scholarly journals Improving the efficiency of antennas of MIMO communication systems

2019 ◽  
Vol 30 ◽  
pp. 05008
Author(s):  
Victor Obukhovets
Keyword(s):  
Mobile Communication ◽  
Communication Systems ◽  
Information Transfer ◽  
Mimo Systems ◽  
Mimo System ◽  
Mutual Correlation ◽  
Spectral System ◽  
Communication Devices ◽  
Comparative Results ◽  
System Effectiveness

The last two decades were marked by increasing of interest in problems of application of the MIMO systems in a radar and wireless communication. Use of the principles of creation of MIMO systems in communication complexes allows increasing the capacity of channels and speed of information transfer due to increase in number of the transferring and reception antennas. In the report questions of modernization of antennas of the wearable mobile communication devices allowing to reduce correlation of channels and to increase spectral system effectiveness of communication are considered. Results of a research of mutual correlation reduction between two antennas of MIMO system are given. Using method of numerical modelling influence of several options of the decoupling structures on interconnection size between radiators and on their directional patterns were investigated. Comparative results of a pilot study of the model of antennas with the outcome device having the best characteristics and without the decoupling device are presented.

scholarly journals Normalized Structured Compressed Sensing Based Signal Detection in Spatial Modulation 3D-MIMO Systems

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Wei Ren ◽  
Guan Gui ◽  
Fei Li
Keyword(s):  
Compressed Sensing ◽  
Signal Detection ◽  
Communication Systems ◽  
Mimo Systems ◽  
Mimo System ◽  
Minimum Mean Square Error ◽  
Iteration Process ◽  
High Energy ◽  
Spatial Modulation ◽  
3D Mimo

Signal detection is one of the fundamental problems in three-dimensional multiple-input multiple-output (3D-MIMO) wireless communication systems. This paper addresses a signal detection problem in 3D-MIMO system, in which spatial modulation (SM) transmission scheme is considered due to its advantages of low complexity and high-energy efficiency. SM based signal transmission typically results in the block-sparse structure in received signals. Hence, structured compressed sensing (SCS) based signal detection is proposed to exploit the inherent block sparsity information in the received signal for the uplink (UL). Moreover, normalization preprocessing is considered before iteration process with the purpose of preventing the noise from being overamplified by the column vector with inadequately large elements. Simulation results are provided to show the stable and reliable performance of the proposed algorithm under both Gaussian and non-Gaussian noise, in comparison with methods such as compressed sensing based detectors, minimum mean square error (MMSE), and zero forcing (ZF).

Mobile Communication in Hospitals

2019 ◽  
pp. 278-301
Author(s):  
Terje Solvoll
Keyword(s):  
Medical Errors ◽  
Mobile Communication ◽  
Communication Systems ◽  
Psychological Theory ◽  
Alarm Fatigue ◽  
Critical Part ◽  
Communication Devices ◽  
Wireless Phones ◽  
Communication Methods ◽  
Usage Area

Mobile communication for healthcare workers is a critical part of hospitals infrastructure. Many of these systems do not work well together, leading to difficulties regarding multiple communication devices with different usage area, unavailable or missing equipment, and alarm fatigue. Physicians and nurses often need information fast, and any delay between the decision and the action taken could cause medical errors. One suggested solution for this problem is to implement wireless phone systems. However, psychological theory and empirical evidence, both suggest that wireless phones have the potential of creating additional problems related to interruptions. The fact that hospital workers prefer interruptive communication methods before non-interruptive methods, amplifies the risk of overloading staff. The key is how to handle the balance between increased availability and increased interruptions. In this chapter, the authors present solutions and possibilities based on context aware communication systems that aim to reduce interruptions and thereby also alarm fatigue.

scholarly journals Near Optimal Receive Antenna Selection Scheme for MIMO System under Spatially Correlated Channel

2018 ◽  
Vol 8 (5) ◽  
pp. 3732
Author(s):  
Patel Sagar ◽  
Bhalani Jaymin
Keyword(s):  
Communication Systems ◽  
Mimo Systems ◽  
Antenna Selection ◽  
Mimo System ◽  
Symbol Error Rate ◽  
Selection Scheme ◽  
Spatially Correlated ◽  
Spatially Correlated Channel ◽  
Correlated Channel ◽  
Receive Antenna

Spatial correlation is a critical impairment for practical Multiple Input Multiple Output (MIMO) wireless communication systems. To overcome from this issue, one of the solutions is receive antenna selection. Receive antenna selection is a low-cost, low-complexity and no requirement of feedback bit alternative option to capture many of the advantages of MIMO systems. In this paper, symbol error rate (SER) versus signal to noise ratio (SNR) performance comparasion of proposed receive antenna selection scheme for full rate non-orthogonal Space Time Block Code (STBC) is obtained using simulations in MIMO systems under spatially correlated channel at transmit and receive antenna compare with several existing receive antenna selection schemes. The performance of proposed receive antenna selection scheme is same as conventional scheme and beat all other existing schemes.

scholarly journals Improvement of FER using Differential Space-Time Block Code

2020 ◽  
Vol 8 (5) ◽  
pp. 4144-4148
Keyword(s):  
Communication Systems ◽  
Mimo Systems ◽  
Mimo System ◽  
Radio Channel ◽  
Block Code ◽  
Space Time ◽  
Coherent Detection ◽  
Doppler Spectrum ◽  
Time Block ◽  
Space Time Block Code

Over recent years, various modulation and coding techniques have been proposed in MIMO wireless communication systems. A MIMO system uses the concept of spatial diversity which is very successful and promising technique. When a coherent transmission system is considered, the estimation of radio channel impulse response is done precisely. In MIMO systems, the radio channel is estimated among every transmitting and receiving antennas such that the complexity can be increased. For this reason, in MIMO systems differential modulation schemes are estimated. A Differential Space-Time Block Code (DSTBC) is useful in the Raleigh fading channel as they do not require channel estimates. Space-time coding with MIMO antennas at transmitting and receiving reduces the consequences of fading in multiple paths and therefore the performance of digital transmission throughout wireless radio channel can be improved. So it has been presumed that perfect CSI is available at the receiver and coherent detection is employed. This paper presents improvement of Frame Error Rate (FER) for differential space-time block code using various Doppler spectra. When the channels estimates are not available the DSTBC system noticed that at SNR of 10 dB, for two transmitting and four receiving antennas the FER is 0.0067 for rounded Doppler spectrum. The differential schemes attains full transmit diversity owing to orthogonal designs. However, the receiver or the transmitter needs the channel state information so these differential schemes are 3 dB worse than the STBC with coherent detection.

scholarly journals Main-Branch Structure Iterative Detection Using Approximate Message Passing for Uplink Large-Scale Multiuser MIMO Systems

2016 ◽  
Vol 2016 ◽  
pp. 1-12
Author(s):  
Qifeng Zou ◽  
Xuezhi Tan ◽  
Mei Liu ◽  
Lin Ma
Keyword(s):  
Message Passing ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Large Scale ◽  
Mimo Systems ◽  
Mimo System ◽  
Detection Methods ◽  
Iterative Detection ◽  
Multiuser Mimo ◽  
Approximate Message Passing

The emerging large-scale/massive multi-input multioutput (MIMO) system combined with orthogonal frequency division multiplexing (OFDM) is considered a key technology for its advantage of improving the spectral efficiency. In this paper, we introduce an iterative detection algorithm for uplink large-scale multiuser MIMO-OFDM communication systems. We design a Main-Branch structure iterative turbo detector using the Approximate Message Passing algorithm simplified by linear approximation (AMP-LA) and using the Mean Square Error (MSE) criterion to calculate the correlation coefficients between main detector and branch detector for the given iteration. The complexity of our method is compared with other detection algorithms. The simulation results show that our scheme can achieve better performance than the conventional detection methods and have the acceptable complexity.

scholarly journals Impact of Hardware Impairment Analysis on Channel Capacity Bounds of MIMO Antenna Configurations

2020 ◽  
Vol 9 (3) ◽  
pp. 1981-1985
Keyword(s):  
Channel Capacity ◽  
System Performance ◽  
Communication Systems ◽  
Mimo Systems ◽  
Mimo System ◽  
Mimo Antenna ◽  
Hardware Impairments ◽  
Hardware Impairment ◽  
The Impact ◽  
Capacity Performance

with the increasing demand f the higher data reates the utilization of the MIMO system have exponentially increased in the cellular communication systems. There are many reasons due to which the performance of the MIMO systems degrades in real time. The major challenge is the any kind of noise or erro in the system due to hardware issues and problems. The any kind of hardware error is called as hardware impairment in the systems. These impairments are represented by Kapa values in the systems. Paper is primarily focused to define and evaluate the impact of the hardware impairment on the system performance of MIMO. The paper first defines the basic MIMO systems antenna configurations and then the channel capacity performance is compared with and without hardware impairments. the antenna configurations depends on the number of input and output antenna in the system. As the number of antennas increases the probability of having hardware impairment also increases. This may reduce the capacity performance significantly. New channel capacity formulation is given for antenna configurations. Paper evaluated the performance under the different channel sizes on the capacity. Finally the capacity of the channel is plotted as the function of the different Signal to noise ratios. It is concluded the MIMO system performance is degraded under the presence of the hardware impairments.

scholarly journals Capacity Optimization of MIMO Systems Involving Conformal Antenna Arrays using a Search Group Algorithm

2020 ◽  
Vol 5 (4) ◽  
pp. 209-214
Author(s):  
Abdelmadjid RECIOUI
Keyword(s):  
Wireless Communication ◽  
Antenna Arrays ◽  
Communication Systems ◽  
Mimo Systems ◽  
Mimo System ◽  
Wireless Communication Systems ◽  
Capacity Optimization ◽  
Mimo Communication ◽  
Conformal Antenna

MIMO systems constitute a backbone of the fourth and fifth generations of wireless communication systems. The purpose of this paper is to introduce the involvement of conformal antenna arrays into MIMO systems. The Search Group Algorithm (SGA) is then used to further enhance the capacity of MIMO system employing conformal antenna arrays at both ends (Transmitter; Tx and Receiver; Rx). The results reveal that compared to the linear and 2D cases, conformal antenna arrays promise higher capacity values which motivates their employment in future MIMO communication systems.

A practical approach to improve product of energy efficiency and capacity rate in MU-MIMO systems

2020 ◽  
Vol 16 (2) ◽  
pp. 183-202
Author(s):  
Ashu Taneja ◽  
Nitin Saluja
Keyword(s):  
Energy Efficiency ◽  
Power Consumption ◽  
Communication Systems ◽  
Mimo Systems ◽  
Mimo System ◽  
Practical Approach ◽  
System Capacity ◽  
Content Type ◽  
Channel Interference ◽  
Sum Rate

Purpose The major challenges in the modern-day wireless communication systems are increased co-channel interference owing to large number of users and the increased energy consumption owing to high circuit and/or hardware power consumption. Hence, the purpose of this paper is to present a practical approach involving linear precoding, channel estimation, user selection (US) and transmit antenna selection (AS) for enhanced reliability in multiuser multiple-input multiple output (MU-MIMO) system. Design/methodology/approach The proposed technique considers systematic and optimum deployment of users and transmits antennas for each selected user which enhances the sum rate or the system capacity. The comparison of algorithms, namely, norm-based and capacity-based US is presented with its implementation with precoding techniques, namely, block-diagonalization (BD) and zero-forcing with combining (ZFC) which is used to minimize co-channel interference. In this paper, a power consumption model is proposed for energy efficiency calculation in MU-MIMO system. Also, post analysis, the variant of US and AS algorithms optimizing the performance of BD and ZFC precoding technique is proposed. Findings It is seen that the proposed MU-MIMO system with norm-based US and norm-based AS improves over existing US-based systems by 43% in terms of sum rate and 19% in terms of energy efficiency for 100 users. Originality/value It is seen that the proposed MU-MIMO system with norm-based US and norm-based AS improves over existing US-based systems by 43% in terms of sum rate and 19% in terms of energy efficiency for 100 users.

scholarly journals A Physical Layer Security Technique for NOMA Systems with MIMO SC-FDE Schemes

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 240
Author(s):  
João Madeira ◽  
João Guerreiro ◽  
Hugo Serra ◽  
Rui Dinis ◽  
Paulo Montezuma ◽  
...  
Keyword(s):  
Physical Layer Security ◽  
Communication Systems ◽  
Multiple Access ◽  
Mimo Systems ◽  
Mimo System ◽  
Physical Layer ◽  
Hardware Complexity ◽  
Secrecy Rate ◽  
Security Issues ◽  
Single Carrier

Current wireless communication systems employ Multi-Input, Multi-Output (MIMO) techniques to increase spectral efficiency, at the cost of higher hardware complexity. Most of these systems continue to employ traditional Orthogonal Multiple Access (OMA) schemes, which are suboptimal when compared to Non-Orthogonal Multiple Access (NOMA) schemes. By combining NOMA with MIMO, it is possible to achieve higher spectral efficiencies. However, security in NOMA-MIMO systems remains a problem. In this paper, we study the physical layer security issues of a power based NOMA-MIMO system with a Singular Value Decomposition (SVD) scheme, employed along with Single Carrier with Frequency Domain Equalization (SC-FDE) techniques. We consider a scenario where there is an unintended eavesdropper attempting to listen to the messages being exchanged. It is shown that the higher the channel estimate correlation between transmitter and receiver, the higher the secrecy rate, particularly for a scenario where there is a Line-Of-Sight (LOS) between all users. Therefore, power based NOMA MIMO-SVD schemes, combined with SC-FDE, can be considered efficient options for highly secure MIMO communications.

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