OFDM 定时同步设计与FPGA实现

提出了一种基于滑动窗能量检测来实现OFDM定时同步的算法，并阐述基于FPGA实现的过程。为了避免符号之间的干扰（ISI），通常在信号的起始位置添加保护间隔。该算法利用保护间隔信号能量最小的特点来寻找符号定时同步点。该算法分为粗同步和细同步，通过改变滑动窗的长度，两次寻求滑动窗内信号能量最小值，来确定最佳的符号定时起点。仿真结果表明，该算法具有良好的估计精度。同时给出该算法面向硬件平台的实现方案，具有复杂度低、便于工程实现的特点。

Design and FPGA Based Implementation of OFDM Timing Synchronization

In this paper, an OFDM symbol synchronization algorithm based on the sliding window energy detection is presented, and its implementation on FPGA is also given. In order to avoid the inter-signal interference, a guard interval is added at the beginning of each frame. This algorithm makes use of the characteristic that the signal energy in guard interval is minimal to find symbol timing position. There are two steps in the algorithm, i.e. the rough synchronization and the accurate synchronization. By changing the length of the sliding window and finding the minimum value of the symbol energy inside the sliding window two times, the optimal synchronization position is found. Simulation results show that the algorithm has high estimation accuracy. Finally, the realization of the algorithm on the hardware platform is given, which has low complexity and is easy to implement.