Phase Shift

This block will phase shift the input signal by the specified phase by multiplying the input times a shift value:

gr_complex(cos(d_shift_in_radians),sin(d_shift_in_radians))

Notes:
If degrees are provided, the block automatically handles the conversion.

This block functions like a Multiply Constant, but with the constant set to e^j·shift, i.e. the corresponding value on the complex unit circle.

Parameters

(R): Run-time adjustable

Phase Shift

default: '0.0'

Units

options: ['Radians', 'Degrees']

Example Flowgraph

This flowgraph demonstrates how the Phase Shift block will change the phase of a complex sinusoid. It also demonstrates how shifting the phase will change its appearance on a constellation diagram. It creates a complex sinusoid (the Signal Source block), runs the sinusoid through the Phase Shift block, then into a QT GUI Time Sink for display of the time domain of the signal. The phase within the Phase Shift block is controlled by a QT GUI Range block. The range block allows the phase to be adjustable between -360 to +360 degrees (-2 π to +2 π).

Along with that is a Complex Conjugate block that is used to show the phase in the QT GUI Constellation Sink. (NOTE: If the signal going into the constellation or Argand diagram is not at 0 Hz, or centered around 0 Hz, it will spin. This makes it impossible to see the actual phase.) By multiplying the phase-shifted sinusoid with its non-phase-shifted complex conjugate, we can see the phase shift as the range value is adjusted. Two Vector Source blocks create a more-visible cross bar showing the real and imaginary axes.

This is a display from the flowgraph above. This shows the time domain and constellation diagram of a 125 degree (3π/4 radians) phase shift.

Gnu Radio blocks used for this demonstration: Signal Source, Complex Conjugate, QT GUI Time Sink, QT GUI Range, Variable, Vector Source, Multiply, QT GUI Constellation Sink

GRC File

File:PhaseShiftDemo.grc

Source Files

C++ files

peak_detector_impl.cc

Header files

phase_shift_impl.h

Public header files

phase_shift.h

Block definition

blocks_phase_shift.block.yml