摘要
受数字信号处理器件处理速度的制约,宽带数字中频处理带宽、滤波器性能等重要指标难以提高。硬件实现时FPGA(field programmable gate array)无法提供与采样率相匹配的数据处理速度直接对原始采样数据下变频,将多相结构应用到传统的数字下变频运算中。推导了应用于数字下变频多相结构的多路NCO(numerically controlled oscillator)数字本振信号数学表达式,并讨论了在FPGA中实现多路NCO时相关参数的选取原则。MATLAB仿真结果及硬件平台验证了采用多路NCO本振信号实现数字下变频的正确性。
Inter mediate frequency（IF） processing bandwidth and filter performance of wideband digital IF processing are restricted by the processing speed of digital signal processing device.Field programmable gate array（FPGA） can not provide the data processing speed that matches the sampling rate to perform DDC to original sampling data directly,so polyphase structure is applied to the traditional digital down conversion（DDC） structure.The mathematics expressions of numerically controlled oscillator（NCO） digital local oscillator applied to polyphase structure of DDC are deduced,and the selection principles of the correlated parameters are discussed for the realization in FPGA.The simulation results of MATLAB and experimental platform show the correctness of the NCO digital local oscillator.
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2012年第5期998-1004,共7页
Chinese Journal of Scientific Instrument
基金
国家自然科学基金(60827001)资助项目
关键词
数字下变频
多相结构
NCO实现
多相参数选取
digital down conversion（DDC）
polyphase structure
numerically controlled oscillator（NCO） realization
polyphase parameter selection
