APPARATUS, SYSTEMS AND METHODS FOR PRODUCING COHERENT SYMBOLS IN A SINGLE FREQUENCY NETWORK

• US 20070223612A1
• Filed: 02/28/2006
• Published: 09/27/2007
• Est. Priority Date: 03/02/2005
• Status: Active Grant

• Current Assignee: Rohde & Schwarz GmbH & Company KG
• Original Assignee: Rohde & Schwarz (Philippines), Inc. (Rohde & Schwarz GmbH & Company KG)
• Inventors: Simon, Michael
• Granted Patent: US 7,532,677 B2
• Time in Patent Office: Days
• US Class Current: 375/265
• CPC Class Codes: H03M 13/15 Cyclic codes, i.e. cyclic shifts of codewords produce other codewords, e.g. codes defined by a generator polynomial, Bose-Chaudhuri-Hocquenghem [BCH] codes H03M13/17 takes precedence
• CPC Class Codes: H03M 13/151 using error location or error correction polynomials
• CPC Class Codes: H03M 13/23 using convolutional codes, e.g. unit memory codes
• CPC Class Codes: H03M 13/235 Encoding of convolutional codes, e.g. methods or arrangements for parallel or block-wise encoding
• CPC Class Codes: H03M 13/253 with concatenated codes
• CPC Class Codes: H03M 13/256 with trellis coding, e.g. with convolutional codes and TCM
• CPC Class Codes: H03M 13/2732 Convolutional interleaver; Interleavers using shift-registers or delay lines like, e.g. Ramsey type interleaver
• CPC Class Codes: H03M 13/2936 comprising an outer Reed-Solomon code and an inner convolutional code
• CPC Class Codes: H03M 13/6538 ATSC VBS systems
• CPC Class Codes: H04H 20/18 Arrangements for synchronising broadcast or distribution via plural systems
• CPC Class Codes: H04H 20/67 Common-wave systems, i.e. using separate transmitters operating on substantially the same frequency
• CPC Class Codes: H04L 1/0042 Encoding specially adapted to other signal generation operation, e.g. in order to reduce transmit distortions, jitter, or to improve signal shape H04L1/0067 takes precedence
• CPC Class Codes: H04L 1/006 Trellis-coded modulation
• CPC Class Codes: H04L 1/0065 Serial concatenated codes
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/009 arrangements specific to transmitters
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 27/02 Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation H04L27/32 takes precedence
• CPC Class Codes: H04L 27/2656 Frame synchronisation, e.g. packet synchronisation, time division duplex [TDD] switching point detection or subframe synchronisation
• CPC Class Codes: H04L 27/2657 Carrier synchronisation
• CPC Class Codes: H04N 21/235 : Processing of additional data, e.g. scrambling of additional data or processing content descriptors
• CPC Class Codes: H04N 21/23608 : Remultiplexing multiplex streams, e.g. involving modifying time stamps or remapping the packet identifiers
• CPC Class Codes: H04N 21/23611 : Insertion of stuffing data into a multiplex stream, e.g. to obtain a constant bitrate synchronisation arrangements in time-division multiplex systems using bit stuffing for systems with different or fluctuating information rates H04J3/073
• 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 21/242 : Synchronization processes, e.g. processing of PCR [Program Clock References] arrangements for synchronising broadcast or distribution via plural systems in broadcast distribution systems H04H20/18
• CPC Class Codes: H04N 21/435 : Processing of additional data, e.g. decrypting of additional data, reconstructing software from modules extracted from the transport stream
• CPC Class Codes: H04N 7/173 : with two-way working, e.g. subscriber sending a programme selection signal

Abstract

A system, method, apparatus and computer code are provided for producing coherent symbols from digital RF transmitters. A receiver receives a first initialization packet containing a plurality of stuff bytes and Trellis coders are deterministically initialized using the first initialization packet.

Claims

18. A apparatus for producing a plurality of coherent symbols from a plurality of digital RF transmitters, comprising:

a packet receiver operable to receive a first initialization packet, the initialization packet containing a plurality of stuff bytes; and

a plurality of Trellis coders operable to deterministically initialize using the first initialization packet.

19. The apparatus according to claim 18, wherein the receiver is further operable to detect another initialization packet after a multiple of a predetermined number of packets.

20. The apparatus of claim 18, wherein the initialization packet is received from a transport stream.

21. The apparatus of claim 18, further comprising:

a decoder operable to error-correction decode the initialization packet.

22. The apparatus of claim 18, wherein the initialization packet further contains a synchronization timestamp based from a common timebase, a predetermined maximum delay value, an offset delay value, and a transmitter address corresponding to the offset delay.

23. The apparatus according to claim 22, wherein the common timebase is the global positional system (GPS).

24. The apparatus according to claim 18, further comprising:

an interleaver operable to interleave the initialization packet.

25. The apparatus of claim 18, further comprising:

a timing unit operable to lock a symbol clock and a carrier frequency to a common timebase.

26. The apparatus of claim 25 further comprising:

a timing unit operable to lock a digital signal including the initialization packet to the common timebase.

27. The apparatus according to claim 26, wherein the common timebase is the global positional system (GPS).

28. The apparatus of claim 18, further comprising:

a signal processor operable to modulate a digital signal carrying the initialization packet using at least one of an eight-level vestigial sideband (8-VSB) modulation and an eight-level Trellis vestigial sideband (8T-VSB) modulation.

29. The apparatus of claim 18, further comprising:

a timing unit operable to synchronize a plurality of data frames based on the arrival of the initialization packet.

30. The apparatus of claim 18, further comprising:

a controller operable to slave a plurality of data frames to be broadcasted from the plurality of digital RF transmitters based on reception of an initialization packet.

31. The apparatus of claim 18, further comprising:

a timing unit operable to calculate a delay metric corresponding to a synchronization timestamp, a maximum delay value, and an offset delay value in the initialization packet, and a common timebase, wherein the synchronization timestamp is a value of the common timebase observed when the initialization packet is transmitted into a distribution network, wherein the maximum delay value corresponds to a delay in a distribution network, and the offset delay value corresponds to a delay value addressed to a respective one of the plurality of digital RF transmitters.

32. The apparatus according to claim 31, wherein the common timebase is the global positional system (GPS).

33. The apparatus of claim 18, further comprising:

a timing unit operable to delay the digital signal from being transmitted by the plurality of RF transmitters by a predetermined delay.

34. The apparatus of claim 33, wherein the predetermined delay is greater than the longest delay path in a distribution network to the plurality of digital RF transmitters.

35. A computer program product comprising a computer usable medium having control logic stored therein for causing a computer to produce a plurality of coherent symbols from a plurality of digital RF transmitters, said control logic comprising:

computer readable program code means for causing the computer to receive a first initialization packet, the initialization packet containing a plurality of stuff bytes; and

computer readable program code means for causing the computer to deterministically initialize a plurality of Trellis coders using the first initialization packet.

36. The computer program product of claim 35, further comprising:

computer readable program code means for causing the computer to receive another initialization packet after a multiple of a predetermined number of packets.

37. The computer program product of claim 35, wherein the initialization packet is received from a transport stream.

38. The computer program product of claim 35, further comprising:

computer readable program code means for causing the computer to error-correction decode the initialization packet.

39. The computer program product of claim 35, wherein the initialization packet further contains a synchronization timestamp based from a common timebase, a predetermined maximum delay value, an offset delay value, and a transmitter address corresponding to the offset delay.

40. The computer program product of claim 35, wherein the common timebase is the global positional system (GPS).

41. The computer program product of claim 35, further comprising:

computer readable program code means for causing the computer to interleave the initialization packet.

42. The computer program product of claim 35, further comprising:

computer readable program code means for causing the computer to lock a symbol clock and a carrier frequency to a common timebase.

43. The computer program product of claim 35, further comprising:

computer readable program code means for causing the computer to lock a digital signal comprising the initialization packet to the common timebase.

44. The computer program product of claim 43, wherein the common timebase is the global positional system (GPS).

45. The computer program product of claim 35, further comprising:

computer readable program code means for causing the computer to modulate a digital signal carrying the initialization packet using at least one of an eight-level vestigial sideband (8-VSB) modulation and an eight-level Trellis vestigial sideband (8T-VSB) modulation.

46. The computer program product of claim 35, further comprising:

computer readable program code means for causing the computer to synchronize a plurality of data frames based on the arrival of the initialization packet.

47. The computer program product of claim 35, further comprising:

computer readable program code means for causing the computer to slave a plurality of data frames to be broadcasted from the plurality of digital RF transmitters based on reception of an initialization packet.

48. The computer program product of claim 35, further comprising:

computer readable program code means for causing the computer to calculate a delay metric corresponding to a synchronization timestamp, a maximum delay value, and an offset delay value in the initialization packet, and a common timebase, wherein the synchronization timestamp is a value of the common timebase observed when the initialization packet is transmitted into a distribution network, wherein the maximum delay value corresponds to a delay in a distribution network, and the offset delay value corresponds to a delay value addressed to a respective one of the plurality of digital RF transmitters.

49. The computer program product of claim 48, wherein the common timebase is the global positional system (GPS).

50. The computer program product of claim 35, further comprising:

computer readable program code means for causing the computer to delay the digital signal from being transmitted by the plurality of RF transmitters by a predetermined delay.

51. The computer program product of claim 50, wherein the predetermined delay is greater than the longest delay path in a distribution network to the plurality of digital RF transmitters.

52. An apparatus for producing a plurality of coherent symbols from a plurality of digital RF transmitters, comprising the steps of:

means for receiving a first initialization packet, the initialization packet containing a plurality of stuff bytes; and

means for deterministically initializing a plurality of Trellis coders using the first initialization packet.

1. A method for producing a plurality of coherent symbols from a plurality of digital RF transmitters, comprising the steps of:

receiving a first initialization packet, the initialization packet containing a plurality of stuff bytes; and

deterministically initializing a plurality of Trellis coders using the first initialization packet.

2. The method according to claim 1, further comprising the steps of:

receiving another initialization packet after a multiple of a predetermined number of packets.

3. The method of claim 1, wherein the initialization packet is received from a transport stream.

4. The method of claim 1, further comprising the step of:

error-correction decoding the initialization packet.

5. The method of claim 1, wherein the initialization packet further contains a synchronization timestamp based from a common timebase, a predetermined maximum delay value, an offset delay value, and a transmitter address corresponding to the offset delay.

6. The method according to claim 5, wherein the common timebase is the global positional system (GPS).

7. The method according to claim 1, further comprising:

interleaving the initialization packet.

8. The method of claim 1, further comprising the step of:

locking a symbol clock and a carrier frequency to a common timebase.

9. The method of claim 8, further comprising the step of:

locking a digital signal comprising the initialization packet to the common timebase.

10. The method according to claim 9, wherein the common timebase is the global positional system (GPS).

11. The method of claim 1, further comprising the step of:

modulating a digital signal using at least one of an eight-level vestigial sideband (8-VSB) modulation and an eight-level Trellis vestigial sideband (8T-VSB) modulation.

12. The method of claim 1, further comprising the step of:

synchronizing a plurality of data frames based on the arrival of the initialization packet.

13. The method of claim 1, further comprising the step of:

slaving a plurality of data frames to be broadcasted from the plurality of digital RF transmitters based on reception of an initialization packet.

14. The method of claim 1, further comprising the step of:

calculating a delay metric corresponding to a synchronization timestamp, a maximum delay value, and an offset delay value in the initialization packet, and a common timebase, wherein the synchronization timestamp is a value of the common timebase observed when the initialization packet is transmitted into a distribution network, wherein the maximum delay value corresponds to a delay in a distribution network, and the offset delay value corresponds to a delay value addressed to a respective one of the plurality of digital RF transmitters.

15. The method according to claim 14, wherein the common timebase is the global positional system (GPS).

16. The method of claim 1, further comprising the step of:

delaying the digital signal from being transmitted by the plurality of RF transmitters by a predetermined delay.

17. The method of claim 16, wherein the predetermined delay is greater than the longest delay path in a distribution network to the plurality of digital RF transmitters.

53. The apparatus according to claim 52, further comprising:

means for receiving another initialization packet after a multiple of a predetermined number of packets.

54. The apparatus of claim 52, further comprising:

means for error-correction decoding the initialization packet.

55. The apparatus of claim 52, wherein the initialization packet further contains a synchronization timestamp based from a common timebase, a predetermined maximum delay value, an offset delay value, and a transmitter address corresponding to the offset delay.

56. The apparatus according to claim 55, wherein the common timebase is the global positional system (GPS).

57. The apparatus according to claim 52, further comprising:

means for interleaving the initialization packet.

58. The apparatus of claim 52, further comprising:

means for locking a symbol clock and a carrier frequency to a common timebase.

59. The apparatus of claim 58, further comprising:

means for locking a digital signal comprising the initialization packet to the common timebase.

60. The apparatus according to claim 59, wherein the common timebase is the global positional system (GPS).

61. The apparatus of claim 52, further comprising:

means for modulating a digital signal using at least one of an eight-level vestigial sideband (8-VSB) modulation and an eight-level Trellis vestigial sideband (8T-VSB) modulation.

62. The apparatus of claim 52, further comprising:

means for synchronizing a plurality of data frames based on the arrival of the initialization packet.

63. The apparatus of claim 52, further comprising:

means for slaving a plurality of data frames to be broadcasted from the plurality of digital RF transmitters based on reception of an initialization packet.

64. The apparatus of claim 52, further comprising:

means for calculating a delay metric corresponding to a synchronization timestamp, a maximum delay value, and an offset delay value in the initialization packet, and a common timebase, wherein the synchronization timestamp is a value of the common timebase observed when the initialization packet is transmitted into a distribution network, wherein the maximum delay value corresponds to a delay in a distribution network, and the offset delay value corresponds to a delay value addressed to a respective one of the plurality of digital RF transmitters.

65. The apparatus according to claim 64, wherein the common timebase is the global positional system (GPS).

66. The apparatus of claim 52, further comprising:

means for delaying the digital signal from being transmitted by the plurality of RF transmitters by a predetermined delay.

67. The apparatus of claim 66, wherein the predetermined delay is greater than the longest delay path in a distribution network to the plurality of digital RF transmitters.

53-1. The apparatus of claim 52, wherein the initialization packet is received from a transport stream.

68. A system for producing a plurality of coherent symbols from a plurality of digital RF transmitters, comprising:

a multiplexer operable to receive a digital signal containing content data to be broadcast from the plurality of digital RF transmitters and to insert a first initialization packet into the digital signal, the initialization packet containing a plurality of stuff bytes, and to transmit the digital signal to the plurality of digital RF transmitters; and

a modulator having a plurality of Trellis coders, the modulator operable to receive the digital signal, extract the first initialization packet and to deterministically initialize the plurality of Trellis coders using the initialization packet.

69. The system of claim 68, wherein the multiplexer is further operable to generate another initialization packet after a multiple of a predetermined number of packets.

70. The system of claim 68, wherein the multiplexer transmits the digital signal to the modulator in over a distribution network.

71. The system of claim 68, the multiplexer further comprising an encoder operable to error-correction encode the initialization packet and the modulator further comprising a decoder operable to error-correction decode the initialization packet.

72. The system of claim 68, wherein the initialization packet further contains a synchronization timestamp based from a common timebase, a predetermined maximum delay value, an offset delay value, and a transmitter address corresponding to the offset delay.

73. The system according to claim 72, wherein the common timebase is the global positional system (GPS).

74. The system according to claim 68, the modulator further comprising:

an interleaver operable to interleave the initialization packet.

75. The system of claim 68, further comprising:

a timing unit operable to lock a symbol clock and a carrier frequency to a common timebase.

76. The apparatus of claim 68, further comprising:

a timing unit operable to lock a digital signal including the initialization packet to the common timebase.

77. The system according to claim 76, wherein the common timebase is the global positional system (GPS).

78. The system of claim 68, wherein the modulator is further operable to modulate a digital signal carrying the initialization packet using at least one of an eight-level vestigial sideband (8-VSB) modulation and an eight-level Trellis vestigial sideband (8T-VSB) modulation.

79. The system of claim 68, the modulator further comprising:

a timing unit operable to synchronize a plurality of data frames based on the arrival of the initialization packet.

80. The system of claim 68, the modulator further comprising:

a controller operable to slave a plurality of data frames to be broadcasted from the plurality of digital RF transmitters based on reception of an initialization packet.

81. The system of claim 68, further comprising:

a timing unit operable to calculate a delay metric corresponding to a synchronization timestamp, a maximum delay value, and an offset delay value in the initialization packet, and a common timebase, wherein the synchronization timestamp is a value of the common timebase observed when the initialization packet is transmitted into a distribution network, wherein the maximum delay value corresponds to a delay in a distribution network, and the offset delay value corresponds to a delay value addressed to a respective one of the plurality of digital RF transmitters.

82. The system according to claim 81, wherein the common timebase is the global positional system (GPS).

83. The system of claim 68, further comprising:

a timing unit operable to delay the digital signal from being transmitted by the plurality of RF transmitters by a predetermined delay.

84. The system of claim 83, wherein the predetermined delay is greater than the longest delay path in a distribution network to the plurality of digital RF transmitters.