scholarly journals Investigation of MIMO Channel Characteristics in a Two-Section Tunnel at 1.4725 GHz

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Rongchen Sun ◽  
David W. Matolak ◽  
Cheng Tao ◽  
Liu Liu ◽  
Zhenhui Tan ◽  
...  
Keyword(s):  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Vertical Wall ◽  
Path Loss ◽  
Wide Band ◽  
Singular Values ◽  
Mimo Channel ◽  
Center Frequency ◽  
Delay Spread ◽  
Single Input Single Output

This paper presents results from a wide band single-input–single-output (SISO) and 16 × 16 virtual multiple-input–multiple-output (MIMO) measurement campaign at a center frequency of 1.4725 GHz in a 100-meter long tunnel laboratory which is terminated by a vertical wall with a metallic door. The path loss, root-mean-square delay spread (RMS-DS) characteristics, and power delay profiles (PDPs) are described. In addition, we provide results for the MIMO channel amplitude matrix, which offers a new perspective in understanding MIMO characteristics in tunnel scenarios. Our measurement results are analyzed and compared to ray tracing simulations. The relationships among the angle spread, channel matrix singular values, and MIMO capacity at various link distances are illustrated, and these provide insights into MIMO system deployment.

scholarly journals MMSE-NP-RISIC-Based Channel Equalization for MIMO-SC-FDE Troposcatter Communication Systems

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Zedong Xie ◽  
Xihong Chen ◽  
Xiaopeng Liu ◽  
Yu Zhao
Keyword(s):  
Interference Cancellation ◽  
Communication Systems ◽  
Intersymbol Interference ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Channel Equalization ◽  
Single Input Single Output ◽  
Single Carrier ◽  
Single Output ◽  
The Impact

The impact of intersymbol interference (ISI) on single-carrier frequency-domain equalization with multiple input multiple output (MIMO-SC-FDE) troposcatter communication systems is severe. Most of the channel equalization methods fail to solve it completely. In this paper, given the disadvantages of the noise-predictive (NP) MMSE-based and the residual intersymbol interference cancellation (RISIC) equalization in the single input single output (SISO) system, we focus on the combination of both equalization schemes mentioned above. After extending both of them into MIMO system for the first time, we introduce a novel MMSE-NP-RISIC equalization method for MIMO-SC-FDE troposcatter communication systems. Analysis and simulation results validate the performance of the proposed method in time-varying frequency-selective troposcatter channel at an acceptable computational complexity cost.

scholarly journals Frequency-Selective Wallpaper for Indoor Interference Reduction and MIMO Capacity Improvement

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 695
Author(s):  
José-Víctor Rodríguez ◽  
Mats Gustafsson ◽  
José-María Molina-García-Pardo ◽  
Leandro Juan-Llácer ◽  
Ignacio Rodríguez-Rodríguez
Keyword(s):  
Mimo Systems ◽  
Radio Channel ◽  
Multiple Input Multiple Output ◽  
Singular Values ◽  
Indoor Environments ◽  
Radio Communication ◽  
Single Input Single Output ◽  
Communication Signals ◽  
Frequency Selective ◽  
5 Ghz

This paper presents the design and features of frequency-selective wallpaper—based on periodic and symmetric metallic hexagons—intended to be attached to standard walls for filtering out 5 GHz signals (e.g., IEEE 802.11a systems) without blocking other selected radio communication services (e.g., cellular mobile communication signals). It analyzes the characteristics of the radio channel—as found within standard indoor environments—with both regular walls and walls with the proposed frequency-selective wallpaper, examined using a ray-launching program for single-input single-output (SISO) and multiple-input multiple-output (MIMO) systems. This allows the harvesting of parameters, including channel capacity, power delay profile, and signal-to-interference ratio, for proper comparison between the two environments under study: with and without the presented wallpaper. The achieved results clearly show that the use of the proposed frequency-selective wallpaper in an indoor scenario reduces interference levels by an additional attenuation of up to 20 dB in comparison to an unpapered wall. Additionally, with MIMO systems, radio channel characteristics, such as capacity, are improved due to the increase in the magnitude of all singular values of the channel transfer matrix compared to the unpapered wall case, thereby leading to the existence of more relevant subchannels.

scholarly journals Conceiving Inferential Prototypes of MIMO Channel Models via Buckingham’s Similitude Principle for 30+ GHz through THz Spectrum

2021 ◽  
Vol 9 (3) ◽  
pp. 1-35
Author(s):  
Perambur Neelakanta ◽  
Dolores De Groff
Keyword(s):  
Multiple Input Multiple Output ◽  
Path Loss ◽  
Spatial Multiplexing ◽  
Mimo Channel ◽  
Channel Models ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Channel Statistics ◽  
Wave Range ◽  
Test Spectrum

Facilitating newer bands of ‘unused’ segments (windows) of RF spectrum falling in the mm-wave range (above 30+ GHz) and seeking usable stretches across unallocated THz spectrum, could viably be considered for Multiple Input Multiple Output (MIMO) communications. This could accommodate the growing needs of multigigabit 3G/4G applications in outdoor-based backhauls in picocellular networks and in indoor-specific multimedia networking. However, in contrast with cellular and Wi-Fi, wireless systems supporting sub-mm wavelength transreceive communications in the outdoor electromagnetic (EM) ambient could face “drastically different propagation geometry”; also, in indoor contexts, envisaging pertinent spatial-multiplexing with directional, MIMO links could pose grossly diverse propagation geometry across a number of multipaths; as such, channel-models based on stochastic features of diverse MIMO-specific links in the desired test spectrum of mm-wave/THz band are sparsely known and almost non-existent. To alleviate this niche, a method is proposed here to infer sub-mm band MIMO channel-models (termed as “prototypes”) by judiciously sharing “similarity” of details available already pertinent to traditional “models” of lower-side EM spectrum, (namely, VLF through micro-/mm-wave). Relevant method proposed here relies on the “principle of similitude” due to Edgar Buckingham. Exemplar set of “model-to-(inferential)-prototype” transformations are derived and prescribed for an exhaustive set of fading channel models as well as, towards estimating path-loss of various channel statistics in the high-end test spectrum.

scholarly journals A Triply Selective MIMO Channel Simulator Using GPUs

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
R. Carrasco-Alvarez ◽  
R. Carreón-Villal ◽  
J. Vázquez Castillo ◽  
J. Ortegón Aguilar ◽  
O. Longoria-Gandara ◽  
...  
Keyword(s):  
Graphics Processing Units ◽  
Multiple Input Multiple Output ◽  
Direct Consequence ◽  
Mimo Channel ◽  
Computational Time ◽  
Space Correlation ◽  
Single Input Single Output ◽  
Single Output ◽  
Input Multiple Output ◽  
Channel Simulator

A methodology for implementing a triply selective multiple-input multiple-output (MIMO) simulator based on graphics processing units (GPUs) is presented. The resulting simulator is based on the implementation of multiple double-selective single-input single-output (SISO) channel generators, where the multiple inputs and the multiple received signals have been transformed in order to supply the corresponding space correlation of the channel under consideration. A direct consequence of this approach is the flexibility provided, which allows different propagation statistics to each SISO channel to be specified and thus more complex environments to be replicated. It is shown that under some specific constraints, the statistics of the triply selective MIMO simulator are the same as those reported in the state of art. Simulation results show the computational time improvement achieved, up to 650-fold for an 8 × 8 MIMO channel simulator when compared with sequential implementations. In addition to the computational improvement, the proposed simulator offers flexibility for testing a variety of scenarios in vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) systems.

scholarly journals A Semiempirical MIMO Channel Model in Obstructed Viaduct Scenarios on High-Speed Railway

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Tao Zhou ◽  
Cheng Tao ◽  
Liu Liu ◽  
Zhenhui Tan
Keyword(s):  
High Speed ◽  
Channel Model ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Time Correlation ◽  
Time Correlation Function ◽  
Mimo Channel ◽  
High Speed Railway ◽  
Single Input Single Output ◽  
Single Output

A semiempirical multiple-input multiple-output (MIMO) channel model is proposed for high-speed railway (HSR) viaduct scenarios. The proposed MIMO model is based on the combination of realistic single-input single-output (SISO) channel measurement results and a theoretical geometry-based stochastic model (GBSM). Temporal fading characteristics involvingK-factor and Doppler power spectral density (PSD) are derived from the wideband measurement under an obstructed viaduct on Zhengzhou-Xi’an HSR in China. The GBSM composed of a one-ring model and an elliptical model is employed to describe the entire propagation environment. Environment-related parameters in the GBSM are determined by the measured temporal fading properties. And a close agreement is achieved between the model results and measured data. Finally, a deterministic simulation model is established to perform the analysis of the space-time correlation function, the space-Doppler PSD, and the channel capacity for the measured scenario. This model is more realistic and particularly beneficial for the performance evaluation of MIMO systems in HSR environments.

scholarly journals A Comprehensive Review on Various Estimation Techniques for Multi Input Multi Output Channel

2019 ◽  
Vol 27 (1) ◽  
pp. 262-274 ◽  
Author(s):  
Awwab Qasim Jumaah Althahab ◽  
Sameer Abdul Kadhim Alrufaiaat
Keyword(s):  
Channel Estimation ◽  
Communication Systems ◽  
Multiple Input Multiple Output ◽  
Wireless Channel ◽  
Mimo Channel ◽  
Estimation Accuracy ◽  
Blind Estimation ◽  
Quality Of Data ◽  
Single Input Single Output ◽  
Estimation Algorithms

The problem of wireless channel estimation has been evolving due to some undesirable effects of channel physical properties on transmitted signals. At the receiver end, distortions, delays, attenuations, interferences, and phase shifts are the most issues encounter together with the received signals. In order to overcome channel effects and provide almost a perfect quality of data transmission, channel parameter estimation is needed. In Multiple Input-Multiple Output systems (MIMO), channel estimation is a more complicated step as compared with the Single Input-Single Output systems, SISO, because of the fact that the number of sub-channels that needs estimate is much greater than SISO systems. The fundamental objective of this research paper is to go over the famous and efficient algorithms that have been innovated to solve the problem of MIMO channel estimation in wireless communication systems. In this paper, these techniques have been classified into three groups: non-blind, semi-blind and blind estimation. For each group, a brief illustration is presented for familiar estimation algorithms. Finally, we compare between these techniques based on computational complexity, latency and estimation accuracy.

scholarly journals Fisher-Information-Matrix Based Analysis of Semiblind MIMO Frequency Selective Channel Estimation

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Aditya K. Jagannatham ◽  
Bhaskar D. Rao
Keyword(s):  
Fisher Information ◽  
Fisher Information Matrix ◽  
Finite Impulse Response ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Information Matrix ◽  
Wireless Channel ◽  
Mimo Channel ◽  
Minimum Number ◽  
Frequency Selective

We present a study of semiblind (SB) estimation for a frequency-selective (FS) multiple-input multiple-output (MIMO) wireless channel using a novel Fisher-information matrix (FIM) based approach. The frequency selective MIMO system is modeled as a matrix finite impulse response (FIR) channel, and the transmitted data symbols comprise of a sequence of pilot symbols followed by the unknown blind symbols. It is demonstrated that the FIM for this system can be expressed as the sum of the blind FIM Jb and pilot FIM Jp. We present a key result relating the rank of the FIM to the number of blindly identifiable parameters. We then present a novel maximum-likelihood (ML) scheme for the semiblind estimation of the MIMO FIR channel. We derive the Cramer-Rao Bound (CRB) for the semiblind scheme. It is observed that the semi-blind MSE of estimation of the MIMO FIR channel is potentially much lower compared to an exclusively pilot-based scheme. Finally, we derive a lower bound for the minimum number of pilot symbols necessary for the estimation of an FIR MIMO channel for any general semi-blind scheme. Simulation results are presented to augment the above analysis.

scholarly journals The BER Analysis of MIMO System for M-PSK over Different Fading Channels using STBC Code Structure

2019 ◽  
Vol 8 (3) ◽  
pp. 5831-5836
Keyword(s):  
Fading Channels ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Spatial Diversity ◽  
Single Input Single Output ◽  
Single Output ◽  
Code Structure ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Rician Channel

High information rates inside the restricted frequency (RF) spectrum is often fascinating that results in radios with capabilities on the far side a single-input single-output (SISO) topology. In recent days introduced wireless systems have adopted multiple-input multiple-output (MIMO) topologies that use 2 or more transmitters and 2 or more receivers to send information at the same time over same RF bandwidth. The performance of MIMO system may be improved by involving multiple antennas at transmitter and receiver therefore on offer spatial diversity. during this paper, the performance analysis of MIMO system over AWGN attenuation channel and Rician Channel with ZF receiver is bestowed. The consequences of the antenna choice can even be analyzed from the simulated results. The BER (Bit Error Rate) performance characteristics of ZeroForcing (ZF) receiver is investigated for M-PSK modulation technique over the AWGN channel and Rician Channel.

scholarly journals Relay Selection Scheme for Multi-Hop Transmission of MU-MIMO System

2018 ◽  
Vol 8 (10) ◽  
pp. 1747 ◽  
Author(s):  
Won-Chang Kim ◽  
Min-Jae Paek ◽  
Hyoung-Kyu Song
Keyword(s):  
Communication Systems ◽  
Relay Selection ◽  
Mimo System ◽  
Singular Values ◽  
Mimo Channel ◽  
Wireless Communication Systems ◽  
Transmission Scheme ◽  
Selection Scheme ◽  
Channel Matrix ◽  
Cell Coverage

Recently, wireless communication systems use a multi-hop transmission scheme using a relay to expand the cell coverage of the system. The multi-hop transmission scheme can expand the cell coverage of wireless communication systems. However, if an appropriate relay is not selected, errors generated during signal processing in the relay are transmitted to the receiver. Therefore, a relay selection scheme is essential for reliable multi-hop transmission. This paper proposes a relay selection scheme for reliable multi-hop transmission in a multi user-multiple input multiple output (MU-MIMO) system. The proposed relay selection scheme uses a MIMO channel matrix between the transmitter and relays to select an appropriate relay. The proposed relay selection scheme obtains the singular values of the MIMO channel matrix using the singular value decomposition (SVD). Then, the sum of the singular values is calculated, and the relay having the largest value is selected. Therefore, in the proposed relay selection scheme, although the transmitter only knows the channel information between the transmitter and relays, the transmitter can select an appropriate relay for reliable multi-hop transmission.

scholarly journals Improvement of Complexity and Performance of Least Square Based Channel Estimation in MIMO System

2016 ◽  
Vol 1 ◽  
pp. 11
Author(s):  
Anand Kumar Sah ◽  
Arun Kumar Timalsina
Keyword(s):  
Channel Estimation ◽  
Mimo Systems ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Estimation Method ◽  
Vital Role ◽  
Least Square ◽  
Mimo Channel ◽  
Fourth Generation ◽  
Simulation Results

<p>Multiple-input multiple-output (MIMO) systems play a vital role in fourth generation wireless systems to provide advanced data rate. In this paper, a better performance and reduced complexity channel estimation method is proposed for MIMO systems based on matrix factorization. This technique is applied on training based least squares (LS) channel estimation using STBC for performance improvement. Simulation results indicate that the proposed method not only alleviates the performance of MIMO channel estimation but also significantly reduces the complexity caused by matrix inversion. The performance evaluations are validated through computer simulations using MATLAB in terms of bit error rate (BER) for modified LS with LS and MMSE channel estimation techniques. Simulation results show that the BER performance and complexity of the proposed method clearly outperforms the conventional LS channel estimation method.</p><p><em>Journal of Advanced College of Engineering and Management, Vol. 1, 2015</em>, pp. 11-24</p>

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