M-PSK Demodulator Baseband (Communications Blockset)

Demodulate PSK-modulated data

Library

PM, in Digital Baseband sublibrary of Modulation

Description

The M-PSK Demodulator Baseband block demodulates a signal that was modulated using the M-ary phase shift keying method. The input is a baseband representation of the modulated signal. The input and output for this block are discrete-time signals. The input can be either a scalar or a frame-based column vector. The M-ary number parameter, M, is the number of points in the signal constellation.

Binary or Integer Outputs

If the Output type parameter is set to Integer, then the block maps the point

to m, where is the Phase offset parameter and m is an integer between 0 and M-1.

If the Output type parameter is set to Bit and the M-ary number parameter has the form 2^K for some positive integer K, then the block outputs binary representations of integers between 0 and M-1. It outputs a group of K bits, called a binary word, for each symbol.

In binary output mode, the Constellation ordering parameter indicates how the block maps an integer to a corresponding group of K output bits. See the reference page for the M-PSK Modulator Baseband block for details.

Processing an Upsampled Modulated Signal

The input signal can be an upsampled version of the modulated signal. The Samples per symbol parameter is the upsampling factor. It must be a positive integer. For more information, see Upsampled Signals and Rate Changes in Using the Communications Blockset.

Dialog Box

M-ary number: The number of points in the signal constellation.
Output type: Determines whether the output consists of integers or groups of bits. If this parameter is set to Bit, then the M-ary number parameter must be 2^K for some positive integer K.
Constellation ordering: Determines how the block maps each integer to a group of output bits. This field is active only when Output type is set to Bit.
Phase offset (rad): The phase of the zeroth point of the signal constellation.
Samples per symbol: The number of input samples that represent each modulated symbol.

Pair Block

M-PSK Modulator Baseband

M-PAM Modulator Passband M-PSK Demodulator Passband