APPARATUS, SYSTEMS, METHODS AND COMPUTER PROGRAM PRODUCTS FOR PRODUCING A SINGLE FREQUENCY NETWORK FOR ATSC MOBILE / HANDHELD SERVICES

• US 20090323729A1
• Filed: 06/25/2009
• Published: 12/31/2009
• Est. Priority Date: 06/25/2008
• Status: Active Grant

• Current Assignee: Rohde & Schwarz GmbH & Company KG
• Original Assignee: Rohde & Schwarz GmbH & Company KG
• Inventors: Simon, Michael, Kramer, Michael
• Granted Patent: US 8,355,458 B2
• Time in Patent Office: Days
• US Class Current: 370/509
• CPC Class Codes: H04H 20/67 Common-wave systems, i.e. using separate transmitters operating on substantially the same frequency
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/006 Trellis-coded modulation
• CPC Class Codes: H04L 1/0065 Serial concatenated codes
• CPC Class Codes: H04L 1/007 Unequal error protection for format H04L1/0078; for codes per se H03M13/35
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27

Abstract

Producing coherent symbols from a plurality of digital RF transmitters is achieved by selecting data bytes corresponding to mobile-handheld encapsulation (MHE) packets and setting trellis coders to a predetermined state when a predetermined number of bits of the data bytes enter a corresponding trellis coder.

Claims

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

selecting, by a processor, a plurality of data bytes corresponding to one of a plurality of mobile-handheld (MH) encapsulation (MHE) packets; and

setting each one of the plurality of trellis coders to a predetermined state when a predetermined number of bits of the data bytes enter a corresponding trellis coder, thereby causing the plurality of digital RF transmitters to transmit a plurality of symbols coherently.

2. The method according to claim 1, wherein the predetermined state of each corresponding trellis coder is coincident with the arrival of the predetermined number of bits over a predetermined number of symbol clock cycles.

3. The method according to claim 2, wherein the predetermined number of bits is 4 and the predetermined number of symbol clock cycles is 2.

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

selecting each of the plurality of data bytes from a packet/byte pair identified in accordance with a mapping of a data interleaver.

5. The method according to claim 4, wherein the mapping identifies a time dispersion of positions of the data bytes before and after the data interleaver.

6. The method according to claim 1, wherein the plurality of data bytes located within the MHE packets are non-systematic Reed-Solomon (RS) parity bytes.

7. An apparatus for producing a plurality of coherent symbols, comprising:

a processor operable to select a plurality of data bytes corresponding to one of a plurality of mobile-handheld (MH) Encapsulation (MHE) packets; and

a plurality of trellis coders operable to set to a predetermined state based on a predetermined number of bits of the data bytes, correspondingly, thereby causing the plurality of digital RF transmitters to transmit a plurality of symbols coherently.

8. The apparatus according to claim 7, wherein the predetermined state of each corresponding trellis coder is coincident with the arrival of the predetermined number of bits over a predetermined number of symbol clock cycles.

9. The apparatus according to claim 8, wherein the predetermined number of bits is 4 and the predetermined number of symbol clock cycles is 2.

10. The apparatus according to claim 7, further comprising:

a memory operable to store locations of the bytes to obtain by said selecting, based on a packet/byte pair identified in accordance with a mapping of a data interleaver.

11. The apparatus according to claim 10, wherein the mapping identifies a time dispersion of positions of the data bytes before and after the data interleaver.

12. The apparatus according to claim 7, wherein the plurality of data bytes located within the MHE packets are non-systematic Reed-Solomon (RS) parity bytes.

13. A computer-readable medium having stored thereon sequences of instructions, the sequences of instructions including instructions which when executed by a computer system causes the computer system to perform:

selecting a plurality of data bytes corresponding to one of a plurality of mobile-handheld (MH) encapsulation (MHE) packets; and

setting each one of a plurality of trellis coders to a predetermined state when a predetermined number of bits of the data bytes enter a corresponding trellis coder, thereby causing a plurality of digital RF transmitters to transmit a plurality of symbols coherently.

14. The computer-readable memory according to claim 13, wherein the predetermined state of each corresponding trellis coder is coincident with the arrival of the predetermined number of bits over a predetermined number of symbol clock cycles.

15. The computer-readable memory according to claim 14, wherein the predetermined number of bits is 4 and the predetermined number of symbol clock cycles is 2.

16. The computer-readable medium of claim 13, further having stored thereon a sequence of instructions which when executed by the computer system causes the computer system to perform:

selecting each of the plurality of data bytes from a packet/byte pair identified in accordance with a mapping of a data interleaver.

17. The computer-readable medium according to claim 16, wherein the mapping identifies a time dispersion of positions of the data bytes before and after the data interleaver.

18. The computer-readable medium according to claim 16, wherein the plurality of data bytes located within the MHE packets are non-systematic Reed-Solomon (RS) parity bytes.

19. A method for performing data frame synchronization, comprising the steps of:

replacing a predetermined number of bytes to be transmitted onto a studio-transmitter link with a plurality of bytes containing signalling information; and

transmitting the predetermined number of bytes in a transport stream over the studio-to transmitter link,

thereby creating a point-to-point communications link.

20. The method according to claim 19, further comprising:

resetting the plurality of bytes containing signalling information with dummy bytes at a post-processor.

21. The method according to claim 19, wherein the signalling information includes a sub-frame number and a slot number.

22. The method according to claim 19, further comprising:

assigning a packet identifier to a predetermined number of transport stream packets, the packet identifier being unknown to a post processor on the studio-transmitter link;

calculating a first checksum on the plurality of bytes containing the signalling information; and

transmitting the first checksum onto the studio-transmitter link to the post-processor.

23. The method according to claim 22, further comprising:

receiving the transport stream from the studio-transmitter link;

parsing the transport stream to obtain the packet identifier of each transport stream packet;

searching for a predetermined number of consecutive transport stream packets having the same packet identifier;

calculating a second checksum of a portion of the predetermined number of transport stream packets;

comparing the first checksum and the second checksum;

extracting the signalling information if the first checksum and the second checksum are the same; and

using the signalling information obtained from said extracting to perform frame synchronization.

24. The method according to claim 19, further comprising:

assigning a packet identifier to a predetermined number of transport stream packets, the packet identifier being prestored in a memory of a post processor on the studio-transmitter link;

calculating a first checksum on the plurality of bytes containing the signalling information; and

transmitting the first checksum onto the studio-transmitter link to the post-processor.

25. The method according to claim 24, further comprising:

receiving the transport stream from the studio-transmitter link;

parsing the transport stream to obtain the packet identifier of each transport stream packet;

searching for the predetermined number of transport stream packets having the packet identifier prestored in the memory;

calculating a second checksum of a portion of the predetermined number of transport stream packets;

comparing the first checksum and the second checksum;

extracting the signalling information if the first checksum and the second checksum are the same; and

using the signalling information obtained from said extracting to perform frame synchronization.

26. A system for performing data frame synchronization, comprising:

a group formatter operable to replace a predetermined number of bytes to be transmitted onto a studio-transmitter link with a plurality of bytes containing signalling information; and

a packet transmitter operable to transmit the predetermined number of bytes in a transport stream over the studio-to transmitter link.

27. The system according to claim 26, wherein the plurality of bytes containing signalling information are reset with dummy bytes at a post-processor.

28. The system according to claim 26, wherein the signalling information includes a sub-frame number and a slot number.

29. The system according to claim 26, further comprising:

a multiplexer operable to assigning a packet identifier to a predetermined number of transport stream packets, the packet identifier being unknown to a post processor on the studio-transmitter link;

a checksum calculator operable to calculate a first checksum on the plurality of bytes containing the signalling information; and

the packet transmitter further operable to transmit the first checksum onto the studio-transmitter link to the post-processor.

30. The system according to claim 29, further comprising:

a packet receiver operable to receive the transport stream from the studio-transmitter link;

a processor operable to;

parse the transport stream to obtain the packet identifier of each transport stream packet,

search for a predetermined number of consecutive transport stream packets having the same packet identifier,

calculate a second checksum of a portion of the predetermined number of transport stream packets,

compare the first checksum and the second checksum,

extract the signalling information if the first checksum and the second checksum are the same, and

use the signalling information to perform frame synchronization.

31. The system according to claim 26, further comprising:

a multiplexer operable to assign a packet identifier to a predetermined number of transport stream packets, the packet identifier being prestored in a memory of a post processor on the studio-transmitter link;

a checksum calculator operable to calculate a first checksum on the plurality of bytes containing the signalling information; and

the packet transmitter further operable to transmitting the first checksum onto the studio-transmitter link to the post-processor.

32. The system according to claim 31, further comprising:

a packet receiver operable to receive the transport stream from the studio-transmitter link;

a processor operable to;

parse the transport stream to obtain the packet identifier of each transport stream packet,

search for the predetermined number of transport stream packets having the packet identifier prestored in the memory,

calculate a second checksum of a portion of the predetermined number of transport stream packets,

compare the first checksum and the second checksum,

extract the signalling information if the first checksum and the second checksum are the same, and

use the signalling information to perform frame synchronization.

33. A computer-readable medium having stored thereon sequences of instructions, the sequences of instructions including instructions which when executed by a computer system causes the computer system to perform:

replacing a predetermined number of bytes to be transmitted onto a studio-transmitter link with a plurality of bytes containing signalling information; and

transmitting the predetermined number of bytes in a transport stream over the studio-to transmitter link.

34. The computer-readable medium according to claim 33, further having stored thereon a sequence of instructions which when executed by the computer system causes the computer system to perform:

resetting the plurality of bytes containing signalling information with dummy bytes at a post-processor.

35. The computer-readable medium according to claim 33, wherein the signalling information includes a sub-frame number and a slot number.

36. The computer-readable medium according to claim 33, further having stored thereon a sequence of instructions which when executed by the computer system causes the computer system to perform:

assigning a packet identifier to a predetermined number of transport stream packets, the packet identifier being unknown to a post processor on the studio-transmitter link;

calculating a first checksum on the plurality of bytes containing the signalling information; and

transmitting the first checksum onto the studio-transmitter link to the post-processor.

37. The computer-readable medium according to claim 36, further having stored thereon a sequence of instructions which when executed by the computer system causes the computer system to perform:

receiving the transport stream from the studio-transmitter link;

parsing the transport stream to obtain the packet identifier of each transport stream packet;

searching for a predetermined number of consecutive transport stream packets having the same packet identifier;

calculating a second checksum of a portion of the predetermined number of transport stream packets;

comparing the first checksum and the second checksum;

extracting the signalling information if the first checksum and the second checksum are the same; and

using the signalling information obtained from said extracting to perform frame synchronization.

38. The computer-readable medium according to claim 33, further having stored thereon a sequence of instructions which when executed by the computer system causes the computer system to perform:

assigning a packet identifier to a predetermined number of transport stream packets, the packet identifier being prestored in a memory of a post processor on the studio-transmitter link;

calculating a first checksum on the plurality of bytes containing the signalling information; and

transmitting the first checksum onto the studio-transmitter link to the post-processor.

39. The computer-readable memory according to claim 38, further having stored thereon a sequence of instructions which when executed by the computer system causes the computer system to perform:

receiving the transport stream from the studio-transmitter link;

parsing the transport stream to obtain the packet identifier of each transport stream packet;

searching for the predetermined number of transport stream packets having the packet identifier prestored in the memory;

calculating a second checksum of a portion of the predetermined number of transport stream packets;

comparing the first checksum and the second checksum;

extracting the signalling information if the first checksum and the second checksum are the same; and

using the signalling information obtained from said extracting to perform frame synchronization.

40. A method for signalling a change in single frequency network (SFN) modes including a SFN with mobile-handheld (MH) data services mode and an SFN without MH data services mode, the method comprising the steps of:

receiving a signalling packet containing a mode element for switching each RF transmitter between the SFN with MH data services mode and the SFN without MH data services mode; and

signalling to the exciter, based on the value of the mode element, that a predetermined number of data frames following the signalling packet will correspond to at least one of (1) the SFN mode with MH data services, and (2) the SFN mode without MH data services.

41. The method for according to claim 40, wherein the signalling packet is at least one of a mobile handheld encapsulated (MHE) transport stream (TS) data packet and a VSB synchronization packet (VSP).

42. The method according to claim 40, wherein the MHE TS data packet contains the signalling data in dummy byte locations.

43. The method according to claim 40, wherein the frames following the signalling packet are mobile handheld encapsulated (MHE) transport stream (TS) data packets for performing data framing.

44. The method according to claim 40, wherein the predetermined number of data frames include a VSB synchronization packet (VSP) for performing data framing and trellis initialization.

45. An apparatus for signalling a change in single frequency network (SFN) modes including a SFN with mobile-handheld (MH) data services mode and an SFN without MH data services mode, comprising:

a packet receiver operable to receive a signalling packet containing a mode element for switching each RF transmitter between the SFN with MH data services mode and the SFN without MH data services mode; and

a processor operable to generate a signal to an exciter, based on the value of the mode element, that a predetermined number of data frames following the signalling packet will correspond to at least one of (1) the SFN mode with MH data services, and (2) the SFN mode without MH data services.

46. The apparatus according to claim 45, wherein the signalling packet is at least one of a mobile handheld encapsulated (MHE) transport stream (TS) data packet and a VSB synchronization packet (VSP).

47. The apparatus according to claim 46, wherein the MHE TS data packet contains the signalling data in dummy byte locations.

48. The apparatus according to claim 45, wherein the frames following the signalling packet are mobile handheld encapsulated (MHE) transport stream (TS) data packets for performing data framing.

49. The apparatus according to claim 45, wherein the predetermined number of data frames include a VSB synchronization packet (VSP) for performing data framing and trellis initialization.

50. A computer-readable medium having stored thereon sequences of instructions, the sequences of instructions including instructions which when executed by a computer system causes the computer system to perform:

receiving a signalling packet containing a mode element for switching each RF transmitter between a single frequency network (SFN) with mobile-handheld (MH) data services mode and an SFN without MH data services mode; and

signalling to an exciter, based on the value of the mode element, that a predetermined number of data frames following the signalling packet will correspond to at least one of (1) the SFN mode with MH data services, and (2) the SFN mode without MH data services.

51. The computer-readable medium according to claim 50, wherein the signalling packet is at least one of a mobile handheld encapsulated (MHE) transport stream (TS) data packet and a VSB synchronization packet (VSP).

52. The computer-readable medium according to claim 51, wherein the MHE TS data packet contains the signalling data in dummy byte locations.

53. The computer-readable memory according to claim 50, wherein the frames following the signalling packet are mobile handheld encapsulated (MHE) transport stream (TS) data packets for performing data framing.

54. The computer-readable memory according to claim 50, wherein the predetermined number of data frames include a VSB synchronization packet (VSP) for performing data framing and trellis initialization.