Method and apparatus for spectral efficient data transmission in satellite systems

Patent metadata

Field	Value
Publication number	US-9893800-B2
Application number	US-201514865590-A
Country	US
Kind code	B2
Filing date	Sep 25, 2015
Priority date	Mar 20, 2015
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

A communication satellite system provides for spectral efficient data transmissions by a gateway to multiple user terminals by way of a satellite. The gateway transmits multiple blocks in a single slot, each block intended for one of the user terminals, where each block is encoded and modulated according to a scheme that may be different for each intended user terminal. Upon re-transmission of a block if that block is lost or received in error, the block may be encoded and modulated according to another scheme that is less spectrally efficient than in the first transmission of the block.

First claim

What is claimed is:

1. A method comprising:
demodulating, at a gateway, channel state information from a plurality of user terminals via a satellite;
encoding by the gateway a plurality of blocks into a plurality of encoded blocks, each block for a corresponding user terminal, wherein the gateway encodes each block according to the value of the channel state information of its corresponding user terminal;
modulating by the gateway the plurality of encoded blocks into a plurality of modulated and encoded blocks, wherein the gateway modulates each encoded block according to the value of the channel state information of its corresponding user terminal; and
transmitting by the gateway to the plurality of user terminals via the satellite a slot comprising the plurality of modulated and encoded blocks.

2. The method of claim 1 ,
wherein the encoding by the gateway comprises a first encoding of a block into a first encoded block according to the value of the channel state information of its corresponding user terminal; and
wherein the modulating by the gateway comprises a first modulating of the first encoded block into a first modulated and encoded block according to the value of the channel state information of its corresponding user terminal;
the method further comprising:
receiving a negative acknowledgement for the first modulated and encoded block;
a second encoding by the gateway of the block into a second encoded block;
a second modulating by the gateway of the second encoded block into a second modulated and encoded block; and
transmitting by the gateway a second slot comprising the second modulated and encoded block.

3. The method of claim 2 , wherein the second encoding provides greater error correction than the first encoding.

4. The method of claim 3 , wherein the second modulating has a lower order than the first modulating.

5. The method of claim 3 , wherein the first modulating and the second modulating are the same modulating scheme.

6. The method of claim 3 , wherein the first encoding does not include an outer code.

7. The method of claim 6 , wherein the second encoding includes concatenated encoding.

8. The method of claim 2 , wherein the second modulating has a lower order than the first modulating.

9. The method of claim 8 , wherein the first encoding and the second encoding are the same encoding scheme.

10. The method of claim 1 , the slot comprising a pilot for synchronization of the plurality of user terminals.

11. The method of claim 1 , wherein the encoding by the gateway comprises:
selecting a first modulation and coding scheme with no concatenated coding, the first modulation and coding scheme having an error floor; and
encoding and modulating a block according to the first modulation and coding scheme if a target block error rate for the block and the error floor satisfy a relationship, otherwise if the target block error rate for the block and the error floor do not satisfy the relationship then encoding and modulating the block according to a second modulation and coding scheme where the second modulation and coding scheme includes an outer code.

12. The method of claim 11 , wherein the relationship is the less than inequality.

13. The method of claim 11 , wherein the second modulation and coding scheme includes an inner turbo code and an outer BCH code.

14. A gateway comprising:
a modem; and
at least one processor in communication with the modem, the at least one processor and the modem configured, in combination, to:
demodulate channel state information from a plurality of user terminals via a satellite;
encode a plurality of blocks into a plurality of encoded blocks, each block for a corresponding user terminal, wherein each block is encoded according to the value of the channel state information of its corresponding user terminal;
modulate the plurality of encoded blocks into a plurality of modulated and encoded blocks, wherein each encoded block is modulated according to the value of the channel state information of its corresponding user terminal; and
cause the gateway to transmit the plurality of user terminals via the satellite a slot comprising the plurality of modulated and encoded blocks.

15. The gateway of claim 14 , wherein the at least one processor and the modem are further configured, in combination, to:
encode a block into a first encoded block according to the value of the channel state information of its corresponding user terminal;
modulate the first encoded block into a first modulated and encoded block according to the value of the channel state information of its corresponding user terminal; and
in response to the gateway receiving a negative acknowledgement for the first modulated and encoded block, encode the block into a second encoded block, modulate the second encoded block into a second modulated and encoded block, and cause the gateway to transmit a second slot comprising the second modulated and encoded block.

16. The gateway of claim 15 , wherein the second encoded block has greater error correction than the first encoded block.

17. The gateway of claim 16 , wherein the second modulated and encoded block has a lower order modulation than the first modulated and encoded block.

18. The gateway of claim 16 , wherein the at least one processor and the modem are further configured, in combination, to modulate the first encoded block and the second encoded block according to the same modulation scheme.

19. The gateway of claim 16 , wherein the at least one processor and the modem are further configured, in combination, to encode the block into the first encoded block without concatenating encoding.

20. The gateway of claim 19 , wherein the at least one processor and the modem are further configured, in combination, to encode the block into the second encoded block with concatenated encoding.

21. The gateway of claim 15 , wherein the second modulated and encoded block has a lower order modulation than the first modulated and encoded block.

22. The gateway of claim 21 , wherein the at least one processor and the modem are further configured, in combination, to encode the block into the first encoded block and encode the block into the second encoded block according to the same encoding scheme.

23. The gateway of claim 14 , the slot comprising a pilot for synchronization of the plurality of user terminals.

24. The gateway of claim 14 , wherein the at least one processor and the modem are further configured, in combination, to
select a first modulation and coding scheme with no concatenated coding, where the first modulation and coding scheme has an error floor; and
encode and modulate a block according to the first modulation and coding scheme if a target block error rate for the block and the error floor satisfy a relationship, otherwise if the target block error rate for the block and the error floor do not satisfy the relationship, then encode and modulate the block according to a second modulation and coding scheme where the second modulation and coding scheme includes an outer code.

25. The gateway of claim 24 , wherein the relationship is the less than inequality.

26. The gateway of claim 24 , wherein the second modulation and coding scheme comprises an inner turbo code and an outer BCH code.

27. A non-transitory computer-readable media having stored instructions that, when executed by at leas

Assignees

• Qualcomm Inc

Inventors

• Wu Qiang
• Black Peter John

Classifications

• H04B7/18543

  for adaptation of transmission parameters, e.g. power control (for detecting or preventing errors in the information received H04L1/00) · CPC title

• H04L1/1867

  Arrangements specially adapted for the transmitter end · CPC title

• H04W72/0446

  Resources in time domain, e.g. slots or frames · CPC title

• H04L1/0041

  Arrangements at the transmitter end · CPC title

• H04B7/1858

  Arrangements for data transmission on the physical system, i.e. for data bit transmission between network components · CPC title