Symbol-by-symbol maximum a posteriori (MAP) decoding algorithms for nonbinary block and convolutional codes over an extension field GF(p/sup a/) are presented. Equivalent MAP decoding rules employing the dual code are given which are computationally more efficient for high-rate codes. It is shown that these algorithms meet all requirements needed for iterative decoding as the output of the decoder can be split into three independent estimates: soft channel value, a priori term and extrinsic value. The discussed algorithms are then applied to a parallel concatenated coding scheme with nonbinary component codes in conjunction with orthogonal signaling.
展开▼
机译：提出了扩展字段GF（p / sup a /）上非二进制块和卷积码的逐个符号最大后验（MAP）解码算法。给出了使用双码的等效MAP解码规则，这些规则在计算上对于高速率码更有效。结果表明，这些算法满足了迭代解码所需的所有要求，因为解码器的输出可以分为三个独立的估计：软通道值，先验项和外在值。然后，将所讨论的算法应用于具有非二进制分量码并结合正交信令的并行级联编码方案。
展开▼
