基于变量节点更新的梯度下降比特翻转译码算法

由于变量节点自身的可靠性度量值不会随着迭代译码过程中比特被翻转而更新,因此翻转函数值的计算并不准确,进而影响了梯度下降比特翻转算法的译码性能。在深入分析梯度下降比特翻转译码算法的基础上,提出了一种基于变量节点更新的加权梯度下降比特翻转译码算法。该算法为翻转函数引入了校验节点的可靠度外信息权重和变量节点可靠性的更新规则,从而使翻转函数值的计算更加精确。仿真结果表明,与现有的梯度下降译码算法相比,在加性高斯白噪声信道下,该算法有效提升了误码率性能。

Gradient Descent Bit-flipping Decoding Algorithm Based on Updating of Variable Nodes

The reliability metric of the variable node does not change with flipping the bits during the process of iterative decoding,so the calculation of flipping-function is not accurate,which affects the decoding performance of gradient descent bit-flipping(GDBF) algorithm.Based on the analysis of gradient descent bit-flipping decoding algorithm,a weighted GDBF algorithm was proposed based on updating of variable nodes.This algorithm introduces extrinsic reliability information weights of the check nodes and update rules of the variable nodes for flipping-function,which makes the calculation of flipping-function more accurate.Simulation results show that the BER performance of the proposed algorithm is better than that of the gradient descent bit-flipping decoding algorithm over the additive white Gaussian noise channel.