基于FPGA的FFT算法优化及其在磁共振谱仪中的应用

摘要

A FPGA-based design approach of NMR spectrometer signal gain and phase skewing calibration is presented, which depends on spectrum analyzer of the NMR dual-channel. The design and realization methods of the FFT algorithm with FPGA is expounded in particular. The FFT processor in the module is implemented based on multiplexing of 64-point parallel modules. The complex multiplication is completed by shifters and adders. As a result the portability and the power dissipation are improved. The noise imported by effective word length effect is reduced effectively by optimized measure. The results show that the design greatly improved both accuracy of signal detection and ease of use.%提出了一种基于FPGA的依据核磁共振谱仪双通道频谱图对其信号增益和相位差不平衡进行调节的设计方案,详细阐述了FFT算法在FPGA中的设计与实现方法.该模块中的FFT处理器通过多个64点并行FFT模块复用实现,复数乘法全部采用移位相加来完成,大大降低了功耗,可移植性很强；并通过优化措施有效地降低了由于有限字长效应引入的噪声.结果表明,该设计大大提高了谱仪信号检测的准确性与使用的方便性.