Novel RLL-ECC Concatenation Scheme for High-Density Magnetic Recording

We propose a new run-length-limited (RLL)/error correction coding (ECC) concatenation scheme based on uniform interleaving. The new scheme reverses the positions of the ECC encoder and the RLL encoder in the classical RLL-ECC structure. Further, a uniform interleaver on the sender side and a uniform deinterleaver on the receiver side are added to the new scheme. We prove that uniform interleaving can impose the required RLL constraint to the ECC encoded data. Our scheme solves the error propagation problem. It also adopts the use of soft decoding ECC such as low-density parity-check (LDPC) codes. Simulation results demonstrate that the new scheme can have a 7 dB gain over the traditional one