Parity check outer code and runlength constrained outer code usable with parity bits

摘要

A method uses an outer code that is a concatenation of code words generated by a parity check encoder. The outer code word is permuted by an interleaver. The high rate coding provides good performance with a simple structure. An odd parity check bit is generated for each data word of received systematic dates. Code words are formed by adding a generated parity bit to each data word. Groups of code words are permuted to form encoded input for transmission in a communication channel. The invention further includes encoding to maintain a runlength-limiting (RLL) constraint at the channel input. Interleaved runlength encoded system data is used to generate error code bits. Insertion of error code bits in the system data at the channel input is controlled. This guarantees that the channel input stream comprised of the runlength-limited system data and inserted error code bits meets the runlength constraints.