Towards systems beyond 3G based on adaptive OFDMA transmission
2007 (English)In: Proceedings of the IEEE, ISSN 0018-9219, Vol. 95, no 12, 2432-2455 p.Article, review/survey (Refereed) Published
High data rates, high spectral efficiency, flexibility, and low delays over the air interface will be important features in next-generation wireless systems. The overall challenge will be packet scheduling and adaptive radio transmission for multiple users, via multiple antennas and over frequency-selective wideband channels. This problem needs to be structured to obtain feasible solutions. The basic simplifying assumptions used here are clustering of antennas into cells, orthogonal transmission by use of cyclic-prefix orthogonal frequency-division multiplexing (OFDM) and a time-scale separation view of the total link adaptation, scheduling and intercell coordination problem. Based on these assumptions, we survey techniques that adapt the transmission to the temporal, frequency, and spatial channel properties. We provide a systematic overview of the design problems, such as the dimensioning of the allocated time-frequency resources, the influence of duplexing schemes, adaptation control issues for downlinks and uplinks, timing issues, and their relation to the required performance of channel predictors. Specific design choices are illustrated by recent research within the Swedish Wireless IP program and the EU IST-WINNER project. The presented results indicate that high-performance adaptive OFDM transmission systems are indeed feasible, also for challenging scenarios that involve vehicular velocities, high carrier frequencies, and high bandwidths
Place, publisher, year, edition, pages
2007. Vol. 95, no 12, 2432-2455 p.
Broadband radio transmission, channel estimation, channel prediction, channel quality feedback, channel-aware scheduling, link adaptation, mobile radio systems, new air interfaces, orthogonal frequency-division multiple access (OFDMA), orthogonal frequency-division multiplexing (OFDM), scheduling, spatial division multiple access (SDMA), time-division multiple access (TDMA), wireless broadband
Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-13382DOI: 10.1109/JPROC.2007.907119ISI: 000251787100012OAI: oai:DiVA.org:uu-13382DiVA: diva2:41152