MIMO Architecture Modelling Utilizing Overlapped Element Antenna Arrays

In this paper, the design of a 3×3 multiple input multiple output (MIMO) array of rectangular dielectric resonator antenna (RDRA) at 3.5 GHz for sub 6 GHz 5G communication systems is presented. The designed MIMO DRA Array consists of four dielectric resonator (DR) elements fed by three ports using corporate feeding network thus making a 3×3 MIMO system. The ports are arranged in such a way that two ports excite TEx111 and TEy111 mode while the third ports excite TM111 mode in each DR thus ensuring polarization diversity. The impedance bandwidth of the proposed MIMO DRA array is 160 MHz and a maximum gain of about 9.43 dBi is achieved. A massive MIMO array can be constructed based on the proposed MIMO array which compared to the massive MIMO arrays available in literature can offer three times higher channel capacity, thus making it an ideal candidate for massive MIMO array which are an integral part of any 5G system.

Visible Light Communication (VLC) has emerged as a powerful technique for wireless communication systems. Providing high data rate and increasing capacity are the major problems in VLC. Recent evidence suggests that Multiple Input Multiple Output (MIMO) technique can offers improved data rates and increased link range. This paper describes the design and implementation of visible light communication system in indoor environment exploring the benefits of MIMO. The specific objective of this research was to implement a 4×4 Multiple Input (LEDs) Multiple Output (photodetectors)-VLC communication system, where a 16 white power LEDs in four arrays are setting up at transmitter and four RX modules are setting up at receiver side without the need for additional power or bandwidth as well as analyze a mathematical model for a VLC- 4×4 MIMO with different modes such as the suitable angles to cover the entire room. The research designs practically an electronic circuit for the transmitter and receiver with inexpensive components. The power distribution of different propagation modes is calculated for Single Input Single Output (SISO) and MIMO channels in typical room dimensions. The results in this paper indicate that the power is distributed uniformly for entire room when implemented VLC-MIMO as compared to VLC-SISO. Furthermore, a 4×4 MIMO implementing VLC is compared in term of BER vs. SINR with SISO communication system for both Line of Sight (LOS) and Non Line of Sight (NLOS) propagation modes. Comparing the two results of LOS and NLOS, it can be seen that a 4×4 MIMO implementing VLC for LOS perform better than the same system with NLOS due to decreasing in the received power resulted from the multipath effect.

Multiple Input - Multiple Output (MIMO) is a new communications paradigm which brings significant benefits to future communication systems. In contrast to conventional wireless communication systems, MIMO systems exploit the spatial diversity available in multipath propagation to create parallel channels within a common bandwidth. The multiple channels can be used for capacity enhancement, coverage improvement, lower radiated power spectral density, interference/jammer suppression, multi-beam communication and battery power savings. Research, development and exploitation of MIMO technology for tactical communication systems is significantly limited by lack of mobile, real-time MIMO testbeds to verify and validate extensive theoretical results. We report a 4x4 mobile, wideband, real-time MIMO-OFDM testbed designed and developed by the team of San Diego Research Center (SDRC) and Brigham Young University (BYU). Using this testbed we have successfully demonstrated the feasibility of peer-to-peer Mobile MIMO by closing 1000m links, at 50 mph speeds, at 12 bps/Hz spectral efficiency.

Different multiple input - multiple output (MIMO) channel models are analyzed with regard to the indoor line-of-sight (LOS) MIMO channel. In the literature this channel is proven to achieve high capacities while being highly correlated. The modeling results from physical as well as analytical models are compared with measured channels, showing that none of the established models is exactly suitable for the considered indoor LOS MIMO channel. However, there is a promising approach that applies an extended Saleh model in conjunction with the physically correct spherical wave propagation. Although in its current state this basic approach cannot be regarded as a complete MIMO channel model, at least it provides an adequate origin for the correct prediction of MIMO capacities in different types of LOS channels. This is due to the fact, that the crucial prerequisites for an appropriate LOS MIMO channel model, which are by name the application of the physically correct spherical wave propagation, the correct modeling of the high correlation in LOS channels and the inclusion of the geometrical antenna setup, are regarded correctly. Contrarily, these prerequisites are included in none of the current models that are widely accepted in MIMO radio communications nowadays. The proof of this statement using measured data is a major objective of this paper.

Three dimensional (3D) Multiple Input and Multiple Output (MIMO) is one of the most promising techniques for the 5th Generation (5G) mobile communication systems. Thus there is an urgent need for one reliable 3D MIMO channel model to research and evaluate 3D MIMO techniques. In this paper, we focus on the statistic characteristics of elevation angle in urban microcell (UMi) and propose a novel elevation angle modeling methodology. In order to capture enough 3D channel characteristics, field 3D channel measurements at 3.5 GHz with 100 MHz bandwidth are conducted in UMi scenario. Based on the existing 3D channel model frame, the proposed elevation angle model is introduced and the updated 3D channel model is used to perform channel capacity analysis. Comparisons among the updated 3D channel model, the traditional two dimensional (2D) channel model and the field 3D channel data are made. The updated 3D channel model obtains obvious capacity gain compared with 2D channel model. The proposed elevation angle model and the updated 3D channel model can optimally match the channel capacity of the real 3D channel data.

This thesis describes the analytical design and the performance analysis of optimum receivers for Multiple Input - Multiple Output (MIMO) fading channels. In particular, a novel Optimum Receiver for separately-correlated MIMO channels is proposed. This novel pilot-aided receiver is able to process jointly the pilot symbols, transmitted within each time frame as a preamble, and the information symbols and to decode the transmitted data in a single step, avoiding the explicit estimation of the channel matrix. The optimum receiver is designed for the following two scenarios, corresponding to different transmission schemes and channel models: 1) Narrowband Rician fading MIMO channel with spatial separate correlation; 2) MIMO-OFDM Rician fading channel with space and frequency separate correlation. For each system the performance of the optimum receiver is studied in detail under different channel conditions. The optimum receiver is compared with: - the ideal Genie Receiver, knowing perfectly the Channel State Information (CSI) at no cost; - the standard Mismatched Receiver, estimating the CSI in a first step, then using this imperfect estimate in the ideal channel metric. Since the optimum receiver requires the knowledge of the channel parameters for the decoding process, an estimation algorithm is proposed and tested. Moreover, a complexity analysis is carried out and methods for complexity reduction are proposed. Furthermore, the narrowband receiver is tested in realistic conditions using measured channel samples. Finally, a blind version of the receiver is proposed

An adaptive dual control algorithm is presented for multiple-input, multiple output (MIMO) linear systems with input and output noise and unknown parameters. The system parameters are assumed to belong to a finite set on which a prior probability distribution is available. The difficulties in characterizing the future evolution if MIMO system information as required by the dynamic programming are overcome through a novel way of using preposterior analysis. This provides a probabilistic characterization of the future adaptation process and allows the controller to take advantage of the dual effect.

<span>In this article, a planar monopole two-element multiple input multiple output (MIMO) array has been designed and characterized with the intention of ultra-wideband (UWB) applications. The array has a voltage standing wave ratio (VSWR) working bandwidth (BW) of 13.258 GHz between 3.394-16.652 GHz, with a fractional BW (FBW) of 132.28% with respect to a center frequency of 10.023 GHz. The two elements of the MIMO array are 900 polarizations mismatched for better isolation. Consequently, less than 20 dB of isolation has been achieved throughout the entire BW. Also observed was a good combined realized peak gain of up to 5.85 dBi and total efficiency of greater than 85%. For MIMO performance key parameters, the array exhibits the envelope correlation coefficient (ECC) <0.0033, diversity gain (DG) >9.983, total active reflection coefficient (TARC) <0.445, mean effective gain difference (MEG12) ≈0 dB, and the channel capacity loss (CCL) <0.4 bps/Hz. This design would encourage designers to create high-performance MIMO antennas for UWB frequency-related applications.</span>

We propose a Taylor expansion multiple signal classification (TE MUSIC) method for joint direction of departure (DOD) and direction of arrival (DOA) estimation in a bistatic multiple-input multiple-output (MIMO) array. First, using a Taylor expansion of the steering vector, a two-dimensional (2D) search in the conventional MUSIC method for MIMO arrays is reduced to a two-step one-dimensional (ID) search in the proposed TE MUSIC method. Second, DOAs of the targets can be achieved via Lagrange multiplier by a ID search. Finally, substituting the DOA estimates into the 2D MUSIC spectrum function, DODs of the targets are obtained by another ID search. Thus, the DOD and DOA estimates can be automatically paired. The performance of the proposed method is better than that of the MIMO ESPRIT method, and is similar to that of the 2D MUSIC method. Furthermore, due to the ID search, the TE MUSIC method avoids the high computational complexity of the 2D MUSIC method. Simulation results are presented to show the effectiveness of the proposed method.

Wireless network is one of the most important things in the development of telecommunication. However, the existing wireless technology has not been able to efficiently create a very high data rate because it was very sensitive to fading. Therefore, Orthogonal Frequency Division Multiplexing (OFDM) technology combined with MIMO (Multiple Input Multiple Output) transceiver system was used to gain more diversity and bandwidth efficiency. The propagation performed on the OFDM MIMO system was multipath propagation. To reduce Intersymbol Interference (ISI) was used Zero Forcing (ZF) equalizer which works by combining channel response and equalizer response itself to eliminate ISI. This study aims to determine the effect of Zero Forcing Equalizer on OFDM MIMO system using rayleigh fading channel and compared the result with OFDM MIMO STBC system. The research method used was simulation using MatLab R2015a. The simulation results showed that the performance of OFDM MIMO ZF system was worse than OFDM MIMO STBC system i.e BER vs EbNo simulation, eye diagram simulation, and constellation diagram simulation. The OFDM MIMO ZF system was required an Eb / No value more than 25 dB to achieve BER 10-4 while the OFDM MIMO STBC system only required an Eb / No value of 10.5 dB to achieve BER 10-4. The eye pattern generated by the OFDM MIMO ZF system was more closed and the dispersion of constellation signals away from the ideal point while OFDM MIMO STBC system displayed a more open eye pattern and the dispersion of its constellation signal closer to the ideal point. It indicated more ISI occurs in the OFDM MIMO ZF system than that in OFDM MIMO STBC system.

As the evolution of the 3G standards, multiple input and multiple output (MIMO) has been adopted to enhance the performance of 3G systems for the potential of beamforming, spatial multiplexing or spatial diversity. So far, no MIMO scheme has been adopted for time division-synchronous code division multiple access (TD-SCDMA). In this paper, 2times8 MIMO eigen beamforming is proposed to improve the performance of TD-SCDMA. As size limited, the antennas at the UE or Node B are correlated, only one eigen mode of the spatial correlation matrix is found to be useful, and only the beamforming gain and spatial diversity gain can be obtained efficiently. The simulation results of high speed uplink packet access (HSUPA) in the fixed reference channel show that, compared to single input and multiple output (SIMO) 1times8, 3 dB performance gain can be obtained by MIMO 2times8 eigen beamforming; while compared to that of single input and single output (SISO), the performance gain is 8-3 dB

Research in Multiple Input Multiple Output (MIMO) communication system has been developed rapidly in order to improve the effectiveness of communication among users. However, trade-off phenomenon between performance and computational complexity always become the hugest dilemma suffered by researchers. As an alternative solution, this paper proposes an optimization in 3x3 spatial multiplexing MIMO communication system using end-to-end based learning, specifically, it adapts autoencoder based model with the knowledge of Channel State Information (CSI) in the receiver side, make it fairly compared with the baseline method. The proposed models were evaluated in one of the most common channel impairment which is fast Rayleigh fading with additional Additive White Gaussian Noise (AWGN). By appropriately determining hyperparameters and the help of PReLU (Parametric Rectified Linear Unit), the results show that this autoencoder based MIMO communication system results in very promising results by exceeding the baseline methods (methods widely used in conventional MIMO communication) by reaching BER lower than at SNR 22.5 dB.

This paper investigates the performance of IEEE 802.11ac physical layer (PHY) when the following multiple input multiple output (MIMO) detectors are implemented: Sphere Decoding (SD); QRM-Maximum Likelihood (QRM-MLD); List Minimum Mean Squared Error Successive Interference Cancellation (List MMSE-SIC); List Zero-Forcing SIC (List ZF-SIC); Lattice Reduction MMSE-SIC (LR MMSE-SIC) and List LR MMSE-SIC. The conclusions are founded on simulation results, validated using first order techniques, over TGac channel models. The IEEE 802.11ac simulator implements hard-decision Viterbi decoding and realistic synchronization and channel estimation algorithms. The List MMSE-SIC scheme presents power gains around 2 dB in relation to the List ZF-SIC MIMO detector. The QRM-MLD MIMO detector has a highly superior performance regarding to the List MMSE-SIC MIMO detector since this latter scheme cannot overcome the propagation errors that degrade the performance of MMSE-SIC MIMO detectors. However, for moderate list lengths of 4 and 8, the QRM-MLD MIMO detector presents severe power losses in relation to the optimal SD MIMO detector. The LR MMSE-SIC MIMO detector allows power losses of only 1–2 dB in reference to the optimal SD MIMO receiver. There are no noticeable power gains when List detection techniques in MMSE-SIC MIMO detectors are implemented since the diversity gains due to implementation of LR basis change overcome the error propagation in SIC MIMO detectors with original channel basis.

Multiple input multiple output (MIMO) technology has evolved over the past few years into a technology with great potential to drive the direction of future wireless communications. MIMO technology has become a solid reality when massive MIMO systems (MIMO with large number of antennas and transceivers) were commercially deployed in several countries across the world in the recent past. Moreover, MIMO has been integrated into state-of-the-art paradigms such as fifth-generation (5G) networks as one of the main enabling technologies. MIMO possesses many attractive and highly desirable properties such as spatial multiplexing, diversity gains, and adaptive beamforming gains that leads to high data rates, enhanced reliability, and other enhancements. Nevertheless, beyond 5G technologies demand wireless communication systems with, among other properties, immensely higher data rates and better reliability simultaneously at the same time. In this work, a new, novel MIMO technique for simultaneously achieving multiplexing and diversity gains as well as completely eliminating any processing at the MIMO receiver, leading to advantages such as low complexity and low power consumption, is proposed. The proposed technique employs the design of interference-canceling matrices, which are calculated from the channels between the transceiver antennas, where the matrices are employed at the base station to help achieve multiplexing and diversity gains simultaneously. The novelty and efficiency of the introduced paradigm is demonstrated via mathematical models and validated by Monte Carlo simulations. Results indicate that the proposed system outperforms conventional MIMO models.

This paper addresses the problem of coded waveform design for Multiple Input - Multiple Output (MIMO) radar systems. The paper proposes a signal model based on the assumption of a small array aperture relative to the signal wavelength and a single target in far field. It is argued that near maximum likelihood performance can be obtained by choosing the transmitted waveforms on different antennas to be orthogonal. The Cramer-Rao Bound (CRB) for estimating the target distance, radial velocity and wavenumber is derived. The paper presents a convex optimisation procedure to yield an optimal energy distribution across the transmitted signals. Simulations demonstrate a reduction in CRB in the order of 25% compared to the use of a random unitary code. The paper concludes by indicating a natural generalisation of the method to optimal design for MIMO tracking radars.