中文摘要：

在基于现场可编程门阵列（field programmable gate array,FPGA）平台实现的实时光正交频分复用无源光网（optical orthogonal frequency division multiplexing-passive optical network,OOFDM-PON）系统中,由于实时全并行快速傅里叶变换/快速傅里叶反变换（fast Fourier transform/inverse fast Fourier transform,FFT/IFFT）模块计算复杂度高,成为实时OOFDM-PON系统设计的主要瓶颈之一.构建OOFDM-PON发送与接收仿真平台,通过联合优化OOFDM-PON发送端的IFFT与接收端FFT蝶形运算的旋转因子和输出字长来降低模块的系统逻辑资源占用率.采用基于缩短字长界限范围的方法来减少最优化字长的搜索时间,同时构建了实时OOFDM-PON系统的基于DIF-2的64点IFFT/FFT的字长优化映射表.该映射表在离线OOFDM-PON平台上的验证结果与仿真结果之间的误差控制在0.5 d B,验证了该优化算法的正确性.与Spiral设计方案相比,该设计的基于上述映射表的FFT模块可以节约大约37.2%的逻辑资源.

英文摘要：

High-speed parallel fast Fourier transform/inverse fast Fourier transform （FFT/ IFFT） module has become one of the most significant obstacle to practically developing real- time high-speed optic orthogonal frequency division multiplexing （OOFDM） system based on field programmable gate array （FPGA） platform due to its high complexity. This paper builds a simulation platform for OOFDM transceivers and realizes joint optimization of the IFFT and FFT module to reduce logic resource usage. The algorithm shortens word-length boundaries to reduce the time for searching optimized word-length and builds a mapping table of the optimal word-lengths. Error between simulation results and verification results on an of/line platform is within 0.5 dB indicating correctness of the proposed optimization algorithm. In addition, the FFT module based on the mapping table saves about 37.2% resource compared to the Spiral design.