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The MIMO system convincingly promises a better bit rate in comparison with a SISO system. The system gets even efficient when OFDM is implemented with MIMO to obtain better data rates even in hostile channel environment. Research establishes OFDM as a potential candidate for use in MIMO systems for the reasons like inherent FFT, waveform adaptation, advanced antenna techniques, multiple access, interoperability,...
Multiple antennas in conjunction with Multiple Input Multiple Output (MIMO) systems offer significant increases in capacity without increasing transmit power or spectrum and are becoming an integral part of all modern wireless communication systems. For example multiple antenna technology is already used in wireless communication systems such as in IEEE 802.11n, WiMAX and LTE. This paper reviews some...
The concept of interference alignment has been studied mainly from an information-theoretic and signal processing point of view, focusing on scenarios with a high degree of coordination among nodes often achieved by means of transmission scheduling. However, many real-world networks employ random access policies rather than deterministic scheduling, and it is therefore important to understand how...
This paper establishes three kinds of mean-square-error (MSE) uplink-downlink duality for multiple-input multiple-output (MIMO) systems. Our duality is established for the practically relevant scenario where the noise vector of each mobile station (MS) is a zero-mean circularly symmetric complex Gaussian (ZMCSCG) random variable with arbitrary covariance matrix. As an application example of our duality,...
Mobile broadcasting MIMO systems differ in several essential ways from conventional MIMO applications, especially when they are operating in single-frequency networks. There are certain channel features, like the imbalance of received average powers, which should be taken into account in system design. In this paper, space-time coding that allows reduced complexity maximum likelihood decoding of the...
The rate balancing problem is considered in the multiple-input single-output (MIMO) broadcast channel with linear transceivers. After introducing relative per-stream rate targets as auxiliary variables, the optimization is performed by a gradient projection algorithm. In addition, the transmit and receive filters are updated and the mean square error matrices are diagonalized in each iteration. Although...
This paper investigates the effect of nonlinearity on the capacity of MIMO systems and develops a capacity-enhancing MIMO transmission technique suitable for deployments over nonlinear channels. Nonlinearity arises in communication systems in several ways. In this work, we focus on the nonlinearity introduced at the transmitter side by the High Power Amplifier (HPA), the last stage in the communication...
The following topics are dealt with:context aware computing; sensor networks; MIMO communication systems; ad-hoc networks and routing; wireless computing; wireless multimedia; and emerging networks.
We consider a multiuser multiple-input multiple output (MIMO) Gaussian broadcast channel (BC). Assuming a sum-power constraint over all transmit antennas, the sum capacity of such a system can be achieved with dirty paper coding (DPC) which has been found as a very promising strategy. Rather than the usual sum-power constraint, in this paper we focus on the downlink of a cooperative multicellular...
Application of multiple has attracted many attentions due to their high rate and high. Multiple antennas have a practical drawback, multiple antennas require more radio frequency (RF) chains and it results in higher computational complexity and cost. Besides, in many applications such as the mobile sets we have a limitation of array size to place multiple antennas. This limitation results in mutual...
Weibull MIMO channels are difficult to analyze due to their non-linear characteristic. While phase is not a major factor in SISO systems, the analysis of Weibull MIMO systems cannot easily discard it. The capacity upper bound in this work includes the contributions of both envelope and phase through the application of first and second moments of channel matrix elements. The capacity bound allow us...
Long Term Evolution (LTE) is an emerging 4G wireless access technology. Multiple-Input Multiple-Output (MIMO) systems are a primary enabler of the high data rate sought to be achieved by LTE. Closed-Loop-Spatial-Multiplexing and Open-Loop-Spatial-Multiplexing are the two primary MIMO transmission modes used in the LTE downlink. An LTE Base Station (eNodeB) is expected to select and switch transmission...
The following topics are dealt with: user mobile terminal antennas; ultra wide band antennas and systems; metamaterial applications; MIMO systems and smart antennas; integral techniques in electromagnetics; small antennas; channel modelling for free space optical links; pattern comparison techniques; channel characterization and antenna-channel interactions; RF exposure assessment; radar imaging and...
This paper introduces a complete model for the analysis of MIMO systems, obtaining a factorization of the channel matrix into four matrices, each having its physical meaning. Particular attention is given to the propagation matrix, that describes the electromagnetic propagation between two domains.
Physical implementations of radio-frequency (RF) transceivers are known to suffer from a variety of non-idealities that defy proper compensation. As shown in Studer et al., WSA 2010, such residual transmit-RF (Tx-RF) impairments have a considerable impact on the performance of multiple-input multiple-output (MIMO) wireless communication systems, even for high-quality RF chains. In this paper, we analyze...
In this paper a Tunable multi-band meander line printed monopole antenna for multiple-input-multiple-output (MIMO) system is presented. The proposed meander line monopole antenna can create a single resonance within the WLAN range. Placement of two resonance paths with length λg/2 vertical on it, leads to creating two extra resonances. The antenna parameters covering 2.4, 5.8 GHz for WLAN and 3.5...
We analyze the asymptotic performance of rate adaptation for Transmit Antenna Selection (TAS) and Maximum Eigenmode Beamforming (MEB) schemes in Multiple-Input Multiple-Output (MIMO) systems under imperfect channel state information (CSI) and feedback delay. The rate is adapted according to a target outage probability. We derive lower and upper bounds to this rate. We also asymptotically characterize...
This paper proposed a detection method combined the list detection with partial successive interference cancellation (SIC) based on the reciprocal lattice-reduction in MIMO system. List detection is an effective detection method for improving the performance of MIMO signal detection, but the computational expense depending on the list length is the bottleneck. To reduce the complexity of the list...
Sphere decoding (SD), as an algorithm searching for the closest lattice point within a certain search radius, is a corrected maximum likelihood (ML) algorithm for multiple- input multiple-output (MIMO) systems, with low complexity. The sphere radius and the number of search floating points visited throughout the tree traversal searching are the decisive factors for the complexity of the algorithm...
In this paper, joint transmitter and receiver beamforming algorithms are proposed for downlink in multiuser multi-input multi-output (MIMO) communication systems. The proposed beamforming algorithms are developed based on non-cooperative and cooperative utility functions. In non-cooperative approach, utility function of each user is defined based on the performance of the user without considering...
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