Symbol by symbol variable code rate capable communication device

• US 7,472,335 B1
• Filed: 01/08/2003
• Issued: 12/30/2008
• Est. Priority Date: 05/31/2002
• Status: Expired due to Fees

• Current Assignee: Broadcom Corporation (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Shen, Ba-Zhong, Tran, Hau Thien, Cameron, Kelly Brian
• Primary Examiner(s): Lamarre; Guy J
• Application Number:
  US10/338,185
• Time in Patent Office: 2,183 Days
• Field of Search: 714/777, 714/704, 714791-797, 714/774, 714/758, 714/760, 714/782, 714/784, 714/790, 375/262, 375/265, 375/341, 375/375
• US Class Current: 714/794
• CPC Class Codes: H03M 13/258 with turbo codes, e.g. Turbo Trellis Coded Modulation [TTCM]
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/006 Trellis-coded modulation
• CPC Class Codes: H04L 1/0066 Parallel concatenated codes
• CPC Class Codes: H04L 1/0068 by puncturing

Abstract

Symbol by symbol variable code rate capable communication device. A communication device is operable to perform processing of a variable code rate signal whose code rate varies on a symbol by symbol basis. This may involve performing encoding of input to generate the variable code rate signal; alternatively, this may involve performing decoding of a variable code rate signal. In doing so, this approach may involve using a single encoder and/or decoder (depending on the application). In some instances, a single device is operable to encode a first variable code rate signal (for transmission to another device) and to decode a second variable code rate signal (that has been received from another device). In addition, a method of coding (including one or both of encoding and decoding) may also operate of a variable code rate signal whose code rate varies on a symbol by symbol basis.

Claims

1. An apparatus, comprising:

a rate control sequencer that provides a rate control sequence having a plurality of rate controls; and

an encoder that;

receives the rate control sequence;

based on a first of the plurality of rate controls, encodes a first input bit in accordance with a first code rate thereby generating a first plurality of encoded bits; and

based on a second of the plurality of rate controls, encodes a second input bit in accordance with a second code rate thereby generating a second plurality of encoded bits; and

wherein;

a first encoded symbol and a second encoded symbol are generated from the first plurality of encoded bits and the second plurality of encoded bits, respectively.

2. The apparatus of claim 1, further comprising:

a puncturing functional block that punctures the first plurality of encoded bits to produce the first encoded symbol; and

wherein;

the puncturing functional block punctures the second plurality of encoded bits to produce the second encoded symbol.

3. The apparatus of claim 2, wherein the puncturing functional block punctures the first plurality of encoded bits to produce the first encoded symbol and a third encoded symbol.

4. The apparatus of claim 2, wherein the puncturing functional block punctures the second plurality of encoded bits to produce the second encoded symbol and a third encoded symbol.

5. The apparatus of claim 1, wherein:

the encoder is a systematic encoder; and

at least one of the first encoded symbol and the second encoded symbol includes a plurality of redundancy bits and the first input bit or the second input bit.

6. The apparatus of claim 1, wherein the encoder is a non-systematic encoder.

7. The apparatus of claim 6, wherein:

the non-systematic encoder is a rate 2/5 non-systematic encoder; and

the rate 2/5 non-systematic encoder includes a rate 1/2 recursive convolutional encoder.

8. The apparatus of claim 1, wherein:

the encoder generates output; and

the output includes the first encoded symbol, the second encoded symbol, and at least one uncoded bit.

9. The apparatus of claim 1, wherein the encoder provides at least one of the first encoded symbol and the second encoded symbol on an Additive White Gaussian Noise (AWGN) communication channel.

10. The apparatus of claim 1, wherein:

the encoder produces a plurality of encoded symbols;

the plurality of encoded symbols includes the first encoded symbol and the second encoded symbol; and

the plurality of encoded symbols is arranged in a frame.

11. The apparatus of claim 1, wherein:

a plurality of input bits is provided serially to the encoder; and

a predetermined number of input bits of the plurality of input bits are grouped to form an input symbol that is provided to the encoder.

12. The apparatus of claim 1, wherein:

a plurality of input bits is provided serially to the encoder; and

two consecutive input bits of the plurality of input bits, that are provided serially to the encoder, form an input symbol that is provided to the encoder.

13. The apparatus of claim 1, wherein:

the apparatus is contained within a satellite transmitter;

the satellite transmitter is communicatively coupled to a satellite receiver via a wireless communication channel; and

the satellite receiver includes a decoder that is operable to decode the first encoded symbol and the second encoded symbol.

14. The apparatus of claim 1, wherein the apparatus is contained within at least one of a satellite communication system, a high definition television (HDTV) communication system, a cellular communication system, a microwave communication system, a point-to-point radio communication system, and a turbo trellis coded modulation (TTCM) communication system.

15. An apparatus, comprising:

a rate control sequencer that provides a rate control sequence having a plurality of rate controls; and

an encoder that;

receives the rate control sequence;

based on a first of the plurality of rate controls, encodes a first input bit in accordance with a first code rate thereby generating a first plurality of encoded bits; and

based on a second of the plurality of rate controls, encodes a second input bit in accordance with a second code rate thereby generating a second plurality of encoded bits;

a puncturing functional block punctures the first plurality of encoded bits to produce a first encoded symbol; and

wherein;

the puncturing functional block punctures the second plurality of encoded bits to produce a second encoded symbol.

16. The apparatus of claim 15, wherein the puncturing functional block punctures the first plurality of encoded bits to produce the first encoded symbol and a third encoded symbol.

17. The apparatus of claim 15, wherein the puncturing functional block punctures the second plurality of encoded bits to produce the second encoded symbol and a third encoded symbol.

18. The apparatus of claim 15, wherein:

the encoder is a systematic encoder; and

at least one of the first encoded symbol and the second encoded symbol includes a plurality of redundancy bits and the first input bit or the second input bit.

19. The apparatus of claim 15, wherein the encoder is a non-systematic encoder.

20. The apparatus of claim 19, wherein:

the non-systematic encoder is a rate 2/5 non-systematic encoder; and

the rate 2/5 non-systematic encoder includes a rate 1/2 recursive convolutional encoder.

21. The apparatus of claim 15, wherein:

the encoder generates output; and

the output includes the first encoded symbol, the second encoded symbol, and at least one uncoded bit.

22. The apparatus of claim 15, wherein the encoder provides at least one of the first encoded symbol and the second encoded symbol on an Additive White Gaussian Noise (AWGN) communication channel.

23. The apparatus of claim 15, wherein:

the puncturing functional block produces a plurality of encoded symbols;

the plurality of encoded symbols includes the first encoded symbol and the second encoded symbol; and

the plurality of encoded symbols is arranged in a frame.

24. The apparatus of claim 15, wherein:

a plurality of input bits is provided serially to the encoder; and

a predetermined number of input bits of the plurality of input bits are grouped to form an input symbol that is provided to the encoder.

25. The apparatus of claim 15, wherein:

a plurality of input bits is provided serially to the encoder; and

two consecutive input bits of the plurality of input bits, that are provided serially to the encoder, form an input symbol that is provided to the encoder.

26. The apparatus of claim 15, wherein:

the apparatus is contained within a satellite transmitter;

the satellite transmitter is communicatively coupled to a satellite receiver via a wireless communication channel; and

the satellite receiver includes a decoder that is operable to decode the first encoded symbol and the second encoded symbol.

27. The apparatus of claim 15, wherein the apparatus is contained within at least one of a satellite communication system, a high definition television (HDTV) communication system, a cellular communication system, a microwave communication system, a point-to-point radio communication system, and a turbo trellis coded modulation (TTCM) communication system.

28. A coding method that is performed within a communication device, the method comprising:

encoding a first input bit according to a first code rate as directed by a first of a plurality of rate controls to produce a first plurality of encoded bits;

encoding a second input bit according to a second code rate as directed by a second of a plurality of rate controls to produce a second plurality of encoded bits;

generating a first encoded symbol using the first plurality of encoded bits;

generating a second encoded symbol using the second plurality of encoded bits;

wherein the first encoded symbol and the second encoded symbol form a first variable code rate signal whose code rate varies on a symbol by symbol basis;

wherein a third encoded symbol, encoded according to a third code rate as directed by a third of the plurality of rate controls, and a fourth encoded symbol, encoded according to a fourth code rate as directed by a fourth of the plurality of rate controls, form a second variable code rate signal whose code rate varies on a symbol by symbol basis;

calculating a first soft symbol decision for the third encoded symbol;

calculating a second soft symbol decision for the fourth encoded symbol;

generating a first hard symbol decision for the first soft symbol decision thereby making a best estimate for the third encoded symbol; and

generating a second hard symbol decision for the second soft symbol decision thereby making a best estimate for the fourth encoded symbol.

29. The method of claim 28, further comprising providing the first variable code rate signal on an Additive White Gaussian Noise (AWGN) communication channel.

30. The method of claim 28, further comprising receiving the second variable code rate signal from an Additive White Gaussian Noise (AWGN) communication channel.

31. The method of claim 28, wherein at least one of the first variable code rate signal and the second variable code rate signal includes at least one uncoded bit.

32. The method of claim 28, further comprising grouping at least some of a plurality of input bits to form an input symbol that includes the first input bit or the second input bit.

33. The method of claim 28, further comprising grouping two consecutive input bits of a plurality of input bits to form an input symbol that includes the first input bit or the second input bit.

34. The method of claim 28, further comprising calculating a plurality of soft bit decisions when calculating at least one of the first soft symbol decision for the third encoded symbol and the second soft symbol decision for the fourth encoded symbol.

35. The method of claim 28, further comprising making a best estimate for at least one uncoded bit using at least one of the best estimate for the third encoded symbol and the best estimate for the fourth encoded symbol.

36. The method of claim 28, wherein:

the communication device is contained within at least one of a satellite communication system, a high definition television (HDTV) communication system, a cellular communication system, a microwave communication system, a point-to-point radio communication system, and a turbo trellis coded modulation (TTCM) communication system.

37. An encoding method that is performed within a communication device, the method comprising:

encoding a first input bit according to a first code rate to produce a first plurality of encoded bits;

encoding a second input bit according to a second code rate to produce a second plurality of encoded bits

generating a first encoded symbol using the first plurality of encoded bits;

generating a second encoded symbol using the second plurality of encoded bits; and

wherein;

the first encoded symbol and the second encoded symbol form a variable code rate signal whose code rate varies on a symbol by symbol basis.

38. The method of claim 37, further comprising providing the variable code rate signal on an Additive White Gaussian Noise (AWGN) communication channel.

39. The method of claim 37, wherein the variable code rate signal includes at least one uncoded bit.

40. The method of claim 37, further comprising:

grouping at least some of a plurality of input bits to form an input symbol that includes the first input bit or the second input bit; and

encoding the input symbol to form at least one of the first encoded symbol and the second encoded symbol.

41. The method of claim 37, further comprising:

grouping two consecutive input bits of a plurality of input bits to form an input symbol that includes the first input bit or the second input bit; and

encoding the input symbol to form at least one of the first encoded symbol and the second encoded symbol.

42. The method of claim 37, wherein:

the communication device is contained within at least one of a satellite communication system, a high definition television (HDTV) communication system, a cellular communication system, a microwave communication system, a point-to-point radio communication system, and a turbo trellis coded modulation (TTCM) communication system.