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We consider the problem of quantifying the Pareto optimal boundary in the achievable rate region over multiple-input single-output (MISO) interference channels, where the problem boils down to solving a sequence of convex feasibility problems after certain transformations. The feasibility problem is solved by two new distributed optimal beamforming algorithms, where the first one is to parallelize...
Block diagonalization (BD) is a practically favorable precoding technique that eliminates the interuser interference in downlink multiuser multiple-input multiple-output (MIMO) systems. In this paper, we apply BD to the downlink transmission in a cooperative multi-cell system, where the signals from different base stations (BSs) to all the mobile stations (MSs) are jointly designed with the perfect...
This paper studies the downlink beamforming for a multi-cell system, where multiple base stations (BSs) each with multiple antennas cooperatively design their respective transmit beamforming vectors to optimize the overall system performance. It is assumed that all mobile stations (MSs) are equipped with a single antenna each, and there is one active MS in each cell at one time. Accordingly, the system...
This paper studies the design of a decentralized multiuser MIMO system for spectrum sharing over a fixed bandwidth, where the coexisting users independently update their transmit covariance matrices for individual rate maximization via an iterative manner. This design problem was usually investigated in the literature by assuming that each user treats the co-channel interference from all the other...
This paper studies the achievable rates of the multi-antenna or multiple-input multiple-output (MIMO) secrecy channel with multiple single-/multi-antenna eavesdroppers. It is known that the maximum achievable secrecy rate is obtained with the optimal transmit covariance matrix that maximizes the minimum difference between the channel mutual information of the secrecy user and those of the eavesdroppers...
We consider a spectrum sharing based cognitive radio wireless communications system which consists of a secondary transmitter (ST) and a secondary receiver (SR), both equipped with multiple antennas, and a single-antenna primary user (PU). ST is composed of an orthogonal space-time block code (OSTBC) followed by a linear precoder which acts as a multimode beamformer. Given a fixed OSTBC, our goal...
In this paper, we study a multi-antenna-based cognitive radio (CR) system that is able to operate concurrently with the primary radio (PR) system. We propose a novel CR transmission frame structure consisting of three stages, including a new environment learning stage in addition to the conventional channel training and data transmission stages. During the environment learning stage, the CR terminals...
This paper studies the information-theoretic limits for the fading multiple-input single-output broadcast channel (MISO-BC) for support of data traffic with heterogeneous transmission delay requirements. First, this paper derives the optimal dynamic resource allocation algorithm for simultaneous transmission of both delay-tolerant "packet" data and delay-sensitive "circuit" data...
This paper considers the two-hop relay broadcast channel (BC) in a wireless cellular network where the downlink transmission from the base station (BS) to mobile users is assisted by a fixed relay station (RS). Assuming both the BS and RS equipped with multi-antennas, we consider joint optimization of beamforming weights and power allocations at the BS and RS so as to minimize their weighted sum-power...
In this paper, power-efficient transmission schemes are studied for MIMO-OFDM block-fading channels under the assumption that the channel is perfectly known at the receiver but unknown at the transmitter. Based on the well-known V-BLAST architecture that employs the horizontal encoding and the interference-nulling based successive decoding, this paper presents a closed-loop V-BLAST extension for MIMO-OFDM...
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