Lecture

OFDM: Orthogonal Frequency Division Multiplexing

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In course

COM-405: Mobile networks

This course provides a detailed description of the organization and operating principles of mobile and wireless communication networks, as well as the use of wireless signals for sensing and imaging. ...

Description

This lecture introduces Orthogonal Frequency Division Multiplexing (OFDM), a technique widely used in high throughput mobile networks like Wi-Fi and 4G. The instructor explains how OFDM simplifies signal decoding and reduces interference, highlighting its importance in modern communication systems. The lecture covers the concept of cyclic prefix to deal with synchronization and inter-symbol interference, as well as packet detection methods to accurately identify the start of data transmission. The instructor also discusses the trade-offs involved in choosing the size of the cyclic prefix and the impact on data throughput.

Instructors (2)

Jean-Pierre Hubaux

Jean-Pierre Hubaux is a full professor at EPFL and head of the Laboratory for Data Security. Through his research, he contributes to laying the foundations and developing the tools for protecting privacy in today’s hyper-connected world. He has pioneered the areas of privacy and security in mobile/wireless networks and in personalized health. He is the academic director of the Center for Digital Trust (C4DT). He leads the Data Protection in Personalized Health (DPPH) project funded by the ETH Council and is a co-chair of the Data Security Work Stream of the Global Alliance for Genomics and Health (GA4GH). From 2008 to 2019 he was one of the seven commissioners of the Swiss FCC. He is a Fellow of both IEEE (2008) and ACM (2010). Recent awards: two of his papers obtained distinctions at the IEEE Symposium on Security and Privacy in 2015 and 2018. He is among the most cited researchers in privacy protection and in information security. Spoken languages: French, English, German, Italian

Haitham Al Hassanieh

Teaching & PhD PhD Students Eduard Vlad, Raphael Cannatà, Arman Maghsoudnia, Jiachen Lu, Samah Hussein Youssef, Hailan Zhang Shanbhag, Aoyu Gong Courses Intelligent systems: communications & AI COM-304 The course teaches the development of systems that solve real-world challenges in communications, signal processing, foundation models, and AI. Students will work in teams, construct their ideas, and either program available hardware prototypes or build their hardware or software system.

Official source

Related concepts (32)

Modulation

In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a separate signal called the modulation signal that typically contains information to be transmitted. For example, the modulation signal might be an audio signal representing sound from a microphone, a video signal representing moving images from a video camera, or a digital signal representing a sequence of binary digits, a bitstream from a computer.

Network throughput

Network throughput (or just throughput, when in context) refers to the rate of message delivery over a communication channel, such as Ethernet or packet radio, in a communication network. The data that these messages contain may be delivered over physical or logical links, or through network nodes. Throughput is usually measured in bits per second (bit/s or bps), and sometimes in data packets per second (p/s or pps) or data packets per time slot. The system throughput or aggregate throughput is the sum of the data rates that are delivered to all terminals in a network.

Cellular network

A cellular network or mobile network is a telecommunications network where the link to and from end nodes is wireless and the network is distributed over land areas called cells, each served by at least one fixed-location transceiver (typically three cell sites or base transceiver stations). These base stations provide the cell with the network coverage which can be used for transmission of voice, data, and other types of content.

Orthogonal frequency-division multiplexing

In telecommunications, orthogonal frequency-division multiplexing (OFDM) is a type of digital transmission used in digital modulation for encoding digital (binary) data on multiple carrier frequencies. OFDM has developed into a popular scheme for wideband digital communication, used in applications such as digital television and audio broadcasting, DSL internet access, wireless networks, power line networks, and 4G/5G mobile communications. OFDM is a frequency-division multiplexing (FDM) scheme that was introduced by Robert W.

Telecommunications

Telecommunication, often used in its plural form, is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that feasible with the human voice, but with a similar scale of expediency; thus, slow systems (such as postal mail) are excluded from the field.

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