A decoder performs forward error correction based on quasi-cyclic regular column-partition low density parity check codes. A method for designing the parity check matrix reduces the number of short-cycles of the matrix to increase performance. An adaptive quantization post-processing technique further improves performance by eliminating error floors associated with the decoding. A parallel decoder architecture performs iterative decoding using a parallel pipelined architecture.

A semiconductor integrated circuit includes a combinational circuit to output a state value and a parity value, a first parity check circuit to perform a parity check based on the state value and the parity value stored in a first FF circuit and output a first parity error, a second parity check circuit to perform a parity check based on the state value and the parity value stored in a second FF circuit and output a second parity error, and a selector to, when the first parity error is not output but the second parity error is output, output the state value in the first FF circuit to the combinational circuit, and when the first parity error is output but the second parity error is not output, output the state value in the second FF circuit to the combinational circuit.

Certain aspects of the present disclosure provide low-density parity-check (LDPC) codes having pairwise orthogonality of adjacent rows, and a new decoder that exploits the pairwise row orthogonality for flexible decoder scheduling without performance loss. An apparatus includes a receiver configured to receive a codeword in accordance with a radio technology across a wireless channel via one or more antenna elements situated proximal the receiver. The apparatus includes at least one processor coupled with a memory and comprising decoder circuitry configured to decode the codeword based on a LDPC code to produce a set of information bits. The LDPC code is stored in the memory and defined by a base matrix having columns in which all adjacent rows are orthogonal in a last portion of the rows.