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
Splits a string : The strtok function splits a string into pieces; it can be called in many ways. The function receives one string as an input argument. It appears for the fir

Illustration of Set operations: For illustration, given the vectors as shown below: >> v1 = 2:6 v1 = 2  3  4  5  6 >> v2 = 1:2:7 v2 = 1  3  5  7

str2num function - String: The function str2num does the opposite; it takes the string in which a number is stored and converts it to the type double: >> num = str2num('123.

Illustration of Subfunctions: This is an illustration of running this program: >> rectarea Please enter the length: 6 Please enter the width: 3 For a rectan

Graphics Properties: The MATLAB uses the Handle Graphics in all its figures. All figures consist of various objects, each of which is assigned a handle. The object handle is a

I have a frequency response data. How do I convert that to state space? I am given a 6 row and 3 column data (steady state). How do i convert that to state space model?

Passing Structures to Functions: The whole structure can be passed to a function, or separate fields can be passed. For illustration, here are the two distinct versions of a f

Implementation of binary search: The binary search can be implemented as a recursive function. The recursive function below also implements this binary search algorithm. It re

Finding a sting - function strfind: The function strfind does necessarily similar thing, except that the order of the arguments does make dissimilarity. The common form is str

Expanding a function: The expand function will multiply out terms, and factor will do the opposite: >> expand((x+2)*(x-1)) ans = x^2 x-2 >> factor(ans)