| 摘要 |
Constellation display allows a user to evaluate the quality of a signal under test with the constellation display even if the signal is a digital modulation signal that has many possible ideal phases. A signal analyzer 10 acquires time domain data of the signal under test that has N ideal phases. The signal analyzer 10 demodulates the signal under test to measure the phases &thetas;m and amplitudes Am of the symbols of the signal. Phase differences d&thetas; between the ideal and measured phases of the measured symbols are calculated. K group phases &thetas;gi are assigned to N of the ideal phases. The signal analyzer displays a constellation using phases &thetas;gi+d&thetas; and the measured amplitudes Am. That is, points are plotted at locations of X=Am*cos (&thetas;gi+d&thetas;)+jAm*sin (&thetas;gi+d&thetas;) on a complex plane.
|
