Abstract: A product code and interleaving/de-interleaving process are designed to work in combination to improve the coding gain of the product code. Such improvement of coding gain is based on an error constraint. The error constraint is a maximum number of values in error per block in the detected decisions for received output channel samples. The error constraint may be a burst error constraint, such as a maximum number of errors in a block introduced by burst noise in the communication channel; or the error constraint may be an error event constraint, such as the error event generated by an incorrect decision for a path through the trellis of the Viterbi algorithm employed by the detector or a combination of both. In one implementation, a block of data of length N is encoded with a product code of two dimensions with N a positive integer. The product code includes an error correcting capability of detection and correction by a receiver of single one-bit errors in the encoded block.

Abstract: A method for monitoring a digital channel is provided that includes several steps such as receiving an analog input signal corresponding to a digital signal, and equalizing the analog input signal to generate an equalized signal to a predetermined partial response target. The method further includes generating a pseudoternary signal from the equalized signal, and analyzing the pseudoternary signal to detect polarity alternation violations, as well as RLL global and interleave constraint violations.