes in such a manner that the one of the plurality of spreading codes is allocated to the characteristic data at a predetermined interval.

26. A method according to claim 22, wherein the image data includes luminance data and color difference data, and the plurality of image data is allocated in said allocating step to the plurality of spreading codes in such a manner that the one of the plurality of spreading codes is allocated to the luminance data and the color difference data alternately.

27. A method according to claim 22, wherein each of the plurality of image data consists of plural bits, and each bit of the plurality of image data is allocated in said allocating step to the plurality of spreading codes.

28. A code division multiplex communication apparatus for communicating color image data including luminance data, said apparatus comprising:

allocating means for allocating the color image data to a plurality of spreading codes in such a manner that one of the plurality of spreading codes is allocated to the luminance data and to one of the plurality of color image data other than the luminance data at different timing; and

communicating means for communicating the color image data code-divided by the plurality of spreading codes allocated by said allocating means.

29. An apparatus according to claim 28, wherein the image data includes a color difference signal.

30. An apparatus according to claim 28, wherein said allocating means allocates the plurality of color image data to the plurality of spreading codes in such a manner that the one of the plurality of spreading codes is allocated to the luminance data at a predetermined interval.

31. An apparatus according to claim 28, wherein the color image data includes color difference data, and said allocating means allocates the plurality of color image data to the plurality of spreading codes in such a manner that the one of the plurality of spreading codes is allocated to the luminance data and the color difference data alternately.

32. An apparatus according to claim 28, wherein each of the plurality of color image data consists of plural bits, and said allocating means allocates each bit of the plurality of color image data to the plurality of spreading codes.

33. A code division multiplex communication method for communicating a plurality of color image data including luminance data, said method comprising the steps of:

allocating the plurality of color image data to a plurality of spreading codes in such a manner that one of the plurality of spreading codes is allocated to the luminance data and to one of the plurality of color image data other than the luminance data at different timing; and

communicating the color image data code-divided by the plurality of spreading codes allocated in said allocating step.

34. A method according to claim 33, wherein the color image data includes a color difference signal.

35. A method according to claim 33, wherein the plurality of color image data is allocated in said allocating step to the plurality of spreading codes in such a manner that the one of the plurality of spreading codes is allocated to the luminance data at a predetermined interval.

36. A method according to claim 33, wherein the color image data includes color difference data, and the plurality of color image data is allocated in said allocating step to the plurality of spreading codes in such a manner that the one of the plurality of spreading codes is allocated to the luminance data and the color difference data alternately.

37. A method according to claim 33, wherein said each of the plurality of color image data consists of plural bits, and each bit of the plurality of color image data is allocated in said allocating step to the plurality of spreading codes.