Apparatus and Method for Uncompressed, Wireless Transmission of Video

• US 20070098063A1
• Filed: 10/20/2006
• Published: 05/03/2007
• Est. Priority Date: 10/21/2005
• Status: Active Grant

• Current Assignee: Amimon Limited (Vitec Group PLC)
• Original Assignee: Amimon Limited (Vitec Group PLC)
• Inventors: Elnathan, Nathan, Freundlich, Shay, Feder, Meir, Reznic, Zvi
• Granted Patent: US 8,559,525 B2
• Time in Patent Office: Days
• US Class Current: 375/240.2
• CPC Class Codes: H04N 11/044 involving transform coding
• CPC Class Codes: H04N 19/60 using transform coding

Abstract

An apparatus and method for wireless transmission of uncompressed HDTV video overcomes the challenges of sending vast amounts of information over a wireless link. This is achieved by direct mapping of transformation coefficients of the video components to communication symbols, such as OFDM symbols. A main portion of the important transform coefficients, for example the MSBs of the coefficients representing lower frequencies of each of the video components, and in particular the quantized values of the lower frequencies components, are sent in a coarse representation using, for example, QPSK or QAM. The coefficients representing higher frequencies of the video components, and the quantization error values of the lower frequencies components, or some, non-linear transformation thereof, are sent as pairs of real and imaginary portions of a complex number that comprises a point in a fine constellation. The invention further provides a delay-less and buffer-less implementation of transmitter and receiver pairs.

Claims

1. Apparatus for transmission of a substantially uncompressed high definition video signal without substantial delay, comprising:

means for receiving uncompressed video signal components;

means for performing a de-correlating transform on said uncompressed video signal components to provide a plurality of coefficients; and

means for mapping each of said coefficients to a transmission symbol.

2. The apparatus of claim 1, said transmission comprising a wireless transmission.

3. The apparatus of claim 1, further comprising:

means for removing a portion of said transform'"'"'s coefficients.

4. The apparatus of claim 3, said means for removing a portion of said transform'"'"'s coefficients further comprising means for performing said removal without dependency on a previous frame of said high definition video signal.

5. The apparatus of claim 1, said transmission of said high definition video signal comprising buffer-less transmission.

6. The apparatus of claim 1, said de-correlating transform comprising:

a discrete cosine transform (DCT).

7. The apparatus of claim 1, said transmission symbol comprising:

a symbol of an orthogonal frequency division multiplexing (OFDM) transmission scheme.

8. The apparatus of claim 7, further comprising:

an OFDM transmitter for sending said transform'"'"'s coefficients.

9. The apparatus of claim 8, said OFDM transmitter comprising means for transmitting over a multi-input multi-output (MIMO) link.

10. The apparatus of claim 1, said uncompressed components comprising a component digital format comprising a luminance signal and color difference signals.

11. The apparatus of claim 10, further comprising:

means for converting a color space of said high definition video signal into said component digital format.

12. The apparatus of claim 3, said means for removing a portion of said transform'"'"'s coefficients comprising means for removing only a number of said coefficients that is sufficient to maintain a substantially uncompressed wireless transmission of said high definition video signal.

13. The apparatus of claim 12, said means for removing said transform'"'"'s coefficients leaving between forty-five and sixty four out of a total of sixty four coefficients with respect to a luminance signal of said high definition video signal.

14. The apparatus of claim 12, said means for removing a portion of said transform'"'"'s coefficients leaving between twelve and sixty four out of a total of sixty four coefficients with respect to color difference signals of said high definition video signal.

15. The apparatus of claim 1, said means for mapping further comprising:

means for separating said plurality of coefficients into a first group comprising coefficients representing low-frequencies and into a second group comprising coefficients representing high-frequencies.

16. The apparatus of claim 15, further comprising:

quantization means for generating coarse values from said first group.

17. The apparatus of claim 16, further comprising:

means for mapping a coarse value to one of a plurality of constellation points of a symbol.

18. The apparatus of claim 17, further comprising:

means for generating extra pilot signals in addition to standard pilot signals; and

means for using at least one of said extra pilot signals to send one of said coarse values.

19. The apparatus of claim 15, further comprising:

means for generating quantization error values from said first group;

means for representing said quantization error values and said coefficients representing high frequencies as a plurality of complex values of a symbol, wherein each complex value comprises both a first value and a second value from said quantization error values and said coefficients representing high frequencies, wherein said first value is represented as a real portion of a complex value and said second value is represented as an imaginary portion of said complex value.

20. The apparatus of claim 1, wherein said high definition video signal has a transmission rate of at least 45 frames per second.

21. The apparatus of claim 1, said high definition video signal having an uncompressed data rate of above 100 Mbit per second.

22. The apparatus of claim 1, said high definition video signal having an uncompressed data rate that is greater than 0.6 Gbit per second.

23. The apparatus of claim 1, said means for performing a de-correlating transform comprising means for processing a block of pixels of said high definition video signal.

24. The apparatus of claim 23, said block of pixels comprising a rectangle of eight pixels by eight pixels.

25. The apparatus of claim 23, said means for performing a de-correlating transform comprising means for processing a plurality of blocks of pixels of said high definition video signal in parallel.

26. The apparatus of claim 1, comprising:

means for performing said de-correlating transform on all t pixels of a frame of a video signal.

27. The apparatus of claim 1, further comprising:

means for performing a non-linear transformation of at least one of said coefficients.

28. The apparatus of claim 28, said means for performing a non-linear transformation comprising means for adjusting the power of a non-linear function of a coefficient to the power of said coefficient prior to said non-linear transformation.

29. A method for transmission of a substantially uncompressed high definition video signal, comprising the steps of:

receiving uncompressed components of said high definition video signal;

performing a de-correlating transform on said uncompressed video signal components to provide a plurality of coefficients; and

mapping each of said coefficients to a transmission symbol.

30. The method of claim 29, further comprising the step of:

transmitting said transmission symbol over any of a wireless link and a wired link.

31. The method of claim 29, said step of removing a portion of said coefficients is performed without dependency on a previous frame of said high definition video signal.

32. The method of claim 29, said de-correlating transform comprising a discrete cosine transform (DCT).

33. The method of claim 29, said transmission symbol comprising a symbol of an orthogonal frequency division multiplexing (OFDM) transmission scheme.

34. The method of claim 29, further comprising the step of:

converting a color space of said high definition video signal into a component digital format.

35. The method of claim 29, further comprising the step of:

transmitting a symbol stream with an OFDM transmitter.

36. The method of claim 35, said step of transmitting said symbol stream further comprising the step of:

transmitting over a multi-input multi-output (MIMO) link.

37. The method of claim 29, further comprising the step of:

removing a portion of said transform'"'"'s coefficients.

38. The method of claim 37, said step of removing a portion of said transform'"'"'s coefficients further comprising the step of:

removing only a number of said coefficients that is sufficient to maintain a substantively uncompressed wireless transmission of said high definition video signal.

39. The method of claim 38, said step of removing said coefficients further comprising the step of:

leaving between forty five and sixty four out of a total of sixty four coefficients with respect to a luminance signal of said high definition video signal.

40. The method of claim 38, said step of removing said coefficients further comprising the step of:

leaving between twelve and sixty four out of a total of sixty four coefficients with respect to color difference signals of said high definition video signal.

41. The method of claim 29, said step of mapping further comprising the step of:

separating said plurality of coefficients into a first group comprising low frequency coefficients and a second group comprising high frequency coefficients.

42. The method of claim 41, said step of mapping further comprising the step of:

generating coarse values by quantizing the values of said first group.

43. The method of claim 42, further comprising the step of:

mapping a coarse value to one of a plurality of constellation points of a symbol.

44. The method of claim 43, further comprising the steps of:

generating extra pilots in addition to standard pilots; and

using at least one of said extra pilots to send one of said coarse values.

45. The method of claim 42, said step of mapping further comprising the steps of:

generating quantization error values from said first group; and

representing said quantization error values and said high frequency coefficients as a plurality of complex values of symbols, wherein each complex value comprises both a first value and a second value from said quantization error values and said coefficients representing high frequencies, wherein said first value is represented as a real portion of said complex value and said second value is represented as an imaginary portion of said complex value.

46. The method of claim 29, said step of performing said de-correlating transform further comprising the step of:

processing a block of pixels of said high definition video signal.

47. The method of claim 46, said block of pixels comprising a rectangle of eight pixels by eight pixels.

48. The method of claim 29, said uncompressed components comprising a component digital format comprising a luminance signal and color difference signals.

49. The method of claim 29, wherein said step of performing a de-correlating transform comprises performing said transform on all the pixels of a frame of a video signal.

50. The method of claim 29, further comprising the step of:

performing a non-linear transformation of at least one of said coefficients.

51. The method of claim 50, said step of performing a non-linear transformation comprises the step of the adjusting power- of a non-linear function of a coefficient to the power of said coefficient prior to said non-linear transformation.

52. A system for transmission and reception of a substantially uncompressed high definition video signal, comprising:

a transmitter comprising;

means for receiving uncompressed components of the high definition video signal;

means for performing a de-correlating transform on said uncompressed components to provide a plurality of coefficients; and

means for mapping each remaining coefficient to a transmission symbol; and

means for transmitting a stream of symbols over a communication link, said stream of symbols comprising at least said transmission symbol; and

a receiver for receiving said stream of symbols from said transmitter over a communication link and for recreating said plurality of coefficients from said stream of symbols;

wherein said transmitter and said receiver provide essentially delay-less transmission of said high definition video signal.

53. The system of claim 52, said communication link comprises any of a wireless link and a wired link.

54. The system of claim 52, further comprising:

means for removing a portion of said transform'"'"'s coefficients, said means for removing a portion of said transform'"'"'s coefficients performing the removal without dependency on a previous frame of said high definition video signal.

55. The system of claim 54, said transmitter and said receiver comprising means for effecting buffer-less transmission and reception of said high definition video signal.

56. The system of claim 52, said transmission symbol comprising a symbol of an orthogonal frequency division multiplexing (OFDM) transmission scheme.

57. The system of claim 52, said transmitter further comprising:

means for transmitting data comprising said high definition video signal over a multi-input multi-output MIMO link.

58. The system of claim 57, said receiver further comprising:

means for receiving data comprising said high definition video signal from a multi-input multi-output MIMO link.

59. The system of claim 52, further comprising:

means for generating extra pilots; and

means for receiving said extra pilots;

wherein at least one of said extra pilots comprises a digital value of most significant bits that reject from performing said de-correlating transform.

60. The system of claim 52, said means for mapping further comprising:

means for separating said plurality of coefficients into a first group comprising coefficients representing low-frequencies and into a second group comprising coefficients representing high-frequencies.

61. The system of claim 60, further comprising:

quantization means for generating coarse values from said first group.

62. The system of claim 61, further comprising:

means for mapping a coarse value to one of a plurality of constellation points of a symbol.

63. The system of claim 62, further comprising:

means for generating extra pilot signals in addition to the standard pilot signals; and

means for using at least one of said extra pilot signals to send one of said coarse values.

64. The system of claim 60, further comprising:

means for generating quantization error values from said first group;

means for representing said quantization error values and said coefficients representing high frequencies as a plurality of complex values of a symbol, wherein each complex value contains both a first value and a second value from said quantization error values and said coefficients representing high frequencies, wherein said first value is represented as a real portion of a complex value and said second value is represented as an imaginary portion of said complex value.