摘要
全数字接收机是在最近几年内提出的一个新的概念,它要求解调用的本地参考载波和采样时钟都振荡于固定的频率,不需要进行反馈控制,其他一些工作:载波相位误差和时钟定时误差的消除、信号的判定等全部由采样后的数字信号处理器完成。载波相位恢复问题和时钟同步问题是目前关于全数字接收机研究中的两个最主要的问题。本文仅讨论载波相位恢复问题。在本文中研究了载波相位估计算法中估计e^(jθ)和估计θ的差异,从理论上证明了估计e^(jθ)比估计θ有更好的统计特性,并且给出了一种估计e^(jθ)的方法,此方法有二个突出的优点:(1)它可以消除载波相位恢复过程中的相位区间跳变。(2)相位估计器的结构简单,它是全线性的,易于实现。利用16-QAM信号进行计算机仿真证实了此算法的可行性。
All digital receiver is a new concept proposed in recent years. It needs that a local reference carrier used to demodulation (mixing osicillator) and the A/D converter sampling clock run at fixed fre-quencys and do not require feedback control of signals. It is also needed to carry out some other works such as the elimination of carrier phase difference and clock synchronization error, the detection of signals etc. In the subsequent digital signal processing part. The carrier phase recovery and clock synchronization are two main problems for the all digital receivers. In this paper, the problem of carrier phase recovery is considered. It has discussed the difference between estimation of eiθ and estimation of θ about algorithms of carrier phase recovery and the theoretical analysis is given. The result of theoretical analysis has shown that estimation of eiθ has much better performance than estimation of θ in statistics. A new method to estimate eiθ is proposed. The new method gains two advantages: (1) The phase interval jump doss not exist. (2) The phase estimator has a simple and fully linear structure which is easy to be implemented. The results of computer simulation for 16-QAM signal are also reported which shows the new method is feasible.
出处
《通信学报》
EI
CSCD
北大核心
1992年第6期30-37,共8页
Journal on Communications
