提出一种性能接近联合界的北斗B1I信号BCH码译码算法. 以北斗卫星导航系统B1I公开服务信号ICD为基础,分析导航电文的BCH(15,11)编码的纠错能力和联合界,针对ICD标准译码算法的编码增益低和译码失败门限高提出改进算法. 以Chase算法为基础提出一种新的BCH编码软判决译码算法,使用格雷码排序优化伴随式计算,证明最大相关性与最小欧氏距离的等价关系,优化算法在不损失编码增益的条件下复杂度降低50%. 仿真结果表明在误码率10-5时距离联合界仅0.01 dB,新算法可获得2.5 dB的编码增益,译码失败门限从4.4 dB下降到1.2 dB
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