Selected Topics in Communications (OFDM and Beyond)
Due to their ability to provide high data rates for multimedia applications, multi-carrier modulation techniques are gaining a strong interest for wide area, local area, and personal area networks. A special case of multi-carrier modulation is orthogonal frequency division multiplexing (OFDM) that can overcome many problems that arise with high bit rate communication, the biggest of which is the time dispersion. OFDM has found applications in many wireless technologies including digital audio and video broadcasting in Europe, high-speed wireless local area networks (WLANs) standards in Europe (Hyperlan2) and USA (IEEE 802.11a/g/n). Recently, it has been applied to wireless metropolitan area networks (WMANs) for fixed and mobile wireless access (e.g. 802.16- 2004 for fixed and 802.16-2005 for mobile WiMAX), fourth generation cellular wireless with Long Term Evolution (LTE) and LTE Advanced, wireless personal area networks (WPANs) through multiband Ultrawideband, and wireless regional area networks (WRANs) through cognitive radio (IEEE 802.22). In summary, OFDM and its derivatives are everywhere today and their dominance is expected to continue for a long time. Therefore, understanding OFDM and related technologies is very important for those students who seek for a career in communications.
This course will cover the details of OFDM and OFDM based technologies. The targeted students are the graduate students as well as the non-degree seeking engineers that are working in wireless communications area in local companies. The course will include the following topics:
- Wireless channel overview: Broadband communication, delay spread, ISI, mobility, Doppler spread relations.
- Equalization in wireless communication (time domain and frequency domain)
- Multicarrier systems and orthogonal frequency division multiplexing (OFDM)
- OFDM system design issues
- OFDM receiver design and digital baseband receiver algorithms
- Multiple accessing in OFDM - OFDMA and other alternatives
- Filterbank Multicarrier and relation with OFDM
- Scheduling in OFDMA
- OFDMA relatives: Single carrier FDMA, DFT-spread-OFDMA
- Orthogonality issues in OFDM
- OFDM impairments and their effects in the system, and handling these impairments
- Spectral sidelobe issues and PAPR problems
- Future of OFDM based waveforms
- Adaptive OFDM(A) design, Cognitive OFDM
- Hybrid waveforms
- Simulation of OFDMA based systems
- OFDM based standards (LTE, WiMAX, WiFi, 802.22, multiband UWB)
Some background on communications systems and digital signal processing is needed to follow the course easily. EEL-6593 (Mobile and Personal Comm. Sys.) or EEL6534 (Digital communications, Comm. Sys.) would perfect preparations for this course. However, students who haven't taken this course should be able to follow the course with some communications and signal processing background.
Books & References
We will not be using a specific text book for the course. The related references will be provided by the instructor. The lecture slides will be provided to the students through myUsf (blackboard).