In all such cases the term " modulation index " loses its value as it refers to the ratio of the modulation amplitude to a rather small ( or zero ) remaining carrier amplitude.
12.
The high-frequency signal components are emphasized to produce a more equal modulation index for the transmitted frequency spectrum, and therefore a better signal-to-noise ratio for the entire frequency range.
13.
Thus double-sideband transmission is generally " not " referred to as " AM " even though it generates an identical RF waveform as standard AM as long as the modulation index is below 100 %.
14.
However, sleep deprivation does not affect the attention modulation index of the PPA . With this information, researchers have concluded that the psychophysiological interaction ( PPI ) is more involved in selective attention than the IPS and PPA.
15.
With a tone-modulated FM wave, if the modulation frequency is held constant and the modulation index is increased, the ( non-negligible ) bandwidth of the FM signal increases but the spacing between spectra remains the same; some spectral components decrease in strength as others increase.
16.
When the AC output is at frequency fc with its amplitude at v c, and the triangular carrier signal is at frequency f ? with its amplitude at v ?, the PWM becomes a special sinusoidal case of the carrier based PWM . This case is dubbed sinusoidal pulse-width modulation ( SPWM ) . For this, the modulation index, or amplitude-modulation ratio, is defined as "'v c / v " } } " '.
