易于硬件实现的OFDM系统采样频率同步算法

分析了正交频分复用（OFDM）系统中采样频率偏移对系统性能的影响,提出了一种在频域进行估计和校正的采样频率同步算法.该算法易于硬件实现,与采用最小二乘法（LS）的估计算法相比可以减少20%的硬件资源,提高1倍的工作速度.根据IEEE 802.11a无线局域网（WLAN）标准进行了算法仿真和现场可编程门阵列（FPGA）上的硬件实现研究.仿真结果表明,无论是在高斯白噪声（AWGN）信道还是多径信道下,该算法均可以有效地对采样频率偏移进行校正,使系统性能符合标准要求.通过在FPGA上的硬件实现以及使用Xilinx的Chip scope Pro进行的在线实时验证表明,该算法可以在占用较少硬件资源的条件下,实时、连续地对信号进行处理,可以作为一个完整OFDM基带处理器的子模块.

Easy-hardware-implementation algorithm of sampling frequency synchronization in OFDM systems

After analyzing the impacts of sampling frequency offset on the performance of orthogonal frequency division multiplexing(OFDM) systems,a new sampling frequency synchronization algorithm in frequency domain was proposed and its mathematical analysis was presented.This algorithm was optimized to be easy for hardware implementation,and obtained 20% reduction in logic gates and double speed than the algorithm using least square(LS) method.Matlab simulations were conducted on an 802.11a system platform.Simulation showed that this algorithm worked effectively and fulfilled the standard requirements in both the additive white Gaussian noise(AWGN) channel and the multi-patch channel.The algorithm was successfully implemented on an 802.11a field programmable gate array(FPGA) platform.On-chip real-time analysis of the algorithm using Xilinx Chipscope Pro demonstrate that this algorithm can work efficiently and effectively as ablock of an OFDM baseband receiver processor.