Posts Tagged ‘implementation’
Energy Spectral Density and its Implementation in Matlab
Introduction:
ESD shows energy distribution in frequency spectrum. Its units are jouls/hz. Total Energy of signal is area under ESD of signal. This relation is provided by Parseval’s Theorem, which relates energy in time domain to the energy in frequency domain.
That is:
Where |X(f)|2 is Read the rest of this entry »
Implementing Amplitude Modulation on Matlab
In this tutorial we are writing a code in MATLAB for amplitude modulation of a signal and understanding the different cases of modulation in context of modulation index.
Steps to Follow:
- Generate a message signal of frequency 1Hz with m(t) = A + Amcos(2πfmt), and |m(t)|>0
- Generate a carrier signal of frequency 20Hz
- Plotting both the signals and their spectrum.
- Plotting the modulated signal and it’s spectrum
- Amplitude modulation of the message signal with µ = 0.5, µ = 1, µ = 1.5
- Mention the case of over modulation.
Description:
Message Signal: To generate the message signal, the values of amplitude Am, frequency fm, offset value A and time axis have been defined. The value of fm is chosen as specified and values of Am and t are taken arbitrarily. A>Am to satisfy the condition |m(t)|>0. t is chosen such that sampling frequency is 500 samples/sec
m(t) = A + Am cos(2πfmt)
Carrier Signal: For generation of carrier signal fc is taken as specified. The Amplitude Ac is taken arbitrarily. Read the rest of this entry »