Fundamental of Wireless Communication PDF
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Uploaded by GutsyNashville
Engr. Harry Bert Rolle
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Summary
This document provides an introduction to fundamental concepts in wireless communication, explaining the key components of communication systems (transmitter and receiver) and discussing various aspects such as frequency bands, historical milestones, and essential principles. The document also includes diagrams and references to further learning materials.
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Fundamental of Wireless Communication Engr. Harry Bert Rolle Block Diagram of Communication System Source Tx Channel Rx Destination Source – a source of information (e.g. voice, data file, YouTube video) Tx – a transmitter Channel – a path (link) fro...
Fundamental of Wireless Communication Engr. Harry Bert Rolle Block Diagram of Communication System Source Tx Channel Rx Destination Source – a source of information (e.g. voice, data file, YouTube video) Tx – a transmitter Channel – a path (link) from the Tx to the Rx (e.g. cable, wireless medium, etc.) Rx – a receiver Destination– a place where the information has to be delivered Transmitter Source Channel Modulator PA A code coder LO Transmitter (Tx) Source coder – encodes the message to remove redundancy Channel coder – encodes the input to protect against errors introduced by the channel Local oscillator (LO) – generates the carrier Modulator – modulates the carrier using the encoded message Power amplifier (PA) – amplifies the modulated signal to required power level. Antenna (A) – radiates the modulated signal as an electromagnetic wave Receiver (Rx) Demodula Channel LNA Mixer IFA A tor Decoder Source LO Decoder Receiver Source decoder – decodes the source-encoded message Channel decoder – decodes the channel code Local oscillator (LO) – generates the carrier Mixer – down-converts the RF signal to IF frequencies IF amplifier (IFA): amplifies the IF signal significantly (up to 10^6) and rejects adjacent channel signals and interference (frequency selectivity). Its bandwidth is the same as the signal bandwidth. Demodulator: demodulates the modulated signal Low-noise amplifier (LNA): amplifies a weak RF signal coming out of the antenna. Rejects the image frequency. Bandwidth: much wider than the signal bandwidth. Antenna (A) – receives an incoming electromagnetic wave carrying the message Introduction Various terms: “wireless”, “mobile”, “portable”, “radio”, “personal” communications (additionally: “digital”). Major differences and similarities. There are few essential principles that make mobile/wireless communications special. Differences between: “mobile” and “fixed wireless/radio”; “wireless” and “wired” etc. Introduction WiFi (wireless Internet access, WLAN) Cell/cordless phones Remote control Bluetooth Radio/TV broadcast (incl. satellite) Navigation (GPS, radar) Introduction Historical Perspective 1844: invention of telegraph by Morse 1876: invention of telephone by Bell 1895/96: invention of radio by Popov/Marconi early 1900s: 1st use of radio 1900: 1st transatlantic transmission by Marconi 1933: invention of FM by Amstrong 1936: 1st TV broadcast by BBC 1947: transistor is invented in Bell lab Introduction Historical Perspective 1948: Shannon discovers information theory 1957: Sputnik is launched by USSR 1973: 1st cell phone call (by Martin Cooper of Motorola to his rival at AT&T; the phone weighted 1kg and cost approximately $4000) 1981: IBM PC is introduced. 1990s: launch of Internet. 2000s: launch of WiFi 2007: launch of iPhone 2010: launch of iPad 1998-2008: Google, Youtube, Facebook, Twitter, etc. Introduction View of the Wireless World P. Demestichas et al, 5G on the Horizon, IEEE Vehicular Technology Magazine, Sep. 2013. Introduction Wireless Frequency Reference: https://soundgirls.org/a-beginners-guide-to-wireless-frequencies/ Introduction Microwave Frequency Bands Reference: https://www.rfpage.com/microwave-frequency-bands/ Introduction Introduction Low-band VHF range of 49 MHz includes transmission of wireless microphones, cordless phones, radio controlled toys and more. slightly higher VHF range of 54-72 MHz operates television channels 2-4, as well as wireless systems defined as “assistive listening.” VHF frequencies 76-88 MHz operate channels 5 and 6. Band III is the name of the range of radio frequencies within the very high frequency (VHF) part of the electromagnetic spectrum from 174 to 240 megahertz (MHz). It is primarily used for radio and television broadcasting. It is also called high-band VHF, in contrast to Bands I and II.” Reference: Advanced Electronic Communications Systems by Wayne Tomasi (P. 529)
