Adaptive Iterative Decoding of Finite-Length Differentially Encoded LDPC Coded Systems with Multiple-Symbol Differential Detection
Adaptive Iterative Decoding of Finite-Length Differentially Encoded LDPC Coded Systems with Multiple-Symbol Differential Detection
复制标题
DOI：
10.1587/transcom.e96.b.847
复制
发表时间：
2013-03
期刊：
影响因子：
--
通讯作者：
Yang Yu;S. Handa;F. Sasamori;O. Takyu
中科院分区：
文献类型：
--
作者：
Yang Yu;S. Handa;F. Sasamori;O. Takyu
本文通过外在信息传输（EXIT）带图分析，提出了一种自适应迭代解码方法（AIDA），以降低具有多符号差分检测（MSDD）的有限长度差分编码低密度奇偶校验（DE-LDPC）编码系统的迭代解码复杂度和延迟。所提出的AIDA可以自适应地调整MSDD软输入软输出解调器（SISOD）的观察窗口大小（OWS）和迭代解码器（由MSDD SISOD和LDPC解码器组成）的外迭代次数，而不是为所考虑系统的两个参数设置固定值。 AIDA的性能取决于其停止准则（SC），该准则用于在达到最大外迭代次数之前终止迭代解码。已经提出了许多 SC；然而，这些方法主要针对 Turbo 编码系统，并且已被证明它们不太适合 LDPC 编码系统。为了解决这个问题，提出了一种新的SC，称为差分互信息（DMI）准则，可以跟踪迭代解码的收敛状态；它基于跟踪所考虑系统的两个连续外部迭代之间 LDPC 解码器的输出互信息的差异。使用DMI准则的AIDA可以根据迭代解码的收敛情况自适应地调整迭代次数和OWS。仿真结果表明，与使用现有的SC相比，使用DMI准则的AIDA可以进一步降低译码复杂度和延迟，并且其性能不受LDPC码和传输信道参数变化的影响。关键词: 自适应迭代译码, 低密度奇偶校验(LDPC)码, 差分编码LDPC编码系统, 多符号差分检测, 外在信息传输(EXIT)能带图
In this paper, through extrinsic information transfer (EXIT) band chart analysis, an adaptive iterative decoding approach (AIDA) is proposed to reduce the iterative decoding complexity and delay for finite-length differentially encoded Low-density parity-check (DE-LDPC) coded systems with multiple-symbol differential detection (MSDD). The proposed AIDA can adaptively adjust the observation window size (OWS) of the MSDD soft-input soft-output demodulator (SISOD) and the outer iteration number of the iterative decoder (consisting of the MSDD SISOD and the LDPC decoder) instead of setting fixed values for the two parameters of the considered systems. The performance of AIDA depends on its stopping criterion (SC) which is used to terminate the iterative decoding before reaching the maximum outer iteration number. Many SCs have been proposed; however, these approaches focus on turbo coded systems, and it has been proven that they do not well suit for LDPC coded systems. To solve this problem, a new SC called differential mutual information (DMI) criterion, which can track the convergence status of the iterative decoding, is proposed; it is based on tracking the difference of the output mutual information of the LDPC decoder between two consecutive outer iterations of the considered systems. AIDA using the DMI criterion can adaptively adjust the out iteration number and OWS according to the convergence situation of the iterative decoding. Simulation results show that compared with using the existing SCs, AIDA using the DMI criterion can further reduce the decoding complexity and delay, and its performance is not affected by a change in the LDPC code and transmission channel parameters. key words: adaptive iterative decoding, low-density parity-check (LDPC) codes, differential encoded LDPC coded systems, multiple-symbol differential detection, extrinsic information transfer (EXIT) band chart