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As indicated in [link] , pulses are initiated at intervals of T t seconds, and each is scaled by the 4-PAM symbol value. This translates the discrete-time symbol sequence s [ i ] (composed of the messages interleaved with the preamble) into a continuous time signal

s ( t ) = i s [ i ] δ ( t - i T t - ϵ t ) .

The actual transmitter symbol period T t is required to be within some tolerance of the nominal symbol period T , but the B 3 I G Transmitter allows the introduction of a non-ideal clock that is slightly different from the specified (true)clock at the receiver. The transmitter symbol period clock is assumed to be steady enough that the timing offset ϵ t and its period T t are effectively time-invariant over the duration of a single frame.

Signal flow diagram of the B^3IG Transmitter closely follows the M^6 transmitter of Figure 15-1 on page 213.
Signal flow diagram of the B 3 I G Transmitter closely follows the M 6 transmitter of [link] .

The pulse-shaping filter P ( f ) is a square-root raised cosine filter symmetrically truncated to a specified number ofsymbol periods. The rolloff factor β of the pulse-shaping filter is fixed within some range and is known at the receiver,though it could take on different values with different transmissions. The pulse-shaped signal is then converted to theRF frequency and passed through the channel. Since the receiver is assumed to employ a sampled IF architecture,the IF frequency completely specifies the behavior of the signal in the frequency domain.While it might seem preferable to build a transmitter that operates at the RF frequency to more accurately model the real transmitter, the number of samples necessary to represent such a signal is large enough that it is rarely desirable.

The channel may be near ideal, i.e. a unit gain multi-symbol delay, or it may have significant intersymbol interference. In addition it can be time-varying, and the B 3 I G code allows two ways to introduce time variation. The first permits specification of the channel impulse response c 1 at the start of the transmission and the channel impulse response c 2 at the end of the transmission. At any time in between, the actual impulse response moves linearly from c 1 to c 2 . The second method of introducing time variation is to model the channel variation as a random walk. The variance of therandom walk process can be specified. In either case, the impulse response of the channel is unknownat the receiver, though an upper bound on its delay spread may be available in practice.There are also other disturbances which may be present, including interference from adjacent channels and narrowband interferers.These disturbances can also be controlled using the B 3 I G Transmitter, and they are assumed to be unknown at the receiver.

The achieved intermediate frequency is required to be within some user-specified tolerance of its assigned value.The carrier phase θ ( t ) is unknown to the receiver and may vary over time, albeit slowly, due to phase noise.This means that the phase of the intermediate frequency signal presented to the receiver sampler may also vary.

The frontend of the sampled IF receiver, as shown in [link] , consists of a low noise amplifier, a preselect filter, AGC, mixer for downconversion to IF, and the sampler. The preselect filter partially attenuates adjacentFDM user bands. The automatic gain control is presumed locked and fixed over each transmission, and outputs a signalwhose average power is unity. The free-running sampler frequency f s needs to be well above twice the baseband bandwidth of the user of interest to allow proper functioning of thebaseband analog signal interpolator in the DSP timer in the the receiver. However, f s need not be twice the highest frequency of the IF signal. This implies that the sampled received signal hasreplicated the spectrum of the user transmission at the output of the front-end analog downconverter lowpass filter to frequencies betweenzero and IF.

Questions & Answers

what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
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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