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DVBS-APSK Modulator Baseband

DVB-S2/S2X/SH standard-specific amplitude phase shift keying (APSK) modulation

  • DVBS-APSK Modulator Baseband block

Libraries:
Communications Toolbox / Modulation / Digital Baseband Modulation / APM
Communications Toolbox / Modulation / Digital Baseband Modulation / Standard-Compliant

Description

The DVBS-APSK Modulator Baseband block modulates the input signal using Digital Video Broadcasting (DVB-S2/S2X/SH) standard-specific amplitude phase shift keying (APSK) modulation.

Examples

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Apply DVB-S APSK modulation to random data symbols, pass the modulated signal through an AWGN channel, and then plot the signal constellation.

The slex_dvbs_apsk_mod model is configured for the S2 standard suffix and modulation order 16. For you to get desired results, all blocks in the model must align their configuration to the same modulation order. To set the modulation order for the DVBS-APSK Modulator Baseband block, select a value from the dropdown list in the block mask. The set of modulation orders available varies depending on the DVB standard suffix parameter setting. The InitFcn callback defines the workspace variable, M = 16, and this variable is used to set the:

The Constellation Diagram block has the Reference constellation parameter set to Custom and the Custom value parameter set to align with the modulation order of the DVBS-APSK Modulator Baseband block. To see the values, open Reference Constellation in the Measurements tab on the Constellation Diagram window.

Change the EbN0 of the AWGN channel block to 10 dB. Run the model and observe the increase in noise shown in the plotted constellation diagram.

You can try running the model with a different modulation order. To adjust the modulation order, you must align the:

  • Modulation order setting in the DVBS-APSK Modulator Baseband block

  • Value of the workspace variable M

  • Reference constellation in the Constellation Diagram block

If these parameters are not aligned with each other, the reference constellation and input signal do not display the desired constellation.

Ports

Input

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Input signal, specified as a scalar, vector, or matrix. The input signal must be binary values or integers in the range [0, (M – 1)], where M is the Modulation order. This port is unnamed on the block.

Note

To process the input signal as binary elements, set the Input type parameter value to Bit. For binary inputs, the number of rows must be an integer multiple of log2(M). Groups of log2(M) bits in a column are mapped onto a symbol, with the first bit representing the MSB and the last bit representing the LSB.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32 | Boolean

Output

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DVB-S2/S2X/SH standard-specific APSK modulated signal, returned as a complex scalar, vector, or matrix. The output signal dimensions depend on the specified Input type value. This port is unnamed on the block.

Input typeDimensions of Output Signal
IntegerThe output signal has the same dimensions as the input signal.
BitThe number of rows in the output signal equals the number of rows in the input signal divided by log2(M), where M is the Modulation order.

Use Output data type to specify the output data type.

Parameters

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To edit block parameters interactively, use the Property Inspector. From the Simulink® Toolstrip, on the Simulation tab, in the Prepare gallery, select Property Inspector.

Standard suffix for DVB modulation variant, specified as S2, S2X, or SH.

Frame length, specified as Normal or Short.

Dependencies

This parameter applies only when DVB standard suffix is set to S2 or S2X.

Modulation order, M, specified as a power of two. The modulation order specifies the total number of points in the constellation of the output signal. The list of valid modulation orders varies depending on the values of DVB standard suffix and Frame length.

DVB standard suffixFrame lengthModulation order Options
S2Normal or Short16 or 32
S2XNormal8, 16, 32, 64, or 256
Short16 or 32
SHNot applicable16

Code identifier, specified as a character vector. The list of valid code identifier values varies depending on the specified values of DVB standard suffix, Frame length, and Modulation order. This table lists the options for Code identifier values.

Modulation orderDVB standard suffixFrame lengthCode identifier Options
8

S2X

Normal

100/180 or 104/180

16

S2 or S2X

Normal

2/3, 3/4, 4/5, 5/6, 8/9, or 9/10

Short

2/3, 3/4, 4/5, 5/6, or 8/9

16

S2X

Normal

26/45, 3/5, 28/45, 23/36, 25/36, 13/18, 140/180, 154/180, 100/180, 96/180, 90/180, 18/30, or 20/30

Short

7/15, 8/16, 26/45, 3/5, or 32/45

32

S2 or S2X

Normal

3/4, 4/5, 5/6, 8/9, or 9/10

Short

3/4, 4/5, 5/6, or 8/9

32

S2X

Normal

128/180, 132/180, 140/180, or 2/3

Short

2/3 or 32/45

64

S2X

Normal

128/180 , 132/180, 7/9, 4/5, or 5/6

128

S2X

Normal

135/180 or 140/180

256

S2X

Normal

116/180, 124/180, 128/180, 20/30, or 135/180

For more information, refer to Tables 9 and 10 in the DVB-S2 standard [1] and Table 17a in the DVB-S2X standard [2].

Dependencies

This parameter applies only when DVB standard suffix is set to S2 or S2X.

Constellation scaling, specified as Outer radius as 1 or Unit average power.

Dependencies

This parameter applies only when DVB standard suffix is set to S2 or S2X.

Input type, specified as Integer or Bit. To use Integer, the input signal must consist of integers in the range [0, (M – 1)]. To use Bit, the input data must contain binary values, and the number of rows must be an integer multiple of log2(M), where M is the Modulation order.

Output data type, specified as double or single.

To plot the reference constellation, click the View Constellation button.

Type of simulation to run, specified as:

  • Code generation –– Simulate the model using generated C code. The first time you run a simulation, Simulink generates C code for the block. The C code is reused for subsequent simulations as long as the model does not change. This option requires additional startup time.

  • Interpreted execution –– Simulate the model using the MATLAB® interpreter. This option shortens startup time. In Interpreted execution mode, you can debug the source code of the block.

Block Characteristics

Data Types

Boolean | double | integer | single

Multidimensional Signals

yes

Variable-Size Signals

no

More About

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References

[1] ETSI Standard EN 302 307 V1.4.1: Digital Video Broadcasting (DVB); Second generation framing structure, channel coding and modulation systems for Broadcasting, Interactive Services, News Gathering and other broadband satellite applications (DVB-S2), European Telecommunications Standards Institute, Valbonne, France, 2005-03.

[2] ETSI Standard EN 302 307-2 V1.1.1: Digital Video Broadcasting (DVB); Second generation framing structure, channel coding and modulation systems for Broadcasting, Interactive Services, News Gathering and other broadband satellite applications (DVB-S2X), European Telecommunications Standards Institute, Valbonne, France, 2015-02.

[3] ETSI Standard EN 302 583 V1.1.1: Digital Video Broadcasting (DVB); Framing structure, channel coding and modulation for Satellite Services to Handheld devices (SH), European Telecommunications Standards Institute, Valbonne, France, 2008-03.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2018b