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On the capacity of a cellular CDMA system, " IEEE Trans. Abstract—In this paper, we propose a new frequency synchronization algorithm for orthogonal frequency division multiplexing (OFDM) systems requiring only one training symbol, based on a conventional method which requires two training symbols. While the timing synchronization is obtained by using the(More)
—We consider a multi-pair multi-antenna relay system , delivering data from multi-sources to their destinations simultaneously with the help of a massive antenna relay. We analyze the spectral efficiency and power scaling laws under perfect and imperfect channel state information (CSI) for zero-forcing relay beamforming. The analysis shows that the transmit(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, we propose an LDPC-coded OFDMA system with a resource allocation method suitable for the uplink of mobile cellular environments. At the receiver of the proposed system, an iterative channel estimation and decoding (IED) method with a Wiener filter adapting to the channel variation rate is employed to support high mobility without boosting(More)
—In this paper, we propose and analyze a multiuser receiver using a decorrelating filter and Viterbi decoders for trellis-coded direct-sequence code-division multiple-access (DS/CDMA) systems with biorthogonal signal constellation in asynchronous channels. The biorthogonality is implemented by user signature waveforms and the decorrelating filter. The(More)
—To reduce the influence of interference on the OFDM-based cognitive radio overlaid with narrowband primary users, we consider a scheme called the variable subband nulling (VSN), in which a VSN mode is selected adaptively according to the result of spectrum sensing for the frames following the sensing period. For reliable detection of the VSN mode embedded(More)
We propose a new detector of which the basis is on the median-shift (MS) sign: the median-shift sign (MSS) detector is a generalization of the classical (standard) sign detector. We obtain the finite sample size and asymptotic optimum MS values for various noise probability density functions (pdfs). We analyze the problem of detecting known signals in noise(More)
— In this correspondence, an efficient implementation of the D-homomorphism for generating de Bruijn sequences is presented. The number of exclusive–or operations required to generate the next bit for de Bruijn sequences of order n from a de Bruijn function of order k is shown to be approximately k(2 W(n0k) 0 1), where W(r) is the number of one's in the(More)
—We consider a two-way relay (TWR) network with multiple relays, where the relays adopt physical layer network coding based on decode-and-forward. A joint relay selection and power allocation (RS-PA) scheme is proposed to improve the symbol error probability (SEP) of the TWR network using BPSK modulation under the total power constraint. For the proposed(More)