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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, we propose a generalized formula for generating bit-wise puncturing patterns for block-type low density parity-check (B-LDPC) codes with dual-diagonal parity structure. The proposed formula distributes punctured bits uniformly in the zigzag edge connections, as well as maximizes the minimum recovery speed and the reliability of each punctured(More)
—In this paper, the best-M feedback, where each user reports the channel quality indicators (CQIs) on its M best resource blocks (RBs), for orthogonal frequency division multiple access (OFDMA) systems is analyzed and optimized. First, the closed-form expression of the average sum-rate is derived as a function of M and the number of bits for a signal to(More)
— In this paper, we propose an efficient puncturing method for LDPC codes. The proposed algorithm provides the order of variable nodes for puncturing based on the proposed cost function. The proposed cost function tries to maximize the minimum reliability among those provided from all check nodes. Also, it tries to allocate survived check nodes evenly to(More)
—This letter provides the distributions on the association region of a small-cell BS (sBS) and that of a macro-cell BS (mBS) in a two-tier heterogeneous cellular network (HCN) as functions of the power and density ratios between tiers. Computer simulation results confirm that the proposed distributions are quite accurate for a wide range of network(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)
Dietary antigens are normally rendered nonimmunogenic through a poorly understood "oral tolerance" mechanism that involves immunosuppressive regulatory T (Treg) cells, especially Treg cells induced from conventional T cells in the periphery (pTreg cells). Although orally introducing nominal protein antigens is known to induce such pTreg cells, whether a(More)
— In this paper, we consider the quasi-maximum-likelihood (quasi-ML) detectors of the reverse link system that uses antenna arrays in asynchronous channels when the channel vector is time-invariant and time-varying. A channel vector estimation method based on eigendecomposition for time-invariant channels and its adaptive version suitable for the(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 non-uniform Poisson point process (PPP). Approximated closed-form SIR distributions are provided according to the tier,(More)
— In this paper, a novel preamble structure, including a synchronization field (S-field) and a cell searching field (C-field), is proposed. An efficient algorithm for downlink synchronization and cell searching using the preamble is also proposed. The synchronization process includes initial symbol timing estimation using continuously or at least(More)