Puncturer

Punctures data according to puncture vector

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Libraries:
Wireless HDL Toolbox / Error Detection and Correction

Description

The Puncturer block punctures input data based on a specified puncture vector. The block accepts puncture vector either from the Input port or from the Property of the block and supports encoder rates from 1/2 to 1/7. It provides an architecture suitable for HDL code generation and hardware deployment.

The block supports Continuous and Frame mode operations and accepts both scalar and vector data. In Continuous mode, the block accepts input data and puncture vector, along with control signals valid and syncPunc and outputs punctured data with a valid signal. In Frame mode, the block accepts input data and puncture vector, along with a samplecontrol bus and outputs punctured data with a samplecontrol bus.

The block supports communication standards such as Wi-Fi (802.11a/b/g/n/ac), digital satellite communications, digital video broadcast (DVB), WiFi (IEEE 802.11a/b/g/n/ac), WiMax (IEEE 802.16), IEEE 802.16, HIPERLAN, and HiperMAN.

Examples

Convolutional Encode and Puncture Streaming Samples

Use Convolutional Encoder and Puncturer blocks to encode samples at WLAN code rates.

• Open Script

Ports

Input

data — Input data sample

scalar | column vector of size from 2 to 7

Input data sample, specified as a scalar or vector.

If input is of vector type, the size of the input data must match with the selected Encoder rate parameter value.

For example, if the Encoder rate is 1/2, the input data size must be 2-by-1.

Data Types: Boolean | fixdt(0,1,0)

valid — Indicates valid input data samples

scalar

Control signal that indicates if the input data is valid. When this value is 1 (true), the block accepts the values on the data input port. When this value is 0 (false), the block ignores the values on the data input port.

Dependencies

To enable this port, set the Operation mode parameter to Continuous.

Data Types: Boolean

puncVector — Puncture vector

column vector of binary values

Puncture vector, specified as a column vector of binary values. The length of the puncture vector must be an integral multiple of n, where Encoder rate is 1/n. For encoder rates 1/2, 1/3, 1/5, and 1/6, the maximum length of the puncVector is 30 and for encoder rates 1/4 and 1/7, the maximum length of the puncVector is 28.

You can change the puncVector pattern, but its length must remain constant. If the maximum puncture vector length provided is 10, the block supports all the vector lengths below 10.

Example: For an encoder rate 1/2 and its puncture rates 2/3, 3/4, and 5/6, the respective vector lengths are 4, 6, and 10. To achieve these multiple rates, set the Puncture vector source parameter to Input port. To support the largest vector size, the vector length must be 10 for all rates. For 2/3 and 3/4 rates, pad the puncVector input with zeros to create a 10-element vector. The puncture vector for rate 3/4 is [1 1 0 1 1 0]'. For a vector length of 10, use [0 0 0 0 1 1 0 1 1 0]' as the input puncVector.

When the Operation mode parameter is set to Continuous, the block captures the value of puncVector when both syncPunc and input valid port signals are 1 (true).

When the Operation mode parameter is set to Frame, the block captures the value of puncVector when both ctrl.start and ctrl.valid signals are 1 (true).

Dependencies

To enable this port, set the Puncture vector source parameter to Input port.

Data Types: Boolean

syncPunc — Puncture synchronization signal

scalar

Puncture synchronization signal, specified as a Boolean scalar value. This input is a control signal that synchronizes the puncture vector input with the input sample. When both syncPunc and valid are 1 (true), the block aligns the puncture vector to begin puncturing. The block captures the vector from either the puncVector input port or from the Puncture vector parameter.

The block ignores the puncVector signal values when syncPunc signal value is 0 (false).

Dependencies

To enable this port, set the Operation mode parameter to Continuous.

Data Types: Boolean

ctrl — Control signals accompanying sample stream

samplecontrol bus

Control signals accompanying the sample stream, specified as a samplecontrol bus. The bus includes the start, end, and valid control signals, which indicate the boundaries of the frame and the validity of the input samples.

• start — Indicates start of input frame.

• end — Indicates end of input frame.

• valid — Indicates that the data on the input data port is valid.

Dependencies

To enable this port, set the Operation mode parameter to Frame. In this mode, the block synchronizes the puncture vector using control signals in the input samplecontrol bus.

Data Types: bus

Output

data — Punctured output data

n-by-1 column vector

Punctured output data, returned as an n-by-1 column vector, where n value ranges from 1 to 7.

Data Types: Boolean | fixdt(0,1,0)

valid — Validity of output data samples

scalar

Control signal that indicates when the sample from the data output port is valid. The block sets the valid port to 1 (true) when there is a valid sample on the output data port.

Dependencies

To enable this port, set the Operation mode parameter to Continuous.

Data Types: Boolean

ctrl — Control signals accompanying sample stream

samplecontrol bus

Control signals accompanying the sample stream, returned as a samplecontrol bus. The bus includes the start, end, and valid control signals, which indicate the boundaries of the frame and the validity of the samples.

• start — Indicates start of output frame.

• end — Indicates end of output frame.

• valid — Indicates that the data on the output data port is valid.

Dependencies

To enable this port, set the Operation mode parameter to Frame.

Data Types: bus

Parameters

Operation mode — Mode of operation

Continuous (default) | Frame

Mode of operation, specified as one of these modes:

• Continuous — Allows changes to puncVector at any time. To force the block to capture the new puncture vector, set the syncPunc parameter to 1 (true).

• Frame — Allows changes to puncVector only at the start of a frame, indicated by ctrl.start.

Encoder rate — Rate of encoder

1/2 (default) | range from 1/2 to 1/7

Select the encoder rate for puncturing the data.

Puncture vector source — Source of puncture vector

Input port (default) | Property

Source of puncture vector, specified as:

• Input port — Specify the puncture vector using the puncVector port.

• Property — Specify the puncture vector using the Puncture vector parameter.

Puncture vector — Location of data to be punctured

[1;1;1;0;0;1] (default) | column vector of binary values

The length of the puncture vector must be an integral multiple of n, where Encoder rate is 1/n. For encoder rates 1/2, 1/3, 1/5, and 1/6, the maximum length of the puncture vector is 30 and for encoder rates 1/4 and 1/7 the maximum length of the puncture vector is 28.

Dependencies

To enable this port, set the Puncture vector source parameter to Property.

Algorithms

The puncturing algorithm checks every n elements of a puncture vector, with an Encoder rate 1/n, until it reaches a nonzero combination. Then, it punctures the input data and provides the punctured output data.

For example, if the Encoder rate is 1/3 and the puncture vector is [0;0;0;1;0;1], the block checks every 3 elements until it reaches a nonzero combination in the puncture vector and then punctures the input data based on the type of inputs (scalar or vector) and operation modes (Continuous or Frame).

Scalar Input

• Continuous mode — When the puncture vector element is 0, the block punctures the input data and provides no output. When the puncture vector element is 1, the block provides the corresponding input data as output.

  

• Frame mode — When the puncture vector element is 1, the block stores the corresponding input data in a buffer. It waits till it encounters the next 1 in the puncture vector and then provides the previous buffered data as output.

  When the puncture vector element is 0, the block punctures the input data and provides no output. But, if the endIn signal is 1 (high), the block provides the previous buffered data as output. The block repeats the similar process throughout the frame.

  

Vector Input

• Continuous mode — For a 3-by-1 vector input data with Encoder rate 1/3, the block selects 3 elements of the puncture vector at a time. When the puncture vector element is 0, the block punctures the data and provides no output. When the puncture vector element is 1, the block stores the corresponding input data. The block provides the output only when the stored data count reaches 3.

  

• Frame mode — The block behaves similarly as when in Continuous mode. But, when the endIn signal is 1 (high) and the stored data count is less than 3, the block pads zeros and then outputs the data.

  

Latency

The latency of the block varies with the puncture vector and encoder rate. The above waveforms show the latency of the block for a sample scalar and vector input data with different puncture vectors.

Performance

These resource and performance data are the synthesis results from the generated HDL targeted to an AMD^® Zynq^®-7000 ZC706 board. The block is using Boolean input samples, in continuous mode with default settings with puncture vector length 6. The design achieves a clock frequency of 559 MHz.

Resource	Number Used
LUT	50
FFS	40

If you set the Puncture vector source parameter to Property, the design uses fewer LUT and FFS resources with more frequency. The hardware resources and frequencies vary based on the encoder rate and the puncture vector size.

References

[1] Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications. IEEE Std 802.11™- 2016 Part 11.

[2] EN 300 421 V1.1.2 Digital Video Broadcasting (DVB); Framing structure, Channel coding and modulation for 11/12 GHz satellite services.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using Simulink® Coder™.

This block supports C/C++ code generation for Simulink^® accelerator and rapid accelerator modes and for DPI component generation.

HDL Code Generation

Generate VHDL, Verilog and SystemVerilog code for FPGA and ASIC designs using HDL Coder™.

HDL Coder™ provides additional configuration options that affect HDL implementation and synthesized logic.

This block does not have any HDL Block Properties.

Version History

Introduced in R2019b