LDPC编码系统符号同步技术  

Timing error recovery for LDPC-coded systems

作　　者：薛英健[1] 吴晓富[1] 项海格[1] 

机构地区：[1]北京大学信息科学技术学院,北京100871

出　　处：《通信学报》2005年第3期130-135,共6页Journal on Communications

基　　金：国家自然科学基金资助项目(60302006;60402026);武器装备预研基金资助项目(51421060203JW0205)

摘　　要：根据低密度校验码(LDPC)译码算法的统计特性,分析了接收端符号同步误差对译码性能的影响。针对 LDPC 编码系统的特点提出了一种新的符号同步误差校正算法,该算法通过 4 倍过采样技术判断同步误差的大小,并通过插值方式对精确同步采样点的信号进行估计。对于信噪比极低的通信系统,当存在较大符号同步误差时,该算法可以保证 LDPC 编码系统的性能接近精确同步情况下的性能。Based on the statistical properties of LDPC decoding algorithm, the effect of the symbol synchronization error on the decoding performance was investigated in detail. A new timing error recovery algorithm was developed based on the algorithm in [3]. The new algorithm estimated the timing error with four times of over-sampling rate, and the estimated value of the signal with precise timing was given by interpolation of the over-sampled data. With the proposed algorithm, little performance degradation has been observed for LDPC coded system with severe symbol timing error when working at very low SNR.

关 键 词：低密度校验码 符号同步 高斯近似 

分 类 号：TN911.22[电子电信—通信与信息系统]