METHOD AND APPARATUS FOR ENCODING AND DECODING DATA

• US 20080098273A1
• Filed: 10/06/2006
• Published: 04/24/2008
• Est. Priority Date: 10/06/2006
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Nimbalker, Ajit, Classon, Brian K., Blankenship, T. Keith, Blankenship, Yufei Wu
• Granted Patent: US 8,356,232 B2
• Time in Patent Office: Days
• US Class Current: 714/746
• CPC Class Codes: H03M 13/05 using block codes, i.e. a predetermined number of check bits joined to a predetermined number of information bits H03M13/2906 takes precedence
• CPC Class Codes: H03M 13/6306 Error control coding in combination with Automatic Repeat reQuest [ARQ] and diversity transmission, e.g. coding schemes for the multiple transmission of the same information or the transmission of incremental redundancy H03M13/3761, H03M13/3769 and H03M13/635 take precedence
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0066 Parallel concatenated codes
• CPC Class Codes: H04L 1/06 using space diversity
• CPC Class Codes: H04L 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]

Abstract

A method and apparatus for turbo coding and decoding is provided herein. During operation, a concatenated transport block (CTB) of length X is received and a forward error correction (FEC) block size K_I is determined from a group of available non-contiguous FEC block sizes between K_min and K_max, and wherein K_min≦K_I<K_max and wherein K_I is additionally based on X. The concatenated transport block of length X is segmented into C segments each of size substantially equal K_I. An FEC codeword for each of the C segments is determined using FEC block size K_I; and the C FEC codewords are transmitted over the channel.

Claims

1. A method of operating a transmitter, the method comprising the steps of:

receiving a concatenated transport block of length X;

determining an available FEC block size K, from a group of non-contiguous FEC block sizes, wherein the available non-contiguous FEC block sizes are between K_min and K_max, and wherein K_min≦

K_I<

K_max, and wherein K_I is additionally based on X;

segmenting the concatenated transport block of length X into C segments of sizes substantially equal to K_I;

determining an FEC codeword for each of the C segments using FEC block size K_I; and

transmitting the C FEC codewords over the channel.

2. The method of claim 1 wherein C=┌

X/K_max┐

.

3. The method of claim 1 wherein the step of determining an FEC codeword further comprises the steps of:

inserting filler bits into the segment to form an FEC input block;

FEC encoding the FEC input block; and

discarding bits related to the filler bits.

4. The method of claim 1 further comprising the steps of:

receiving information bits of length A to be transmitted on one or more spatial streams;

designating X′

bits as a transport block, where X′

≦

A;

attaching CRC bits to the X′

bits to form the concatenated transport block of length X; and

wherein the concatenated transport block of length X is mapped to a first HARQ channel.

5. The method of claim 4 further comprising the steps of:

designating W′

=A−

X′

bits from the information bits as a second transport block;

attaching CRC bits to form a second concatenated transport block; and

wherein the concatenated transport block is mapped to a second HARQ channel.

6. The method of claim 1 wherein the step of determining an FEC codeword further comprises the steps of

inserting groups of consecutive filler bits into a segment to form an FEC input block wherein the group length is a multiple of 7;

FEC encoding the FEC input block; and

discarding bits related to the filler bits.

7. The method of claim 6 wherein the method of discarding bits further comprises the steps of

discarding groups of systematic bits corresponding to the filler bits;

and

discarding the parity bits corresponding to the groups of filler bits at the output of constituent encoder 1, wherein constituent encoder takes the FEC input block without interleaving for tail-biting turbo coders.

13. The method of claim 6 wherein the step of determining an FEC codeword further comprises the steps of

inserting groups of consecutive filler bits into a segment to form an FEC input block wherein the group length is a multiple of 7;

FEC encoding the FEC input block; and

discarding bits related to the filler bits.

14. The method of claim 13 wherein the method of discarding bits further comprises the step of

discarding groups of systematic bits corresponding to the filler bits;

and

discarding the parity bits corresponding to the groups of filler bits at the output of constituent encoder 1, wherein constituent encoder takes the FEC input block without interleaving for tail-biting turbo coders.

8. A method of operating a transmitter, the method comprising:

receiving a concatenated transport block of length X;

determining two available FEC block sizes K<sub>I−

1</sub> and K_I from a group of non-contiguous FEC block sizes, wherein the available non-contiguous FEC block sizes are between K_min and K_max, and wherein K_min≦

K<sub>I−

1</sub><

K_max, K_min≦

K_I≦

K_max, and wherein K<sub>I−

1</sub> and K_I are additionally based on X;

segmenting the concatenated transport block of length X into C segments of sizes substantially equal to K<sub>I−

1</sub> or K_I;

determining an FEC codeword for each of the C segments using FEC block sizes K_I or K<sub>I−

1</sub>; and

transmitting the C FEC codewords over the channel.

9. The method of claim 8 wherein C=┌

X/K_max┐

=C<sub>I−

1</sub>+C_I, where

Y=CK_I−

X,

C<sub>I−

1</sub>=└

Y/D┘

,

C_I=C−

└

Y/D_I┘

,′

and C<sub>I−

1</sub> and C_I are the number of segments that are encoded using FEC block sizes K<sub>I−

1</sub> and K_I, respectively, where K_I is the smallest size from available FEC block sizes that is greater than or equal to ┌

X/C┐ and

D_I denotes the difference between the adjacent interleaver sizes K<sub>I−

1</sub> and K_I.

10. The method of claim 8 wherein the step of determining an FEC codeword further comprises the steps of

inserting filler bits into the segment to form an FEC input block;

FEC encoding the FEC input block; and

discarding bits related to the filler bits.

11. The method of claim 8 further comprising the steps of:

receiving information bits of length A to be transmitted on one or more spatial streams;

designating X′

bits as a transport block, X′

<

A;

attaching CRC bits to form the concatenated transport block of length X; and

wherein the concatenated transport block of length X is mapped to a first HARQ channel.

12. The method of claim 11 further comprising the steps of:

designating W′

=A−

X′

bits the information bits as a second transport block;

attaching CRC bits to Y bits to form a second concatenated transport block;

wherein the concatenated transport block is mapped to a second HARQ channel.

15. An apparatus comprising:

receiving circuitry receiving a concatenated transport block of length X;

logic circuitry determining an available FEC block size K_I from a group of non-contiguous FEC block sizes, wherein the available non-contiguous FEC block sizes are between K_min and K_max, and wherein K_min≦

K_I<

K_max, and wherein K_I is additionally based on X;

code block segmentation circuitry segmenting the concatenated transport block of length X into C segments of sizes substantially equal to K_I;

encoding circuitry determining an FEC codeword for each of the C segments using FEC block size K_I; and

transmission circuitry transmitting the C FEC codewords over a channel.

16. The apparatus of claim 15 wherein C=┌

X/K_max┐

.

17. The apparatus of claim 15 further comprising:

filler circuitry inserting filler bits into at least one segment to form an FEC input block.

18. The apparatus of claim 15 further comprising:

receive circuitry receiving information bits of length A to be transmitted on one or more spatial streams;

TB formation circuitry designating X′

bits as a transport block, where X′

≦

A; and

a HARQ1 processor attaching CRC bits to the X′

bits to form the concatenated transport block of length X;

, and wherein the concatenated transport block of length X is mapped to a first HARQ channel.

19. The apparatus of claim 18 further comprising:

TB formation circuitry designating W′

=A−

X′

bits from the information bits as a second transport block;

a HARQ2 processor attaching CRC bits to form a second concatenated transport block; and

wherein the concatenated transport block is mapped to a second HARQ channel.

20. An apparatus comprising:

receiving circuitry receiving a concatenated transport block of length X;

logic circuitry determining two available FEC block sizes K<sub>I−

1</sub> and K_I from a group of non-contiguous FEC block sizes, wherein the available non-contiguous FEC block sizes are between K_min and K_max, and wherein K_min≦

K<sub>I−

1</sub><

K_max, K_min≦

K_I≦

K_max, and wherein K<sub>I−

1</sub> and K_I are additionally based on X;

code block segmentation circuitry segmenting the concatenated transport block of length X into C segments of sizes substantially equal to K<sub>I−

1</sub> or K_I;

encoding circuitry determining an FEC codeword for each of the C segments using FEC block sizes K_I or K<sub>I−

1</sub>; and

transmission circuitry transmitting the C FEC codewords over the channel.