Uplink transmission and reception techniques for a processing satelliteation satellite

• US 6,466,569 B1
• Filed: 09/29/1999
• Issued: 10/15/2002
• Est. Priority Date: 09/29/1999
• Status: Expired due to Term

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Perahia, Eldad, Wright, David A., Linsky, Stuart T., Wilcoxson, Donald C., Caso, Gregory S.
• Primary Examiner(s): Hunter, Daniel
• Assistant Examiner(s): D AGOSTA, STEPHEN M
• Application Number:
  US09/408,331
• Time in Patent Office: 1,112 Days
• Field of Search: 455/427, 455/428, 455/429, 455/430, 455/423, 714/755, 714/756, 370/314, 370/319, 370/321, 370/347
• US Class Current: 370/347
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system

Abstract

Uplink transmission and reception techniques for a processing satellite including one or more earth terminals 400 connected to receive ATM data cells. One or more encoders 418 are connected to coordinate four data cells with an error correction code to generate data bursts and to coordinate the data bursts with synchronizing bursts to generate data frames. One or more modulators 420 are connected to modulate the data frames by frequency division multiple access modulation to enable placement of the modulated data frames into a plurality of channels. One or more antennas 406 transmit the modulated data frames to a satellite 100 over 48 beams with various forms of polarization.

In satellite 100, a receiving multibeam antenna and feed 106 responds to one or more beams of radiocarrier signals having one or more forms of polarization. One or more demodulators 138 demodulate the radio carrier signals into data frames from various channels including a plurality of channel types. One or more decoders 146 decode data bursts and synchronizing bursts from the data frames and decode four data cells from the bursts using error correction code.

Claims

1. Apparatus for generating and transmitting data in an available spectrum of frequencies suitable for use by a processing communication satellite comprising in combination:

one or more earth terminals connected in order to provide data cells and a synchronizing burst timing signal;

one or more encoders connected in order to group a predetermined number of the data cells with a selectable one of a predetermined first error correction code having a first code rate and a predetermined second error correction code having a second code rate to generate data bursts and to group the data bursts with synchronizing bursts timed in response to said synchronizing burst timing signal in order to generate data frames selected from a group of data frame types, said first code rate being a multiple of said second code rate;

one or more modulators connected to modulate the data frames by a predetermined form of modulation to enable placement of the modulated data frames into a plurality of channels selected from a group of channel types having a plurality of channel rates definable in symbols per second; and

one or more antennas connected to transmit the modulated data frames to the satellite over one or more beams with a predetermined form of polarization.

2. Apparatus, as claimed in claim 1, wherein said frames define multiple frequency TDMA channel slots.

3. Apparatus, as claimed in claim 1, wherein the predetermined number of data cells is four.

4. Apparatus, as claimed in claim 1, wherein the predetermined first error correction code comprises Reed-Solomon outer code.

5. Apparatus, as claimed in claim 1, wherein the predetermined second error correction code comprises a Reed-Muller code resulting in a biorthogonal signal set over four quadraphase phase shift keying channel symbols concatenated with said Reed-Solomon outer code.

6. Apparatus, as claimed in claim 1, wherein the data frame types differ by the number of data bursts transmitted per frame as a function of the channel rate.

7. Apparatus, as claimed in claim 1, wherein the data frame types differ by the number of synchronizing bursts transmitted per frame as a function of the channel rate.

8. Apparatus, as claimed in claim 1, wherein the predetermined form of modulation comprises quaternary phase shift keying modulation.

9. Apparatus, as claimed in claim 8, wherein the predetermined form of modulation further comprises square-root raised cosine pulse shaping on quaternary phase shift keying.

10. Apparatus, as claimed in claim 1, wherein the one or more modulators generates a sufficient number of different frequencies so as to allow up to a predetermined number of bands of frequencies-within the available spectrum of frequencies and generates a sufficient number of different frequencies so as to allow up to a predetermined number of channels of frequencies within each of the bands and generates a sufficient number of different frequencies so as to allow up to a predetermined number of first subohannels of frequencies or up to a predetermined number of second subchannels of frequencies within each channel.

11. Apparatus, as claimed in claim 10, wherein said channels, first subchannels and second subchannels are separated by predetermined frequency spacings and transmit symbols at predetermined symbol rates, wherein said frequency spacings and said symbol rates defined channel spacing ratios and wherein said channel spacing ratios are integer ratios.

12. Apparatus, as claimed in claim 11, wherein said channel spacing ratios are about 5/4.

13. Apparatus, as claimed in claim 10, wherein the number of bands is four, the number of channels is seven, the number of first subchannels is five and the number of second subchannels is 25.

14. Apparatus, as claimed in claim 10, wherein said channels, said first subchannels and said second subchannels each carry frames of the same duration.

15. Apparatus, as claimed in claim 1, wherein each said frame is 92-93 milliseconds in duration.

16. Apparatus, as claimed in claim 10, wherein at least some of said frames in said second subchannels carry 26 synch burst slots and 52 traffic burst slots.

17. Apparatus, as claimed in claim 16, wherein at least some of said traffic burst slots comprise a 16 symbol preamble.

18. Apparatus, as claimed in claim 10, wherein at least some of said frames in said first subchannels carry 130 synch burst slots and 260 traffic burst slots.

19. Apparatus, as claimed in claim 1, wherein at least some of said frames in said channels carry 650 synch burst slots and 1300 traffic burst slots.

20. Apparatus, as claimed in claim 19, wherein said synch burst slots comprise 64 symbols in duration and are accommodated in 74 symbol slots.

21. Apparatus, as claimed in claim 10, wherein the transmission rate in symbols per second of the first subchannels is one fifth the transmission rate of the channels in symbols per second and the transmission rate in symbols per second of the second subchannels is one twenty-fifth the transmission rate of the channels in symbols per second.

22. Apparatus, as claimed in claim 1, wherein the transmission rate of the channels is substantially 14 megasymbols per second.

23. Apparatus, as claimed in claim 1, wherein the one or more modulators shift up the generated frequencies to form carrier frequencies and wherein said beams comprise two beams each transmitted with a different form of polarization.

24. Apparatus, as claimed in claim 23, wherein the forms of polarization comprises a form of polarization selected from the group consisting of right hand circular polarization, left hand circular polarization and both right hand and left hand circular polarization.

25. Apparatus, as claimed in claim 1, wherein the one or more beams comprises a plurality of beams transmitted from a plurality of earth locations using at least some of the same carrier frequencies so that the carrier frequencies may be reused spatially by the satellite.

26. Apparatus, as claimed in claim 1, wherein the one or more modulators generate a sufficient number of different frequencies so as to allow up to a predetermined number of bands of frequencies within the available spectrum of frequencies and wherein the beams are arranged in a cluster configuration in which each beam of a cluster includes the predetermined number of bands and each band occupies a different portion of the available spectrum of frequencies.

27. Apparatus, as claimed in claim 10, wherein each of the bands is transmitted with each of two polarization'"'"'s.

28. Apparatus, as claimed in claim 1, wherein one or more of the data bursts includes a coded message identifying one of the one or more terminals beginning to transmit data to the satellite.

29. A method for generating and transmitting data in an available spectrum of frequencies suitable for use by a processing communication satellite comprising the steps of:

providing data cells and a synchronizing burst timing signal at one or more earth terminals;

grouping a predetermined number of the data cells with one of a selectable predetermined first error correction code having a first code rate and a predetermined second error correction code having a second code rate to generate data bursts, said first code rate being a multiple of said second code rate;

grouping the data bursts with synchronizing bursts timed in response to said synchronizing burst timing signal to generate data frames selected from a group of data frame types;

modulating the data frames by a predetermined form of modulation to enable placement of the modulated data frames into a plurality of channels selected from a group of channel types having a plurality of channel rates definable in symbols per second; and

transmitting the modulated data frames over one or more beams with a predetermined form of polarization.

30. A method, as claimed in claim 29, wherein the data frame types differ by the number of data bursts transmitted per frame as a function of the channel rate.

31. A method, as claimed in claim 29, wherein the data frame types differ by the number of synchronizing bursts transmitted per frame as a function of the channel rate.

32. A method, as claimed in claim 29, wherein the step of modulating comprises the step of shifting up the generated frequencies to form carrier frequencies and wherein the step of transmitting comprises the step of transmitting at least two of said beams each with a different form of polarization.

33. A method, as claimed in claim 29, wherein the form of polarization comprises a form of polarization selected from the group consisting of right hand circular polarization, left hand circular polarization and both right hand and left hand circular polarization.

34. A method, as claimed in claim 29, wherein the one or more beams comprises a plurality of beams transmitted from a plurality of earth locations using at least some of the same carrier frequencies so that the carrier frequencies may be reused spatially by the satellite.

35. A method, as claimed in claim 29, wherein the step of modulating comprises the steps of generating a sufficient number of different frequencies so as to allow up to a predetermined number of bands of frequencies within the available spectrum of frequencies and wherein the step of transmitting comprises the step of arranging the one or more beams in a cluster configuration in which each beam of a cluster includes the predetermined number of bands and each band occupies a different portion of the available spectrum of frequencies.

36. A method, as claimed in claim 35, wherein the predetermined number of bands is four.

37. A method, as claimed in claim 29, wherein the step of transmitting comprises the step of transmitting at least two of said one or more beams each with a different form of polarization.

38. A method, as claimed in claim 29, wherein one or more of the data bursts includes a coded message suitable for identifying an earth terminal beginning to transmit data to the satellite.

39. A method, as claimed in claim 29, wherein the step of modulating comprises the steps of:

generating a sufficient number of different frequencies so as to allow up to a predetermined number of channels of frequencies within each of the bands; and

generating a sufficient number of different frequencies so as to allow up to a predetermined number of first subchannels of frequencies within each channel or up to a predetermined number of second subchannels of frequencies within each channel.

40. A method, as claimed in claim 39, wherein the number of channels is seven, the number of first subchannels is five and the number of second subchannels is 25.

41. A method, as claimed in claim 39, wherein the transmission rate in symbols per second of the first subchannels is one fifth the transmission rate of the channels in symbols per second and the transmission rate in symbols per second of the second subchannels is one twenty-fifth the transmission rate of the channels in symbols per second.

42. A method, as claimed in claim 39, wherein said channels, first subchannels and second sitchannels are separated by predetermined frequency spacings and transmit symbols at predetermined symbol rates, wherein said frequency spacings and said symbol rates defined channel spacing ratios and wherein said channel spacing ratios are integer ratios.

43. A method, as claimed in claim 42, wherein said channel spacing ratios are about 5/4.

44. A method, as claimed in claim 39, wherein said channels, said first subchannele and said second subchannels each carry frames of the same duration.

45. A method, as claimed in claim 44, wherein each said frame is 92-93 milliseconds in duration.

46. A method, as claimed in claim 45, wherein at least some of said frames in said second subchannels carry 26 synch burst slots and 52 traffic burst slots.

47. A method, as claimed in claim 46, wherein at least some of said traffic burst slots comprise a 16 symbol preamble.

48. A method, as claimed in claim 44, wherein at least some of said frames in said first subchannels carry 130 synch burst slots and 260 traffic burst slots.

49. A method, as claimed in claim 29, wherein at least some of said frames in said channels carry 650 synch burst slots and 1300 traffic burst slots.

50. A method, as claimed in claim 49, wherein said synch bursts comprise 64 symbols in duration and are accommodated in 74 symbol slots.

51. A method, as claimed in claim 29, wherein the transmission rate of the channels is substantially 14 megasymbols per second.

52. A method, as claimed in claim 29, wherein said frames define multiple frequency TDMA channel slots.

53. A method, as claimed in claim 29, wherein the predetermined number of the data cells is four.

54. A method, as claimed in claim 29, wherein the predetermined first error correction code comprises Reed-Solomon outer code.

55. A method, as claimed in claim 29, wherein the predetermined second error correction code comprises a Reed-Muller code resulting in a biorthogonal signal set over four quadraphase phase shift keying channel symbols concatenated with said Reed-Solomon outer code.

56. A method, as claimed in claim 29, wherein the predetermined form of modulation comprises quatenary phase shift keying modulation.

57. A method, as claimed in claim 56, wherein the predetermined form of modulation further comprises square-root raised cosine pulse shaping on quatenary phase shift keying.