Version 2.5 (R13) Communications Blockset™ Software Release Notes Release Notes

Version 2.5 (R13) Communications Blockset™ Software Release Notes

This table summarizes what's new in Version 2.5 (R13):

New features and changes introduced in this version are

• RF Impairments Library

• Sequence Generators Library

• Eye Diagram, ScatterPlot, and Signal Trajectory Scopes

• CRC Library

• Enhancements to Reed-Solomon Blocks

• New Demos

• Enhancements to CPM Modulator Block

• Fixed Bugs

• Known Problems

• Old Models Using the Baseband or Passband SSB Modulators Must Be Resaved

• Change the Boolean Logic Signals Parameter to Off

RF Impairments Library

The new RF Impairments library contains blocks to simulate radio frequency (RF) impairments at the receiver. The blocks in the library are listed in the following table.

Sequence Generators Library

The Comm Sources library is now divided into four sublibraries for Version 2.5. Three of these sublibraries contain the blocks from the Version 2.0.1 Comm Sources library:

• Data Sources

• Noise Sources

• Controlled Sources

The fourth, the Sequence Generators sublibrary, contains the PN Sequence Generator block and five new blocks for Version 2.5. You can use the blocks in the Sequence Generators sublibrary to generate sequences for spreading or synchronization in a communication system. The following table lists the blocks in the Sequence Generators sublibrary.

Eye Diagram, ScatterPlot, and Signal Trajectory Scopes

The Version 2.0.1 Discrete-Time Eye and Scatter Diagram block, in the Comm Sinks library, has been replaced by three new blocks for Version 2.5, as described in the following table.

These blocks greatly enhance the features of the Discrete-Time Eye and Scatter Diagram.

CRC Library

The Channel Coding library has been renamed the Error Correction and Detection library, and a new sublibrary, CRC, has been added to the Error Detection and Correction library. The CRC library contains new blocks for appending cylic redundancy check (CRC) bits to data and for detecting errors in transmission.

The following table lists the blocks in the CRC library.

Enhancements to Reed-Solomon Blocks

The following four blocks, in the Block sublibrary of the Error Detection and Correction Library, have new features:

• Binary-Input RS Endoder

• Binary-Input RS Decoder

• Integer-Input RS Encoder

• Integer-Input RS Decoder

You can now specify the primitive polynomial and generator polynomial, which are used to generate the codes. This enables you to use a much wider range of Reed-Solomon codes. There is also a new option to output the number of corrected errors from the Binary-Input RS Decoder and Integer-Input RS Decoder blocks.

New Demos

The Communications Blockset contains eleven new demos for Version 2.5. These include a large-scale demo model of a commercial application of a third generation (3G) wireless system using wide-band code division multiple access (WCDMA). The demo presents an end-to-end transmission between a base station and a mobile station, as specified by the Third Generation Partnership Project (3GPP).

The new demos are as follows:

• WCDMA End-to-End Physical Layer Demo

• WCDMA Coding and Multiplexing Demo

• WCDMA Spreading and Modulation Demo

• RF Satellite Link Demo

• HiperLAN/2 Demo

• Bluetooth Voice Transmission Demo

• Adaptive Equalization Demo

• CPM Phase Tree Demo

• GMSK vs. MSK Demo

• Filtered QPSK vs. MSK Demo

• Raleigh Fading Channel Demo

Enhancements to CPM Modulator Block

The CPM modulator block now enables you to specify both the entire pulse length and the pulse main lobe length when simulating an LSRC frequency pulse length. This feature enables you to simulate a modulation such as 3SRC6.

Fixed Bugs

Fading channels

The accuracy of Doppler spread of the Rayleigh and Rician Fading Channel Blocks has been improved. The blocks now give better results for high sampling rates and small Doppler frequencies, as specified in communication standards such as WCDMA.

List of demos for which code can now be generated using Real Time Workshop

The following demos now generate code using Real Time Workshop:

• dmt_sim

• dvbt_sim

• tstgraycod

• phasenoise_sim

• dmt_alt_sim

• tstconvcod

Passband FSK and CPM modulators and demodulators are more accurate

The passband FSK and CPM modulators have been modified to generate more accurate waveforms by performing FIR interpolation when upsampling. The FIR filters significantly reduce the levels of any spectral copies revealed by upsampling. They also introduce delay into the modulators.

Reed-Solomon blocks now encode and decode correctly

The Reed-Solomon blocks now encode and decode signals correctly.

Known Problems

Several Communications Blockset blocks are incompatible with Real-Time Workshop

Several Communications Blockset blocks are incompatible with Real-Time Workshop. As a result, Real-Time Workshop cannot generate code for models that include these blocks:

• Continuous-Time Eye and Scatter Diagrams

• Triggered Read from File

• Triggered Write to File

• Integer-Input RS Encoder

• Integer-Output RS Decoder

• Binary-Input RS Encoder

• Binary-Output RS Decoder

• Blocks in the CPM sublibrary of the Digital Baseband sublibrary of the Modulation library

Several Communications Blockset demos are incompatible with Real-Time Workshop

Several Communications Blockset demos are incompatible with Real-Time Workshop. As a result, Real-Time Workshop cannot generate code for these demos:

• 256 Channel ADSL

• Adaptive Equalization

• Bluetooth Voice Transmission

• CPM Phase Tree Example

• Digital Video Broadcasting Model

• Discrete Multitone Signaling

• Filtered QPSK vs. MSK

• GMSK vs. MSK

• WCDMA Coding and Multiplexing Example

• WCDMA End-to-End Physical Layer

• WCDMA Spreading and Modulation Example

Old Models Using the Baseband or Passband SSB Modulators Must Be Resaved

Compatibility Considerations

The baseband and passband SSB modulators have been updated for Release 13 to include a pop-up menu enabling you to choose between upper and lower sideband modulation. You should resave any models using the old SSB modulators before running them in Release 13, to avoid producing Simulink warnings.

Change the Boolean Logic Signals Parameter to Off

The Communications Blockset does not support signals with boolean data type.

Compatibility Considerations

In Release 13, the Simulink Boolean logic signals parameter is now set to On by default. If you use Simulink blocks such as the Logical Operator block together with Communications Blockset blocks in a model, you must change the default setting of the Boolean logic signals parameter setting to Off. To do so, enter

commstartup 

at the beginning of each MATLAB session, before you create a model. This sets the Boolean logic signals parameter to Off for every model you create during the current MATLAB session.

To manually change the Boolean logic signals parameter in a model to Off, do the following steps:

1. Select Simulation parameters from the model window's Simulation menu.

2. Click the Advanced tab in the Simulation Parameters dialog box.

3. Select Boolean logic signals in the Optimizations field.

4. Under Action, select the Off check box.

5. Click OK.

Note that this changes the Boolean logic signals parameter to Off only for the current model.

Because the default setting of the Boolean logic signals parameter prior to Release 13 was Off, it is not necessary to make changes to models that you created prior to Release 13.

Version 3.0 (R14) Communications Blockset™ Software Release Notes

Version 2.0.1 (R12.1) Communications Blockset™ Software Release Notes