FirstRanker Logo

FirstRanker.com - FirstRanker's Choice is a hub of Question Papers & Study Materials for B-Tech, B.E, M-Tech, MCA, M.Sc, MBBS, BDS, MBA, B.Sc, Degree, B.Sc Nursing, B-Pharmacy, D-Pharmacy, MD, Medical, Dental, Engineering students. All services of FirstRanker.com are FREE

📱

Get the MBBS Question Bank Android App

Access previous years' papers, solved question papers, notes, and more on the go!

Install From Play Store

Download Anna University B-Tech ECE 5th Sem Communication Systems CS Lab Manual Question Paper

Download Anna University B.Tech (Bachelor of Technology) ECE (Electronics And Communications Engineering) 5th Sem Communication Systems CS Lab Manual Question Paper.

This post was last modified on 13 December 2019

Anna University B.Tech Lab Manual


FirstRanker.com

DEPARTMENT OF

ELECTRONICS COMMUNICATION ENGINEERING

--- Content provided by‍ FirstRanker.com ---

V SEMESTER - R 2013

EC6512 – COMMUNICATION SYSTEMS LABORATORY

LABORATORY MANUAL

Name : __________________________

Register No. : __________________________

--- Content provided by⁠ FirstRanker.com ---

Section : __________________________

FirstRanker.com

DHANALAKSHMI

VISION

College of Engineering is committed to provide highly disciplined, conscientious

--- Content provided by‌ FirstRanker.com ---

enterprising professionals conforming to global standards through value based quality education training.

MISSION

  • To provide competent technical manpower capable of meeting requirements of the industry
  • To contribute to the promotion of Academic Excellence in pursuit of Technical Education at different levels
  • To train the students to sell his brawn brain to the highest bidder but to never put a price tag on heart soul
  • --- Content provided by⁠ FirstRanker.com ---

DEPARTMENT OF ELECTRONICS AND COMMUNICATION

ENGINEERING

VISION

To impart professional education integrated with human values to the younger generation, so as to

shape them as proficient dedicated engineers, capable of providing comprehensive solutions to the challenges

--- Content provided by‌ FirstRanker.com ---

in deploying technology for the service of humanity

MISSION

  • To educate the students with the state-of-art technologies to meet the growing challenges of the electronics industry
  • To carry out research through continuous interaction with research institutes industry, on advances in communication systems
  • To provide the students with strong ground rules to facilitate them for systematic learning, innovation ethical practices
  • --- Content provided by⁠ FirstRanker.com ---

FirstRanker.com

PROGRAMME EDUCATIONAL OBJECTIVES (PEOS)

1. Fundamentals

To provide students with a solid foundation in Mathematics, Science fundamentals of engineering,

enabling them to apply, to find solutions for engineering problems use this knowledge to acquire higher

--- Content provided by‌ FirstRanker.com ---

education

2. Core Competence

To train the students in Electronics Communication technologies so that they apply their knowledge

training to compare, to analyze various engineering industrial problems to find solutions

3. Breadth

--- Content provided by⁠ FirstRanker.com ---

To provide relevant training experience to bridge the gap between theory practice this enables them to

find solutions for the real time problems in industry, to design products

4. Professionalism

To inculcate professional effective communication skills, leadership qualities team spirit in the students

to make them multi-faceted personalities develop their ability to relate engineering issues to broader social

--- Content provided by⁠ FirstRanker.com ---

context

5. Lifelong Learning/Ethics

To demonstrate practice ethical professional responsibilities in the industry society in the large,

through commitment lifelong learning needed for successful professional career

FirstRanker.com

--- Content provided by⁠ FirstRanker.com ---

PROGRAMME OUTCOMES (POS)

a) To demonstrate apply knowledge of Mathematics, Science engineering fundamentals in Electronics

Communication Engineering field

b) To design a component, a system or a process to meet the specific needs within the realistic constraints

such as economics, environment, ethics, health, safety manufacturability

--- Content provided by​ FirstRanker.com ---

c) To demonstrate the competency to use software tools for computation, simulation testing of electronics

communication engineering circuits

d) To identify, formulate solve electronic communication engineering problems

e) To demonstrate an ability to visualize work on laboratory multidisciplinary tasks

f) To function as a member or a leader in multidisciplinary activities

--- Content provided by⁠ FirstRanker.com ---

g) To communicate in verbal written form with fellow engineers society at large

h) To understand the impact of Electronics Communication Engineering in the society demonstrate awareness

of contemporary issues commitment to give solutions exhibiting social responsibility

i) To demonstrate professional and ethical responsibilities

j) To exhibit confidence in self-education ability for lifelong learning

--- Content provided by⁠ FirstRanker.com ---

k) To participate succeed in competitive exams

FirstRanker.com

EC6512 - COMMUNICATION SYSTEMS LABORATORY

COURSE OBJECTIVES

To visualize the effects of sampling and TDM

--- Content provided by‌ FirstRanker.com ---

  • To Implement AM and FM modulation and demodulation
  • To implement PCM and DM
  • To implement FSK, PSK and DPSK schemes
  • To implement Equalization algorithms
  • To implement Error control coding schemes
  • --- Content provided by​ FirstRanker.com ---

LIST OF EXPERIMENTS

1. Signal Sampling and reconstruction

2. Time Division Multiplexing

3. AM Modulator and Demodulator

4. FM Modulator and Demodulator

--- Content provided by​ FirstRanker.com ---

5. Pulse Code Modulation and Demodulation

6. Delta Modulation and Demodulation

7. Observation (simulation) of signal constellations of BPSK, QPSK and QAM

8. Line coding schemes

9. FSK, PSK and DPSK schemes (Simulation)

--- Content provided by‌ FirstRanker.com ---

10. Error control coding schemes – Linear Block Codes (Simulation)

11. Communication link simulation

12. Equalization – Zero Forcing and LMS algorithms (simulation)

COURSE OUTCOMES

Simulate end-to-end Communication Link

--- Content provided by⁠ FirstRanker.com ---

Demonstrate their knowledge in base b signaling schemes through implementation of FSK, PSK DPSK.

Apply various channel coding schemes and demonstrate their capabilities towards the improvement of the noise

performance of communication system.

FirstRanker.com

EC6512 - COMMUNICATION SYSTEMS LABORATORY

--- Content provided by​ FirstRanker.com ---

CONTENTS

Sl. No. Name of the Experiment Page No.
CYCLE 1 - EXPERIMENTS
1 Signal sampling reconstruction 7
2 Time division multiplexing 13
3 AM modulation demodulation 18
4 Frequency modulation demodulation 26
5 PCM modulation demodulation 33
6 Delta modulation demodulation 38
7 Line coding decoding techniques 45
CYCLE 2 – EXPERIMENTS
8 Error control coding using MATLAB 51
9 Design of BPSK, QPSK, QAM using MATLAB 53
10 Design of FSK, PSK DPSK using MATLAB 55
11 Communication link simulation using MATLAB 57
12 Zero forcing LMS equalization algorithms using MATLAB 59
ADDITIONAL EXPERIMENTS BEYOND THE SYLLABUS
13 Pulse amplitude modulation 61
14 Amplitude modulation demodulation using LabVIEW 64

FirstRanker.com

Expt. No. 1

CYCLE 1 - EXPERIMENTS

SIGNAL SAMPLING AND RECONSTRUCTION

--- Content provided by⁠ FirstRanker.com ---

Aim:

To study the process of sampling and reconstruction of signals using analog sampling trainer kit

Apparatus required:

1. Analog signal sampling and reconstruction trainer kit – 1 No.

2. Dual Power Supply – 1 No.

--- Content provided by​ FirstRanker.com ---

3. Patch cords – 6 Nos.

4. CRO (30 MHz) – 1 No.

Theory:

Sampling is defined as measuring the value of an information signal at predetermined time interval. The rate at

which the signal is sampled is known as the sampling rate or sampling frequency. The types of sampling are

--- Content provided by FirstRanker.com ---

natural sampling and flat top sampling.

A continuous time signal can be processed by processing its samples through a discrete time system. For

reconstructing the continuous time signal from its discrete time samples without any error, the signal should be

sampled at a sufficient rate that is determined by the sampling theorem.

Sampling theorem

--- Content provided by‌ FirstRanker.com ---

If a signal is band limited and its samples are taken at sufficient rate than those samples uniquely specify the

signal and the signal can be reconstructed from those samples. The condition in which this is possible is known

as Nyquist sampling theorem.

A signal whose spectrum is band limited to D Hz [X(f) = 0 for f >D can be reconstructed from its samples

taken uniformly at a rate fs > 2D samples/sec. The minimum sampling frequency is fs = 2D Hz.

--- Content provided by FirstRanker.com ---

Reconstruction of Signals

The process of reconstructing a continuous time signal x(t) from its samples is known as interpolation. In the

sampling theorem a signal x(t) band limited to D Hz can be reconstructed from its samples. This reconstruction is

accomplished by passing the sampled signal through an ideal low pass filter of bandwidth D Hz.To

recover x(t) or X(f), the sampled signal must be passed through an ideal low pass filter having bandwidth D Hz

--- Content provided by‌ FirstRanker.com ---

and gain T.

FirstRanker.com

Sample and hold circuit is used to operate on analog information in a time frame which is expedient. This circuit

works by sampling a segment of the information holding it and then converts it into some readout or a form of

control signal.

--- Content provided by​ FirstRanker.com ---

Procedure:

1. Assemble the sample and hold circuit with the desired components.

2. Give the input signal from the function generator.

3. Do not exceed the input signal above 10 volt.

4. Set the frequency of the input signal to 600 Hz.

--- Content provided by⁠ FirstRanker.com ---

5. Set the frequency of the sample signal to 5600 Hz.

6. Integrate the sampling inputs.

Circuit Diagram

FirstRanker.com

FirstRanker.com

--- Content provided by‍ FirstRanker.com ---

FirstRanker.com

FirstRanker.com

FirstRanker.com

FirstRanker.com

FirstRanker.com

--- Content provided by‍ FirstRanker.com ---

FirstRanker.com

Tabulation

Signal Amplitude (V) Time period (s)
Message signal
Carrier signal
Sampled output

Analog signal sampling and reconstruction trainer kit

Result:

Thus the sampling and reconstruction of signal was studied and verified using sampling reconstruction trainer

--- Content provided by⁠ FirstRanker.com ---

kit.

FirstRanker.com

Outcome:

After completion of this experiment, the students will be able to understand the discretization process of

continuous time signal.

--- Content provided by‌ FirstRanker.com ---

Applications:

1. Analog-to-digital conversion (ADC)

2. Digital-to-analog conversion (DAC)

3. Storage, and transmission

4. Telephone and encrypted walkie-talkie (8000 Hz sample rate)

--- Content provided by‌ FirstRanker.com ---

5. Wireless intercom and wireless microphone transmission (Audio Sampling)

Viva - voce

1. Define - Sampling Theorem

2. What is the necessary sufficient condition for sampling reconstruction of a signal?

3. Define - Nyquist rate

--- Content provided by‌ FirstRanker.com ---

4. Define - Nyquist interval

5. What are the different types of sampling techniques?

6. What is the effect on sampled signal if fs< 2 fm?

7. Draw the amplitude spectrum of sampled signal if fs< 2 fm, fs =2 fm, fs > 2 fm.

8. What is aliasing effect in sampling? How to avoid it?

--- Content provided by​ FirstRanker.com ---

9. Why do we use pre-filtering in sampling?

10. What is reconstruction of sampling theorem?

11. What are the types of filters used in reconstruction?

12. Define - Sample Hold Circuits

13. Differentiate second order; fourth order and sixth order low pass filters in reconstruction process.

--- Content provided by​ FirstRanker.com ---

14. Explain the sampling reconstruction process.

15. What is the difference between discrete and digital signals?

16. Define - Digital Signal

17. What is the need for converting a continuous signal into a discrete signal?

18. Explain zero-order hold circuit.

--- Content provided by‌ FirstRanker.com ---

19. How to convert an analog signal into a digital signal?

20. Differentiate flat top sampling from natural sampling.

21. Define - Natural Sampling

FirstRanker.com

Expt. No. 2

--- Content provided by‌ FirstRanker.com ---

TIME DIVISION MULTIPLEXING

Aim:

To study the process of time division multiplexing of four signals using sampling trainer kit

Apparatus required:

1. TDM trainer kit – 1 No.

--- Content provided by‍ FirstRanker.com ---

2. Dual Power Supply – 1 No.

3. Patch cords – 6 No.

4. CRO (30 MHz) – 1 No.

Theory:

Time Division Multiplexing (TDM) is a method of transmitting and receiving independent signals over a common

--- Content provided by‌ FirstRanker.com ---

signal path by means of synchronized switches at each end of the transmission line so that each signal appears

on the line only a fraction of time in an alternating pattern.

Procedure:

1. Switch ON the power supply.

2. Make initial settings on TDM Trainer kit as follows.

--- Content provided by‍ FirstRanker.com ---

(a) Set all sine wave voltages to 2V,

(b) Make the wiring connections as in wiring diagram.

3. Display the multiplexed signal at test point T14 on channel 1 and 250Hz sine wave at test point T2 on

channel 2 of oscilloscope.

4. Display the 500Hz sine wave at test point T3 on channel 2 in place of 250Hz, identify sampled version of this

--- Content provided by‍ FirstRanker.com ---

sine wave in TDM signal note down.

5. Observe 1 KHz 2 KHz waveforms at test point T4 T5 respectively on oscilloscope

6. Display the TDM waveform (test point T14) on channel 1 channel synchronization signal (test point T13)

on channel 2 of oscilloscope .

7. Display 250Hz sine wave at test point T2 on channel 1 and output sine wave at test point T16 on channel 2 of

--- Content provided by​ FirstRanker.com ---

Oscilloscope.

8. Similarly, observe input output 500Hz, 1 KHz and 2 KHz sine waves on oscilloscope .

FirstRanker.com

Circuit Diagram

Time division multiplexing

--- Content provided by​ FirstRanker.com ---

FirstRanker.com

FirstRanker.com

FirstRanker.com

FirstRanker.com

Tabulation

--- Content provided by​ FirstRanker.com ---

Sl. No. Signal Amplitude Time period (s)
1. Message signal 1
2. Message Signal 2
3. TDM signal

Result:

Thus the TDM was studied the different types of signals are multiplexed using TDM Technique.

Outcomes:

After completion of this experiment the students will be able to understand the concept of multiplexing the

signals.

--- Content provided by⁠ FirstRanker.com ---

FirstRanker.com

Applications:

1. The plesiochronous digital hierarchy (PDH) system, also known as the PCM system, for digital

transmission of several telephone calls over the same four-wire copper cable (T-carrier or E-carrier)

or fiber cable in the circuit switched digital telephone network

--- Content provided by​ FirstRanker.com ---

2. The synchronous digital hierarchy (SDH)/synchronous optical networking (SONET) network

transmission standards that have replaced PDH.

3. The Basic Rate Interface and Primary Rate Interface for the Integrated Services Digital

Network (ISDN).

4. The RIFF (WAV) audio standard interleaves left and right stereo signals on a per-sample basis

--- Content provided by‍ FirstRanker.com ---

5. The GSM telephone system

Viva - voce

1.What is meant by multiplexing technique ?

2.What are the different types of multiplexers?

3. What is the transmission band width of a PAM/TDM signal?

--- Content provided by⁠ FirstRanker.com ---

4. What is the crosstalk effect in PAM/TDM system?

5. What are the advantages of TDM system?

6. Distinguish between TDM and FDM.

7. What is the value of Ts in TDM system?

8. What are the applications of TDM system? Give some example.

--- Content provided by⁠ FirstRanker.com ---

9. What is meant by signal overlapping?

10. Which type of modulation technique will be used in TDM?

FirstRanker.com

Expt. No. 3

AM MODULATION & DEMODULATION

--- Content provided by‍ FirstRanker.com ---

Aim:

To transmit a modulating signal after amplitude modulation using AM transmitter receives the signal back after

demodulating using AM receiver

Apparatus required:

1 Resistor - 4 No.

--- Content provided by⁠ FirstRanker.com ---

2 Capacitor - 1 No.

3 Diode 2 No.

4 AM transmitter receiver

trainer kit - 1 No.

5 CRO-1 No.

--- Content provided by⁠ FirstRanker.com ---

6 Patch cards – 6 No.

Theory:

AMPLITUDE MODULATION

Amplitude Modulation is a process by which amplitude of the carrier signal is varied in accordance with the

instantaneous value of the modulating signal, but frequency and phase of carrier wave remains constant.

--- Content provided by FirstRanker.com ---

The modulating carrier signal are given by

Vm(t) = Vm sin?mt

Vc (t) = Vc sin?ct

The modulation index is given by, ma = Vm/ Vc.

Vm = Vmax - Vmin Vc = Vmax + Vmin

--- Content provided by‌ FirstRanker.com ---

The amplitude of the modulated signal is given by,

VAM(t) = Vc (1+ma sin@mt) sin?ct

FirstRanker.com

Where

Vm = maximum amplitude of modulating signal

--- Content provided by‍ FirstRanker.com ---

Vc = maximum amplitude of carrier signal

Vmax = maximum variation of AM signal

Vmin = minimum variation of AM signal

Formula Used:

M= (Vmax - Vmin / Vmax + Vmin ) * 100

--- Content provided by​ FirstRanker.com ---

Where, M = Modulation index

Vmax = Maximum peak amplitude

Vmin = Minimum peak amplitude

if

M < 1 Under modulation

--- Content provided by FirstRanker.com ---

M = 1 Critical modulation

M > 1 over modulation

Procedure:

1. Give the modulating signal input to the Amplitude modulator.

2. Increase the amplitude of the modulating signal to the required level.

--- Content provided by‌ FirstRanker.com ---

3. Observe the amplitude and the time duration of the modulating signal using CRO.

4. Observe the amplitude modulated output from the output of amplitude modulator stage .

5. Calculate the modulation index

FirstRanker.com

Circuit Diagram

--- Content provided by‌ FirstRanker.com ---

AM Modulation

AM Demodulation

FirstRanker.com

FirstRanker.com

FirstRanker.com

--- Content provided by​ FirstRanker.com ---

FirstRanker.com

Tabulation

Signal Amplitude (V) Time Period (s) Frequency (Hz)
Message
Carrier
Modulated
Demodulated

Result:

Thus the AM signal was transmitted using AM trainer kit the AM signal detected using AM detector kit.

Outcome:

--- Content provided by‍ FirstRanker.com ---

After the completion of this experiment the students will be able to design construct the amplitude modulated

demodulated wave.

Applications:

1. Commercial broadcasting of both audio and video signals

2. Two way mobile radio communication such as citizen band (CB) radio.

--- Content provided by​ FirstRanker.com ---

3. Facsimile transmission

Viva - voce

1. What is modulation and demodulation?

2. Draw the phasor diagram of AM signal.

3. What is the degree of modulation?

--- Content provided by⁠ FirstRanker.com ---

4. Explain the need of modulation and demodulation?

5. What is analog modulation? State the various techniques.

6. Why frequency modulation is better than amplitude modulation?

7. Which type of modulation is used in TV transmission?

8. What is depth of modulation?

--- Content provided by⁠ FirstRanker.com ---

9. What are the different types of AM generation?

10. Define Modulation Index

11. What are different types of analog modulation techniques?

FirstRanker.com

12. What are the other names of message signal? What are the other names of carrier signal?

--- Content provided by‌ FirstRanker.com ---

13. Write the equation of AM signal .Explain each parameter of the equation.

14. Define - Amplitude modulation

15. What is the range of Audio frequency signals? What is the range of Radio frequency signal?

16. What are the applications of Amplitude modulators?

17. How many generation methods are there to generate an AM wave? What are the methods of

--- Content provided by​ FirstRanker.com ---

demodulation of an AM wave?

18. Explain the operation of diode detector circuit.

19. Write the formula for modulation index. Differentiate under, over perfect modulation in AM.

20. As the amplitude of message signal increases, modulation index increases or decreases?

21. Define - Single tone modulation

--- Content provided by‍ FirstRanker.com ---

22. Draw the frequency spectrum of AM wave.

23. If modulation index is 100%, calculate the ratio of total power to carrier power of an AM wave.

FirstRanker.com

Expt. No. 4

FREQUENCY MODULATION & DEMODULATION

--- Content provided by‌ FirstRanker.com ---

Aim:

To transmit a modulating signal after frequency modulation using FM transmitter receive the signal back after

demodulating using FM receiver

Apparatus required:

1. Resistor 4 No.

--- Content provided by⁠ FirstRanker.com ---

2. Capacitor - 1 No.

3. Diode 2 No.

4. AM transmitter Receiver

trainer kit - 1 No.

5. CRO 1 No.

--- Content provided by FirstRanker.com ---

6. Patch cards - 6 No.

Theory:

Frequency modulation (FM) is a form of modulation that represents information as variations in the

instantaneous frequency of a carrier wave. In analog applications, the carrier frequency is varied in direct

proportion to changes in the amplitude of an input signal. Shifting the carrier frequency among a set of discrete

--- Content provided by⁠ FirstRanker.com ---

values can represent digital data, a technique known as frequency-shift keying. FM is commonly used at VHF

radio frequencies for high-fidelity broadcasts of music speech Normal TV sound is also broadcast using FM. A

narrowband form is used for voice communications in commercial amateur radio settings. The type of FM used

in broadcast is generally called wide-FM, or W-FM.

In two-way radio, narrow-fm (N-FM) is used to conserve bandwidth. In addition, it is used to send signals into

--- Content provided by‍ FirstRanker.com ---

space.

FirstRanker.com

FM is also used at intermediate frequencies by most analog VCR systems, including VHS, to record the

luminance (black,white) portion of the video signal. FM is the only feasible method of recording video and

retrieving video from magnetic tape without extreme distortion, as video signals have a very large range of

--- Content provided by‍ FirstRanker.com ---

frequency components — from a few hertz to several megahertz, it is too wide for equalizers to work with due to

present of electronic noise below -60 dB. FM also keeps the tape at saturation level, therefore acts as a form of

noise reduction, a simple limiter can mask variations in the playback output.The FM capture effect removes

print-through pre-echo.

Procedure:

--- Content provided by‌ FirstRanker.com ---

FM Modulator:

1. Switch ON the Power supply.

2. Connect the sine wave generator output to frequency modulator input.

3. Select the low frequency carrier (or) high frequency carrier.

4. Connect the CRO input to the frequency modulator output.

--- Content provided by‌ FirstRanker.com ---

This download link is referred from the post: Anna University B.Tech Lab Manual