中文说明：
一项半盲技术，用于估计OFDM通信系统中的载波频偏。这种方法利用信道矩阵与信号子空间之间的相关性对其进行优化以提高估计值精度。利用第一个OFDM符号中的若干空子载波，在一帧中推算分数和整数频率的偏移量。利用子信道矩阵对各个子块进行分块处理，从而实现对所有子载波的快速精确估计。传统的空子载波估计方法采用全局搜索来推算偏移量，然而该方法运用了双层估计策略，从而显著降低了计算复杂度。
English Description：
A semi-blind technique for estimating carrier frequency bias in OFDM communication systems. This method optimizes the correlation between channel matrix and signal subspace to improve the estimation accuracy. The offsets of fractions and integer frequencies are calculated in a frame using several empty subcarriers in the first OFDM symbol. Each subblock is segmented by using the subchannel matrix to obtain a fast and accurate estimation of all subcarriers. The traditional method uses global search to estimate offsets, but it uses a two-tier estimation strategy to reduce the computational complexity.