signals,systems and networks, MATLAB in Engineering

Q.1: Consider the transmission of a sinusoid x(t) = cos(2f0t) through a channel a ected
by multipath and Doppler. Let there be two paths, and assume the sinusoid is being sent
from a moving transmitter so that a Doppler frequency shift occurs. Let the received signal
be
r(t) = 0cos(2(f0 ?? v)(t ?? L0=c)) + 1cos(2(f0 ?? v)(t ?? L1=c))
where 0  i  1 are attenuations, Li are the distances from the transmitter to the receiver
that the signal travels in the ith path i = 1,2, c = 3  108 m/sec, and the frequency shift
v is caused by the Doppler e ect.
(a) Let f0 = 2 KHz, v = 50 Hz, 0 =1, 1 = 0.9 and L0 = 10,000 meters. What would
be L1 if the two sinusoids have a phase di erence of =2 ?
(b) Is the received signal r(t), with the parameters given above but L1 = 10,000, periodic?
If so, what would be its period and how much does it di er from the period of the
original sinusoid? If x(t) is the input and r(t) the output of the transmission channel,
considered a system, is it linear and time invariant? Explain.
(c) Sample the signals x(t) and r(t) using a sampling frequency Fs = 10 KHz. Plot the
sampled sent x(nTs) and received r(nTs) signals for n = 0 to 2000.
(d) Consider the situation where f0 = 2 KHz, but the parameters of the paths are random,
trying to simulate real situations where these parameters are unpredictable, although
somewhat related. Let
r(t) = 0cos(2(f0 ?? v)(t ?? L0=c)) + 1cos(2(f0 ?? v)(t ?? L1=c))
where v = 50 HZ, L0 = 1,000, L1 = 10,000, 0 = 1 - , 1 = 0/10 and  is a
random number between 0 and 1 with equal probability of being any of these values
1
(this can be realized by using the rand MATLAB function). Generate the received
signal for 10 di erent events, use Fs = 10,000 Hz as the sampling rate, and plot them
together to observe the e ects of the multipath and Doppler.
Posted Date: 11/6/2012 8:10:23 AM | Location : USA







Related Discussions:- signals,systems and networks, Assignment Help, Ask Question on signals,systems and networks, Get Answer, Expert's Help, signals,systems and networks Discussions

Write discussion on signals,systems and networks
Your posts are moderated
Related Questions
Illustration of gauss-jordan: Here's an illustration of performing such substitutions by using MATLAB >> a = [1 3 0; 2 1 3; 4 2 3] a = 1 3 0 2 1 3 4 2

Help command: The help command is used with the script rectarea, the function readlenwid, and the major function printrectarea. To see the first comment in the subfunction, as

Modular programs: In a modular program, the answer is broken down into modules, and each is executed as a function. The script is usually known as the main program. In orde

Passing arguments to functions: In all these functions examples faraway, at least one of the arguments was passed in the function call to be the value(s) of the equivalent inp

Reading from a Mat-File: The load function is used to read from various types of files. As with save function, by default the file will be supposed to be a MAT-file, and load

Related Structure Functions: There are many functions which can be used with structures in a MATLAB. The function isstruct will return 1 for logical true when the variable arg

Vectors of Structures: In numerous applications, involving database applications, information generally would be stored in the vector of structures, instead of in individual s

Function fieldnames - structure functions: The function fieldnames will return the names of the fields which are contained in the structure variable. >> pack_fields = fiel

Illustration of anonymous functions: Dissimilar functions stored in the M-files, when no argument is passed to an anonymous function, the parentheses should still be in the fu

Individual structure variable: The individual structure variable for one software package may look like this: The name of the structure variable is a package; it has f