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Lecture Wireless and mobile computing – Chapter 18: Signal encoding techniques

The following will be discussed in this chapter: Where we stand on layers, data representation and signaling used, data encoding, reasons for choosing encoding schemes, factors involved, digital data to analog signal (ASK, FSK, PSK), analog data to digital signal. | Signal Encoding Techniques Lecture 18 Overview Where we Stand on Layers Data Representation and Signaling Used Data Encoding Reasons for Choosing Encoding Schemes Factors Involved Digital Data to Analog Signal (ASK, FSK, PSK) Analog Data to Digital Signal Where We Stand @ Present Physical Layer Transmission Medium Data Link Transmission Media Signals and their transmission over media, Impairments Encoding: From data to signals Data Link: Flow and Error control Data Communication: Synchronization, Error detection and correction Improved utilization: Multiplexing Antenna and Propagation Data Signal Combination Data, Signaling and its Treatment What's Going Up Digital Data Digital Signal Analog Signal Analog Data Less complex, less expensive than digital-analog modulation equipment Use of modern digital transmission And switching equipment Some transmission media will only propagate analog signals Efficient use of transmission channel : FDM Data Encoding Techniques Digital Data, Analog Signals [Modem] Digital Data, Digital Signals [Wired LAN] Analog Data, Digital Signals [Codec] Frequency Division Multiplexing (FDM) Wave Division Multiplexing (WDM) [Fiber] Time Division Multiplexing (TDM) Pulse Code Modulation (PCM) [T1] Delta Modulation Encoding Techniques Digital data as digital signal Digital data as analog signal: Converter (Modem) Analog data as digital signal: Converter (Codec) Analog data as analog signal In general: When the outcome is a digital signal we use an Encoding process When the outcome is an analog signal we use a Modulation process But we call the modulation of analog signal by digital data shift-keying Reasons for Choosing Encoding Techniques Digital data, digital signal Equipment less complex and expensive than digital-to-analog modulation equipment Analog data, digital signal Permits use of modern digital transmission and switching equipment Reasons for Choosing Encoding Techniques Digital data, analog signal Some | Signal Encoding Techniques Lecture 18 Overview Where we Stand on Layers Data Representation and Signaling Used Data Encoding Reasons for Choosing Encoding Schemes Factors Involved Digital Data to Analog Signal (ASK, FSK, PSK) Analog Data to Digital Signal Where We Stand @ Present Physical Layer Transmission Medium Data Link Transmission Media Signals and their transmission over media, Impairments Encoding: From data to signals Data Link: Flow and Error control Data Communication: Synchronization, Error detection and correction Improved utilization: Multiplexing Antenna and Propagation Data Signal Combination Data, Signaling and its Treatment What's Going Up Digital Data Digital Signal Analog Signal Analog Data Less complex, less expensive than digital-analog modulation equipment Use of modern digital transmission And switching equipment Some transmission media will only propagate analog signals Efficient use of transmission channel : FDM Data Encoding Techniques .