TAILIEUCHUNG - Lecture Wireless and mobile computing – Chapter 6: Transmission fundamentals review
The following will be discussed in this chapter: Signals for conveying information, time domain concepts, frequency domain concepts, relationship between data rate and bandwidth, analog and digital data transmission, analog and digital data, analog and digital signaling, analog and digital transmission, channel capacity, transmission media. | TRANSMISSION FUNDAMENTALS Review Lecture 6 Overview Signals for Conveying Information Time Domain Concepts Frequency Domain Concepts Relationship between Data Rate and Bandwidth Analog and Digital Data Transmission Analog and Digital Data Analog and Digital Signaling Analog and Digital Transmission 2 Channel Capacity Nyquist Bandwidth Shannon Capacity Formula Transmission Media Microwave Transmission Analog and Digital Differentiate between an analog and a digital electromagnetic signal. 3 Review Question: Analog Signals 4 Digital data, analog signal: Some transmission media, such as optical fiber and satellite, will only propagate analog signals. Analog data, analog signal: Analog data are easily converted to an analog signal. 4 Analog and Digital Signals Stallings DCC9e Figure shows a communications system, data are propagated from one point to another by means of electromagnetic signals. An analog signal is a continuously varying electromagnetic wave that may be propagated over a variety of media, depending on spectrum; examples are wire media, such as twisted pair and coaxial cable; fiber optic cable; and unguided media, such as atmosphere or space propagation Data and Computer Communications, Ninth Edition by William Stallings, (c) Pearson Education - Prentice Hall, 2011 Digital Signals 5 Digital data, digital signal: In general, the equipment for encoding digital data into a digital signal is less complex and less expensive than digital-to analog Equipment. Analog data, digital signal: Conversion of analog data to digital form permits the use of modern digital transmission and switching equipment for analog data. 5 Data and Signals In the foregoing discussion, we have looked at analog signals used to represent analog data and digital signals used to represent digital data. Generally, analog data are a function of time and occupy a limited frequency spectrum; such data can be represented by an electromagnetic signal occupying the same spectrum. Digital .
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