System for error control by subdividing coded information units into subsets reordering and interlacing the subsets, to produce a set of interleaved coded information units

• US 6,311,306 B1
• Filed: 04/26/1999
• Issued: 10/30/2001
• Est. Priority Date: 04/26/1999
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Emeott, Stephen Paul, White, Gregory Charles
• Primary Examiner(s): Ton, David
• Application Number:
  US09/300,419
• Time in Patent Office: 918 Days
• Field of Search: 714/790, 714/755, 375/245, 375/265, 375/264, 375/279, 375/280, 370/468
• US Class Current: 714/790
• CPC Class Codes: H03M 13/256 with trellis coding, e.g. with convolutional codes and TCM
• CPC Class Codes: H03M 13/27 using interleaving techniques
• CPC Class Codes: H03M 13/356 Unequal error protection [UEP]
• CPC Class Codes: H03M 13/6362 by puncturing
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/0083 Formatting with frames or packets; Protocol or part of protocol for error control
• CPC Class Codes: H04L 2001/0098 Unequal error protection

Abstract

The invention provides a method of interleaving information units in order to provide improved error control. A communication device codes the information units, subdivides the coded information units into multiple subsets, reorders each of the multiple subsets, and interlaces the multiple reordered subsets to produce a set of interleaved coded information units. By reordering and interlacing the subsets, the impact of burst errors is diminished and the coded information units are formatted to take advantage of the different levels of error protection provided to the various bits underlying a symbol assigned by a symbol mapper.

Claims

1. A method of interleaving information units in order to provide improved error control, the method comprising the steps of:

receiving a plurality of information units;

subdividing the plurality of information units into a plurality of subsets, wherein the information units subdivided into at least one of the plurality of subsets require a lower probability of bit-error than the information units subdivided into another of the plurality of subsets;

reordering information units within each subset to produce a plurality of reordered subsets, wherein the plurality of reordered subsets comprises a first reordered subset and a second reordered subset;

interlacing at least one information unit contained in the first reordered subset with at least one information unit contained in the second reordered subset to produce interleaved coded information units;

wherein the step of subdividing comprises the steps of;

coding the information units to produce a set of coded information units; and

subdividing the set of coded information units into a plurality of subsets;

wherein the step of coding the information units comprises the steps of;

coding the information units to produce an unpunctured set of coded information units; and

puncturing the unpunctured set of coded information units to produce a set of coded information units, wherein the at least one of the plurality of subsets that requires a lower probability of bit-error than the other of the plurality of subsets is punctured less than the other of the plurality of subsets.

2. The method of claim 1, wherein the step of coding the information units comprises the steps of:

splitting the information units into a set of codeable information units and a set of uncoded information units;

coding the set of codeable information units to produce a set of coded codeable information units; and

combining the set of coded codeable information units and the set of uncoded information units to produce a set of coded information units.

3. The method of claim 2, wherein the step of combining the set of coded codeable information units and the set of uncoded information units comprises the steps of:

puncturing the set of coded codeable information units to produce a punctured set of coded codeable information units; and

combining the punctured set of coded codeable information units and the set of uncoded information units to produce a set of coded information units.

4. A method of transmitting information units by a communication device, the method comprising the steps of:

providing information units to be transmitted;

subdividing the information units into a plurality of subsets, wherein the information units subdivided into at least one of the plurality of subsets require a lower probability of bit-error than the information units subdivided into another of the plurality of subsets;

reordering information units within each subset to produce a plurality of reordered subsets, wherein the plurality of reordered subsets comprises a first reordered subset and a second reordered subset;

interlacing at least one information unit contained in the first reordered subset with at least one information unit contained in the second reordered subset to produce interleaved coded information units;

transmitting the interleaved coded information units;

wherein the step of subdividing comprises the steps of;

coding the information units to produce a set of coded information units; and

subdividing the set of coded information units into a plurality of subsets;

wherein the step of coding information units comprises the steps of;

coding the information units to produce an unpunctured set of coded information units; and

puncturing the unpunctured set of coded information units to produce a set of coded information units, wherein the at least one of the plurality of subsets that requires a lower probability of bit-error than the other of the plurality of subsets is punctured less than the other of the plurality of subsets.

5. The method of claim 4, wherein the step of coding the information units comprises the steps of:

splitting the information units into a set of codeable information units and a set of uncoded information units;

coding the set of codeable information units to produce a set of coded codeable information units; and

combining the set of coded codeable information units and the set of uncoded information units to produce a set of coded information units.

6. The method of claim 5, wherein the step of combining the set of coded codeable information units and the set of uncoded information units comprises the steps of:

puncturing the set of coded codeable information units to produce a punctured set of coded codeable information units; and

combining the punctured set of coded codeable information units and the set of uncoded information units to produce a set of coded information units.

7. The method of claim 4, wherein the step of transmitting the interleaved coded information units comprises the steps of:

assigning a symbol to the interleaved coded information units; and

transmitting the symbol.

8. The method of claim 7, wherein the step of transmitting the symbol comprises the steps of:

modulating the symbol onto a waveform to produce a modulated waveform; and

transmitting the modulated waveform.

9. A communication device comprising:

an information source for providing information units to be transmitted;

a processing system, coupled to the information source, capable of receiving the information units, capable of subdividing the information units into a plurality of subsets, wherein the information units subdivided into at least one of the plurality of subsets require a lower probability of bit-error than the information units subdivided into another of the plurality of subsets, capable of reordering information units within each subset to produce a plurality of reordered subsets, wherein the plurality of reordered subsets comprises a first reordered subset and a second reordered subset, capable of interlacing at least one information unit contained in the first reordered subset with at least one information unit contained in the second reordered subset to produce interleaved coded information units, and capable of assigning a symbol to the interleaved coded information units, wherein subdividing by the processing system of the information units comprises coding the information units to produce a set of coded information units and subdividing the set of coded information units into a plurality of subsets, wherein coding by the processing system of the information units to produce a set of coded information units comprises coding information units to produce an unpunctured set of coded information units and puncturing the unpunctured set of coded information units to produce a set of coded information units, and wherein the at least one of the plurality of subsets that requires a lower probability of bit-error than the other of the plurality of subsets is punctured less than the other of the plurality of subsets; and

a transmitter, coupled to the processor, capable of transmitting the symbol.

10. The communication device of claim 9, wherein coding by the processing system of the information units to produce a set of coded information units comprises splitting the information units into a set of codeable information units and a set of uncoded information units, coding the set of codeable information units to produce a set of coded codeable information units, and combining the set of coded codeable information units and the set of uncoded information units to produce a set of coded information units.

11. The communication device of claim 10, wherein combining by the processing system of the set of coded codeable information units and the set of uncoded information units comprises puncturing the set of coded codeable information units to produce a punctured set of information units and combining the punctured set of information units and the set of uncoded information units to produce a set of coded information units.

12. The communication device of claim 9, wherein the processing system comprises a processor.

13. The communication device of claim 9, wherein the processing system comprises:

a coder, wherein the coder codes the information units to produce a set of coded information units;

a subdividing interleaver coupled to the coder, wherein the subdividing interleaver subdivides the set of coded information units into a plurality of subsets, reorders information units within each subset to produce a plurality of reordered subsets, and interlaces at least one information unit contained in a reordered subset with at least one information unit contained in a different reordered subset to produce interleaved coded information units; and

a symbol coder coupled to the subdividing interleaver, wherein the symbol coder assigns a symbol to the interleaved coded information units.

14. The communication device of claim 13, wherein the subdividing interleaver comprises:

a subdivider, wherein the subdivider subdivides the set of coded information units into a plurality of subsets;

a plurality of interleavers, wherein each interleaver is coupled to the subdivider, and wherein each interleaver reorders information units within a subset to produce a reordered subset; and

an interlacer coupled to each interleaver, wherein the interlacer interlaces at least one information unit contained in a reordered subset with at least one information unit contained in a different reordered subset to produce interleaved coded information units.

15. The communication device of claim 13, wherein the processing system further comprises a puncturer coupled between the coder and to the subdividing interleaver, wherein the puncturer punctures the set of coded information units to produce a punctured set of coded information units, and wherein the subdividing interleaver subdivides the punctured set of coded information units into a plurality of subsets.

16. The communication device of claim 13, further comprising:

a splitter coupled between the information source and the coder, wherein the splitter splits the information units into a set of codeable information units and a set of uncoded information units, and wherein the coder codes the set of codeable information units to produce a set of coded codeable information units; and

a combiner coupled between the coder and the subdividing interleaver, and further coupled to the splitter, wherein the combiner combines the set of coded codeable information units and the set of uncoded information units to produce a set of coded information units.

17. The communication device of claim 16, further comprising:

a puncturer coupled between the coder and the combiner, wherein the puncturer punctures the coded codeable information units to produce a punctured set of coded codeable information units, and wherein the combiner combines the punctured set of coded codeable information units and the set of uncoded information units to produce a set of coded information units.