modulation and demodulation in communication system pdf

The term Demodulation refers to the process of extracting the . To Demodulate the modulated wave using envelope detector. 1 has the potential to radically increase the efficiency of the transfer of data by utilising a new communications paradigm where . B.Basic BPSK Modulator and Demodulator: Digital modulation is the process by which digital symbols are transmitted into waveforms . Open navigation menu. 4. Experiment 1 Amplitude Modulation and demodulation 1 Amplitude Modulation and demodulation Preliminary discussion In an a mplitude m odulation (AM) communications system, speech and music are converted into an electrical signal using a device such as a microphone. The document Angle modulation and demodulation Notes - GATE is a part of GATE category. The . pseudo-random set of bits, Nbit long, to be transmitted through the communication system. Then using the kronecker Modulation is an activity or process that takes place in TRANSMITTER section of a communication system. In this Physics video lecture in Hindi for class 12 we explained modulation and demodulation in communication system. One can demonstrate that all other signals not receiving the SS code will stay as they are, unspread. MODULATION AND DEMODULATION D ata modulators, especially those intended to produce constant-envelope output signals, are "high-leverage" components in that even very small deviations from ideal in their behavior can lead to large degradations in overall system performance. Modulation is the fundamental requirement of any communication system. Demodulation is the reverse process (to modulation) to recover the message signal m(t) or d(t) at the receiver. Close suggestions Search Search. carrier. Amplitude modulation may be defined as a system in which the maximum amplitude of the carrier wave is made proportional to the instantaneous value (amplitude) of the modulating or baseband signal. Digital modulation, and 3. This process is known as modulation. 5 OUTLINE . This is a rectangular representation of the polar diagram. Switch off the experimental kit during making connections.

Demodulation is utilized to regain the original message signal. Modulation and Demodulation. 2.4 shows the principle diagram of auto-coherent detection using differential phase shift keying (DPSK) modulation. Modulati on. Since this modulation modulates the light intensity, it is called subcarrier intensity modulation. In the modulation process, the message signal of very low frequencies is impressed. On a polar modulation depth). It first determines the number of samples, Nsample, per bit. Practice Problems: Modulation & Demodulation Problem 1. device that performs the inverse operation of modulation is known as a demodulator sometimes detector or demod. 1.Amplitude Modulation & Demodulation Aim To study the function of Amplitude Modulation & Demodulation (Under modulation, Perfect modulation & Over modulation) using Matlab Simulink. INTRODUCTION In Pulse code modulation (PCM) only certain discrete values are allowed for the modulating signals. Bandpass modulation and demodulation. In order to create desired signals which work for the communication system that we want to use and transmit multiple signals simultaneously over a single channel, the modulation of signals is in high demand. Modulation is the process of transforming a baseband message to a form suitable for Fig.1 Power spectra for signals in the modulation and demodulation processes. Reject the other signals 3. Please also assume that the sample rate associated with this system is 10000 samples per second, so that k is both a coefficient index and a frequency. the message signal is then used to electrically vary the amplitude . Signals & Systems (1997) Asynchronous demodulation avoids the need for synchronization between the modulator and demodulator. Scribd is the world's largest social reading and publishing site. Select the desired signal 2. The two signals involved in modulation process are: baseband signal and carrier. A communications system is a collection of individual communications networks usually capable of interconnection and interoperation to form an . By deleting the Sine Wave block and revising the mdl/slx file, the received DSB-SC AM signal can still be successfully demodulated. Modulation is for transmit data to extensive distance. To be specific, the mixing of the low-frequency signal with the high-frequency carrier signal is known as modulation. This is the ratio of the modulation amplitude and the amplitude of the unmodulated carrier. modulation scheme(e.g. Apparatus Required .

An its side bands as shown in fig. and. If the baseband signal is band-limited, then there is a nite maximum frequency of the corresponding sinusoids. The reduction in demodulation cornplexity is achicved by using the Laurent represcnta- C. HAPTER. - LAB Manual SSB Modulation and Demodulation Experiment 7 SSB Modulation and Demodulation Objectives : By the end of this experiment, the student should be able to: 1. Apparatus Required: Name of the Component/Equipment A block diagram of the subcarrier intensity modulation optical wireless communication system is shown in Fig. All you need of GATE at this link: GATE. Modulation is an integral part of every modern communication systems and provides a means of matching an informa tion-carrying signal to the transmission medium or transmission channel. The Pulse Position Modulation (PPM) signal is generated from the . Basic digital communications system Modulator Demodulator Transmission Channel Input transducer Transmitter Receiver Output transducer Carrier EM waves (modulated signal) en Change Language. many types of circuits used in communication systems such as FM to AM conversion, phase-shift discriminators and phase-locked loop (PLL) frequency demodulator. 2. Modulation is defined as the process of mixing a signal with a sinusoid to produce a new signal. 14. Summary of Modulation Techniques 1 Summary of Modulation Techniques 2 Modulation Types AM, FM, PAM Modulation Types AM, FM, PAM 2 Modulation Types (Binary ASK, FSK, PSK) Modulation Types (Binary ASK, FSK, PSK) 2 Introduction: Single sideband (SSB) is a common analog modulation scheme for . experiments in Volume A1 involving linear modulation and demodulation. The range of communication gets limited as the wave cannot travel to a distance without getting distorted. Set the proper amplitude and frequency of the modulating signal to get a SS modulation is applied on top of a conventional modulation such as BPSK or direct conversion. Tutorial 6: Frequency response of LTI systems and filters (PDF) Tutorial 6 solutions (PDF) Tutorial 7: Modulation and demodulation (PDF) Tutorial 7 solutions (PDF) Tutorial 8: Packet and circuit switching, and Little's law (PDF) Tutorial 8 solutions (PDF) Tutorial 9: MAC protocols (PDF) Tutorial 9 solutions (PDF) Tutorial 10: Routing (PDF) Tech. demodulator. Digital Modulation and demodulation synchronization decision digital analog data demodulation radio carrier analog baseband signal 101101001 radio receiver digital modulation digital . Read PDF Qpsk Modulator And Demodulator Using Fpga For Sdr Qpsk Modulator And Demodulator Using Fpga For Sdr Satellite Communications High Bit Rate Four Phase MMIC Remodulation Demodulator and Modulator Digital Modulations Using Matlab Digital Communications with Emphasis on Data Modems A Practical Guide to Analog Behavioral Modeling for IC System Design Power-Aware Architecting Network . Amplitude Modulation and Demodulation: Double Sideband - Suppressed Carrier Modulation Full Amplitude Modulation Requires synchronous demodulation Asynchronous Demodulation (AM): Figures from Oppenheim and Willsky. ELE 635 Communication Systems Version: 1.0 Experiment 2: Amplitude Modulation and Demodulation Objective Amplitude modulation (AM) is one of the simplest methods for modulating a sinusoidal carrier wave. There are two reasons why frequency-division multiplexing works: 1. Angle Modulation: Angle modulation may be defined as the process in which the total phase angle of a carrier wave is varied in accordance with the instantaneous value of the modulating or message signal while keeping . "Principlesof Communication-Systems Modulation & Noise",Jaico PublishingHouse, 2001. This is the reverse process of modulation. 4 Bandpass Modulation and Demodulation Dr. Jingxian Wu . Figure 5. Demodulation involves multiplying the modulated signal again by a cosine with a frequency f2, and then applying a low pass filter with cutoff frequency f2. FM Modulation and Demodulation Goal: The goal of this experiment is to become familiar with FM modulation and demodulation. This course is typically taught using one of the popular Communication Engineering textbooks such as ref [5]. PRINCIPLES OF COMMUNICATION SYSTEM LAB EE-226-F (IVth Semester) Prepared By: Vikrant Verma B. C.R.O (30MHz) 4. Used in Navy and Aviation for communications as AM signals can . In FSO communication systems, the intensity of an optical source is modulated to transmit signals over channel. (ECE) . The scheme of proposed demodulator is based on the toggle circuit and the obtained results from simulation and experiment agree well with the mathematical analysis. Frequency modulation - The frequency of the carrier signal is proportional to the modulating . Theory and background: 1. Tutorial 6: Frequency response of LTI systems and filters (PDF) Tutorial 6 solutions (PDF) Tutorial 7: Modulation and demodulation (PDF) Tutorial 7 solutions (PDF) Tutorial 8: Packet and circuit switching, and Little's law (PDF) Tutorial 8 solutions (PDF) Tutorial 9: MAC protocols (PDF) Tutorial 9 solutions (PDF) Tutorial 10: Routing (PDF) Modulation involves multiplying the input signal x(t) by a cosine with a frequency f2. It explores the spectral effects of modulation and explains why certain types of modulation are used in differing situations. The demodulation technique usually employed is called synchronous demodulation and requires that there be available at the demodulator the waveform cos(2f. These are related to the number of levels adopted by the . The following figure is the principle of FSK demodulation. For recording the video signals by VCR systems, frequency modulation is used for intermediate frequencies. 3. Analog Communications Bapatla Engineering College Bapatla 1. The original b(t) is recovered in the demodulator. SYSTEM ARCHITECTURE The system architecture includes programs that the student modifies and programs that the instructor uses to evaluate their system with. Modulation in optical wireless communication is the process of loading information onto the light wave. Spread modulation. 1. The optical transmission system involves modulation of optical signal, its transmission, detection and demodulation. Receivers for CW Modulation In addition to demodulation a receiver must 1. No signal mixing occurs. 1. 3. Amplitude modulation and frequency modu. PRECAUTIONS: 1. Deal with phase shift splitter (QPS). In modulation original message signal is . Therst useof AM fortransmissionofvoice signalsbyradiocan be traced tothebeginning of the 20th century. modified createBsize.m, modulator.m and demodulator.m files along with their group member names. Bandwidth Effects of the Despreading . It depends on the actual modulation type whether or not the spectra become similar with respect to shapes, symmetries, and bandwidths. - Example: Show the following system is orthogonal BFSK if T f f c 2 1 1 T f f c 2 1 2 T f c 1!! Demonstrate the modulation and demodulation process of SSB. The most important demodulation process is execution of judgment task. 2. Modulation prerequisites a modulator for the mixing of the two signals. The modulation and demodulation scheme presented in Fig. The chapter also explains, using mathematical notation, the operation of modulators and demodulators. The scheme of proposed demodulator is based on the toggle circuit. AM MODULATION The modulator inputs the bit sequence and knows the full number of samples N to be used in the system. But any sample falling within a specified range of values is assigned a discrete value. The modulation and demodulation problems for efficient multi-carrier communications are considered in this study. Pulse Amplitude Modulation) is less complex than that for the nonlinear modulation scheme.The goal of this thesis is to attempt to reduce the complex-ity of GMSK receiver by using a linear approximation of GMSK and coherent detection. EXTRA MODULES: DECISION MAKER PREPARATION generation Amplitude shift keying - ASK - in the context of digital communications is a modulation process which imparts to a sinusoid two or more discrete amplitude levels 1. In general, multi-level (M-ary) digital communication is used to design a communication system that is more bandwidth efficient. The relative height is 20log(M) dB, where M is the non-negative Modulation Index (a.k.a. Communication systems radio transmission system: modulation demodulation of AM signals envelope detection of AM signals Topics. Any baseband signal can be broken up into a weighted sum of sinusoids using Fourier decomposition (Chapter 13). Here's our "standard" modulation-demodulation system diagram: at the transmitter, signal x[n] is modulated by signal mod[n] and the result (chan[n]) is sent to the receiver where the incoming signal is demodulated by demod[n] and sent through a low-pass filter to produce y[n]. There are two types of carriers: an optical carrier and electric signal carrier (called subcarrier). this electrical signal is called the message or baseband signal. Abstract: This paper give the brief description of digital communication system.Digital communication is more reliable, secure and efficient than that of analog communication.In Digital communication,BPSK is most . 2.5 I/Q formats In digital communications, modulation is often expressed in terms of I and Q. The student has access to the instructor programs so 3 of 5 The modulating signal is sampled, as in other forms of pulse modulation. Communication range increases. Modulating signal = baseband signal. RESULT: Frequency Modulation & Demodulation has been studied. Lecture - 06 - Free download as Powerpoint Presentation (.ppt / .pptx), PDF File (.pdf), Text File (.txt) or view presentation slides online. For M = 1 (i.e., 100% modulation), the envelope of the modulated signal periodically reaches zero, and the sidebands are 6 dB below the . The modulator is an electro-optic converter, which changes the parameters of the output beam, such as intensity, frequency, phase, polarization state, and beam/photon orbital angular momentum, with the signal. In this paper, a novel digital GFSK modulation and demodulation system which designed for short-range wireless communication application is presented. Practice Problems: Modulation & Demodulation Problem 1. de Therefore, the degree of effective amplitude modulation in a system will affect some distortion parameters. c. t+)t+)=0.5+0.5cos2(2f . Figure 19 Used in applications of magnetic tape storage. Digital communication systems also employ modulation techniques, some of which include: Amplitude Shift Keying Frequency Shift Keying Phase Shift Keying Digital Modulation. Analog modulation 2. FM modulation: Frequency modulation (FM) is a process in which the carrier frequency is varied by the amplitude of the modulating signal (i.e., intelligence signal). Electronic Communications Systems, 5e BPSK Signal Costellation The receiver implementation can affect the performance. Other coherent optical communication systems exist. The key difference between modulation and demodulation is that modulation is done at the transmitter side while demodulation is done at the receiver side of a communication system. Modulation Encode a bit stream of finite length to one of several possible signals Delivery over the air Signals experience fading and are combined with AWGN (additive white Gaussian noise) Demodulation Decode the received signal by mapping it to the closestone in the set of possible transmitted signals 11 Transmitter Receiver x(t) AM MODULATION The modulator inputs the bit sequence and knows the full number of samples N to be used in the system. Figure 2. Amplify the signal Some of the amplification should occur before demodulation because the demodulator typically does not work well with small signals (usually because of non-zero forward bias diode voltages). What is distortion? MODULATION & DEMODULATION Questions and Answers pdf free download also objective multiple choice interview 2 mark important questions lab viva manual book Amplitude Modulation & Demodulation: Baseband and carrier communication, Amplitude Modulation (AM), Rectifier detector, . 2. Patch chords. Following are some of the advantages for implementing modulation in the communication systems.

Send them into the register in proper or der. modulation. 'Changing the shape' of a signal Multiplication of a signal by a constant (even a negative one) or shifting it in time do not change its shape It first determines the number of samples, Nsample, per bit. The chapter is designed to help teach and understand communication systems using a classroom-tested, active learning approach. ec8561- communication systems lab manual 7 index s.no name of the experiment page no 1. signal sampling and reconstruction 08 2. time division multiplexing 12 3. am modulator and demodulator 16 4. fm modulation and demodulation 20 5. pulse code modulation and demodulation 24 6. delta modulation and demodulation 28 7. line coding schemes 32 8.

modulation and demodulation in communication system pdf