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We study and analyze coverage region for MIMO amplify-and-forward (AF) relay network. We consider the network geometry in which L relays are placed uniformly around the source, and assume that there is no direct link between source and destination. We analyze desired transmission rate with the purpose of maximizing coverage region. Using Monte Carlo simulations the impact of number of transceiver...
In this paper, performance of a Turbo Code (TC) and Vertical Bell Laboratories Layered Space Time (VBLAST) encoded wireless link is evaluated in the presence of Rayleigh fading for Multiple-Input Multiple-Output (MIMO) system. Turbo encoded bits are modulated using QPSK or 16 QAM or 64 QAM modulator and modulated data are further encoded using VBLAST and then split into n streams which are simultaneously...
Long Term Evolution (LTE) is a standard for wireless communication of high speed data for mobile phones and data terminals. LTE is capable of delivering large data rate on the order of several megabits per second, which is even larger than the current 3G systems. This is very challenging as the wireless networks are subjected to interference, multipath and poor propagation channel characteristics...
In this paper, we elaborated on a new interference alignment technique for downlink multi-user system in a MIMO-X channel with multiple antennas. We considered two transmitters, each equipped with M antennas, and L users, each equipped with K antennas. Here, we consider a MIMO-X scenario that some users are receiving transmissions from both transmitters. The proposed approach is focused on rank-1...
Sparse space codes (SSC) are proposed as a novel transmission scheme for an under-determined MIMO channel. Each SSC codeword is a sparse vector of the size of the number of transmit antennas. The information is imparted through: (i) uncertainty in the positions of non-zero elements, and (ii) uncertainty in the symbol-space of non-zero elements. Basis-pursuit (BPD) and LASSO detectors are used with...
In this paper, we present an improved DFT-based channel estimation method. The conventional discrete Fourier transform(DFT)-based approach will cause energy leakage in multipath channel with non-sample-spaced time delays. The improved method uses symmetric property to extend the LS estimate in frequency domain, and calculates the changing rate of the leakage energy, and selects useful paths by the...
Block diagonalization (BD) is a downlink precoding technique that cancels inter-user interference in downlink multiuser MIMO systems. But the number of simultaneously supportable receive antennas is limited by the number of base station transmit antennas for multiuser MIMO systems with BD. When a large number of receive antennas exist, the base station can select a subset of receive antennas for each...
This paper investigates the implementation scenario of Space Division Multiple Access(SDMA) which is a notable application of Multiple Input Multiple Output(MIMO) system. SDMA is one of the most promising techniques aiming at solving the capacity problem of wireless communication systems and achieving higher spectral efficiency, depending on multiplexing signals based on their spatial signature. This...
In this paper, the information extracted from Single-Input Multiple-Output sounding measurements is used to study the effect of several aspects of the receive antenna arrays on system performance. The extracted multipath parameters are used to synthesize the MIMO channel matrices of a hypothesized communication system having a fixed microcellular base-station and a handheld terminal moving throughout...
Multiple input multiple output (MIMO) communication architecture has spectral efficiencies far beyond those offered by conventional techniques, and is greatly to increase the channel capacity. In this paper, we investigate the MIMO channel capacity in correlated channels using the uniform angular distribution, numerical simulations are performed with Matlab to verify the proposed formula. We prove...
MIMO antenna design is one of biggest issues in the LTE deployment. The multiple antennas should be designed compactly without sacrificing radiation efficiency and spatial correlation. Such multiple antennas can be achieved with polarization antennas or decoupling elements. Conventionally, these antenna parameters are designed empirically. In this paper, a method to optimize multiple antenna directivities...
Being an important wireless communication technique, multiple input multiple output (MIMO) system can effectively increase channel throughput by spatial multiplexing. However, the performance of a MIMO system can be further improved through adaptive modulation and intelligence antenna techniques. The affiliation of a controller can save power and diminish mechanical consumption with a guaranteed bit...
We address the main technical challenge encountered in the practical implementations of full-duplex MIMO relays, i.e., how to mitigate efficiently the self-interference that loops back from the relays transmit antenna array to its receive antenna array. In particular, we consider spatial-domain suppression using optimal eigenbeamforming that minimizes the power of the residual self-interference signal...
The problem of blind channel estimation in Multiple-Input-Multiple-Output (MIMO) Orthogonal Frequency-Division Multiplexing (OFDM) systems is investigated in this study, assuming that the transmitted symbols are independent and identically distributed. In particular, by utilizing a generalized linear non-redundant precoder, a simple blind channel estimation technique for MIMO-OFDM systems is developed...
In this paper, we consider user selection algorithms for Multi-user MIMO systems with perfect or partial channel state information at the transmitter (CSIT). A novel user selection algorithm based on chordal distance is proposed. The basic principle is to serve the user subset in which one is approximately orthogonal to the others. Since the chordal distance relies only on the channel direction information,...
In this paper, we consider a slow-fading nt ×nr multiple-input multiple-output (MIMO) channel subjected to block fading. Reliability (in terms of achieved diversity order) and rate (in number of symbols transmitted per channel use) are of interest in such channels. We propose a new precoding scheme which achieves both full diversity (nt ×nrth order diversity) as well as full rate (nt symbols per channel...
A systematic scheme is proposed to facilitate arbitrary virtual channel (VC)-to-user mappings in space dimension, through multiple-input multiple-output physical layer multicasting. It is a divide-and-conquer strategy, which breaks down the VC-to-user mapping to manageable orthogonal sub-mappings, each represented in terms of a multicast antenna group (MAG). A generalized form of block diagonalization...
Novel representations for the multivariate probability density function (PDF) and cumulative distribution function (CDF) of the equi-correlated non-central chi-square (χ2) distribution are derived. The new representations are given as single integral solutions in terms of well known mathematical functions which are available in common mathematical software packages. The advantage of the new representations...
This paper carries out the first-ever study of the feasibility of using chaos shift keying (CSK) in a Multiple-Input, Multiple-Output (MIMO) channel. To that end, an Alamouti space time code scheme is combined with the CSK system for 2 transmit and 2 receiver antennas. Once the design of CSK-MIMO system is presented, the performance of the proposed system is analyzed in a mono-user case. An exact...
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 (TE) scheme with successive interference cancellation for orthogonal frequency division multiplexing...
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