US 2010/0251064 A1 · LDPC codes robust to non-stationary narrowband ingress noise

Abstract

LDPC codes robust to non-stationary narrowband ingress noise. Particularly designed LDPC codes are adapted to address deleterious noise-effects incurred within LDPC coded signals that propagate via a communication channel (such as from a transmitting communication device to a receiving communication device). Such LDPC matrices employed for encoding and/or decoding such LDPC coded signals are composed of sub-matrices (e.g., all-zero values sub-matrices and/or CSI (Cyclic Shifted Identity) sub-matrices). The sub-matrices are generally uniform in size and square in shape. Based on certain operational conditions, such as communication channel noise, various operations within a communication device are adaptively modified (e.g., signaling, modulation, demodulation, symbol mapping, metric generation, decoding, etc.). Various types of signaling may be employed for such LDPC coded signals including orthogonal frequency division multiplexing (OFDM) signaling, which may include employing symbols of different size therein (e.g., symbols with x and y bits, respectively, with x and y being integers).

Claims20

Dependent claims

An apparatus, comprising:

an input for receiving an LDPC (Low Density Parity Check) coded signal;
and
an LDPC decoder for employing an LDPC matrix for decoding the LDPC coded signal to make an estimate of an information bit encoded therein;
and wherein:
the LDPC matrix, composed of a plurality of sub-matrices each having a common size, being partitioned into a left hand side matrix and a right hand side matrix;
and
each sub-matrix within the right hand side matrix being an all zero-valued sub-matrix except those sub-matrices identified in (a) and (b):
(a) each sub-matrix located on a diagonal of the right hand side matrix being a respective CSI (Cyclic Shifted Identity) sub-matrix, the diagonal extending from an upper left most sub-matrix of the right hand side matrix to a lower right hand sub-matrix of the of the right hand side matrix;
and
(b) each sub-matrix being located below the diagonal of the right hand side matrix also being a respective CSI sub-matrix.

7 more elements

An apparatus, comprising:

an input for receiving an LDPC (Low Density Parity Check) coded signal from a communication channel being affected from frequency selective and time-varying narrowband ingress noise;
an analog front end (AFE) for extracting a plurality of symbols from the LDPC coded signal, the plurality of symbols being modulated within the LDPC coded signal in accordance with orthogonal frequency division multiplexing (OFDM) signaling;
an LDPC decoder for employing an LDPC matrix for decoding the plurality of symbols of the LDPC coded signal to make estimates of information bits encoded therein;
and
a bit loading circuitry for adaptively directing operations of the AFE and the LDPC decoder based on the frequency selective and time-varying narrowband ingress noise;
and wherein:
the LDPC matrix, composed of a plurality of sub-matrices each having a common size, being partitioned into a left hand side matrix and a right hand side matrix;
each sub-matrix within the right hand side matrix being an all zero-valued sub-matrix except those sub-matrices identified in (a) and (b):
(a) each sub-matrix located on a diagonal of the right hand side matrix being a respective CSI sub-matrix, the diagonal extending from an upper left most sub-matrix of the right hand side matrix to a lower right hand sub-matrix of the of the right hand side matrix;
and
(b) each sub-matrix being located below the diagonal of the right hand side matrix also being a respective CSI sub-matrix.

8 more elements

A method for operating a communication device, the method comprising:

receiving an LDPC (Low Density Parity Check) coded signal;
and
operating an LDPC decoder, within the communication device, for employing an LDPC matrix for decoding the LDPC coded signal to make an estimate of an information bit encoded therein;
and wherein:
the LDPC matrix, composed of a plurality of sub-matrices each having a common size, being partitioned into a left hand side matrix and a right hand side matrix;
and
each sub-matrix within the right hand side matrix being an all zero-valued sub-matrix except those sub-matrices identified in (a) and (b):
(a) each sub-matrix located on a diagonal of the right hand side matrix being a respective CSI (Cyclic Shifted Identity) sub-matrix, the diagonal extending from an upper left most sub-matrix of the right hand side matrix to a lower right hand sub-matrix of the of the right hand side matrix;
and
(b) each sub-matrix being located below the diagonal of the right hand side matrix also being a respective CSI sub-matrix.

7 more elements

Dependencies are inferred from the claim text.

LDPC codes robust to non-stationary narrowband ingress noise

Life of this patent

LDPC codes robust to non-stationary narrowband ingress noise

Life of this patent

Abstract

Claims20