ESTIMATING AND INTERPRETING THE INSTANTANEOUS FREQUENCY OF A SIGNAL .1. FUNDAMENTALS
ESTIMATING AND INTERPRETING THE INSTANTANEOUS FREQUENCY OF A SIGNAL .1. FUNDAMENTALS
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DOI：
10.1109/5.135376
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发表时间：
1992-04-01
影响因子：
20.6
通讯作者：
BOASHASH, B
中科院分区：
文献类型：
--
作者：
BOASHASH, B
正弦信号的频率是明确定义的数量。但是，在实践中通常，信号不是真正的正弦，甚至是正弦分量的骨料。特别是非平稳信号并不能很好地将分解为正弦分量。对于此类信号，频率的概念失去了其有效性，并且需要使用一个参数来说明该过程的随时间变化。这种需求引起了瞬时频率的想法。信号的瞬时频率（如果）是一个通常具有重要实际重要性的参数。在许多情况下，例如地震，雷达，声纳，通信和生物医学应用，IF是某些物理现象的良好描述符。本文讨论了瞬时频率的概念，其定义，以及为各种数学模型之间的对应关系if的表示。本文还考虑了IF与我们对现实的直观期望相对应的程度。对定义IF的连续尝试的历史回顾，然后IF与群组 - 列表之间的关系，分析信号和带宽时间之间的关系（BT）探索产品，以及与时频分布的关系。最后，讨论了单一分量和多组分信号的概念以及瞬时带宽。结果表明，所有这些概念在提出的理论的背景下得到很好的描述。
The frequency of a sinusoidal signal is a well defined quantity. However, often in practice, signals are not truly sinusoidal, or even aggregates of sinusoidal components. Nonstationary signals in particular do not lend themselves well to decomposition into sinusoidal components. For such signals, the notion of frequency loses its effectiveness, and one needs to use a parameter which accounts for the time-varying nature of the process. This need has given rise to the idea of instantaneous frequency.The instantaneous frequency (IF) of a signal is a parameter which is often of significant practical importance. In many situations such as seismic, radar, sonar, communications, and biomedical applications, the IF is a good descriptor of some physical phenomenon.This paper discusses the concept of instantaneous frequency, its definitions, and the correspondence between the various mathematical models formulated for representation of IF. The paper also considers the extent to which the IF corresponds to our intuitive expectation of reality.A historical review of the successive attempts to define the IF is presented Then the relationships between the IF and the group-delay, analytic signal, and bandwidth-time (BT) product are explored, as well as the relationship with time-frequency distributions. Finally, the notions of monocomponent and multicomponent signals, and instantaneous bandwidth are discussed. It is shown that all these notions are well described in the context of the theory presented.