# 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.

how environment affect demand and supply of commodity ?
Wht at the criteria for market ?
Amos
what is difference between monitory policy and fiscal policy?
monetary policy is a policy thrust by National Govt(CBN) to influence government spending, purchase &taxes
Frank
necessity of economics
I will say want,choice,opportunity cost,scarcity,scale of preference
Alao
what is monopoly market.How price output are determined under monopoly market
bisham
b) Monopoly market is an impecfect market where s single firm having the innovation to produce a particular commodity.Prices are determined through output since there are no other competitive.
Frank
Monopoly market:firm has market power & does not respond to market price
Frank
Explain the process of price determination under perfect competition market with suitable diagram
Price determination under perfect competition via this process :firms have no market power to influence price rather firms respond to market price.
Frank
price is different from demand- demand is amount of commodity
demand is amount /quantity of commodity a potential buyer is willing to buy at a given price at market
Frank
demand is a desire of customer on commodity with the ability to pay it and willing to buy it at given price of commodity
Harika
demand is price of what
show that shortrun average cost
what is economics
what is money
Mbah
what is money
Mbah
Difine macro economics
agaba
money is a medium of exchange between goods and services,maybe inform of currency.
Wesonga
Economics is study of how human beings strive to satisfy numerous wants using limited available resources.
Wesonga
how do you find the maximum number of workers the firms should employ order to produce where there are increasing returns
Jane
what are implications of computing national income?.
agaba
pl
MUDASIRU
what is the formulae for calculating national income
MUDASIRU
it calculated by value added method
Praveen
classify the production units like agriculture, banking, transport etc
Praveen
money is anything that is generally acceptetable for human
Ogbaji
Estimate the net value added(NVA) at fixed cost by each industrial structure
Praveen
definition of unemployment
what are the causes of unemployment?
The main causes of unemployment are listed below. 1. Frictional unemployment 2. Cyclical unemployment 3. Structural unemployment
assani
We can also categorize the causes on a broader sense as: 1. Political and 2. Social cause As unemployeement root causes are embaded in this two.
Yonathan
would opportunity cost exist if there was no scarcity?
assani
yes just because the opportunity cost arose when there is Alternative to choose among the alternatives.
I am thinking that, if our resources were unlimited, then there wouldn't be any need to forgo some wants. Hence the inexistence if opportunity cost
assani
Politics
Job
politics has done what?
assani
consider time assani
Mary
I'm Emmanuel,...I taught the main cause is the change in gov't.
Emmanuel
...Lack of capital to set up a firm respectively
Emmanuel
🙈
Emmanuel
I would like to bring in Educational levels can also be the cause the cause of the problem respectively
Emmanuel
I think the main causes of unemployment is lack of INFRASTRUCTURAL DEVELOPMENT OVER POPULATION OVER DEPENDENT ON GOVERNMENT LACK OF SELF EMPOWERMENT...
ananti
lack of skills among the new generation is the serious issue.
Vishal
Where I come from , I don't see why education or personal aspects seem to do with unimployment, technically the motivation and eigerness in all works of live is there , dispite the cultural influence and physical bearriors;the thing we lacking is Government Support and open market ethics.
Joe
sorry about that-(repation). We have a over powering ethical political system that's displacing the marketing asspects of economy and causing large scale unemployment right across the board...
Joe
can someone Explain Expansionary Monetary Policy and Contractionary Monetary Policy Using one of the instrument of Monetary Policy? Please am kinda lost here?. ta
using a graph show the case of substitute and compliment goods
can anyone give me a simple explanation to Five Sector Macroeconomics?
Emmanuel
Can someone please define what economics is
economics simply is a social science subject that study human behavior.
dajan
economics is a social science which studies human behaviour as a relationship between ends and scarce means that has alternative uses
Alao
Can someone please tell me how to calculate GDP
Emmanuel
emmanual kapal to calculate GDP (Gross Domestic Product) has three method in calculating it (1)income approach (2) expenditure approach (3) value added method
Alao
thanks Alae
Emmanuel
u are welcome
Alao
in basic terms economics is revered to as battery system, it date back to when Men sees the need to exchange sapless goods and produce to gain , either wealth , basic necessities or to establish trading ties for personal benefit or social asspects in terms of coexistence and continuity, future .
Joe
what is the law of demand
keep other thing constant, when the price increases demand decrease when the price decreases demand increases of the commodity.
sj
all things being equal,quantity demanded decrease as price increase and increase as price decrease
Seth
there's practial joke to it ..." the higher the demand ; scarcity, increase in production and drop in quality"... quite the controversy - for example China vs Europe, United States and we are all boxed up in between somewhere...
Joe
Other thing remain constant the low price of commodity the high quantity of commodity and vice versa is true
Baraka
Explain Effective demand
What is effective demand
Anita
like Modi is in demand...best example of effective demand
Pranav
Don't get you
Anita
Anita you mean you don't get me or who?
Onyeking
level of demand that represents a real intention to purchase by people with the means to pay
Pranav
Difference between extinct and extici spicies
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