On modulation theory and FM spike noise

Problems related to the FM spike noise indicate that it is not possible to determine the frequency and phase of a noisy signal in a satisfactory manner. An investigation is, therefore, conducted regarding the definition of the phase of the signal. This definition is closely related to the definition of the signal envelope. The investigation leads to the definition of new concepts which are called synchronous phases and envelopes. The new terms are employed to obtain an exact explanation of the FM spike noise. It is found that FM spikes are basically a deterministic phenomenon. FM spike noise represents a statistically distributed random occurrence of deterministic FM spikes.