一种降低复杂度的迭代载波同步算法  

A complexity-reduced iterative carrier synchronization algorithm

作　　者：沈海鸥[1] 王永民[1] 许华[1] 韩博[1] 李鹏[1] 

机构地区：[1]空军工程大学信息与导航学院,西安710077

出　　处：《中国科学院大学学报（中英文）》2013年第5期694-698,共5页Journal of University of Chinese Academy of Sciences

基　　金：国家自然科学基金(61001111);国防科技点实验室基金(9140C13030111DZ4604)资助

摘　　要：针对低信噪比环境下编码辅助载波同步算法存在复杂度高和实时性差的问题,本工作引入估计积分器不断补偿信号向量、减小待估偏移值.在此基础上,提出新的同步迭代停止准则;当LDPC码的各变量节点的对数似然比绝对值的均值趋于稳定时,提前停止迭代.仿真结果表明,该算法在缩小频率搜索范围的同时,大大减少同步迭代次数,且与理想同步译码相比,性能损失不超过0.12 dB.We consider high complexity and long delay of the code-aided carrier synchronization algorithm at low SNR（signal to noise ratio）.We use the estimation integrator for compensating signal vector and decreasing offset to be estimated.A new iterative synchronization stopping rule is proposed.The system will stop iteration if the mean of the absolute values of LLR（log-likelihood ratio） message at the output of LDPC decoder keeps steady.The simulation results indicate that this algorithm narrows the frequency search range and the average number of iterations is reduced greatly.It also shows that the performance loss is not larger then 0.12 dB.

关 键 词：低信噪比 编码辅助 载波同步 频率搜索 迭代停止 

分 类 号：TN911[电子电信—通信与信息系统]