QAM is used to achieve greater spectrum efficiency. This is accomplished by utilizing both the amplitude and phase components to modulate, or alter, the waveform. In this scenario, the QAM waveform ...

Varying the voltage of a carrier or a direct current in order to transmit analog or digital data. Amplitude modulation (AM) is the oldest method of transmitting human voice electronically. In an ...

classic case: where the carrier is a sine wave at some frequency many times higher than the frequency of the modulating signal, which is also a sine wave. Figure 7-3 illustrates the frequency spectrum ...

Modulation is the process of converting data into radio waves by adding information to an electronic or optical carrier signal. A carrier signal is one with a steady waveform (a constant amplitude and ...

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