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This paper presents a technique to increase the data throughput in Multiple Input Multiple Output (MIMO) systems. The technique uses a meta-heuristic to optimize the data throughput and to choose the best solution. The optimization is based on Genetic Algorithms (GA), with the objective of finding out the best antenna configuration to achieve the highest data throughput from the variation of the distance...
It is necessary to study the spatial evolution of clusters in massive multiple-input multiple-output (MIMO) mobile channel, which is one of the important features in cluster-based models. In this paper, we analyze the data collected from the massive MIMO mobile measurement campaign, with a 256-element virtual array at 3.5 GHz in line of sight (LoS) and non line of sight (NLoS) conditions, respectively...
This paper presents angular characteristics for high-speed railway (HSR) channels, based on virtual single-input multiple-output (SIMO) measurements. A virtual array measurement scheme is investigated and used to generate SIMO channel impulse responses (CIRs) from single-antenna measurements in three typical HSR scenarios, including obstructed viaduct, deep cutting, and open station. According to...
Massive multiple-input multiple-output (Massive MIMO) is acknowledged as a key technology for the 5th generation (5G) of wireless communication systems, which theoretically proved to be of higher throughput, better robustness, superior spectrum- and energy- efficiency. A reliable and realistic channel model serves is the enabling foundation for practical design and testing of communication systems...
This paper presents a 32-element phased-array architecture suitable for fifth-generation (5G) communication links. A 28–32 GHz silicon core chip is designed with 4 transmit/receive elements each with 14 dB gain control, 6-bit phase control, 4.6 dB measured noise figure (NF) in the RX mode and 10 dBm output 1 dB compression point (OP1dB) in the TX mode. Eight of these chips are flipped on a low-cost...
This paper introduces a real-time multiple input and multiple output (MIMO) channel sounder to measure the vehicle-to-vehicle (V2V) propagation channel at 5.9 GHz. Compared to the existing V2V channel sounders, our design emphasizes on improving the stability of the setup and increasing the MIMO snapshot rate. The system stability allows us to develop a high resolution parameter extraction algorithm...
This paper shows the variation of clusters with the increasing number of antennas. The data was collected from the massive MIMO mobile measurement at 3.5 GHz, in line of sight (LoS) and non line of sight (NLoS) conditions, respectively. And the virtual measurement method is used to form the 64-element, 128-element and 256-element virtual antenna array from the 32-element antenna array. After estimating...
The aim of this study is to compare the performance of different multiple-input multiple-output (MIMO) array topologies, intended to be used in ultra-wideband (UWB) near-field imaging applications, by using an analysis method that does not include the effects of image reconstruction algorithm. For this purpose, maximum projection method, previously proposed for the analysis of UWB arrays under far-field...
In this paper we discuss the feasibility of an online failure detection algorithm for large linear arrays for massive MIMO applications. By means of a numerical optimization of the position of few near field probes, a good failure detection performance has been verified.
Cumulative distribution functions (CDFs) for multiple-input-multiple-output (MIMO) capacities are computed for flat-fading indoor channels at 5.8 GHz. These CDFs are based on two measured channels and on reconstructions of the MIMO channels from path parameters that are estimated based on measured data. The measured data was obtained using the stepped-frequency method of channel sounding in combination...
This article presents a near-field magnetic multi-input multi-output (MIMO) communication system test bed using software defined radio (SDR). We propose a heterogeneous multi-pole loop antenna array for near-field magnetic MIMO system. In this paper, we show improved performance of the proposed near-field magnetic MIMO communication system over a conventional magnetic MIMO system employing a circular...
For future 5G systems significant performance benefits are expected from massive MIMO, especially in combination with tight inter-cell cooperation including joint-transmission using cooperative multi-point transmission. Most massive MIMO evaluations concentrate on the base station side with the goal to achieve high spectral efficiency by MU-MIMO or large coverage by strong beamforming gains. Especially...
In this paper, an efficient sparse representation algorithm for direction of arrival (DOA) estimation in a multiple-input multiple-output (MIMO) Radar system is proposed. The proposed method converts the received data into a low-dimensional real-valued one by exploiting the characteristic of MIMO radar system. Then the DOA estimation is realized via the reweighting l1 norm minimization algorithm....
Arrays of GaN light-emitting diodes can be used for rapid display of pattern sequences or high speed parallel data transmission using different sites of the array. These operation modes can be combined with each other and are useful for light-fidelity networks with Gb/s capacity.
Phased array and MIMO (Multiple Input Multiple Output) radar systems are being developed with greater number of channels to achieve more flexibility, speed and range. Each channel contains either an ADC (Analog to Digital Converter) — for a receiver channel — or a DAC (Digital to Analog Converter) — for a transmission channel. In such large array, the channels need to be time synchronized as precisely...
We address the problem of pilot decontamination for massive MIMO systems for finite dimensional channels, wherein the channel vectors between the users and the base station are composed of a finite number of discrete paths. The pilot decontamination problem is addressed using high-resolution parametric spectral estimation methods, such as root multiple-signal classification (root-MUSIC), for resolving...
This article proposes computationally tractable, easy to expand and tight relative gain variation bound for uncertain systems. The proposed bound is a further development of previous work, which is summarized and discussed. Using several examples, the new method is compared with previous results and the advantages are highlighted. The prediction of sign changes in relative gain array elements due...
This paper introduces a new direction of arrival (DOA) estimation method for Doppler radars with Multiple-input multiple-output (MIMO) systems, which have been used in various applications, for example, detection and classification of indoor human activities. To improve DOA estimation accuracy, the temporal-spatial virtual array based on Doppler shift of a moving target has been proposed; hereafter...
In this paper, we study the achievable multiplexing gain of millimeter wave (MMW) line-of-sight (LoS) multiple-input multiple-output (MIMO) channels with non-uniform linear antenna arrays (NULAs) at both the transmitter and receiver. We first present an analytical characterization for the asymptotic channel eigenvalues with arbitrarily deployed NULAs. Then, aiming at achieving an effective multiplexing...
We consider the problem of estimating the singular vectors of low-rank signal matrices buried in noise in the setting where the singular vectors are assumed to be Kronecker products of three unknown vectors. We propose several algorithms for estimating such singular vectors, which explicitly exploit the Kronecker structure of the underlying vectors. We demonstrate improved estimation accuracy and...
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