An article about Quadrature Amplitude Modulation (QAM), a Radio signal modulation method related to AM/Medium Frequency that enables Personal Computers, and Devices such as Smart Cellular Telephones and Tablets to compress vast amounts of digital information onto an Analog Radio Frequency carrier capable of transmitting this information wirelessly; without consuming more bandwidth in the modulation process.

A Microsoft Power Point Presentation and Slideshow that was created by a firm in The Netherlands explaining Quadrature Amplitude Modulation: