Irregular Pattern Design to Improve Error Floor for 3D-Turbo Codes

In 3D-Turbo codes, part of parity bits from conventional Turbo encoder are encoded again by a post-encoder to reduce the number of low-weight codes and achieve better error floor performance. Considering the residual low-weight codes in 3D-Turbo codes, an irregular pattern design is proposed to further improve the error floor. All-zero iterative decoding algorithm is firstly utilized to identify the distribution of “1” in low-weight codes. Then an irregular pattern is optimized based on the distribution to eliminate low-weight codes. Finally, taking a practical 3D-Turbo codes, we adopt the proposed irregular pattern to increase the minimum Hamming distance from 18 to 20, which validates the effectiveness of our contribution.