Combining ECC with modulation: performance comparisons

A technique for combining error correcting codes (ECCs) with modulation codes of the block type is described. Its performance is analyzed with respect to the traditional method in magnetic recording, which involves the concatenation of error-correcting code with a convolutional modulation code. Conditions are established under which the new method is superior to the concatenated scheme. For a fixed number of information bits, the total redundancy with the two methods is calculated and conditions are established under which the redundancy of the new method is smaller than the redundancy of the traditional method. In particular, performance with respect to the