• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.6
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• pp.14-21
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• 2011

In this paper, we propose an efficient symbol mapping method based on LLR (log-likelihood ratio) statistic for HARQ employing CoRe (constellation rearrangement) with 64QAM. The signal constellations for 64QAM with limited number of retransmissions are selected by the proposed mapping rule. Then we determine the transmission order of selected constellations. The proposed scheme reduces the performance deviation between transmit symbols so as to improve the system performance. Through simulation results, the proposed and existing CoRe mapping methods are compared with respect to error rate and throughput in MIMO-OFDM system over fading channel and we confirm the applicability of the proposed scheme in practical wireless communications environment.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.5
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• pp.19-25
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• 2009

In this paper, the constellation rearrangement method for retransmission based on Chase combining, is introduced. And the effectiveness of the recommended constellation rearrangements is analyzed with statistics. Their performance for turbo-coded or convolutional coded bit streams is evaluated with simulation under additive white Gaussian noise environment.