OFDM软件接收机的符号精确同步

提出了一种可用于正交频分复用（OFDM）软件接收机的全数字化内插同步环路。基于前导字
进行粗同步估计，并采用数字控制振荡器（NCO）控制的环路对残留符号定时误差和采样频率偏差进行跟
踪补偿，以获得精确符号同步。环路设计采用双环结构分别对NCO相位和频率控制字进行跟踪，而误差提
取基于OFDM符号中的导频来实现。针对提出的算法结构进行了计算机仿真，结果证明该方法有效。

Fine symbol timing for OFDM soft receiver

A symbol timing loop for orthogonal frequency division multiplexing (OFDM) soft receiver was investigated and a digital interpolation timing loop for OFDM receiver was proposed. To achieve fine symbol timing, a loop controlled by numerical controlled oscillator (NCO) was used to track the residual timing error and the sampling frequency error after coarse timing acquisition based on a preamble. The phase (error) and the frequency error of the NCO were tracked by a twin-structure loop, and the errors were acquired by the pilots of OFDM symbols. According to the algorithm, simulation results prove that the loop is effective.