【摘要】 提出一种基于中国数字电视标准DTMB(Digital Terrestrial/Television Multimedia Broadcasting)的时域定时恢复方案.该方案采用全数字延迟锁定环来跟踪定时误差,与传统的时域鉴相器相比,本文提出的鉴相算法能实现增益的自动归一化,且捕获范围为原算法的三倍,能纠正采样频率偏差达到±90ppm.此外本方案能实现环路带宽的自动调整,以兼顾较快的收敛速度和较小的抖动.本文最后给出了此方案的性能仿真及VLSI实现结果.更多还原

【Abstract】 Proposed a symbol timing recovery(STR)scheme for DTMB(Digital Terrestrial/Television Multimedia Broadcasting)receivers,which is implemented by an all digital DLL(Delay Locked Loop)in time domain.Compared with original time domain phase detector,the improved one is self-normalized and bears sampling frequency offset up to ±90ppm,three times as much as the former method.Besides,automatic adjustment for loop bandwidth is achieved to provide good performance in both convergence speed and loop jitter.At the end of this paper,results of Matlab simulation as well as its VLSI implementation are presented.更多还原