DQPSK Modulator Baseband

Differential quadrature phase modulation.

blockType: DQPSKModulatorBaseband

Path in the library:

/Communication Systems/Modulation/Digital Modulation/PM/DQPSK Modulator Baseband

Description

The DQPSK Modulator Baseband unit performs modulation with usage of the differential quadrature phase shift keying method. The output signal is a modulated signal in the main frequency band. The input signal must be sampled in time.

Signals with integer value

If the parameters Input type are set to the value of Integer`then the acceptable input values are `0, 1, 2 and 3. In this case, the block accepts the input signal as a scalar or column vector.

If the first input signal is m, the modulated symbol at the output will be of the form: ,

where is the phase shift.

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

Signals with binary value

If the parameters Input type is set to . Bit, then the input signal contains pairs of binary values. In this case, the block accepts a column vector whose length is equal to an even integer.

Ports

Input

# IN_1 — input signal
scalar | vector

Details

Input signal as a scalar or vector.

Data types	`Int64`.
Complex numbers support	No

Output

# OUT_1 — DQPSK modulated output signal
scalar | vector

Details

Output DQPSK modulated signal as a scalar or vector.

Data types	`Complex32`, `Complex64`.
Complex numbers support	Yes

Parameters

Main

# Input type — input signal type
Bit | Integer

Details

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

Values	`Bit` \| `Integer`
Default value	`Bit`
Program usage name	`InputType`
Tunable	No
Evaluatable	No

# Constellation ordering — order of signal constellations
Binary | Gray

Details

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

Values	`Binary` \| `Gray`
Default value	`Gray`
Program usage name	`ConstellationOrdering`
Tunable	No
Evaluatable	No

# Phase rotation (rad) — phase rotation
Float64 real number

Details

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

Default value	`pi/4`
Program usage name	`PhaseRotation`
Tunable	No
Evaluatable	Yes

# Output data type — output data type
double | single

Details

Output data type.

Values	`double` \| `single`
Default value	`double`
Program usage name	`OutputDataType`
Tunable	No
Evaluatable	No