【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。更多还原

【Abstract】 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.更多还原