M-PSK Modulator Baseband
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Modulates data using the M-PSK method.
Description
The M-PSK Modulator Baseband block modulates the input signal using M-point phase shift keying (M-PSK) and returns a complex baseband signal at the output. The modulation order, , which is equivalent to the number of points in the signal constellation, is determined by the M-ary number parameters. The block accepts scalars or vector columns as input.
Ports
Input
#
In
—
input signal
scalar | vector
Details
An input signal specified as an integer scalar, integer vector or binary vector.
-
If the Input type parameters are set to
Integer, specify the input signal elements as integers from to . -
If the Input type parameters are set to
Bit, specify the input signal as a binary vector in which the number of elements is an integer multiple of the number of bits per character. The number of bits per character is .
| Data types |
|
| Complex numbers support |
No |
Output
#
Out
—
M-PSK modulated output signal
complex scalar | complex vector
Details
The output signal returned as a complex scalar or vector. The output signal is a complex baseband representation of the PSK modulated signal.
| Data types |
|
| Complex numbers support |
Yes |
Parameters
Parameters
#
M-ary number —
modulation order of the signal PSK constellation
Real number
Details
The modulation order given as a positive integer that is a power of two.
Example: 2 | 4 | 8
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
Yes |
#
Input type —
input signal type
Bit | Integer
Details
Input signal elements specified as integers or bits.
-
If the Input type parameters are set to
Bit, the number of samples in the frame must be an integer multiple of the number of bits per character. The number of bits per character is equal to .
| Values |
|
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
No |
#
Constellation ordering —
character display
Binary | Gray | User-defined
Details
Character mapping of integers or groups of bit inputs specified as Gray, Binary or User-defined.
-
Gray- the input signal is mapped to output symbols using a Gray-encoded signal constellation. -
Binary- the modulated symbol will be , where is the phase shift in radians, is an integer input such that , and is the modulation order. -
User-definedis a vector of size , which has unique integer values in the range, ]. The first element of this vector corresponds to a signal constellation point having the value , and subsequent elements go anti-clockwise.
Example: [0 3 2 1 1].
| Values |
|
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
No |
#
Constellation mapping —
custom character display
Array of real numbers
Details
A user-defined character mapping specified as a -element vector having unique integer values in the range ]. Use this parameters to specify a user-defined mapping of input integers to output integers.
The first element of this vector corresponds to a signal constellation point at , and subsequent elements go counterclockwise. The last element corresponds to a signal constellation point . - is the phase shift value (parameter (Phase offset (rad)), and is the modulation order (parameter M-ary number).
Dependencies
To use this parameter, set the Constellation ordering parameter to User-defined.
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
Yes |
#
Phase offset (rad) —
phase shift
Real number
Details
The phase offset of the initial signal constellation in radians as a real scalar.
Example: pi/2
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
Yes |
Data Type
#
Output data type —
output data type
Float64 | Float32 | Float16 | Fixed-point
Details
The data type of the modulated output signal type. Defined as:
-
Float64. -
Float32 -
Float16 -
Fixed-point
| Values |
|
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
No |
#
Output fixed-point type —
fixed-point vector of values
Data type
Details
Fixed point vector of output signal values.
Dependencies
To use this parameter, set the Output data type parameter to Fixed-point.
| Default value |
|
| Program usage name |
|
| Tunable |
No |
| Evaluatable |
Yes |
Algorithms
For higher-order PSK signal constellations, the complex baseband form for the M-PSK signal usage of binary-ordered symbol mapping looks like:
When the input is set to bits, groups of bits represent complex characters for a customised character display. The mapping can be binary, Gray-encoded, or user-defined.
The advantage of Gray encoding is that only one bit changes between neighbouring points in the signal constellation, resulting in an improved error rate.
This 8-PSK signalling constellation uses Gray symbol coding.
