This letter addresses the problem of robust transceiver design for the multiuser multiple-input-multiple-output (MIMO) downlink where the channel state information at the base station (BS) is imperfect. A stochastic approach which minimizes the expectation of the total mean square error (MSE) of the downlink conditioned on the channel estimates under a total transmit power constraint is adopted...

Performance analysis of maximal-ratio combining receive diversity scheme over Nakagami-0.5 fading channels and its application to the multiuser detection for direct sequence-code division multiple access systems is presented in this paper. A new M-estimator, which performs well in the heavy-tailed impulsive noise, is proposed to robustify the detector. Further, the performance of Eigen mode tra...

The bit error rate of a coded Multiuser OFDM (M-OFDM) system and coded Multicarrier CDMA (MC-CDMA) system with multiuser detection is analyzed. The paper focuses on downlink wireless applications, where the channel suffers from frequency-selective fading. We investigate both systems when long time interleaving is possible, though introducing large delays, and when time interleaving is limited. ...

We propose some robust adaptive multiuser detection schemes for direct-sequence codedivision multiple-access (DS-CDMA) multipath frequency-selective fading channels. Multiple access interference (MAI) and intersymbol interference (ISI) are presented in an identical format using expanded signal subspace, which facilitates multiuser detection in a symbol-by-symbol fashion. This paper contributes ...

We investigate the problem of broadcasting secret information to one or more receivers over wireless links in the presence of potential eavesdroppers. A fast fading channel model is assumed, with perfect channel state information (of intended receivers) at the transmitter. Both the case of independent messages and common message are considered. For the case of independent messages we propose a ...

This paper investigates the performance gain for pilot-aided channel estimation in the uplink of multiuser OFDM mobile radio systems, when array antennas are applied at the receivers. The application of array antennas allows the exploitation of directional information of the desired and the undesired signals at the receivers based on the array geometry and the directions of arrival of the consi...

The use of multiple antenna’s at both transmitter and receiver to form multiple input and multiple output(MIMO) channels currently hold the potential to drastically improve the spectrum efficiency and capacity of future wireless communication system. For broadband systems ,OFDM turns a frequency selective channel into a set of parallel flat channels which reduces the receiver complexity. Design...

Introduction: Detection and estimation theory is one of the core investigation areas in communications. Multiuser detection (MUD) is an estimation problem in which different users transmit their signals through the same channel in a multiple access channel (MAC). In this way the receiver explores desired signal through the ambient noise and interference generated by other user signals. Multiuse...

| In this paper, we develop an iterative multiuser receiver for decoding Turbo coded synchronous CDMA signals in both Gaussian and non-Gaussian noise. A soft-input soft-output non-linear multiuser detector is combined with a set of single user channel decoders in an iterative detec-tion/decoding structure. The non-linear multiuser detector utilizes the prior probabilities of each user's bits to...

We consider multiuser communication on a binary input additive white Gaussian noise channel using Randomly Spread-Code Division Multiple Access. We show concentration of various quantities of the system including the capacity and the free energy. We also obtain a tight upper bound on the capacity of this system in the large user limit which matches with the replica solution. The method is quite...