摘要
提出了一种改进的高效量化和积算法(sum productalgorithm,简称SPA).该算法只涉及加减法、比较和查表运算,并且每轮迭代译码的运算次数少于前/后向算法,从而大大降低了计算复杂度和硬件实现难度.同时,文中还基于这种改进的量化SPA,对采用不同量化方案时LDPC码在AWGN信道下的译码性能进行了仿真.仿真结果表明采用低阶均匀量化时译码性能已经非常接近连续译码.
An efficient implementation of the, Sum-Product algorithm (SPA) in the log-likelihood ratio (LLR) domain is presented in [1]. We modify a formula in [1] such that SPA can be implemented by using two small look-up tables. With this modification, all the calculations involved in this implementation involve only additions, subtractions, comparisons and table looking-ups, which leads to low computation complexity and facility in hardware implementation. Based on this modified implementation, various quantization schemes of SPA for decoding low-density parity-check (LDPC) codes are investigated. And the issues related to quantization, such as clipping levels and variables quantization, are also investigated. Simulation results show that the performance of the uniform quantization scheme is very close to that of the non-quantization over the AWGN channel. Moreover, it can obtain the same performance as that of non-quantization at high SNRs.
出处
《西安电子科技大学学报》
EI
CAS
CSCD
北大核心
2004年第5期709-713,735,共6页
Journal of Xidian University
基金
国家自然科学基金资助项目(60272057)
国家自然基金委
香港科技局联合资助项目(60131160742)
关键词
和积译码算法
迭代译码
前/后向算法
并行实现
低密度校验码
Algorithms
Computational complexity
Computer hardware
Computer simulation
Decoding
Iterative methods
Parallel processing systems
Signal to noise ratio
Table lookup