一种NG-DSL系统的低复杂度时频同步算法

Synchronization Algorithm about Time and Frequency with Low Complexity Based on NG-DSL System

下一代数字用户线(NG-DSL,Next Generation Digital Subscriber Line)技术使用高载波数与高正交振幅的OFDM调制方式,这对信号同步提出了更高的要求.提出了一种新的基于数据辅助型的符号定时算法——基于最小能量差的符号定时同步算法.该算法通过变步长搜索的方法,利用较少的步骤准确快速搜索到最小值,大大降低算法复杂度,最后对算法进行综合性能比较,仿真结果表明,新算法具有复杂度低,在NG-DSL环境下定时准确并且具有抗双绞线信道拖尾干扰能力强的特点,这些特点能够较好地满足NG-DSL对于符号定时同步算法的要求.

Next Generation Digital Subscriber Line(NG-DSL)technology uses high carrier number and high orthogonal amplitude OFDM modulation mode,which puts forward higher requirements for signal synchronization.A new symbol timing algorithm based on data-aided,that is a symbol timing synchronization algorithm based on minimum energy difference is proposed.The algorithm with variable step search method uses less steps to search the minimum accurately and quickly,which greatly reduces the complexity of the algorithm.Finally,the comprehensive performance of the algorithm is compared.The simulation results showed that the new algorithm has low complexity,accurate timing in NG-DSL environment and anti-twisted-pair channel tail interference performance.These characteristics can meet the requirements of NG-DSL for symbol timing synchronization algorithm.