Rate-compatible LDPC codes
AssigneeQUALCOMM Incorporated
InventorsBjorn A. Bjerke, John W. Ketchum, Nagabhushana Sindhushayana, Jay Rod Walton
Life of this patent
Estimating the term…
Abstract
Method and apparatus for generating codewords with variable length and redundancy from a single Low-Density Parity-Check (LDPC) code with variable length input words. A mother code for encoding data words is generated based on a parity-check matrix, wherein the mother code is adjusted to reflect the size of the data word to be encoded. A generator matrix applies the mother code to data words to produce codewords for transmission. In one embodiment, a reduction criteria is determined and the size of the generator matrix reduced in response. The corresponding parity-check matrix is applied at the receiver for decoding the received codeword.
Claims8
A method for encoding transmissions in a communication system, comprising:
- selecting a first code having a bit length, wherein the first code is determined by a variable rate encoder that is responsive to data protection requirements and channel characteristics and is selected by:
- selecting a low-density parity-check matrix;
- and
- selecting a generator matrix based on the low-density parity check matrix;
- receiving a data word for transmission;
- padding the data word with zeroes as necessary to extend the data word to the bit length;
- and
- encoding the padded data word using the first code to generate a codeword.
An apparatus for encoding transmissions in a communication system, comprising:
- means for selecting a first code having a bit length, wherein said means for selecting a first code further comprises:
- means for selecting a low-density parity-check matrix;
- selecting a generator matrix based on the low-density parity-check matrix;
- and
- means for receiving a data word for transmission;
- means for padding the data word with zeroes as necessary to extend the data word to the bit length;
- and
- means for encoding the padded data word using the first code to generate a codeword.
A computer-readable medium having stored thereon computer-executable instructions for:
- selecting a low-density parity-check matrix;
- and
- selecting a generator matrix based on the low-density parity check matrix;
- generating a first code having a bit length using the generator matrix;
- receiving a data word for transmission;
- padding the data word with zeroes as necessary to extend the data word to the bit length;
- and
- encoding the padded data word using the first code to generate a codeword.
An apparatus for encoding transmissions in a communication system, comprising:
- a processor, wherein the processor is configured to perform steps comprising:
- selecting a low-density parity-check matrix;
- and
- selecting a generator matrix based on the low-density parity check matrix;
- generating a first code having a bit length using the generator matrix;
- receiving a data word for transmission;
- padding the data word with zeros as necessary to extend the data word to the bit length;
- and
- encoding the padded data word using the first code to generate a codeword.
Dependencies are inferred from the claim text.