pmmod

Phase modulation

Syntax

y = pmmod(x,Fc,Fs,phasedev)

y = pmmod(x,Fc,Fs,phasedev,ini_phase)

Description

y = pmmod(x,Fc,Fs,phasedev) modulates the message signal x using phase modulation.

y = pmmod(x,Fc,Fs,phasedev,ini_phase) specifies the initial phase of the modulated signal in radians.

Examples

Recover Phase Modulated Signal from AWGN Channel

Set the sample rate. To plot the signals, create a time vector.

fs = 50; 
t = (0:2*fs+1)'/fs;

Create a sinusoidal input signal.

x = sin(2*pi*t) + sin(4*pi*t);

Set the carrier frequency and phase deviation.

fc = 10; 
phasedev = pi/2;

Modulate the input signal.

tx = pmmod(x,fc,fs,phasedev);

Pass the signal through an AWGN channel.

rx = awgn(tx,10,'measured');

Demodulate the noisy signal.

y = pmdemod(rx,fc,fs,phasedev);

Plot the original and recovered signals.

figure; plot(t,[x y]);
legend('Original signal','Recovered signal');
xlabel('Time (s)')
ylabel('Amplitude (V)')

Input Arguments

x — Input signal

vector | matrix

Input signal, specified as a vector or matrix of positive integers. If x is a matrix, pmmod processes the columns independently.

Example: sin(2*pi*t) + sin(6*pi*t)

Data Types: double

Fc — Carrier frequency

positive scalar

Carrier frequency, specified as a positive scalar.

Data Types: double

Fs — Sample rate

positive scalar

Sample rate, specified as a positive scalar. Fs must be at least 2*Fc.

Data Types: double

ini_phase — Initial phase

0 (default) | scalar | []

Initial phase of the modulated signal (in radians), specified as a real scalar.

Example: pi/4

Data Types: double

phasedev — Phase deviation

positive scalar

Phase deviation, specified as a positive scalar in radians.

Data Types: double

Output Arguments

y — PM-modulated output signal

vector | matrix

Complex baseband representation of a PM-modulated signal, returned as vector or matrix of complex values. The columns of y represent independent channels.

Data Types: double | single
Complex Number Support: Yes