Younghoon Whang

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—In this paper, we present a theorem that shows generalized properties for the cross-correlation function of Chu sequences. The theorem gives the information on the maximum magnitude and its position of cross-correlation function for all kinds of Chu sequences with any length. By using this theorem, we design the pilot sequences for multi-cell environment.(More)
—In this paper, optimal pilot sequence designs for MIMO-OFDM systems in multi-cell environments are provided. The proposed multi-cell optimality criterion is to minimize the worst-case MSE of an LS-based channel estimator. To satisfy the multi-cell optimality, it is found that the pilot sequence set, having the perfect auto-correlation property, should meet(More)
—In this letter, a novel time-domain recursive algorithm is proposed for a minimum-mean-squared error (MMSE) with successive interference cancellation (SIC) scheme. This algorithm allows us to reduce the complexity of classical MMSE-SIC equalizer for suppressing intercarrier interference (ICI) caused by time-varying multipath channels in orthogonal(More)
SUMMARY In this paper, we investigate an efficient user selection and sub-band allocation algorithm in which each user transmits two-step partial CQI to reduce the amount of feedback in multiuser downlink OFDMA systems. Simulation results show that we can greatly reduce the feedback rate at the expense of negligible performance degradation compared to the(More)