Common Phase Error vs. Time Display

1 . A method for displaying information on a test and measurement apparatus, comprising the steps of:

displaying a graph of an acquired signal;

displaying a graph of Common Phase Error versus time data generated from the acquired signal; and

aligning the graph of the acquired signal and the graph of the Common Phase Error in time.

2 . The method of claim 1 , wherein the graph of the acquired signal and the graph of the Common Phase Error are displayed on vertically separate grids employing a same horizontal time per division.

3 . The method of claim 1 , further comprising the step of selectively displaying a constellation diagram including low pass common phase error filtering and a constellation diagram excluding low pass common phase error filtering.

4 . The method of claim 1 , wherein the test and measurement apparatus is an oscilloscope.

5 . A method for displaying information on a test and measurement apparatus, comprising the steps of:

selectively displaying a first constellation diagram utilizing a low pass filtering of the Common Phase Error and a second constellation diagram of the Common Phase Error without a low pass filtering thereof;

whereby an effect of this low pass filtering is discernable in accordance with the constellation diagrams.

6 . The method of claim 5 , further comprising the step of measuring error vector magnitude corresponding to each of the first and second constellation diagrams.

7 . The method of claim 5 , further comprising the steps of determining an effect of the low pass filtering in accordance with a comparison of the first and second constellation diagrams.

8 . The method of claim 7 , further comprising the step of determining whether the first or second constellations diagram is displayed.

9 . A test and measurement apparatus for displaying information, comprising:

an acquisition system for acquiring a signal;

a processor for determining a Common Phase Error of the acquired signal versus time; and

a display for displaying a graph of the Common Phase Error of the acquired signal versus time in a time aligned manner with a graph of the acquired signal.

10 . The test and measurement apparatus of claim 9 , wherein the graph of the acquired signal and the graph of the Common Phase Error of the acquired signal are displayed on vertically separate grids employing a same horizontal time per division.

11 . The test and measurement apparatus of claim 9 , wherein the test and measurement apparatus is adapted to selectively display a constellation diagram including low pass common phase error filtering and a constellation diagram excluding low pass common phase error filtering.

12 . The apparatus of claim 9 , wherein the test and measurement apparatus is adapted to measure an error vector magnitude corresponding to each of the first and second constellation diagrams.

13 . The test and measurement apparatus of claim 9 , wherein the test and measurement apparatus is an oscilloscope.

14 . A computer program for displaying information on a test and measurement apparatus, comprising instructions for performing the steps of:

displaying a graph of an acquired signal;

displaying a graph of Common Phase Error versus time data generated from the acquired signal; and

aligning the graph of the acquired signal and the graph of the Common Phase Error in time.

15 . The computer program of claim 14 , wherein the graph of the acquired signal and the graph of the Common Phase Error are displayed on vertically separate grids employing a same horizontal time per division.

16 . The computer program of claim 14 , further comprising instructions to perform the step of turning off low pass filtering of Common Phase Error.

17 . The computer program of claim 14 , wherein the test and measurement apparatus is an oscilloscope.

18 . A computer program for displaying information on a test and measurement apparatus, comprising instructions for performing the steps of:

selectively displaying a first constellation diagram utilizing a low pass filtering of the Common Phase Error;

selectively displaying a second constellation diagram of the Common Phase Error without a low pass filtering thereof;

whereby an effect of this low pass filtering is discernable from a comparison of the first and second constellation diagrams.

19 . The computer program of claim 18 , further comprising the step of determining an Error Vector Magnitude corresponding to each of the first and second constellation diagrams.