Design of repeat-accumulate codes for iterative detection and decoding
IEEE Transactions on Signal Processing
Unveiling turbo codes: some results on parallel concatenated coding schemes
IEEE Transactions on Information Theory
A logarithmic upper bound on the minimum distance of turbo codes
IEEE Transactions on Information Theory
Extrinsic information transfer functions: model and erasure channel properties
IEEE Transactions on Information Theory
Nonuniform error correction using low-density parity-check codes
IEEE Transactions on Information Theory
Convergence Analysis and Optimal Scheduling for Multiple Concatenated Codes
IEEE Transactions on Information Theory
Iterative turbo decoder analysis based on density evolution
IEEE Journal on Selected Areas in Communications
An efficient variable-length code construction foriterative source-channel decoding
IEEE Transactions on Communications
Classification of unique mappings for 8PSK based on bit-wise distance spectra
IEEE Transactions on Information Theory
Hi-index | 754.90 |
We propose a systematic design framework for optimal, low-complexity punctured multiple parallel concatenated codes (MPCCs), based on minimizing the convergence threshold using extrinsic information transfer (EXIT) charts. As the convergence threshold is related to the area between the two EXIT curves, the corresponding optimization problem is equivalent to a curve-fitting problem. The EXIT curves are determined by the respective EXIT functions of the constituents, which can be conveniently shaped through the use of random puncturing and unequal energy allocations across parallel coding streams. The design task is therefore to find the optimal combination of constituents, puncturing ratios, and energy allocation for matching the EXIT curves. A search over all rate-one convolutional codes of memory length four or less is performed, identifying 98 classes of codes with unique EXIT functions out of a total of 310 codes. Low-complexity MPCCs with up to four constituents are found, where the convergence thresholds are observed to be within 0.1 dB or less of the fundamental minimum signal-to-noise ratio (SNR) corresponding to the binary phase-shift keying (BPSK) capacity for code rates 1/3 ≤ R ≤ 7/8. Further allowing for unequal energy allocation, the convergence thresholds for lower code rates are similarly improved.