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 .
Questions & Answers
Three charges q_{1}=+3\mu C, q_{2}=+6\mu C and q_{3}=+8\mu C are located at (2,0)m (0,0)m and (0,3) coordinates respectively. Find the magnitude and direction acted upon q_{2} by the two other charges.Draw the correct graphical illustration of the problem above showing the direction of all forces.
To solve this problem, we need to first find the net force acting on charge q_{2}. The magnitude of the force exerted by q_{1} on q_{2} is given by F=\frac{kq_{1}q_{2}}{r^{2}} where k is the Coulomb constant, q_{1} and q_{2} are the charges of the particles, and r is the distance between them.
Muhammed
What is the direction and net electric force on q_{1}= 5µC located at (0,4)r due to charges q_{2}=7mu located at (0,0)m and q_{3}=3\mu C located at (4,0)m?
Capacitor is a separation of opposite charges using an insulator of very small dimension between them. Capacitor is used for allowing an AC (alternating current) to pass while a DC (direct current) is blocked.
Gautam
A motor travelling at 72km/m on sighting a stop sign applying the breaks such that under constant deaccelerate in the meters of 50 metres what is the magnitude of the accelerate
velocity can be 72 km/h in question. 72 km/h=20 m/s, v^2=2.a.x , 20^2=2.a.50, a=4 m/s^2.
Mehmet
A boat travels due east at a speed of 40meter per seconds across a river flowing due south at 30meter per seconds. what is the resultant speed of the boat
which has a higher temperature, 1cup of boiling water or 1teapot of boiling water which can transfer more heat 1cup of boiling water or 1 teapot of boiling water explain your . answer
I believe temperature being an intensive property does not change for any amount of boiling water whereas heat being an extensive property changes with amount/size of the system.
Someone
Scratch that
Someone
temperature for any amount of water to boil at ntp is 100⁰C (it is a state function and and intensive property) and it depends both will give same amount of heat because the surface available for heat transfer is greater in case of the kettle as well as the heat stored in it but if you talk.....
Someone
about the amount of heat stored in the system then in that case since the mass of water in the kettle is greater so more energy is required to raise the temperature b/c more molecules of water are present in the kettle
pratica A on solution of hydro chloric acid,B is a solution containing 0.5000 mole ofsodium chlorid per dm³,put A in the burret and titrate 20.00 or 25.00cm³ portion of B using melting orange as the indicator. record the deside of your burret tabulate the burret reading and calculate the average volume of acid used?
No. According to Isac Newtons law. this two bodies maybe you and the wall beside you.
Attracting depends on the mass och each body and distance between them.
Dlovan
Are you really asking if two bodies have to be charged to be influenced by Coulombs Law?
Specific heat capacity is a measure of the amount of energy required to raise the temperature of a substance by one degree Celsius (or Kelvin). It is measured in Joules per kilogram per degree Celsius (J/kg°C).
AI-Robot
specific heat capacity is the amount of energy needed to raise the temperature of a substance by one degree Celsius or kelvin
ROKEEB
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