Abstract: After the derivation of Cramer-Rao Bound (CRB) for amplitude estimation in AWGN channel, a decision directed feedback amplitude estimation algorithm for BPSK/QPSK signal is proposed, followed by its performance analysis and simulation. The simulation results show that the variance of the algorithm is very close to the CRBat high signal-to-noise ratio in decision directed feedback mode.

Key words: CRB, parameter estimation, decision-directed feedback

摘要： 推导了理想高斯信道下信号幅度估计的克拉美-罗界（CRB），提出了一种基于直接判决反馈的BPSK/QPSK信号幅度估计算法，并对该算法的性能进行了理论分析和仿真。仿真结果表明，在直接判决反馈模式下，该算法的估计方差在高信噪比下接近克拉美罗界。

关键词: 克拉美-罗界, 参数估计, 直接判决反馈