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Sources of corruption include multipath interference, changing channel gains, interference from other users, broadband noise, and narrowband interferences.
Sources of corruption include multipath interference, changing channel gains, interference fromother users, broadband noise, and narrowband interferences.

Broadband noise

When the signal arrives at the receiver, it is small and must be amplified. While it is possible to build high-gainamplifiers, the noises and interferences will also be amplified along with the signal. In particular, any noise in the amplifier itself will be increased. This is often called “thermal noise” and is usually modelled as white(independent) broadband noise. Thermal noise is inherent in any electronic components and is caused by smallrandom motions of electrons, like the Brownian motion of small particles suspended in water.

Such broadband noise is another reason that a bandpass filter is applied at the front end of the receiver. Byapplying a suitable filter, the total power in the noise (compared to the total power in the signal) can often be improved. [link] shows the spectrum of the signal as a pair of triangles centered at the carrier frequency ± f c with bandwidth 2 B . The total power in the signal is the area under the triangles. The spectrum of the noiseis the flat region, and its power is the shaded area. After applying the bandpass filter, the power in the signalremains (more or less) unchanged, while the power in the noise is greatly reduced. Thus, the signal-to-noise ratio (SNR) improves.

Narrowband noise

Noises are not always white; that is, the spectrum may not always be flat. Stray sine waves (and othersignals with narrow spectra) may also impinge on the receiver. These may be caused by errant transmitters that accidentlybroadcast in the frequency range of the signal, or they may be harmonics of a lower frequency waveas it experiences nonlinear distortion. If these narrowband disturbances occur out of band, they willautomatically be attenuated by the bandpass filter just as if they were a component of the wideband noise.However, if they occur in the frequency region of the signal, they decrease the SNR in proportion to theirpower. Judicious use of a “notch” filter (one designed to remove just the offending frequency) can be an effectivetool.

[link] shows the spectrum of the signal as the pair of triangles, along with three narrowband interferersrepresented by the three pairs of spikes. After the bandpass filter, the two pairs of out-of-band spikes are removed,but the in-band pair remains.

The signal-to-noise ratio is depicted graphically as the ratio of the power of the signal (the area under the triangles) to the power in the noise (the shaded area). After the bandpass filter, the power in the noise decreases, and so the SNR increases.
The signal-to-noise ratio is depicted graphically as the ratio of the power of the signal (the area under thetriangles) to the power in the noise (the shaded area). After the bandpass filter, the power in the noise decreases,and so the SNR increases.
Three narrowband interferers are shown in the top figure (the three pairs of spikes). The BPF cannot remove the in-band interferer, though a narrow notch filter can, at the expense of changing the signal in the region where the narrow band noise occurred.
Three narrowband interferers are shown in the top figure (the three pairs of spikes). The BPF cannot remove the in-band interferer,though a narrow notch filter can, at the expense of changing the signal in the region where the narrow band noise occurred.

Applying a narrow notch filter tuned to the frequency of the interferer allows its removal,although this cannot be done without also affecting the signal somewhat.

Questions & Answers

can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
ninjadapaul
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
ninjadapaul
I don't understand what the A with approx sign and the boxed x mean
ninjadapaul
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
ninjadapaul
oops. ignore that.
ninjadapaul
so you not have an equal sign anywhere in the original equation?
ninjadapaul
Commplementary angles
Idrissa Reply
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Sherica
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Sherica
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Tamia
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Kim
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Al
y=10×
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
is it 3×y ?
Joan Reply
J, combine like terms 7x-4y
Bridget Reply
im not good at math so would this help me
Rachael Reply
yes
Asali
I'm not good at math so would you help me
Samantha
what is the problem that i will help you to self with?
Asali
how do you translate this in Algebraic Expressions
linda Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Software receiver design. OpenStax CNX. Aug 13, 2013 Download for free at http://cnx.org/content/col11510/1.3
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