EngeeComms.DQPSK_ModulatorBaseband

Differential quadrature phase modulation.

Library	`EngeeComms`
Block	DQPSK Modulator Baseband

Description

The system object DQPSK_ModulatorBaseband performs signal modulation using the differential quadrature phase manipulation method usage. The output signal is a modulated signal in the baseband. The input signal must be time-sampled.

To perform modulation using the differential quadrature phase manipulation usage, follow these steps:

Create an object EngeeComms.DQPSK_ModulatorBaseband 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.

Signals with an integer value

If for a property [Property:inputType] value set Integer,then valid input values are 0, 1, 2 and 3. In this case, the system object receives an input signal in the form of a scalar or a column vector.

If the first input signal is m, then the modulated symbol at the output will have the form: ,

Where – phase shift.

If the subsequent input signal is also equal m, then the modulated symbol at the output is equal to the previous modulated symbol multiplied by .

Signals with a binary value

If for the property [Property:inputType] value set Bit, then the Input contains pairs of binary values. In this case, the system object accepts a column vector whose length is equal to an even integer.

More generally, if for a property PhaseRotation value set for some integer k, then the constellation of signals has 2k points.

Syntax

Creation

dqpskmod = EngeeComms.DQPSK_ModulatorBaseband() — creates a system object for performing modulation using the differential quadrature phase manipulation usage method dqpskmod with properties by default.

Example:
```
dqpskmod = EngeeComms.DQPSK_ModulatorBaseband()
```
dqpskmod = EngeeComms.DQPSK_ModulatorBaseband(Name=Value) — creates a system object for performing modulation using the differential quadrature phase manipulation usage method dqpskmod with the specified properties as 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:
```
dqpskmod = EngeeComms.DQPSK_ModulatorBaseband(InputType=Bit)
```

Usage

outsignal = dqpskmod(insignal) — performs modulation of the input signal using the usage of the differential quadrature phase manipulation method, as indicated in dqpskmod. 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

Demodulated signal in the form of a scalar or vector.

Типы данных

ComplexF64, ComplexF32

Properties

# PhaseRotation — phase rotation
Float64 real number

Details

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

# InputType — input signal type
String

Details

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

# ConstellationOrdering — order of signal constellations
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