LDPC (low density parity check) codes with corresponding parity check matrices selectively constructed with CSI (cyclic shifted identity) and null sub-matrices

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;
• the left hand side matrix including a first diagonal sub-matrix band, composed of all zero-valued sub-matrices, located on a first plurality of contiguous diagonals of the left hand side matrix;
• and
• the left hand side matrix including a second diagonal sub-matrix band, composed of a plurality of CSI (Cyclic Shifted Identity) sub-matrices and at least one all zero-valued sub-matrix, located on a second plurality of contiguous diagonals of the left hand side matrix adjacent to the first diagonal sub-matrix band.

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

• via an input of the communication device, receiving an LDPC (Low Density Parity Check) coded signal;
• and
• 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
• the left hand side matrix including at least one diagonal sub-matrix band, composed of all zero-valued sub-matrices, located on a plurality of contiguous diagonals of the left hand side matrix.