André Noll Barreto

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In this paper we propose two precoding schemes for the downlink of CDMA systems which help reduce the multiuser interference by jointly precoding the transmitted signal based on knowledge of the downlink channel. These methods provide a substantial capacity increase without requiring complex multiuser detectors at the mobile terminals and can be applied for(More)
—The downlink capacity tends to be the limiting factor in future communications systems. In this paper, we propose two schemes for the downlink of code-division multiple-access systems that help reduce the multiuser interference by jointly precoding the transmitted signal based on knowledge of the downlink channel. Methods that operate on blocks of bits(More)
'Mobile communications is characterized by a fast growing number of users and an increasingly heterogeneous data traffic due to emerging multimedia packet services. Likewise, users desire more mobility support, thus demanding permanent availability at any place and any speed. The conventional answer to this problem is building new wireless standards. But(More)
In this paper we present a unified comparison of the performance of four detection techniques for centralized data-fusion cooperative spectrum sensing in cognitive radio networks under impulsive noise, namely, the eigenvalue-based generalized likelihood ratio test (GLRT), the maximum-minimum eigenvalue detection (MMED), the maximum eigenvalue detection(More)
—Iterative correction can be employed to mitigate the distortion caused by nonlinear power amplifiers in OFDM systems. However, proposals found in the literature suppose that the receiver has perfect knowledge of the nonlinear conditions encountered in transmission. In this paper, we propose the use of the Extendend Kalman Filter and the Unscented Kalman(More)