摘要
符号同步误差对LDPC译码性能会产生严重恶化,如何在低信噪比下,利用LDPC的编码增益来提高符号同步误差估计性能是本文的核心问题。基于最大似然(ML)准则,提出了似然函数导数归零的码辅助迭代符号同步算法,该算法以单一编码分组为单位进行迭代估计,不但可以应用于连续信道,同样适用于突发通信。仿真结果表明,本文提出算法的估计性能可以在信噪比很低的情况下逼近MCRB,在符号同步误差估计值快速收敛的同时,译码性能接近符号精确同步的理想情况。
The effects of symbol synchronization error on the LDPC decoding performance have been investigated. Then, A ML- Based iterative timing recovery algorithm is given,which seeks ask for proper symbol synchronization error to zero the derivative of the LLF. Simulation results show that the proposed method performs very close to the Cramer-Rao bound, and little performance degradation has been observed than the system with accurate symbol timing.
出处
《信号处理》
CSCD
北大核心
2008年第6期957-959,共3页
Journal of Signal Processing
基金
国家自然科学基金资助项目(60403043)
国防预研基金项目(51421010504JB3801)
