# dsp.PhaseUnwrapper System object

Package: dsp

Unwrap signal phase

## Description

The `PhaseUnwrapper` object unwraps the signal phase input specified in radians.

To unwrap the signal phase input:

1. Define and set up your System object™. See Construction.

2. Call `step` to unwrap the signal phase according to the properties of `dsp.PhaseUnwrapper`. The behavior of `step` is specific to each object in the toolbox.

## Construction

`H = dsp.PhaseUnwrapper` returns a System object, `H`. This System object adds or subtracts appropriate multiples of $2\pi$to each input element to remove phase discontinuities (unwrap).

`H = dsp.PhaseUnwrapper('PropertyName',PropertyValue,...)` returns an unwrapped System object, `H`, with each specified property set to the specified value.

## Properties

 `InterFrameUnwrap` Enable unwrapping of phase discontinuities between successive frames Set this property to `false` to unwrap phase discontinuities only within the frame. Set this property to `true` to also unwrap phase discontinuities between successive frames. The default is `true`. `Tolerance` Jump size as true phase discontinuity Specify the jump size that the phase unwrapper recognizes as a true phase discontinuity. The default is set to $\pi$ (rather than a smaller value) to avoid altering legitimate signal features. To increase the phase wrapper sensitivity, set the `Tolerance` property to a value slightly less than $\pi$.

## Methods

 clone Create phase unwrapper object with same property values getNumInputs Number of expected inputs to the `step` method getNumOutputs Number of outputs of the `step` method isLocked Locked status for input attributes and nontunable properties release Allow property value and input characteristics changes reset Reset internal states of Phase Unwrapper System object step Unwrap input phase signal input

## Examples

Unwrap input phase data:

```hunwrap = dsp.PhaseUnwrapper; p = [0 2/5 4/5 -4/5 -2/5 0 2/5 4/5 -4/5 -2/5 0 2/5 ... 4/5 -4/5, -2/5]*pi; y = step(hunwrap, p'); figure,stem(p); hold stem(y, 'r');```

## Algorithms

This object implements the algorithm, inputs, and outputs described on the Unwrap block reference page. The object properties correspond to the Simulink® block parameters.