ICI mitigation for OFDMA uplink systems

Chao Yuan Hsu*, Wen-Rong Wu

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations

Abstract

Orthogonal frequency-division multiplexing multiple access (OFDMA) has been considered as a promising multiple access technique in OFDM-based communication systems. In an ideal OFDMA system, no intercarrier interference (ICI) occurs. However, in high-speed mobile environments, the channel may be time-variant during one OFDMA symbol period. In such a condition, the mobility-induced ICI will degrade the system performance seriously. To remove the ICI effect, the zero-forcing (ZF) method is one of the simple techniques. Unfortunately, the direct ZF method needs to invert an N × N ICI matrix, requiring a prohibitively high complexity when N is large. In this paper, we first derive a structured OFDMA uplink signal model consisting of FFTs/IFFTs. Exploring this structure and using Newton's iteration for matrix inversion, we develop a low-complexity ZF method. With our formulation, fast Fourier transforms (FFTs) can be used to reduce the complexity. Thus, the proposed method can reduce the complexity from O(N3) to O(Nlog2N). Simulations show that the proposed method can have the similar performance to the direct ZF method while requires much lower complexity.

Original languageEnglish
Title of host publication2008 IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2008
DOIs
StatePublished - 1 Dec 2008
Event2008 IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2008 - Poznan, Poland
Duration: 15 Sep 200818 Sep 2008

Publication series

NameIEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC

Conference

Conference2008 IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2008
CountryPoland
CityPoznan
Period15/09/0818/09/08

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