comm.BPSKModulator System object

Package: comm

Modulate using BPSK method


The BPSKModulator object modulates using the binary phase shift keying method. The output is a baseband representation of the modulated signal.

To modulate a binary phase shift signal:

  1. Define and set up your BPSK modulator object. See Construction.

  2. Call step to modulate a signal according to the properties of comm.BPSKModulator. The behavior of step is specific to each object in the toolbox.


H = comm.BPSKModulator creates a modulator System object™, H, that modulates the input signal using the binary phase shift keying (BPSK) method.

H = comm.BPSKModulator(Name,Value) creates a BPSK modulator object, H, with each specified property set to the specified value. You can specify additional name-value pair arguments in any order as (Name1,Value1,...,NameN,ValueN).

H = comm.BPSKModulator(PHASE,Name,Value) creates a BPSK modulator object, H. The object's PhaseOffset property is set to PHASE, and the other specified properties are set to the specified values.



Phase of zeroth point of constellation

Specify the phase offset of the zeroth point of the constellation, in radians, as a finite, real scalar. The default is 0.


Data type of output

Specify the output data type as one of double | single | Custom. The default is double.

 Fixed-Point Properties


cloneCreate BPSK modulator object with same property values
constellationCalculate or plot ideal signal constellation
getNumInputsNumber of expected inputs to step method
getNumOutputsNumber of outputs from step method
isLockedLocked status for input attributes and nontunable properties
releaseAllow property value and input characteristics changes
stepModulate using BPSK method


expand all

Modulate data using BPSK, then visualize the data in a scatter plot

This example creates binary data, modulates the data, and then displays the data using a scatter plot.

% Create binary data symbols
    data = randi([0 1], 96, 1);
% Create a BPSK modulator System object
    hModulator = comm.BPSKModulator;
% Change the phase offset to pi/16
    hModulator.PhaseOffset = pi/16;
% Modulate and plot the data
    modData = step(hModulator, data);


This object implements the algorithm, inputs, and outputs described on the BPSK Modulator Baseband block reference page. The object properties correspond to the block parameters.

Introduced in R2012a

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