Zoom-FFT的改进、频谱反演与时-频局部化特性

回顾了经典连续分段序列Zoom-FFT方法.定义了时间分段序列的占空比 R _ms.分析了在实际应用中对 R _ms＜1的时间分段序列的Zoom-FFT处理的需求并建立了处理这种序列的新方法.提出并证明了 R _ms为任意值的Zoom-FFT频谱反演回实际频谱的理论公式和修正公式.给出了对跳频信号进行 R _ms=1的Zoom-FFT处理和对话带信号进行 R _ms＜1的Zoom-FFT处理并反演回实际频谱的例子.证明Zoom-FFT方法对解决信号快速搜索和粗分析与信号细节分析的矛盾有实用价值,间断分段序列的Zoom-FFT进一步提高了分析效率.最后讨论了Zoom-FFT具有类似于小波变换的时-频局部化特性问题.

Improvement and Spectrum Inversion for Zoom-FFT and It's Time-Frequency Localization Functions

The classic Zoom-FFT,which is for continues sections of signal sequence,is reviewed.A novel method for Zoom-FFT,which is used for disconnected sections of signal sequence noted as R_ ms <1,is offered.The algorithm and the computing cost of it are discussed.A formula for the spectrum inversion form a Zoom-FFT spectrum under onto the practical spectrum from which the former is imaged is established and proved.Examples of application of Zoom-FFT for hopping-frequency signals in HF band and inversion of the Zoom-FFT spectrum of disconnected sections of six-tone signals in voice band are offered.The new Zoom-FFT method will be useful for resolving the contradiction between quickly searching for signals and precisely analyzing signals in practical engineering.The time-frequency localization function of Zoom-FFT,similar to that of wavelet analysis,is stated and analyzed.