Extract the unwrapped phase of a complex input
The Phase Extractor block extracts the unwrapped phase of a complex input. The input can be a vector or matrix. For 2D inputs, the block treats each column as an independent channel. The first dimension is the length of the channel. The second dimension is the number of channels. The block treats 1D inputs as one channel.
The block preserves the input size and dimension, and the output port rate equals the input port rate.
This example shows how to use the Phase Extractor block to extract the phase of a sign wave. The DSP Sine Wave block represents the system input signal. Set the DSP Sine Wave block parameters to the following:
Frequency set to
Sample mode set to
Output complexity set to
Sample time set to
Sample per frame set to
Do not select the Phase Extractor block parameter Unwrap phase only within the frame.
The Time Scope block displays the extracted phase.
When you clear this check box, the block ignores boundaries between the input frames. 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.
Select the simulation type from the following:
|Port||Supported Data Types|
|DSP System Toolbox|
Consider an input frame of length N:
step method acts on this frame and produces this output:
Here, i runs from 1 to N. The
angle function returns the phase angle in radians.
If the input signal consists of multiple frames:
If you set
step method treats each frame independently. Therefore, in each
step method calculates the phase using the preceding
If you set
step method ignores boundaries between
frames. Therefore, in each frame, the
step method calculates the
phase using the preceding formula where:
is the last unwrapped phase from the previous frame.
is the last sample from the previous frame.