## How do you do amplitude modulation in Matlab?

Create a time vector 100 seconds long.

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

**How do you calculate amplitude modulation?**

The equation for the overall modulated signal is obtained by multiplying the carrier and the modulating signal together. The constant A is required as it represents the amplitude of the waveform. Note also that the sidebands are separated from the carrier by a frequency equal to that of the tone.

**What is modulation index formula?**

The FM modulation index is equal to the ratio of the frequency deviation to the modulating frequency. To give an example of the FM modulation index, take the example where a signal has a deviation of ±5kHz, and the modulating frequency is 1kHz, then the modulation index for this particular instance is 5 / 1 = 5.

### How do you demodulate an AM signal in Matlab?

Demodulate AM Signal

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

**How do you create a carrier signal in Matlab?**

Examples

- Copy Command. Set the sampling frequency to 1kHz and carrier frequency to 200 Hz.
- fs = 1000; fc = 200; t = (0:1/fs:0.2)’;
- x = sin(2*pi*30*t)+2*sin(2*pi*60*t);
- fDev = 50;
- y = fmmod(x,fc,fs,fDev);
- plot(t,x,’c’,t,y,’b–‘) xlabel(‘Time (s)’) ylabel(‘Amplitude’) legend(‘Original Signal’,’Modulated Signal’)

**How is Vmin calculated?**

Each voltage is then rectified and summed up in series as in following examples:

- for 2phases (180deg apart) => series sum yields pulsing voltage with Vmin(2) = 0 volt minimums and Vmax(2) = 2 volt maximums.
- 3p (120d) => Vmin(3) = sqrt(3) and Vmax(3) = 2.
- 4p (90d) => Vmin(4) = 2 and Vmax(4) = 2*sqrt(2)
- …

#### What are the types of amplitude modulation?

Types of Amplitude Modulation They are; Double sideband-suppressed carrier modulation (DSB-SC). Single Sideband Modulation (SSB). Vestigial Sideband Modulation (VSB).

**Which statement is correct for modulation index in amplitude modulation?**

In amplitude modulation the amplitude of the high frequency carrier wave is made to vary in proportion to the amplitude of the audio signal. This is the correct option.

**What is modulation index value?**

Modulation index describes the extent to which modulation is done on a carrier signal. The value of the modulation index is kept less than 1 to avoid distortions in the modulated signal because it is very hard to demodulate the signal.