Function File: z = demodmap (y, fd, fs, "ask", m) ¶

Function File: z = demodmap (y, fd, fs, "fsk", m, tone) ¶

Function File: z = demodmap (y, fd, fs, "msk") ¶

Function File: z = demodmap (y, fd, fs, "psk", m) ¶

Function File: z = demodmap (y, fd, fs, "qask", m) ¶

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

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

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

Function File: z = demodmap (y, [fd, off], …) ¶

Demapping of an analog signal to a digital signal. The function demodmap must have at least three input arguments and one output argument. Argument y is a complex variable representing the analog signal to be demapped. The variables fd and fs are the sampling rate of the of digital signal and the sampling rate of the analog signal respectively. 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. Also the method "fsk" and "msk" can be modified with the flag "/max", in which case y is assumed to be a matrix with m columns, representing the symbol correlations.

The variable m is the order of the modulation to use. By default this is 2, and in general should be specified.

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: modmap, ddemodce, ademodce, apkconst, qaskenco.

Package: communications