Quadrature Amplitude Modulation (QAM) is a modulation technique widely used in telecommunications to transmit data by varying the amplitude of two carrier waves, which are 90 degrees out of phase with each other. This method enables the encoding of multiple bits per symbol, thereby increasing the data transmission rate without requiring additional bandwidth.
In QAM, each symbol represents a unique combination of amplitude levels for the two carriers, effectively creating a constellation of points. The number of points in this constellation determines the modulation order, such as 16-QAM or 64-QAM, indicating the number of distinct symbols and, consequently, the number of bits transmitted per symbol. Higher-order QAM schemes can transmit more bits per symbol, leading to higher data rates. However, they also require a higher signal-to-noise ratio (SNR) to maintain reliable communication, as the symbols are closer together in the signal space, making them more susceptible to noise and interference
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