How do you do AM demodulation in Matlab?

How do you do AM demodulation in Matlab?

Demodulate AM Signal

1. Copy Command Copy Code.
2. fc = 10e3; fs = 80e3; t = (0:1/fs:0.01)’;
3. s = sin(2*pi*300*t)+2*sin(2*pi*600*t);
4. [num,den] = butter(10,fc*2/fs);
5. y = ammod(s,fc,fs);
6. z = amdemod(y,fc,fs,0,0,num,den);
7. plot(t,s,’c’,t,z,’b–‘) legend(‘Original Signal’,’Demodulated Signal’) xlabel(‘Time (s)’) ylabel(‘Amplitude’)

How do I make an AM signal in Matlab?

Examples

1. Copy Command Copy Code. Set the sample rate to 100 Hz.
2. fs = 100; t = (0:1/fs:100)’; Set the carrier frequency to 10 Hz.
3. fc = 10; x = sin(2*pi*t); Modulate x using single- and double-sideband AM.
4. ydouble = ammod(x,fc,fs); ysingle = ssbmod(x,fc,fs);
5. sa = dsp.SpectrumAnalyzer(‘SampleRate’,fs, ‘
6. sa(ysingle)

What demodulator is used for AM?

diode detector
The diode detector is the simplest form of detector or demodulator used for AM demodulation – it detects the AM signal envelope. The diode detector is the simplest and most basic form of amplitude modulation, AM signal detector and it detects the envelope of the AM signal.

How do you demodulate an AM signal?

An AM radio signal can be demodulated by rectifying it to remove one side of the carrier, and then filtering to remove the radio-frequency component, leaving only the modulating audio component. This is equivalent to peak detection with a suitably long time constant.

How does a synchronous detector work?

In electronics, a synchronous detector is a device that recovers information from a modulated signal by mixing the signal with a replica of the un-modulated carrier. This can be locally generated at the receiver using a phase-locked loop or other techniques.

How do you modulate two signals in MATLAB?

y = modulate( x , fc , fs ) modulates the real message signal x with a carrier frequency fc and sample rate fs . If x is a matrix, the modulated signal is computed independently for each column and stored in the corresponding column of y . [ y , t ] = modulate( x , fc , fs ) also returns the internal time vector t .

Why LPF is used in demodulator?

The capacitor and resistor form a low-pass filter to filter out the carrier frequency. Such a device is often used to demodulate AM radio signals because the envelope of the modulated signal is equivalent to the baseband signal.

What is the function of demodulator?

Demodulation. The process of separating the original information or SIGNAL from the MODULATED CARRIER. In the case of AMPLITUDE or FREQUENCY MODULATION it involves a device, called a demodulator or detector, which produces a signal corresponding to the instantaneous changes in amplitude or frequency, respectively.

What are the techniques of AM?

Amplitude modulation (AM) is a modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave. In amplitude modulation, the amplitude (signal strength) of the wave is varied in proportion to that of the message signal, such as an audio signal.

Why do we need to demodulate the signals?

The diaphragm of a telephone receiver or a loud speaker cannot vibrate with high frequency. Moreover, this frequency is beyond the audible range of human ear. So, it is necessary to separate the audio frequencies from radio- frequency carrier waves.