EngeeComms.DQPSK_DemodulatorBaseband

Demodulates data modulated using the DQPSK method.

Library	`EngeeComms`
Block	DQPSK Demodulator Baseband

Description

System object EngeeComms.DQPSK_DemodulatorBaseband demodulates a signal that has been modulated using the differential quadrature phase shift keying (DQPSK) method. A basic representation of the modulated signal is fed to the Input.

The input signal must be a discrete complex signal. The output depends on the phase difference between the current and previous symbol. The first integer (or binary pair, if for the property OutputType value set Bit) at the output of the system object is the initial state of zero, since there is no previous character.

To demodulate a signal that has been modulated using the differential quadrature phase manipulation method, follow these steps:

Create an object EngeeComms.DQPSK_DemodulatorBaseband 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.

Types of output data and constellations

If for a property OutputType value set Integer, then the system object displays the phase difference and , where this is the value of the property PhaseRotation, and takes the value 0, 1, 2, or 3.

If for a property OutputType value set Bit, then pairs of binary values are obtained at the output.

Syntax

Creation

dqpskdemod = EngeeComms.DQPSK_DemodulatorBaseband() — creates a system object dqpskdemod to perform demodulation of a signal that has been modulated using the differential quadrature phase manipulation method, with the properties by default.

Example:
```
dqpskdemod = EngeeComms.DQPSK_DemodulatorBaseband()
```
dqpskdemod = EngeeComms.DQPSK_DemodulatorBaseband(Name=Value) — creates a system object dqpskdemod to perform demodulation of a signal that has been modulated using the differential quadrature phase manipulation method, with specified properties in the form of a pair Name=Value, where Name — the name of the property, and Value — appropriate value. You can specify multiple pairs «name-value» the order of the pairs does not matter. Unspecified properties retain their by default values.

Example:
```
dqpskdemod = EngeeComms.DQPSK_DemodulatorBaseband(OutputType=Bit)
```

Usage

outsignal = dqpskdemod(insignal) — performs demodulation of a signal that has been modulated using the differential quadrature phase manipulation method, as indicated in dqpskdemod. The result is returned in outsignal.

Arguments

Input arguments

In — input DQPSK- modulated signal

+ scalar | vector

Details

The input DQPSK is a modulated signal in the form of a scalar or vector.

Типы данных

Float64

Output arguments

Out — demodulated signal

+ vector | scalar

Details

A demodulated signal in the form of a scalar or vector.

Типы данных

Float16, Float32, Float64, Int8, Int16, Int32, Int64, UInt8, UInt16, UInt32, UInt64, Bool

Properties

# PhaseRotation — phase rotation
Float64 real number

Details

The phase difference between the previous and current modulated symbols when the input is zero.

# OutputType — output signal type
String

Details

Indicates whether the output signal consists of integers or bit pairs.

# ConstellationOrdering — constellation ordering
String

Details

Determines how the system object maps each pair of input bits to the corresponding integer, using either the Binary or Gray scheme.

Methods

Common to all system objects

`step!`	Run the algorithm of the system object
`reset!`	Resetting the internal states of the system object