Scalar Quantizer Decoder

Convert each index value into quantized output value

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  • Scalar Quantizer Decoder block

Libraries:
DSP System Toolbox / Quantizers

Description

The Scalar Quantizer Decoder block transforms the zero-based input index values into quantized output values. For each input index value, the block outputs the corresponding quantized output value (or codeword).

The set of all possible quantized output values is defined by the Codebook values parameter.

Examples

Add a Scalar Quantizer

Add a Scalar Quantizer

In this topic, you add scalar quantizer encoders and decoders to quantize the residual signal E and the reflection coefficients K:

Ports

Input

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Specify the index values in the range, 0 ≤ index < N, where N is the number of distinct codeword vectors in the codebook matrix.

Data Types: int8 | int16 | int32 | uint8 | uint16 | uint32

Specify the codebook values as a vector or a matrix.

Dependencies

To enable this port, set the Source of codebook parameter to Input port.

Data Types: single | double | int8 | int16 | int32 | fixed point

Output

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Quantized output values, returned as a vector or a matrix of the same size as the input data.

If the codebook values are input through the C port, the quantized output values have the same data type as the input codebook values. If the codebook values are specified in the block dialog box, the Codebook and output data type parameter determines the data type of the quantized output values.

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

Parameters

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Main Tab

Specify one of these actions the block must take when an input index value is outside the range 0 ≤ index <N, where N is the length of the codebook vector. Select Clip, when you want any index values less than 0 to be set to 0 and any index values greater than or equal to N to be set to N−1. Select Clip and warn, when you want to be warned when clipping occurs. Select Error, when you want the simulation to stop and the block to display an error when the index values are outside the range.

Specify the source of codebook values as one of these:

  • Specify via dialog –– Enter the codebook values in the Codebook values parameter.

  • Input port –– Specify the codebook values through the input port C.

Enter all possible quantized output values that correspond to each index value as a vector or a matrix. The data type of the codebook values is determined by the setting of the Codebook and output data type parameter.

Tunable: Yes

Dependencies

To enable this parameter, set the Source of codebook parameter to Specify via dialog.

Data Types Tab

Specify the data type of the codebook and quantized output values. You can select one of the following:

  • A rule that inherits a data type, for example, Inherit: Same as input.

  • A built in data type, such as double

  • An expression that evaluates to a valid data type, for example, fixdt(1,16)

Click the Show data type assistant button to display the Data Type Assistant, which helps you set the Output data type parameter.

See Control Data Types of Signals (Simulink) for more information.

Dependencies

This parameter is available only when you set the Source of codebook parameter to Specify via dialog. If you set the Source of codebook parameter to Input port, the quantized output values have the same data type as the input codebook values.

Block Characteristics

Data Types

fixed point | integer

Direct Feedthrough

no

Multidimensional Signals

no

Variable-Size Signals

no

Zero-Crossing Detection

no

References

[1] Gersho, A. and R. Gray. Vector Quantization and Signal Compression. Boston: Kluwer Academic Publishers, 1992.

Extended Capabilities

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

Fixed-Point Conversion
Design and simulate fixed-point systems using Fixed-Point Designer™.

Version History

Introduced before R2006a

See Also

(Simulink) | | |

Topics