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Palestine University Faculty of Information Technology

Palestine University Faculty of Information Technology. IGGC2204 - Understanding Telecommunications Instructor: Dr. Eng. Mohammed Alhanjouri. 1 st Lecture: Overview. Palestine University Faculty of Information Technology Syllabus. (IGGC2204) Understanding Telecommunications.

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Palestine University Faculty of Information Technology

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  1. Palestine University Faculty ofInformation Technology IGGC2204 - Understanding Telecommunications Instructor: Dr. Eng. Mohammed Alhanjouri 1st Lecture: Overview

  2. Palestine University Faculty ofInformation Technology Syllabus (IGGC2204) Understanding Telecommunications Instructor Information  Name of Instructor: Dr. Eng. Mohammed Alhanjouri  Location: Faculty of Engineering (Software Engineering Dept.)  E.mail: Alhanjouri@hotmail.comor mhanjouri@iug.edu.ps  Class Time: Sat (8:00-9:30)am and Mon (8:00-9:30)am

  3. Course Objectives To provide the students with the basics of communication systems. Upon completion of this course, the students should be able to:  To understand communication systems  To understand the frequency domain and the bandwidth concept. To understand the Fourier series and Fourier Transform.  To understand properties of Fourier Transform and the conversion between time and frequency domain.  To understand the types of amplitude modulation (AM)  To understand the Frequency modulation (FM)  To be able to select appropriate modulation techniques for our Applications

  4. Course Textbook(s) B. P. Lathi, "Modern Digital and Analog Communication Systems", Third edition, Oxford University Press, 1998. Simon Haykin, "Communication Systems", Fourth Edition, John Wiley & Sons, 2001. Other Recommended Resources: A. Bruce Carlson, "Communication Systems", Third Edition, McGraw Hill, 1986.

  5. Course Grades: Students grades are calculated according to their performance in the following course work: One week for each Assignment No assignments will be accepted beyond the due date.

  6. CH1: Introduction to Communication Systems The study of communication systems can be divided into two distinct areas: 1. How communication systems work. 2. How they perform in the presence of noise. The study of each of these two areas, in turn, requires specific tools. To study the first area, the students must be familiar with signal analysis (Fourier techniques), and to study the second area, a basic understanding of probability theory and random processes is essential. This course examines communication by electrical signals. In the past, messages have been carried by runners, carrier pigeons, drum beats, and torches.

  7. A short History of Telecommunications:  Thousands of years before the Common Era (B.C.E.) drums were used to send out messages. The fall of Trojan was achieved by signals of torches in 1100 B.C. 490 B.C. a runner delivered message from marathon to athens (he broke down and died). Also Alexander the Great , Hannibal and Caesar used running carriers to transmit their commends 150 A.D. the roman used smoke signals to spread the message (about 4.500 Km).

  8. 1100 Genghis Khan spread the reports of his victories using carrier pigeons. 1600 the British Admiral Sir William Penn developed a comm. Code using flag or light. 1835 Samuel Morse developed his code ( points and dashes). The first long distance message was sent from Baltimore to Washington in 1843.  1876 Alexander Graham Bell applies for a patent with his telephone in March 1876. only 3 hours later Elisha Gray submitted an application for the same device  1861 Maxwell at king’s college in London proposed mathematical theory of EM waves

  9.  1887 Hertz demonstrated the existence of EM waves  1895-1898 Marconi built radio telegraph, his signal bridged the English channel (52km wide)  1921 First analog land mobile by police department in Detroit and London, respectively.  1933 FM was invented which made possible high quality radio comm.  1947 Improved mobile telephone service (IMTS) using FM was developed by AT&T. the 1st mobile system connected to PSTN Bell labs.  1948 extending number of users in cellular concept during and after WW2

  10. Second Generation1990’s Cellular has enjoyed exponential growth since 1988, with over 200 million users worldwide today .. •  1990 Global System Mobile (GSM) is introduced in 800-900 MHz band. • 2.5 Generation- :1998 mobile wireless data: I-mode, a wireless data service and internet “micro-browser” is introduced. • 3rd Generation- 2000: IMT-2000 (International Mobile Telecom.) proposals for a world-wide 3rd generation standard are submitted. • 2??? 4th generation – may be to use W-CDMA-2000 or OFDM (orthogonal frequency division multiplexer) • TV, Satellite, LAN, and 100 Mbps bandwidth

  11. Introduction The purpose of Comm. System is to transport an information signal from a source to a user destination via a comm. channel (transmission system). A comm. system is of an analog or digital type In an analog comm. system, the information signal is continuously varying in both amplitude and time, while for digital comm. system, the information signal is processed so that it can be represented by a sequence of discrete message.

  12. Transmitter Source Transducer Channel Encoder Noise, Interference and distortion Comm. Channel Destination (User) User Transducer Channel Decoder Receiver CommunicationModel Information Source

  13. CommunicationModel (Cont.) Information source: generates the data to be transmitted. Examples are telephones and computers Transmitter: transforms and encodes the information in such a way as to produce electromagnetic signals that can be transmitted across some sort of transmission system (comm. Channel). For example, a MODEM takes a digital bit stream from a personal computer and convert it to analog signal that can be transmitted by the telephone networks

  14. CommunicationModel (Cont.) Transmission system (Comm. channel): this can be a single transmission line or complex network connecting source and destination (wire, Coaxial cable, optical fiber, or radio link) Receiver: accepts the signal from the transmission system and converts it into a form that can be handled by the destination device like as the MODEM Destination: takes the incoming data from the receiver.

  15.    MODEM MODEM Server workstation Public telephone network Receiver Transmitter destination Information source Transmission system (Comm. channel) For Example: the workstation can be connected to the server by the following communication system

  16.  The comm. Channel contents the noise that classified as: • External noise includes interference, human-made noise, fluorescent lights, or natural noise (electrical storms, solar, and intergalacitic radiation). With proper care, this noise can be minimized or eliminated) • Internal noise results from thermal motion of electrons in conductors, random emission, diffusion or recombination of charged carriers in electronics devices. Proper care can reduce the effect of this noise but can never eliminate it

  17. ANALOG AND DIGITAL MESSAGES Messages are digital or analog. Digital messages are constructed with a finite number of symbols. For example, printed language consists of 26 letters, 10 numbers, a space. Thus, a text is a digital message constructed from about 50 symbols.Human speech is also a digital message, because it is made up from a finite vocabulary in a 1anguage.Similarly, a Morse-coded telegraph message is a digital message constructed from a set of only two symbols-mark and space. It is therefore a binary message, implying only two symbols. A digital message constructed with M symbols is called an M-ary message. Analog messages, on the other hand, are characterized by data whose values vary over a continuous range. For example, the temperature or the atmospheric pressure

  18. MODULATION Baseband signals produced by various information sources are not always suitable for direct transmission over a given channel. These signals are usually further modified to facilitate transmission. This conversion process is known as modulation.In this process, the baseband signal is used to modify some parameter of a high-frequency carrier signal. A carrier is a sinusoid of high frequency, and one of its parameters-such as amplitude, frequency, or phase-is varied in proportion to the baseband signal m(t). we have amplitude modulation (AM), frequency modulation (FM), or phase modulation (PM). The Figure shows a baseband signal m(t) and the corresponding AM and FM waveforms. In AM, the carrier amplitude varies in proportion to m(t), and in FM, the carrier frequency varies in proportion m(t) . At the receiver, the modulated signal must pass through a reverse process called demodulation in order to reconstruct the baseband signal.

  19. Definitions: • SNR is defined as the ratio of signal power to noise power The bandwidth of a channel is the range of frequencies that it can transmit with reasonable fidelity. For example, if a channel can transmit with reasonable fidelity a signal whose frequency components occupy a range from 0 (dc) up to a maximum of 5000 Hz (5 kHz), the channel bandwidth B is 5 kHz.

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