New class of turbo-like codes with universally good performance and high-speed decoding

Abstract

Modern turbo-like codes (TLCs), including concatenated convolutional codes and low density parity check (LDPC) codes, have been shown to approach the Shannon limit on the additive white Gaussian noise (AWGN) channel Many design aspects remain relatively unexplored, however, including TLC design for maximum flexibility, very low error rate performance, and amenability to simple or very high-speed hardware codecs. In this paper we address these design issues by suggesting a new class of TLCs that we call systematic with serially concatenated parity (S-SCP) codes. One example member of this family is the Generalized (or Systematic) repeat accumulate code. We describe two other members of this family that both exhibit good performance over a wide range of block sizes, code rates, modulation, and target error probability. One of these provides error floor performance not previously demonstrated with any other TLC construction and the other is shown to offer very low complexity decoding with good performance. These two codes have been implemented in high-speed hardware codecs and performance curves based on these down to bit error rates below 10-10 are provided.