QPSK Modulator Baseband
Modulate using quadrature phase shift keying method
Library
PM in Digital Baseband sublibrary of Modulation
Description
The QPSK Modulator Baseband block modulates using the quadrature phase shift keying method. The output is a baseband representation of the modulated signal.
Integer-Valued Signals and Binary-Valued Signals
If you set the Input type parameter to
Integer
, then valid input values are 0, 1, 2, and 3. When you
set Constellation ordering to Binary
for
input m the output symbol is
exp(jθ + jπm/2)
where θ represents the Phase offset parameter (see the following figure for Gray constellation ordering). In this case, the block accepts a scalar or column vector signal.
If you set the Input type parameter to
Bit
, then the input contains pairs of binary values. For this
configuration, the block accepts column vectors with even lengths. When you set the
Phase offset parameter to , then the block uses one of the signal constellations in the following
figure, depending on whether you set the Constellation ordering
parameter to Binary
or Gray
.
In the previous figure, the most significant bit (i.e. the left-most bit), is the first bit input to the block. For additional information about Gray mapping, see the M-PSK Modulator Baseband help page.
Dialog Box
- Input type
Indicates whether the input consists of integers or pairs of bits.
- Constellation ordering
Determines how the block maps each pair of input bits or input integers to constellation symbols.
- Phase offset (rad)
The phase of the zeroth point of the signal constellation.
- View Constellation
Click View Constellation on the block mask to visualize a signal constellation for the specified block parameters. Before viewing a constellation, apply the parameter settings. For more information, see View Constellation of Modulator Block.
- Output data type
Output data type, specified as
double
,single
,fixdt(1,16)
,fixdt(1,16, 0)
,Inherit via back propagation
, or<data type expression>
.Setting this parameter to
fixdt(1,16)
,fixdt(1,16.0)
, or<data type expression>
enables parameters in which you can further specify details.Inherit via back propagation
sets the output data type and scaling to match the following block.
The Data Type Assistant helps you set data attributes. To use the Data Type Assistant, click Show data type assistant . For more information, see Specify Data Types Using Data Type Assistant (Simulink).
Supported Data Types
Port | Supported Data Types |
---|---|
Input |
|
Output |
|
Examples
Pair Block
Extended Capabilities
Version History
Introduced before R2006a
See Also
Blocks
- M-PSK Modulator Baseband | BPSK Modulator Baseband | DQPSK Modulator Baseband | QPSK Demodulator Baseband