Abstract
In this paper, we propose the Turbo principle (of using parallel concatenated channel encoders by an interleaver and iterative soft-input and soft-output decoding between the constituent decoders)onto Polar and LDPC codes resulting in Turbo-Polar, Turbo-LDPC-Polar, and Turbo-LDPC schemes with the aim of enhancing the BLER performance while alsoreducing the decoding complexity. All the proposed turbocoded schemes are decoded using the traditional Belief Propagation (BP) algorithm based on low-density paritycheck iterative decoding through a factor graph. Monte Carlo simulation results confirm the superiority of TurboLDPC and Turbo-LDPC-Polar schemes in BLER performance over state-of-the-art cyclic redundancy check-aided successive cancellation List decoding (CASCL) of Polar Codes with a large list size of 32 for large block lengths (larger than 3072 bits) while having reduced computational decoding complexity in comparison to CASCL decoding in an additive white Gaussian noise (AWGN) channel. Furthermore, Turbo-LDPC (based on 5G New Radio specifications for LDPC code) outperforms the standalone 5G-NR LDPC code and achieves about 1dB gain at a BLER of − over correlated slow fadingRayleigh channel; however, being turbo-iterative in nature, it has higher complexity (about six-fold) than the standalone 5GNR LDPC code.