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 time sampled.

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