This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: ECE 146A: Communications I Lab 3: Amplitude Modulation and Demodulation Lab Report: Due at the beginning of lab Thursday, February 10 1 Objective The goal of this lab is to implement three types of amplitude modulation: conventional amplitude modulation (AM) (also known as double sideband (DSB) with carrier), single sideband (SSB), and double sideband suppressed carrier (DSB-SC). You will observe and analyze these different types of modulated signals in the time and frequency domains. This lab is designed to give you practice with Simulink. 2 Equipment Matlab, Simulink, and the Communications Toolbox software are available on the workstations in the software lab. 3 Generating Signals Using Simulink Implement the three types of amplitude modulation using Simulink and the formulas given below. You may do so using any blocks available to you including the Communications Toolbox. In your designs, strive for a single block from which you can choose a modulation type, such as the Analog Filter block where you can decide from various types of filters using a pull-down menu. For each case, use different message signals, such as a square wave, a periodic triangular function, and a sinusoidal function. 3.1 Conventional AM: s ( t ) = A c [1 + A m m ( t )]cos(2 πf c t ) (1) where A m is the amplitude of the message m ( t ) and A c is the amplitude of the carrier with frequency f c . 3.2 DSB-SC: s ( t ) = A c A m m ( t )cos(2 πf c t ) . (2) 1 3.3 SSB: s ( t ) = A c A m 2 m ( t )cos(2 πf c t ) + A c A m 2 ˇ m ( t )sin(2 πf c t ) (3) where ˇ m ( t ) is the Hilbert transform of m ( t )....
View Full Document
- Fall '09
- Ac Am, square-wave message signal