What does QAM stand for in wireless communication?

QAM stands for Quadrature Amplitude Modulation, which is a widely used modulation technique in wireless communication. This technique combines two key methods of modulation: amplitude modulation and phase modulation. The "quadrature" aspect refers to the use of two signals that are out of phase by 90 degrees (hence, "quadrature"). By varying the amplitude of both signals, it is possible to encode more information than with either method alone.

In practical applications, QAM can increase the data rate of communication systems by allowing for the transmission of multiple bits of information per symbol. For example, 16-QAM transmits four bits per symbol by utilizing 16 different combinations of amplitude and phase, making it a valuable tool in modern digital communication systems, including Wi-Fi, DSL, and digital television.

The other options do not represent established terminology or techniques within wireless communication, which is why they do not accurately define QAM. Quadratic Amplitude Modulation, Quality Asynchronous Modulation, and Quantum Amplitude Modulation are not recognized forms of modulation used in this field.