High-Rate Short-Block LDPC Codes for Iterative Decoding with   Applications to High-Density Magnetic Recording Channels
  This paper investigates the Triangle Single Parity Check (T/SPC) code, a novel class of high-rate low-complexity LDPC codes. T/SPC is a regular, soft decodable, linear-time encodable/decodable code. Compared to previous high-rate and low-complexity LDPC codes, such as the well-known Turbo Product Code / Single Parity Check (TPC/SPC), T/SPC provides higher code rates, shorter code words, and lower complexity. This makes T/SPC very attractive for practical implementation on integrated circuits.   In addition, we analyze the performance of iterative decoders based on a soft-input soft-output (SISO) equalizer using T/SPC over high-density perpendicular magnetic recording channels. Computer simulations show that the proposed scheme is able to achieve a gain of up to 0.3 dB over TPC/SPC codes with a significant reduction of implementation complexity. 
Damian A. Morero, Graciela Corral-Briones, Carmen Rodriguez, Mario R.   Hueda
cs.IT math.IT