IRA码简化译码算法的研究

不规则重复累计码BP译码算法具有接近Shannon限优越性能,但具有较高的复杂度。为了降低复杂度,提出了IRA码最小和算法和曲线折线化算法。最小和算法具有简单、容易实现的特点,但使译码性能较大幅度地降低。曲线折线化算法使循环译码算法在复杂度和性能之间取得了较好的折衷。仿真结果表明,曲线折线化算法在复杂度大幅度降低的情况下性能接近BP算法。

Reduced Complexity Decoding Algorithms for Irregular Repeat Accumulate Codes

Irregular repeat-accumulate (IRA) codes have a good performance near Shannon limits under BP decoding algorithm. However, BP algorithm has high complicated operations. To reduced complexity of decoding algorithms, two algorithms namely the sum-min algorithms and piecewise linear approximation algorithms, are proposed. Minimum sum algorithm is very simple and is easy for hardware implementation. But the decoding performance is degraded. Piecewise linear approximation algorithm is a good tradeoff between decoding performance and complexities. Simulation results show that with complexity greatly reduced, piecewise linear approximation algorithm achieve a performance very close to that of the BP algorithm.