【作者】 朱建锋； 安建平； 王爱华；

【Author】 Zhu Jianfeng, An Jianping, Wang Aihua Research Institute of Communication Technology, Beijing Institute of Technology, Beijing, 100081, China

【机构】 北京理工大学通信技术研究所；

【摘要】 研究用于卫星导航电文中BCH编码的低复杂度软判决译码算法。卫星导航接收机通常使用硬判决译码处理BCH编码,硬判决译码可提供1dB的编码增益并易于实现,然而硬判决译码中存在一个很高的译码失败门限导致误码率增加。基于Chase算法提出了一种新的BCH编码软判决译码算法,基于格雷码排序优化了伴随式计算,提出采用相关值度量替代最大似然译码中的欧氏距离,在不损失编码增益的条件下将软判决译码的复杂度降低了50%。以BCH(15,11)编码为例进行了仿真验证,仿真结果表明在误码率10-5时优化算法具有2.5dB的编码增益,译码失败门限从4.4dB下降到1.2dB。更多还原

【Abstract】 Low complexity soft-decision decoding algorithm is investigated for BCH codes of satellite navigation message. Hard-decision decoding is a usually used algorithm in satellite navigation receivers. Hard-decision decoding could provide 1dB coding gain and it is easy to implement. However there is a very high decoding failure threshold in hard-decision decoding that would lead to increasing of BER. A new soft-decision decoding algorithm for BCH codes is proposed based on Chase algorithm. The computing of syndromes is optimized based on Gray code ordering. The correlation function merit is advised to replace the Euclidean distance in maximum like decoding. The complexity of optimized soft-decision decoding algorithm reduces 50% without coding gain lost. The simulation results of BCH (15, 11) codes show that the soft-decision decoding algorithm provides 2.5dB coding gain at BER=10-5 . And the decoding failure threshold decreases from 4.4dB to 1.2dB.更多还原