Function File: modmap (method, …) ¶

Function File: y = modmap (x, fd, fs, "ask", m) ¶

Function File: y = modmap (x, fd, fs, "fsk", m, tone) ¶

Function File: y = modmap (x, fd, fs, "msk") ¶

Function File: y = modmap (x, fd, fs, "psk", m) ¶

Function File: y = modmap (x, fd, fs, "qask", m) ¶

Function File: y = modmap (x, fd, fs, "qask/cir", nsig, amp, phs) ¶

Function File: y = modmap (x, fd, fs, "qask/arb", inphase, quadr) ¶

Function File: y = modmap (x, fd, fs, "qask/arb", map) ¶

Mapping of a digital signal to an analog signal. With no output arguments modmap plots the constellation of the mapping. In this case the first argument must be the string method defining one of "ask", "fsk", "msk", "qask", "qask/cir" or "qask/arb". The arguments following the string method are generally the same as those after the corresponding string in the function call without output arguments. The exception is modmap ("msk", Fd).

With an output argument, y is the complex mapped analog signal. In this case the arguments x, fd and fs are required. The variable x is the digital signal to be mapped, fd is the sampling rate of the of digital signal and the fs is the sampling rate of the analog signal. It is required that fs/fd is an integer.

The available mapping of the digital signal are

"ask"

Amplitude shift keying

"fsk"

Frequency shift keying

"msk"

Minimum shift keying

"psk"

Phase shift keying

"qask"

"qsk"

"qam"

Quadrature amplitude shift keying

In addition the "qask", "qsk" and "qam" method can be modified with the flags "/cir" or "/arb". That is "qask/cir" and "qask/arb", etc are valid methods and give circular- and arbitrary-qask mappings respectively.

The additional argument m is the order of the modulation to use. m must be larger than the largest element of x. The variable tone is the FSK tone to use in the modulation.

For "qask/cir", the additional arguments are the same as for apkconst, and you are referred to apkconst for the definitions of the additional variables.

For "qask/arb", the additional arguments inphase and quadr give the in-phase and quadrature components of the mapping, in a similar mapping to the outputs of qaskenco with one argument. Similar map represents the in-phase and quadrature components of the mapping as the real and imaginary parts of the variable map.

See also: demodmap, dmodce, amodce, apkconst, qaskenco.

Package: communications