Nicolae Chiurtu

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In this work, we consider the multiple antenna systems in which a large number of antennas occupy a given physical volume, and investigate the behavior of the capacity when increasing the number of antennas. In this regime the assumptions of the standard multiple antenna models become questionable. We introduce several new channel models that better fit(More)
We consider multiple antenna systems in which a large number of antennas occupy a given physical volume. In this regime the assumptions of the standard models of multiple antennas systems become questionable. We show that for such spatially dense multiple antenna systems one should expect the behavior of the capacity to be qualitatively different than what(More)
This paper presents the implementation of a multiple antenna communication system using low-density parity-check (LDPC) codes on the software-defined radio (SDR) platform developed at EPFL's Mobile Communications Laboratory. After briefly presenting the general structure and the main capabilities of our SR platform, we describe the methods and algorithms(More)
Nowadays it is widely understood that the use of multiple antennas at both ends of a communication system can greatly increase the capacity of the link. In particular, if the entries of the channel transfer matrix are assumed to be i.i.d. Gaussian random variables, the capacity increases linearly with the minimum number of transmit and receive antennas [1].(More)
It is well known and surprising that the uncoded transmission of an independent and identically distributed Gaussian source across an additive white Gaussian noise channel is optimal: No amount of sophistication in the coding strategy can ever perform better. What makes uncoded transmission optimal? In this thesis, it is shown that the optimality of uncoded(More)
In this paper we study the downlink spectral efficiency of a wireless network using Orthogonal Frequency Division Multiple Access (OFDMA), Multiple Input Multiple Output (MIMO) antenna systems and Opportunistic Scheduling (OS) techniques. The main purpose of the study is to understand how these techniques interact and influence the spectral efficiency of(More)
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