Plots a ASK/PSK signal constellation. Argument nsig is a real vector whose length determines the number of ASK radii in the constellation. The values of vector nsig determine the number of points in each ASK radii.
By default the radii of each ASK modulated level is given by the index of nsig. The amplitudes can be defined explicitly in the variable amp, which is a vector of the same length as nsig.
By default the first point in each ASK radii has zero phase, and following points are coding in an anti-clockwise manner. If phs is defined then it is a vector of the same length as nsig defining the initial phase in each ASK radii.
In addition apkconst takes two string arguments "n" and str.
If the string "n" is included in the arguments, then a number is printed
next to each constellation point giving the symbol value that would be
mapped to this point by the modmap function. The argument str
is a plot style string (example "r+") and determines the default gnuplot
point style to use for plot points in the constellation.
If apkconst is called with a return argument, then no plot is
created. However the return value is a vector giving the in-phase and
quadrature values of the symbols in the constellation.
See also: dmod, ddemod, modmap, demodmap.
Package: communications