ICI cancellation for OFDM communication systems in time-varying multipath fading channels

• Published in: IEEE transactions on wireless communications Vol. 4; no. 5; pp. 2100 - 2110
• Main Authors: HOU, Wen-Sheng, CHEN, Bor-Sen
• Format: Journal Article
• Language: English
• Published: Piscataway, NJ IEEE 01.09.2005; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Cancellation; Channels; Cost function; Equalization; Equalizers; Exact sciences and technology; Fading; Filters; Impulse response; Intercarrier interference (ICI); Interference; Mean square error methods; minimum mean square error (MMSE); Noise cancellation; OFDM; Orthogonal Frequency Division Multiplexing; orthogonal frequency division multiplexing (OFDM); parallel interference cancellation (PIC); Performance analysis; Performance enhancement; Prefilters; Studies; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Time varying systems; time-varying channel; Transmission and modulation (techniques and equipments); Wireless networks; Performance evaluation; Noise reduction; Carrier to noise ratio; Equalizer; Subcarrier; Multipath channels; Degradation; Time varying system; Pulse response; Cost function; orthogonal frequency division multiplexing (OFDM); time-varying channel; Fading channels; Fading; minimum mean square error (MMSE); Multistage method; Multicarrier; Intercarrier interference; Frequency domain method; Equalization; Orthogonality; Intercarrier interference (ICI); Weight function; Telecommunication system; Orthogonal frequency division multiplexing; parallel interference cancellation (PIC)
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2005.853837

In orthogonal frequency division multiplexing (OFDM) systems, time-varying multipath fading leads to the loss of subcarrier orthogonality and the occurrence of intercarrier interference (ICI). In this study, an efficient ICI suppression with less noise enhancement for multicarrier equalization is presented by using a parallel canceling scheme via frequency-domain equalization techniques, with the assumption that the channel impulse response (CIR) varies linearly during a block period. In order to avoid performance deterioration due to unreliable initial estimations in the parallel cancellation scheme, a cost function with proper weighting factor is introduced to improve the performance of the proposed equalizer. The proposed equalizer consists of a set of prefilters and a set of ICI cancellation filters, with two stages to perform different functions to achieve minimum mean square error (MMSE) equalization. The prefilters compensate for the multiplicative distortion at the first stage, and the ICI cancellation filters remove the effects of ICI by a parallel cancellation scheme at the second stage. Finally, the performance of the proposed equalizer is analyzed and compared with that of other equalizers, indicating significant performance improvement.