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Digital Communication (Sampling theory) Course Plan 1- Digital Communication: (Sampling theory) 2- Pulse modulation techniques PPM, PWM and PAM, Pulse code modulation (PCM) 3- Noise in PCM 4- Delta modulation (DM) 5- Noise in delta modulation systems and Noise in delta modulation systems comparison of PCM &DM 6- Adaptive Delta Modulation 7- Time Division Multiplexing (TDM) 8- Examples for TDM and Asynchronous TDM 2 Lecture 1-2 Digital Communication (Sampling theory) Course Plan 9- Amplitude shift- keying (ASK ), bandwidth, power, generation and detection 10- Phase shift- keying (PSK) bandwidth, power, generation and detection 11- Frequency shift keying (FSK) bandwidth, power, generation and detection 12-M-ray and Quadrature PSK (QPSK) 13- Quadrature PSK (QPSK) bandwidth, power, generation and detection 14- Multiple-Access Technologies 15- Satellite and Wireless communication 3 Lecture 1-2 Digital Communication (Sampling theory) References: 1. B. P. Lathi, “Modern Digital and Analog Communication system”, Oxford University press, Inc., 1998. 2. Bernard Sklar “Digital communications: fundamentals and applications”, Prentice-Hall, Inc., 1988. 3. Ian Glover etl “Digital Communication”. Prentice-Hall, Inc., 1988. 4. John G. Proakis and Masoud Salehi “Digital Communications”, McGraw-Hill Companies, Inc., 2001. 5. Hwei P. Hsu , “Analog and digital Communications”, Schaum’s outline Series, McGRAW-Hill, 2003. 4 Lecture 1-2 Digital Communication (Sampling theory) Digital signal transmission: In digital communication, the information being transferred is represented in digital form, the most commonly as binary digits, or bits. This is in contrast to analog information, which takes on a continuum of values. Most communication systems used for transferring information today are either digital, or are being converted from analog to digital. Experimental data and mathematical functions are frequently displayed as continuous curve, even though a finite number of discrete points were used to construct the graphs. If these points, or samples, have sufficiently close spacing, a smooth curve drawn through them allows you to interpolate intermediate values to any reasonable degree of accuracy. It can therefore be said that the continuous curve is adequately described by the sample points alone. In similar fashion, an electric signal satisfying certain requirements Can be reproduce entirely from an appropriate set of samples the sampling theory gives the necessary conditions needed to transmitted the sample values only instate of sending the signal continuously this is pulse modulation. The main different between pulse mod. 5 Lecture 1-2 Digital Communication (Sampling theory) C.W modulation is in C.W modulation some parameter of the modulated wave varies continuously with the message. In pulse modulation some parameter of each pulse is modulated by a certain sample value of the message usually the pulse are quit short compared to the time between then so a pulse modulated wave is off most of the time. This pulse modulation offers two advantages over continuous wave modulation. 1- The transmitted power can be concentrated into short bursts rather than being delivered continuously. 2- The time intervals between pulse can be filled with samples value from other message allowing the transmission of many messages on one communication system. 6 Lecture 1-2
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