A clever system designer claims that the
depicted
transmitter has, despite its complexity,
advantages over the usual amplitude modulation system.The message signal
is bandlimited to
Hz, and
the carrier frequency
. The channel attenuates the transmitted signal
and adds white noise of spectral height
.
The transfer function
is given by
Find an expression for the spectrum of
.
Sketch your answer.
Show that the usual coherent receiver
demodulates this signal.
Find the signal-to-noise ratio that results
when this receiver is used.
Find a superior receiver (one that yields a
better signal-to-noise ratio), and analyze itsperformance.
Multi-tone digital communication
In a so-called multi-tone system, several bits are
gathered together and transmitted simultaneously ondifferent carrier frequencies during a
second interval. For
example,
bits would be
transmitted according to
Here,
is the frequency offset for each bit and it is
harmonically related to the bit interval
. The value of
is either
or
.
Find a receiver for this transmission scheme.
An ELEC 241 almuni likes digital systems so much
that he decides to produce a discrete-time version. Hesamples the received signal (sampling interval
). How should
be related to
, the number of
simultaneously transmitted bits?
The alumni wants to find a simple form for the
receiver so that his software implementation runs as
efficiently as possible. How
would you recommend he implement thereceiver?
City radio channels
In addition to additive white noise, metropolitan
cellular radio channels also contain multipath: theattenuated signal and a delayed, further attenuated
signal are received superimposed. As shown in
[link] , multipath occurs
because the buildings reflect the signal and thereflected path length between transmitter and receiver
is longer than the direct path.
Assume that the length of the direct path is
meters and the
reflected path is 1.5 times as long. What is themodel for the channel, including the multipath and the
additive noise?
Assume
is 1 km.
Find and sketch the magnitude of the transfer functionfor the multipath component of the channel. How would
you characterize this transfer function?
Would the multipath affect AM radio? If not, why
not; if so, how so? Would analog cellular telephone,which operates at much higher carrier frequencies (800
MHz vs. 1 MHz for radio), be affected or not? Analogcellular telephone uses amplitude modulation to
transmit voice.
How would the usual AM receiver be modified tominimize multipath effects? Express your modified
receiver as a block diagram.
Downlink signal sets
In digital cellular telephone systems, the base station
(transmitter) needs to relay different voice signals toseveral telephones at the same time. Rather than send
signals at different frequencies, a clever Rice engineersuggests using a different signal set for each data
stream. For example, for two simultaneous data streams,she suggests BPSK signal sets that have the
depicted basic
signals .
is it possible to leave every good at the same level
Joseph
I don't think so. because check it, if the demand for chicken increases, people will no longer consume fish like they used to causing a fall in the demand for fish
Anuolu
is not really possible to let the value of a goods to be same at the same time.....
Salome
Suppose the inflation rate is 6%, does it mean that all the goods you purchase will cost
6% more than previous year? Provide with reasoning.
Not necessarily. To measure the inflation rate economists normally use an averaged price index of a basket of certain goods. So if you purchase goods included in the basket, you will notice that you pay 6% more, otherwise not necessarily.
Good day
How do I calculate this question: C= 100+5yd G= 2000 T= 2000 I(planned)=200.
Suppose the actual output is 3000. What is the level of planned expenditures at this level of output?
I am Camara from Guinea west Africa... happy to meet you guys here
Sekou
ma management ho
Amisha
ahile becheclor ho
Amisha
hjr ktm bta ho
ani k kaam grnu hunxa tw
Amisha
belatari
Amisha
1st year ho
Amisha
nd u
Amisha
ahh
Amisha
kaha biratnagar
Amisha
ys
Amisha
kina k vo
Amisha
money as unit of account means what?
Kalombe
A unit of account is something that can be used to value goods and services and make calculations
Jim
all of you please speak in English I can't understand you're language
Muhammad
I want to know how can we define macroeconomics in one line
Muhammad
it must be .9 or 0.9
no Mpc is greater than 1
Y=100+.9Y+50
Y-.9Y=150
0.1Y/0.1=150/0.1
Y=1500
Kalombe
Mercy is it clear?😋
Kalombe
hi can someone help me on this question
If a negative shocks shifts the IS curve to the left, what type of policy do you suggest so as to stabilize the level of output?
discuss your answer using appropriate graph.