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Extended balanced space-time block coding (EBSTBC) is able to achieve large coding gain and guarantee full diversity for any number of transmit antennas. However, the calculation of feedback information at the receiver employs exhaustive searching scheme which is at a high complexity. In this work, a low-complexity calculating scheme of feedback information is proposed for the receiver in EBSTBC systems...
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...
In this paper, we apply vector perturbation (VP) precoding to a network multiple-input multiple-output (MIMO) scheme, in which downlink transmissions from base stations are coordinated. We propose a multi-cell VP by introducing a common power scaling factor for all base stations in order to satisfy per base station power constraint. In our scenario, we consider multiple-antenna users with heterogeneous...
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...
In a distributed MIMO system (D-MIMO), multiple base stations work in cooperation manner to enhance system throughput by suppressing inter-cell and inter-user interference. In this paper, we propose two practical distributed algorithms that are based on block diagonalization technique. The proposed schemes eliminate the need of iterative computations, and hence can be implemented without information...
A virtual multiple-input multiple-output (MIMO) system based on cooperative communication is studied actively. This system is formed between base station and source node with using of two or more nodes around itself. These transmitters are equipped with a single antenna. This system is one of the solution methods for deterioration in communication quality from that the power supply of the node is...
In order to accurately evaluate spatial processing techniques such as MIMO for wideband mobile communications, a Time-Spatial Propagation (TSP) model that can simulate, at the same time, the characteristics of both the delay profile and the spatial arrival angular profile for travelling waves is required. We proposed the TSP model for wideband mobile communication systems using UHF and SHF bands in...
We study the potential benefits of cooperative multiple-input multiple-output signaling from multiple coherent base stations with one or more mobile stations in an urban macrocellular environment. The analysis uses novel and fully-coherent measurements of the channel from three base stations to a single mobile station equipped with four antennas. The observed channels are used to explore the gains...
MIMO-OTA (Over-the-air) measurement methods of mobile terminals have recently been studied and developed for mobile communications. However, the methods like these for base station antenna have not frequently been reported. In this paper, a novel fading generator using rotated scattering objects is proposed in order to establish an OTA measurement method for MIMO base station emulating radio environment...
Large scale parameters (LSP) mainly describe the distribution of the transmitted power over different dimensions of the channel. The required statistic is obtained from MIMO channel measurements with an appropriate post processing procedure. In this contribution, we perform the characterization of large scale parameters within an urban macro cell scenario. We focus on investigating the influence of...
The major problem of multiuser MIMO precoding and scheduling is the required Channel State Information (CSI) at the base station which needs to be provided to the base station via a feedback channel in case of frequency division duplex. Each user quantizes the channel direction information and computes a Channel Quality Indicator (CQI), e.g., based on the Signal-to-Interference-and-Noise Ratio (SINR),...
It is well known that the availability of M transmit antennas at the base station enables to serve K single-antenna users (K ≤ M), under the assumption of perfect channel state information (CSI) at the base station. However, in practical frequency division duplex (FDD) systems, the channel knowledge available at the base station is not perfect since it is obtained through a limited feedback in the...
For a class of the important problems that seek to maximize the sum rate of the multiple input multiple output relay communication system (MIMO RCS) and compute the optimal transmission distributions, we present their mathematical models, and then develop an efficient algorithm for solving this class of the problems. The fixed point theory is used to prove convergence of the proposed algorithm. The...
In modern cellular systems, base station cooperation multiple-input multiple-output (MIMO) in which multiple base stations transmit desired signals to one user is anticipated to alleviate interference at the cell-edge. Cell-edge user is influenced a great deal by interference between different base stations. Inter-cell interference degrades system performance substantially. An interference alignment...
Energy consumption is an issue in general in information and communication technologies (ICT), but also cellular communications in particular. Base station sites are the main energy consumers in a mobile network. Their energy consumption significantly contributes to green house gas (CO2) emissions. Hence, service providers are looking for energy saving solutions in their existing and future deployments...
This paper reports the performance of a downlink of a multiuser MIMO system which uses a successive beamforming broadcasting scheme. The investigations take into account the effects of mutual coupling that is present in receiving antennas. It is shown that that the mutual coupling changes the received signals statistic properties and impacts the co-channel interference component. The overall mutual...
In this paper, we present a low-complexity coordinated beamforming transmission scheme for multiuser multiple-input-single-output (MISO) systems. With a minimum overhead signaling, the proposed scheme selects the beamforming vector and users while considering the interference from other cells. We develop the exact analytical expressions of the ergodic sum-rate for the resulting system for dual-cell...
In this paper, we consider the multiple base station cooperative transmission, a new technology being developed to lift the interference limits on wireless network. In practice, the biggest challenge facing multiple base station collaboration is the stringent requirement of the high-speed backbone to enable information exchange, especially for large deployment. We address this backbone issue and propose...
In this paper we evaluate a recently proposed multiple-input multiple-output (MIMO) system called the Layered Steered Space-Time Codes (LSSTC). The LSSTC system is evaluated for multi-user environments where scheduling can be used to increase the system capacity by harnessing the multi-user diversity. This evaluation is done by comparing the capacity and the probability of error for several combinations...
In this paper we present a novel multi-cell TDD CSI sounding concept for terminals employing multiple antennas. The objective is to support decentralized downlink beam coordination with minimal or no backhaul traffic between the base stations (BS). Each BS makes its own scheduling and precoding decisions independently, based on the locally available CSI and knowledge of the prior scheduling decisions...
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