Engee documentation

EngeeComms.BPSKDemodulator

Demodulates data modulated using the BPSK method.

Library

EngeeComms
Block

BPSK Demodulator Baseband

Description

The EngeeComms.BPSKDemodulator system object demodulates a signal that has been modulated using the Binary Phase Shift Keying (BPSK) method. The values of exp(jθ) or -exp(jθ) are converted to 0 or 1, respectively. The PhaseOffset property specifies the value of θ in radians.

To demodulate the BPSK modulated signal data, perform the following steps:

  1. Create an EngeeComms.BPSKDemodulator object and set its properties.

  2. Call the object with arguments as if it were a function.

To learn more about how to work with system objects, see Engee system objects.

Syntax

Creation

  • object = EngeeComms.BPSKDemodulatorBaseband creates a system object to demodulate a signal that has been modulated using the Binary Phase Shift Keying (BPSK) method, with by default properties. Example:

    bpskdemodulator = EngeeComms.BPSKDemodulatorBaseband

  • object = EngeeComms.BPSKDemodulatorBaseband(DecisionMethod,PhaseOffset) creates a system object to demodulate a signal that has been modulated using the Binary Phase Shift Keying (BPSK) method, with each specified Name property set to the specified Value (value). You can specify additional arguments as a name-value pair in any order (Name1=Value1,…​, NameN=ValueN). Example:

    bpskdemodulator = EngeeCommsc = BPSKDemodulatorBaseband(DecisionMethod = "Hard decision",PhaseOffset = pi/4)
bpskdemodulator = EngeeComms.

Usage

  • data = bpskdemodulator(waveform) applies demodulation to a BPSK-modulated signal and returns the demodulated input signal.

Arguments

Input arguments

waveform — BPSK modulated baseband signal
vector-column | matrix

Details

A BPSK-modulated wideband signal specified as a column vector or matrix of the same size as the input signal. See the OutputDataType property for details on the output data type.

Типы данных

Float64 | Float32
Support for complex numbers

Yes

var - non-zero scalar noise variance
`non-zero scalar

Details

The noise variance given as a non-zero scalar.

The input modulated signal must be a complex signal. In the case of BPSK, the modulator outputs a complex signal with zero imaginary part. If you instead feed a real signal to the demodulator, you must represent the noise power of the complex signal in the real input signal by setting the variance value to twice the variance of the real input signal.

Output arguments

data - output data
vector-column | matrix

Details

Output data returned as a column vector or matrix.

PhaseOffset - zero point phase shift
0 (By default) | scalar

Details

Zero point phase shift in radians.

Типы данных

Float64

DecisionMethod - demodulation decision type
`Hard decision (by default).

Details

Demodulation decision type specified as Hard decision.

Типы данных

char

Methods

Common for all system objects

step!

Start algorithm of system object operation

Optional

* Hard demodulation of BPSK signal*

When applying hard demodulation, the input signal type and phase offset are taken into account.

This figure shows a BPSK signal demodulator with a rigid solution for a floating point or fixed point signal and a trivial phase offset (multiple of ).

so bpsk demodulator 1 en

This figure shows a BPSK signal demodulator with a rigid solution for a floating point signal and a non-trivial phase shift.

so bpsk demodulator 2 en

This figure shows a BPSK signal demodulator with a rigid solution for a fixed-point signal with non-trivial phase shift.

so bpsk demodulator 3 en

See also

  1. BPSK Demodulator Baseband