Quantizer

Discretize input at given interval

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Libraries:
Simulink / Discontinuities

Description

The Quantizer block discretizes the input signal using a quantization algorithm. The block uses a round-to-nearest method to map signal values to quantized values at the output that are defined by the Quantization interval. A smooth input signal can take on a stair-step shape after quantization.

This equation mathematically describes the round-to-nearest method:

y = q * round(u/q) 

where y is the quantized output, u is the input, and q is the Quantization interval.

Examples

Using the Quantizer and Saturation blocks in sldemo_boiler

This example shows how the Quantizer and Saturation blocks are used in the model ex_sldemo_boiler. The ADC subsystem digitizes the input analog voltage by:

• Multiplying the analog voltage by 256/5 with the Gain block

• Rounding the value to integer floor with the Quantizer block

• Limiting the output to a maximum of 255 (the largest unsigned 8-bit integer value) with the Saturation block

Ports

Input

Port_1 — Input signal to quantize

scalar | vector

Input signal to the quantization algorithm.

Data Types: single | double
Complex Number Support: Yes

Output

Port_1 — Quantized output signal

scalar | vector

Output signal composed of discrete values, quantized with a round-to-nearest approach:

y = q * round(u/q) 

where y is the output, u is the input, and q is the Quantization interval.

Data Types: single | double

Parameters

Quantization interval — Interval that defines quantization levels for the output signal

0.5 (default) | scalar | vector

Specify the quantization interval used in the algorithm. Quantization levels for the Quantizer block output are integer multiples of the Quantization interval.

Programmatic Use

Block Parameter: QuantizationInterval

Type: character vector

Value: Any real or complex value

Default: '0.5'

Treat as gain when linearizing — Specify the gain value

on (default) | off

The linearization commands in Simulink^® software treat this block as a gain in state space. Select this parameter to cause the commands to treat the gain as 1. Clear this parameter to have the commands treat the gain as 0.

Programmatic Use

Block Parameter: LinearizeAsGain

Type: character vector

Value: 'off' | 'on'

Default: 'on'

Sample time (-1 for inherited) — Interval between samples

-1 (default) | scalar | vector

Specify the time interval between samples. To inherit the sample time, set this parameter to -1. For more information, see Specify Sample Time.

Dependencies

This parameter is visible only if you set it to a value other than -1. To learn more, see Blocks for Which Sample Time Is Not Recommended.

Programmatic Use

To set the block parameter value programmatically, use the set_param function.

Parameter:	SampleTime
Values:	"-1" (default) | scalar or vector in quotes

Block Characteristics

Data Types	double | single
Direct Feedthrough	yes
Multidimensional Signals	no
Variable-Size Signals	no
Zero-Crossing Detection	no

Extended Capabilities

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

Version History

Introduced before R2006a