EngeeComms.BPSKDemodulatorBaseband

Demodulates data modulated using the BPSK method.

Library	`EngeeComms`
Block	BPSK Demodulator Baseband

Description

System object EngeeComms.BPSKDemodulatorBaseband demodulates a signal that has been modulated using the binary phase manipulation (BPSK) method. Values exp(jθ) or −exp(jθ) are converted to 0 or 1, respectively. Property PhaseOffset sets the value θ in radians.

To demodulate the BPSK-modulated signal data, follow these steps:

Create an object EngeeComms.BPSKDemodulatorBaseband and set its properties.
Call an 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

bpskdemodulator = EngeeComms.BPSKDemodulatorBaseband() — creates a system object for demodulating a signal that has been modulated using the binary phase manipulation (BPSK) method, with the properties by default.

Example:
```
bpskdemodulator = EngeeComms.BPSKDemodulatorBaseband()
```
object = EngeeComms.BPSKDemodulatorBaseband(Name=Value) — creates a system object for demodulating a signal that has been modulated using the binary phase manipulation (BPSK) method, with specified properties in the form of a pair Name=Value, where Name — the name of the property, and Value — the corresponding value. You can specify multiple pairs «name-value» the order of the pairs does not matter. Unspecified properties retain their by default values.

Example:
```
bpskdemodulator = EngeeComms.BPSKDemodulatorBaseband(DecisionType="Hard decision",PhaseOffset=pi/4)
```

Usage

data = bpskdemodulator(waveform) — applies demodulation to the BPSK-modulated signal waveform and records the demodulated input signal in data.

Arguments

Input arguments

waveform — BPSK-modulated base signal

+ column vector | the matrix

Details

BPSK is a modulated broadband signal specified as a column vector or matrix of the same size as the input signal.

Типы данных	`Float64`, `Float32`
Support for complex numbers	Yes

var — nonzero scalar dispersion of noise

+ a nonzero scalar

Details

The noise variance, given as a nonzero scalar.

The input modulated signal must be complex. In the case of BPSK, the modulator outputs a complex signal with a 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 signal data

+ column vector | the matrix

Details

Output data returned as a column vector or matrix.

Properties

# PhaseOffset — zero point phase shift
Scalar / array of real numbers

Details

Zero point phase shift in radians.

# DecisionType — demodulation solution type
String

Details

The demodulation decision type specified as Hard decision.

Methods

Common to all system objects

step!

Run the algorithm of the system object

Additional information

Rigid demodulation of the BPSK signal

When applying rigid demodulation, the type of input signal 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 shift (multiple of ).

so bpsk demodulator 1 en

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

so bpsk demodulator 3 en