Main Content

Unwrap

Unwrap signal phase

  • Library:
  • DSP System Toolbox / Signal Operations

  • Unwrap block

Description

The Unwrap block unwraps each channel of the input by adding or subtracting appropriate multiples of 2π to each channel element. The block recognizes phase discontinuities larger than the value of the Tolerance parameter. For more information on phase unwrapping, see Definition of Phase Unwrap.

Ports

Input

expand all

Signal input to unwrap, specified as a scalar, vector, or matrix. The input must have radian phase entries.

Data Types: single | double

Output

expand all

Unwrapped signal output, returned as a scalar, vector, or matrix.

The block preserves the input size and dimension, and the output port rate equals the input port rate.

Data Types: single | double

Parameters

expand all

The jump size that the block recognizes as a true phase discontinuity. The default is set to π (rather than a smaller value) to avoid altering legitimate signal features. To increase the block's sensitivity, set the Tolerance to a value slightly less than π.

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

Specify how the block should process the input. You can set this parameter to one of thse options:

  • Columns as channels (frame based) (default) — When you select this option, the block treats each column of the input as a separate channel.

  • Elements as channels (sample based) — When you select this option, the block treats each element of the input as a separate channel.

When you clear this check box, the block ignores boundaries between input frames and does not reset the initial phase value to zero each time a new input is received. In this mode, the block continuously unwraps the data in each column of the input.

This figure illustrates how the block unwraps data in this mode.

When you select this check box, the block treats each frame of input data independently and resets the initial phase value for each new input frame.

This figure illustrates how the block unwraps data in this mode.

For more information, see Frame-Based Processing.

Dependencies

To enable this parameter, set the Input processing parameter to Columns as channels (frame based). In sample-based processing mode, the block does not reset the initial phase value to zero for each new input. See Sample-Based Processing for more information.

Block Characteristics

Data Types

double | single

Direct Feedthrough

no

Multidimensional Signals

no

Variable-Size Signals

no

Zero-Crossing Detection

no

More About

expand all

Extended Capabilities

See Also

Functions

Introduced before R2006a