Hyung Yeol Lee

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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 paper, the uplink (UL) signal-to-interference ratio (SIR) distributions in a two-tier heterogeneous cellular network (HCN) are analyzed by considering the power control effect and approximating the UL interferer locations as a nonuniform Poisson point process (PPP). Approximated closed-form SIR distributions are provided according to the tier,(More)
In this paper, we propose two modified proportional fair scheduling algorithms for multiuser multicarrier systems. Compared to the existing proportional fair scheduling algorithms, our proposed algorithms are devised to support the delay constraint for the real-time applications as well as to guarantee a certain level of fairness. The simulation results(More)
We consider multiuser multicarrier systems, where each non-symmetrically distributed user reports only partial indices of subcarriers whose normalized SNRs exceed the predetermined threshold so that only partial feedback information is available at the base station. To accommodate both efficiency and fairness, the base station is assumed to perform the(More)
In this paper, an uplink (UL) enhanced intercell interference coordination (e-ICIC) scheme using synchronously configured low-power almost blank subframes (SLP-ABSs) is proposed for providing as efficient UL load balancing as in the downlink (DL) of a self-organized heterogeneous cellular network (SO-HCN). An analytical framework is provided as a(More)
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