Evaluation of Encoded MU-MISO-OFDM Systems in TDD Mode with Non-ideal Channel Reciprocity

Authors: M. Petermann, D. W├╝bben, K.-D. Kammeyer
Abstract: In multi-user orthogonal frequency division multiplexing (MU-OFDM) systems operating in time division duplex (TDD) mode downlink pre-equalization can be applied relying on channel state information (CSI) from the uplink direction. Unfortunately, the prerequisite of channel reciprocity is usually not fulfilled due to non-reciprocal transceivers. Hence, this paper deals with a comparison of robust pre-equalization schemes and a calibration approach to enhance the necessary uplink-downlink "link equivalence" for MU-MISO-OFDM systems applying linear and non-linear pre-equalization techniques and strong forward error correction (FEC). Performance evaluations concerning coded bit error rate results show that robust pre-equalizers exclusively improve the performance in moderate non-reciprocity conditions. In contrast, only calibration helps in dealing with severe transceiver mismatch.
Document type: Conference Paper
Publication: Siegen, Germany, 18. - 21. January 2010
Conference: 8th International ITG Conference on Source and Channel Coding (SCC 2010)
scc2010_full_paper.pdf177 KB
Last change on 22.01.2010 by M. Petermann
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