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 ...

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 ...

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 ...

In optical networking, generating the modulated signal by varying the current that creates the laser emission. Direct modulation is used for transmission speeds up to 2.5 GHz or higher speeds for ...