# 0.4 Lab 4 - sampling and reconstruction  (Page 5/7)

 Page 5 / 7

To start the second experiment, double click on the icon named Sampling and Reconstruction Using A Sample and Hold . [link] shows the initial setup for this exercise. It contains 4 Scopes to monitor the processing done in the sampling and reconstruction system. It also contains a Network Analyzer for measuring the frequency response and the impulse response of the system.

The Network Analyzer works by generating a weighted chirp signal (shown on Scope 1 ) as an input to the system-under-test. The frequency spectrumof this chirp signal is known. The analyzer then measures the frequency content of theoutput signal (shown on Scope 4 ). The transfer function is formed by computing the ratio of the outputfrequency spectrum to the input spectrum. The inverse Fourier transform of this ratio, whichis the impulse response of the system, is then computed.

In the initial setup, the Sample-and-Hold and Scope 3 are not connected. There is no sampling in this system, just two cascaded low-pass filters.Run the simulation and observe the signals on the Scopes . Wait for the simulation to end.

Submit the figure containing plots of the magnitude response, the phase response, and the impulse response of this system.Use the tall mode to obtain a larger printout by typing orient('tall') directly before you print.

Double-click the Sample-and-Hold and set its Sample time to 1. Now, insert the Sample-and-Hold in between the two filters and connect Scope 3 to its output. Run the simulation and observethe signals on the Scopes .

Submit the figure containing plots of the magnitude response, the phase response, and the impulse response of this system.Explain the reason for the difference in the shape of this magnitude response versus the previous magnitude response.Give an analytical expression for the behavior of the magnitude plot for frequencies below $0.45$ Hz.

## Discrete-time interpolation

In the previous experiments, we saw that the frequency content of a signal must be limited to half the sampling rate in orderto avoid aliasing effects in the reconstructed signal. However, reconstruction can be difficultif the sampling rate is chosen to be just above the Nyquist frequency. Reconstruction is much easier for a higher samplingrate because the sampled signal will better “track” the original analog signal.

From another perspective, the analog output filter must have a very sharp cutoff in order to accurately reconstructa signal that was sampled just above the Nyquist rate. Such filters are difficult and expensive to manufacture.Alternatively, a higher sampling rate allows the use analog output filters that have a slow roll-off.These filters are much less expensive. However, a high sampling rate is not practical in most applications, asit results in unnecessary samples and excessive storage requirements.

A practical solution to this dilemma is to interpolate the digital signal to create new (artificial) samples between the existing samples.This may be done by first upsampling the digital representation, and then filtering out unwanted components using a discrete-time filter.This discrete-time filter serves the same purpose as an analog filter with a sharp cutoff, but it is generally simplerand more cost effective to implement.

List and explain four factors of production
capital labour entrepreneur natural resources
Thembi
What is supply
when the supply decreases demand also decreases
Thembi
types of demand and the explanation
what is demand
other things remaining same if demend is increases supply is also decrease and if demend is decrease supply is also increases is called the demand
Mian
if the demand increase supply also increases
Thembi
you are wrong this is the law of demand and not the definition
Tarasum
Demand is the willingness of buy and ability to buy in a specific time period in specific place. Mian you are saying law of demand but not in proper way. you have to keep studying more. because its very basic things in Economics.
Hamza
Demand is the price of Quantity goods and services in which consumer's are willing and able to offer at a price in the market over a period of time
Umar
Demand is the quantity of goods and services that the consumer are willing and able to buy at a alternative prices over a given period of time. But mind you demand is quite different from need and want.
Tarasum
Demand can be defined as the graphical representation between price&demand
alkasim
sorry demand is nt a graphical representation between price and quantity demand but instead that is demand curve.
Ebrima
Demand is the willingness and ability of a consumer to buy a quantity of a good over a given period of time assuming all other things remain constant.
Vedaant
what is commercialization?
How to talk loan for bank?
what is the meaning of gpa?
Answer: GPA stands for Grade Point Average. It is a standard way of measuring academic achievement in the U.S. Basically, it goes as follows: Each course is given a certain number of "units" or "credits", depending on the content of the course.
Yusuf
what is small and Microbuisenes
What is fiscal policy
Dansofo
Who is the funder of Economic
Dansofo
founder , that is Adam Smith
Daniel
what is model
The wealth of Nations
the wealth of nations, is it the first?
Umar
Yes very sure it was released in 1759
Yusuf
thank you Yusuf.
Umar
then when did he died?
Umar
17 July 1790 Born: 16 June 1723, Kirkcaldy, United Kingdom Place of death: Panmure House, Edinburgh, United Kingdom
Yusuf
1790
Yusuf
that's my today questions, thank you Yusuf it's bed time see u after.
Umar
what is fiscal policy
what's mode?
mode is the highest occurring frequency in a distribution
Bola
mode is the most commonly occurring item in a set of data.
Umar
Please, what is the difference between monopoly and monopsony?
is there monopsony word?
Umar
I have no idea though
Umar
Umar
monopsony is when there's only one buyer while monopoly is when there's only one producer.
Bola
who have idea on Banter
Ibrahim
Bola
Monopoly is when there's excessively one seller and there is no entry in the market while monopsony is when there is one buyer
kemigisha
Adam smith was born in 1723
Bola
(uncountable) Good humoured, playful, typically spontaneous conversation. verb (intransitive) To engage in banter or playful conversation. (intransitive) To play or do something amusing. (transitive) To tease mildly.
Umar
which book Adam smith published first? the first book of Adam smith pls.
Umar
wealth on nation, 1776
Daniel
what is market power and how can it affect an economy?
market power:- where a firm is said to be a price setter.market power benefits the powerful at the expense of others.
Umar
Market power refers to the ability of a firm (or group of firms) to raise and maintain price above the level that would prevail under competition is referred to as market or monopoly power. The exercise of market power leads to reduced output and loss of economic welfare
Kartheek
find information about the national budget
Molahlegi
three branches of economics in which tourism is likely to figure
What are those three branches?
IlRegno
Difference between extinct and extici spicies
in a comparison of the stages of meiosis to the stage of mitosis, which stages are unique to meiosis and which stages have the same event in botg meiosis and mitosis
Researchers demonstrated that the hippocampus functions in memory processing by creating lesions in the hippocampi of rats, which resulted in ________.
The formulation of new memories is sometimes called ________, and the process of bringing up old memories is called ________.
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