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The following topics are dealt with: information theory; coding; MIMO systems; OFDM systems; antennas; telecommunication channels; relaying; channel estimation; protocols; wireless networks; resource management; beamforming; and multiuser systems.
Secrecy on the physical layer receives increased research interest. Especially in the wireless communication scenarios, the interest in confidentiality of messages increases. In this paper, we discuss the effectiveness of the beamforming strategies maximum ratio transmission (MRT), zero forcing (ZF), and an optimized beamforming (BF) strategy for the transmission under secrecy constraints. The applied...
We propose an optimal minimum sidelobe modal beamforming approach based on the spherical harmonics decomposition for spherical sensor arrays, which provide the ability of three-dimensional broad-band beampattern synthesis. The spherical harmonics domain array processing problem is expressed with a matrix formulation. The weight vector design problem is written as a multiply constrained problem, so...
To suppress co-channel interferences in OFDM systems two main schemes namely, the pre-FFT and the post-FFT schemes have been proposed. While pre-FFT is a time-domain beamforming method, post-FFT uses beamforming in frequency domain to suppress directional interferences. It is generally believed that the post-FFT scheme is superior in performance than the pre-FFT method. In this study we first compare...
This paper introduces a new mathematical framework which is used to derive joint uplink/downlink achievable rate regions for multi-user spatial multiplexing between one base station and multiple terminals. The framework consists of two models: the first one is a simple transmission model for uplink (UL) and downlink (DL), which is capable to give a lower bound on the capacity for the case that the...
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