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qammod

Quadrature amplitude modulation

Syntax

y = qammod(x,M)
y = qammod(x,M,ini_phase)
y = qammod(x,M,ini_phase,symbol_order)

Description

y = qammod(x,M) outputs the complex envelope y of the modulation of the message signal x using quadrature amplitude modulation. M is the alphabet size and must be an integer power of 2. The message signal must consist of integers between 0 and M-1. The signal constellation is rectangular or cross-shaped, and the nearest pair of points in the constellation is separated by 2. If x is a matrix with multiple rows, the function processes the columns independently.

y = qammod(x,M,ini_phase) specifies the initial phase of the modulated signal in radians.

y = qammod(x,M,ini_phase,symbol_order) specifies how the function assigns binary words to corresponding integers. If symbol_order is set to 'bin' (default), the function uses a natural binary-coded ordering. If symbol_order is set to 'gray', it uses a Gray constellation ordering.

Examples

Examples using this function are in Compute the Symbol Error Rate and Examples of Signal Constellation Plots.

See Also

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