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Turbo equalization schemes based on minimum mean square error (MMSE) criteria available in the literature for multiple-input multiple-output (MIMO) systems are computationally expensive as they require a relatively large matrix inversion. In this paper, we propose a low complexity turbo-equalization scheme with successive interference cancellation for the equalization of rapidly time varying multi-path...
This paper presents the analysis of relay multiplexing configuration for IEEE 802.16j systems employing MIMO antennas. The availability of multiple relay paths in IEEE 802.16j motivates two relay configurations: relay diversity and relay multiplexing. Existing works have focused on the relay diversity method. In this paper, we explore the relay multiplexing alternative. Using the concept of code-division...
In this paper we focus on finding a suitable Link Adaptation (LA) algorithm which is implemented as Channel Quality Indicator (CQI) selection technique in the 3GPP Long Term Evolution (LTE) system. The potential of Link Adaptation in the LTE system is not fully exploited. Therefore in our study, we compare the performances from different LA algorithms in the LTE system. The presented LA algorithms...
It is well-known that for single-input and single-output (SISO) narrow-band transmission on frequency-flat fading channels, uncoded communication with only receiver channel state information (Rx-CSI) leads to extremely poor reliability performance whereas transmitter CSI (Tx-CSI) allows us approach the reliability of an additive white Gaussian noise (AWGN) channel via power control. In this paper,...
SDMA (Space-Division Multiple Access) is a MIMO (Multiple-Input and Multiple-Output) based wireless communication network architecture which has the potential to significantly increase the spectral efficiency and system performance. So far several multiuser detection (MUD) schemes like Zero Forcing (ZF), Minimum Mean Square Error estimation (MMSE), ordered successive interference cancellation (OSIC)...
Multiple antenna techniques are used to enhance wireless links and therefore have been studied extensively. Many practical systems differ from ideal schemes which have been discussed in the literature. One example is a system that lacks precise channel information at the transmitter. We evaluate analytically the performance of a multiple input multiple output (MIMO) technique that uses partial channel...
Significant throughput gains can be achieved in a multi-user MIMO (MU-MIMO) wireless system by exploiting the combination of multi-user scheduling and multi-user diversity. Open-loop MU-MIMO (OL-MU-MIMO) is a codebook based precoding technique where precoders are fixed a priori at the base station (BS) in a known fashion and the user needs to feedback which precoding vector is to be chosen referred...
Low-complexity near-optimal detection of large-MIMO signals has attracted recent research. Recently, we proposed a local neighborhood search algorithm, namely reactive tabu search (RTS) algorithm, as well as a factor-graph based belief propagation (BP) algorithm for low-complexity large-MIMO detection. The motivation for the present work arises from the following two observations on the above two...
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...
An Expectation-Maximization (EM) based scheme is presented in the context of compressed image transmission for blind Multiple-Input Multiple-Output (MIMO) wireless channel estimation. This cross-layer content-aware algorithm employs a combination of hard and soft (HS) symbol information from the header blocks of the scalable JPEG compressed image to estimate the complex baseband MIMO wireless channel...
We consider a flashy transmission scheme in multiple-input single-output (MISO) systems. In order to efficiently utilize the limited energy budget, only a portion of the available time is used for the actual transmission. For block-wise transmissions, we define the flashiness as the percentage of blocks used for the actual transmission. Each transmission block consists of a reverse training phase...
Most contributions on nonlinear Tomlinson-Harashima precoding (THP) assume complete channel state information (CSI) at the transmitter. However, complete CSI is not available in many wireless systems, and the conventional THP is sensitive to channel mismatch. This article investigates the THP design with imperfect CSI at base station (BS) in spatially correlated multiuser multiple-input multiple-output...
The designation of the 3-10 GHz frequency band for ultra-wideband (UWB) communications has led to the emergence of competing standards designed to facilitate high data-rate personal area networks (PAN). In particular, the IEEE 802.15.3 standard provides a multi-band physical layer to use all of the wide bandwidth while avoiding the frequency selective fading common to UWB channels. None of the proposed...
In this paper, the outage probability analysis of two-hop amplify-and-forward (AF) multiple-input multiple-output (MIMO) relay networks is presented. The source and the destination are equipped with multiple antennas and communicate with each other, with the help of a single antenna relay which is subject to interference. Two systems are considered; transmit antenna selection with maximal ratio combining...
In this paper, we study various cooperative relaying transmission schemes of multiple amplify-and-forward (AF) relays system for various geometric environments in view of capacity. We consider joint encoding (JE) with channel matched filtering (CMF) and selective transmission (ST) as coordinated AF relay transmission schemes. Through relay channel model considering link SNRs, we find suitable cooperative...
In the present work a novel multi-link MIMO scheme for indoor applications, called Interleaved F-DAS MIMO, is proposed. The performance of an Interleaved F-DAS MIMO deployment in a typical indoor office environment is analyzed, with particular reference to the LTE standard with the help of Ray tracing prediction and an LTE link-level simulator. Results show that the proposed scheme, although simpler...
The increased hardware complexity required to implement the multiple RF chains associated with the multiple antennas in MIMO systems, has led to various antenna selection methods for utilizing only a subset of the total available antennas. Some of these selection methods require the instantaneous channel state information (CSI) of the communication paths between the antennas, while other require only...
Cooperative relay techniques are exploited to reduce the transmission energy consumption which is very important for average and long range transmission in wireless sensor networks (WSNs). In this paper, the system having a two-antenna source, two one-antenna relays and a one-antenna destination is considered. Using distributed space-time code at relays, MIMO simple cooperative relay model (MSCR)...
Off-body wireless data communication using textile antennas integrated into clothing increases the safety of rescue workers operating in an indoor environment as vital information can be communicated to the command station. The indoor radio propagation is influenced by fading and shadowing. Yet, MIMO techniques significantly enhance the reliability of such a wireless link, producing a lower bit error...
In this paper, a 4 × 4 indoor multiple-input multiple-output ultra-wideband (MIMO-UWB) measurement campaign in the 2-5 GHz bandwidth is presented. The aim of this work is analyze the effect of radio-wave polarization as well as the effect of frequency dependence on MIMO-UWB systems working in laboratories environment. To achieve this, many parameters such as the mean path loss, the RMS delay spread,...
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