Method for error display of orthogonal signals
View Patent ↗A method for displaying a plurality of error measures for an error-containing digitally modulated signal formed of a first and a second orthogonal component includes: determining for each digital value a value for an error-free version of the modulated signal; determining for each digital value a value for the error-containing version of the modulated signal; determining for each digital value a vector difference between the value for the error-containing version of the modulated signal and the respective value for the error-free version of the modulated signal; and displaying the vector differences on a two-dimensional display, each difference being displayed with respect to the respective value for the error-free version of the modulated signal, the display providing the plurality of error measures.
1. A method for displaying a plurality of error measures for an error-containing digitally modulated signal formed of a first and a second orthogonal component, said method comprising:
determining for each digital value a value for an error-free version of said modulated signal;
determining for each digital value a value for said error-containing version of said modulated signal;
determining for each digital value a vector difference between said value for said error-containing version of said modulated signal and the respective value for said error-free version of said modulated signal; and
displaying said vector differences on a two-dimensional display of an instrument that receives said vector differences, each difference being displayed as a point, said points forming a cluster of points, one such cluster corresponding to each determined value of said error-free version of said modulated signal, and being located at a position in said display that is determined by that error-free version.
2. A method according to claim 1 , wherein said vector differences are scaled prior to being displayed to reduce overlap between adjacent clusters.
3. A method according to claim 1 wherein said vector differences are scaled to emphasize errors.
4. A method according to claim 1 wherein said vector differences are scaled to localize errors.
5. A method according to claim 1 , wherein said determining for each digital value a value for said error-containing version of said modulated signal is by a process of demodulation.