pulse amplitude modulation

The modulating signal is sampled at the basic rate, usually where f m is the maximum value. The amplitude of the modulation determines the amplitude of the transmitted pulse. The band-width will be great for exact pulse waveform, but m..

In amplitude modulation and frequency modulation, the modulation was done by sinusoidal signals. In pulse modulation, short pulses may do the modulation of a radio-frequency carrier. The simplest of these is the convent..

It is also referred to as pulse-width modulation. It varies the pulse length or duration around a fixed value. This may be done by shifting either the leading or trailing edge, or both, as a function of the sampled amplitude. Greater channel band width is re..

It translates the sampled amplitude data into a code. The code is transmitted as a succession of pulses and spaces. The system enjoys greater freedom from noise and interfering signals than is possible with most other pulse systems. This freedom arises from the fact t..

When the amplitude of high frequency carrier wave is changed in accordance with the intensity of the signal, it is called amplitude modulation. In amplitude modulation, only the amplitude of the carrier wave is changed in accordance with t..

In this type if modulation, w c and q are kept constant. The amplitude E c of the carrier wave is varied in accordance with the modulating wav..

In amplitude modulation, the sidebands contain the signal. The power in the sidebands is the only useful power. The power carrier by the side bands is only 33.3% even when there is 100% modulation. If modulation is 50%, then power carried by the sideban..

The amplitude-modulated band (AM band) contains the radio waves having frequency of less than 30 MHz or having wavelength of 10 m or more. The lower atmosphere is more or less transparent to radio waves. However, the ionosphere reflects back the radio waves. Thus, a signal emitted by an ..

Let us consider the case of electromagnetic radiation in an ionised medium. Suppose we increase/decrease the amplitude of an electromagnetic wave passing through an ionised gas. These modulations of the electromagnetic wave could contain coded information (Morse code for exampl..

The ratio of change of amplitude of carrier wave to the amplitude of normal carrier wave is called the modulation factor ..