Design Digital Filters in Simulink

Fixed-point digital filter design for embedded processors

In signal processing, a digital filter is a computational algorithm that converts a sequence of input numbers to a sequence of output numbers. The algorithm is designed such that the output signal meets frequency-domain or time-domain constraints (desirable frequency components are passed, undesirable components are rejected). In general terms, a discrete transfer function controller is a form of a digital filter. However, a digital controller can contain nonlinear functions such as lookup tables in addition to a discrete transfer function. This guide uses the term digital filter when referring to discrete transfer functions.

In the world of fixed-point numbers, where precision and range are limited, you must carefully select the data type, word size, and scaling for each realization element that results are accurately represented. To assist you with this selection, design rules for modeling dynamic systems with fixed-point math are provided inTargeting an Embedded Processor.

Note

To design and implement a wide variety of floating-point and fixed-point filters suitable for use in signal processing applications and for deployment on DSP chips, use the DSP System Toolbox™.

Topics

Direct Form II
Structure where coefficients of the transfer function appear directly as Gain blocks.
Series Cascade Form
Transfer function that is written as a product of first-order and second-order transfer functions.
平行的形式
扩大的传递函数into partial fractions.
规范的形式
Set of fundamental operations for the processor for a given digital filter.
Targeting an Embedded Processor
Describes issues that arise when targeting a fixed-point design for use on an embedded processor.
fi Objects with DSP System Toolbox
Describes how to pass fixed-point data back and forth between the MATLAB^®工作空间和仿真软件万博1manbetx^®models using DSP System Toolbox blocks.
fi Objects with Simulink
Describes the ways you can use Fixed-Point Designer™fiobjects with Simulink models.

Featured Examples

Develop Fixed-Point Algorithms

Develop and verify a simple fixed-point algorithm.

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Fixed-Point Filters

Bit-true implementations of fixed-point direct type I and II filters with time-varying and time-invariant coefficients. These filters use the fundamental capabilities in Fixed-Point Designer™ and work with the autoscaling tools.

Open Model

Fixed-Point Lead and Lag Filters

Sample fixed-point implementations of a discrete lead filter and a discrete lag filter along with reference implementations in floating point.

Open Model

Fixed-Point Direct Form Filter

Implement a direct form filter in fixed point using fundamental building blocks such as Gain, Delay, and Sum.

Open Model

Fixed-Point Parallel Form Filter

Implement a parallel form filter in fixed point using fundamental building blocks such as Gain, Delay, and Sum.

Open Model

Fixed-Point Series Cascade Form Filter

Construct a fixed-point series cascade form filter using the fundamental building blocks of delay, sum, and gain.

Open Model