摘要
研究了高阶调制系统中的码辅助定时同步和载波恢复的码辅助同步算法,提出一种改进的定时同步算法。该算法首先估计出每组数据的加权值,然后根据估计的结果将软信息进行合并,合并的数据根据设定的门限,将符合要求的数据块乘以权值后再进行合并。同时提出了改进的极性判决相位检测算法,该算法将译码器的输出信息重新调制,然后进行极性判决,将判决结果反馈到PD模块进行相位误差的提取。仿真结果表明,改进后的码辅助定时同步和载波同步算法在低信噪比下比未改进算法的性能提升2 dB。
In this paper, an improved timing method is proposed for high-order QAM system. The timing processing block computes the value of weights for each data block and then combines the soft information based on the estimated results. In addition, an improved polarity decision phase detector algorithm is proposed for the carrier recovery, the soft information fed back from the decoder is modulated and then sent to the polarity module for polarity decision. The polarity decision result is fed to the phase detector （PD） module for the phase estimation. Simulation results show that the improved code-aided timing and carrier synchronization system can perform better than the unimproved algorithm at very low SNR.
出处
《电子科技大学学报》
EI
CAS
CSCD
北大核心
2011年第6期825-828,共4页
Journal of University of Electronic Science and Technology of China
基金
国家自然科学基金(6101092
61032003)
