In the field of digital signal processing, as the signals being processed have limited length and are discreted in time-domain and frequency-domain, when being processed by FFT, the result will generate fan-shaped decline. In order to improve the performance, various of methods are researched. Based on Matlab instruments, the mathematical model used in the signal frequency discriminating by FFT is set up. Based on improving the points of the FFT processing and adding windowing function to the signal being processed, the algorithms being used to improve the fan-shaped decline are established. Through theoretical a-nalysis and Matlab simulation, the performance of FFT improved by the two methods in various of quotas is received, together with their corresponding advantages and disadvantages. Finally, in the implementation, considering both performance and resource factors, appropriate method can be selected.%在数字信号处理中,由于被处理信号记录长度有限且在时域和频域中离散,对该信号作FFT处理时,FFT结果会产生扇形衰落.为提高FFT运算性能,对各种改善扇形衰落的方法进行了研究.基于Matlab工具,建立了通过FFT对信号鉴频的数学模型；基于增加FFT处理点数和对被处理信号加窗函数,建立了改善扇形衰落算法.通过理论分析及Matlab仿真验证,得到两种方法在各项指标条件下对FFT性能的改善情况,并分析了各自对应的优缺点.在硬件实现中,综合考虑性能和资源两方面因素,给出在不同应用领域选择合适方法的依据.
展开▼
