MIMO Technology Research Articles

Разработка программного обеспечения радара с виртуальной антенной решеткой на платформе Digilent Zedboard

MIMO technology allows you to create virtual antenna arrays, significantly reducing the number of receiving and transmitting channels compared to classical phased antenna arrays (PAA). At the same time, the characteristics of the antenna system (width of the radiation pattern, gain factor) and, as a result, the characteristics of the radar (angular resolution, detection range) are preserved. Reducing the number of receiving and transmitting channels leads to a significant reduction in the cost of the radar as a whole. The article describes the process of developing a mathematical model and signal processing software based on the Digilent Zedboard platform. The results of modeling and testing of the hardware and software implementation of the processing algorithm are presented. The degree of loading of the Xilinx Zynq XC7Z020 crystal standing on the Digilent Zedboard platform is estimated.

Deep Joint Source-Channel Coding for CSI Feedback: An End-to-End Approach

The increased throughput brought by MIMO technology relies on the knowledge of channel state information (CSI) acquired in the base station (BS). To make the CSI feedback overhead affordable for the evolution of MIMO technology (e.g., massive MIMO and ultra-massive MIMO), deep learning (DL) is introduced to deal with the CSI compression task. In traditional communication systems, the compressed CSI bits is treated equally and expected to be transmitted accurately over the noisy channel. While the errors occur due to the limited bandwidth or low signal-to-noise ratios (SNRs), the reconstruction performance of the CSI degrades drastically. As a branch of semantic communications, deep joint source-channel coding (DJSCC) scheme performs better than the separate source-channel coding (SSCC) scheme—the cornerstone of traditional communication systems—in the limited bandwidth and low SNRs. In this paper, we propose a DJSCC based framework for the CSI feedback task. In particular, the proposed method can simultaneously learn from the CSI source and the wireless channel. Instead of truncating CSI via Fourier transform in the delay domain in existing methods, we apply non-linear transform networks to compress the CSI. Furthermore, we adopt an SNR adaption mechanism to deal with wireless channel variations. The extensive experiments demonstrate the validity, adaptability, and generality of the proposed framework.

ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ ІНТЕЛЕКТУАЛЬНИХ МЕРЕЖ MIMO НА ОСНОВІ 6G

Methods of increasing the efficiency of 6G radio access networks due to new design principles and optimization criteria of the MIMO structure have been determined. A flexible and versatile network with the possibility of expansion not only due to advances in existing technologies, but also due to numerous new technologies, such as ELAA, RIS, artificial intelligence, scanning, new materials, as well as new designs and structures of antennas, has been studied. The considered technologies will provide a universal set of tools for increasing network bandwidth. Advances in RF components, signal processing, and antenna communications that will affect various aspects of MIMO systems, including modulators, waveforms, and receiver designs, are explored. Functional parameters of transceivers based on electronic, photonic and combined technologies are considered. The use of intelligent radio channels, which significantly improve the quality of communication, system productivity, cell coverage, and the quality of communication at the cell boundary in wireless networks, was investigated, which was proven by numerous simulation results in various scenarios. A promising direction of research for super-massive MIMO 6G, which is relevant when using lattices with an extra-large aperture (ELAA), has been determined. The goal of ELAA is defined, which is that all users use mutually orthogonal channels with a per-user bandwidth similar to an additive Gaussian white noise channel. Intelligent massive MIMO in the 6G network based on AI has been studied, which facilitates learning and increases its efficiency. The OAM technology for high-speed transmission based on multiplexing access with mode separation is considered. The practical application of OAM technology in transit transmission between base stations, device-to-device (D2D) transmission, and communication between artificial satellites, where it is relatively easy to obtain the necessary axis alignment, has been studied. An analysis of the development of MIMO technology was carried out, taking into account the characteristics of the THz channel, in particular, a study of reconfigurable intelligent surfaces, which are characterized by the simplicity of the hardware architecture, low hardware complexity, low energy consumption and high efficiency of spectrum use, was carried out. The peculiarities of creating antenna arrays with an ultra-large aperture when applying new multiplexing schemes, using spatial depth information to separate streams or equipment using pre-coding, are determined. MIMO efficiency has been improved using artificial intelligence, which is capable of minimizing BER and increasing the spectral efficiency of massive MIMO of the millimeter range and significantly reducing computational complexity. A study of alternative MIMO technologies was carried out.

SYSTEM OBJECTS – A NEW TECHNOLOGY FOR STUDYING SIMULATION MODELS OF RADIO ENGINEERING SYSTEMS IN MATLAB

Most of the best universities in the world have adopted MATLAB as a unified software environment in almost all areas of training in all courses of study. The purpose of this work is to illustrate the level of simplicity of programming a simulation modeling of the transmission channel of a wireless broadband access system built on the most modern and future-proof MIMO technology. This can be done without much time, since the developer of the MATLAB product, MathWork, monitors the emergence of new technologies in the field of communications and constantly creates examples of the use of its products for the research and design of new communications equipment, providing them with a detailed description and recommendations for users around the world on how to independently create radio engineering devices and systems. The subject of consideration is object programming technology. Using a particular example, it is shown that the introduction of this technology into the educational process allows not only to reduce the time spent on programming for a computer by several times when students perform experimental studies of radio engineering systems and devices through their simulation, but also to significantly simplify the dialogue between the student and the computer in an interactive mode.

MIMO ANTENNA ARRAY WITH DIRECTIONAL DIAGRAM SPREAD FOR 5G SMARTPHONES

Multiple-input/multiple-output technology can exponentially increase the data transfer rate and spectrum efficiency without any need of increasing the transmission power and bandwidth. It is the most promising technology to be used in the upcoming 5G communications. To be more accurate, the fourth generation smartphones are set to use the long-term evolution MIMO technology and operate in multi-bands. Therefore, MIMO antennas are to use in future portable devices such as mobile handsets and tablets. A new multiple-input/multiple-output (MIMO) antenna design is introduced for future smartphones. The proposed design contains four pairs of double-fed circular-ring resonators located at different edges of the smartphone printed circuit board (PCB) with an FR-4 substrate and a dimension of 75 × 150 mm2. The antenna elements are fed by 50-Ohm microstriplines and provide polarisation and radiation pattern diversity function due to the orthogonal placement of their feed lines. By inserting a rectangular slot under each microstrip feed-line, the mutual coupling characteristic of the antenna ports is reduced. A good frequency bandwidth (S11 ≤ − 10 dB) of 3.3–3.9 GHz has been obtained for the smartphone antenna array. Nevertheless, for S11 ≤ −6 dB, this value is 3.1–4.3 GHz. More than 3 dB realised gain and 80% total efficiency are achieved for the single element radiator. The design provides not only sufficient radiation coverage supporting different sides of the mainboard but also the polarisation diversity. In addition, sufficient properties are obtained in the vicinity of human-hand/human-head. The proposed MIMO antenna design is also capable to generate dual- or multi-band function. Moreover, a new and compact phased array millimeter-wave (mm-wave) antenna design with end-fire radiation beams is introduced which can be easily integrated into smartphones.

MIMO Antenna Array in 5G Communication

The main topics of this study are the fundamental operation of a MIMO antenna array and the benefits of using MIMO technology for 5G communication. Three significant works are recognized as benchmarks by outlining the component sets and spatial reuse that designers should consider in MIMO antenna design. For 5G low and medium frequencies, these include an 8x8 large-scale MIMO antenna array and a circular binary MIMO antenna array. In these designs, the design of the MIMO antenna array will be carried out based on the introduction of the design and parameter selection of the antenna array elements as a priority. Additionally, this study conducts a performance analysis of a multi-cell, Massive MIMO antenna array system, which serves as a high reference point for the Analysis of this system. Numerous possible application domains exist for the study object of this work, including hotspot situations and 3D coverage scenarios. Campus, shopping malls, and halls are examples of hotspot environments.

Flexible UWB and MIMO Antennas for Wireless Body Area Network: A Review

In recent years, there has been a surge of interest in the field of wireless communication for designing a monitoring system to observe the activity of the human body remotely. With the use of wireless body area networks (WBAN), chronic health and physical activity may be tracked without interfering with routine lifestyle. This crucial real-time data transmission requires low power, high speed, and broader bandwidth communication. Ultrawideband (UWB) technology has been explored for short-range and high-speed applications to cater to these demands over the last decades. The antenna is a crucial component of the WBAN system, which lowers the overall system's performance. The human body's morphology necessitates a flexible antenna. In this article, we comprehensively survey the relevant flexible materials and their qualities utilized to develop the flexible antenna. Further, we retrospectively investigate the design issues and the strategies employed in designing the flexible UWB antenna, such as incorporating the modified ground layer, including the parasitic elements, coplanar waveguide, metamaterial loading, etc. To improve isolation and channel capacity in WBAN applications, the most recent decoupling structures proven in UWB MIMO technology are presented.

Mimo technology in multi-radar systems for detecting stealthy air objects

The main trends in the development of air objects are analyzed (the means of air attack in the conduct of the Russian-Ukrainian war are taken as a basis). It has been established that the increase in the efficiency of radar surveillance of airspace is currently being carried out due to the quantitative increase in radar stations. In this paper, to improve the quality of detection of subtle air objects, the use of multi-position location (based on MIMO systems) is proposed. The principle of operation of a spatially coherent MIMO system is considered. The set of spaced positions of a spatially coherent multi-position system is considered as a single sparse antenna array. The possibility of increasing the resolution in planar coordinates in a MIMO system compared to the resolution of a single autonomous radar station is shown. The calculated ratio for increasing the resolution of such a system is given. Detection curves are given for the case of a spatially coherent MIMO radar system for the case when the radar stations of the system operate simultaneously in the transceiver mode. It has been established that the transition from an autonomous radar station to a MIMO system leads to a significant shift in detection characteristics to the left. It has been established that an increase in the number of radar stations in the system leads to a less significant shift in the detection characteristics to the left, which indicates a decrease in the effect. The radar systems proposed by MIMO can be built on the basis of existing radar stations of a predominantly new fleet. It is especially advantageous to use radar facilities based on phased antenna arrays for these purposes. It is advisable to use such systems in particularly dangerous areas to cover important military, government and critical infrastructure facilities

A Method of Spatial Processing for a Railway Crossing Control Radar System

Introduction. Railway crossing is a source of increased danger for vehicles and pedestrians. To increase the safety of traffic at railway crossings, radar systems based on antenna arrays (AA) can be used. The important requirements for radar at a railway crossing are a wide field of view (up to 90 degrees) and, at the same time, a high accuracy in determining coordinates. Therefore, an analysis of methods for constructing AAs and spatial processing for an automatic traffic control system at a railway crossing seems to be a relevant research task. Aim. Design of a method for constructing the topology of an AA and spatial processing of a radar system for monitoring traffic at a railway crossing, providing a wide field of view with a high accuracy in determining the coordinates of targets. Materials and methods. The considered method was developed based on the theory of space-time signal processing. The design of the analyzed AA topologies was carried out by the finite element method (FEM) and the finite differ-ence time domain method (FDTD) based on segments of a microstrip transmission line. Results. A method for constructing a filled transceiver antenna array and a beamforming algorithm, which provide high angular resolution and unambiguous measurement of the target's angular coordinates in a wide field of view with relatively low computational complexity, was developed. Mathematical and electrodynamic modeling of the designed AA topologies was performed. Adjusted values of the radiation patterns (RP) of the transmitting and receiving AA were obtained, which showed good agreement with the calculated values. The main design solutions regarding the construction of AA radar for a railway crossing control system are presented to provide a wide field of view when determining the coordinates of targets. Conclusion. It was shown that the width of the resulting RP can be reduced by several times compared to the width of the receiving RP when using two transmitting antennas located at the edges of the aperture. This approach is similar to that used in the MIMO technology, although requiring no coherence of transmission channels and use of a system of orthogonal signals. The findings determine the prospects of using the developed method.

Optimal transmit antenna selection using hybrid algorithm for massive MIMO technology

SummaryMassive multiple input multiple output (M‐MIMO) methods make reference to a useful method for using multipath propagation to communicate and receive multiple data signals at once over a single radio channel. To simultaneously transfer numerous data streams, it makes use of various antennas. The quantity of power used grows as the quantity of antennas rises. As a result, choosing the best transmit antennas, which is a major difficulty in M‐MIMO systems, becomes important. In this research, “Hybrid Sea Lion‐Whale Algorithm (HS‐WA)” is introduced by choosing a best transmit antenna while taking into account several objectives. This method optimizes overall capacity and efficiency. The chosen method combines the “Whale Optimization Algorithm (WOA) and Sea Lion Optimization Algorithm (SLnO)” that determines which antenna should be chosen while also optimizing the antenna quantity. Finally, energy efficiency (EE) and capacity analysis results demonstrate that the provided approach is superior to all other models.

Improvement of Capacity and QoE: Distributed Massive MIMO (DM-MIMO) Technology-5G

Distributed massive MIMO is an arising answer for improve 5G limit, throughput, and QoE inside. There are various ways to advance indoor execution. The indoor cell network should have totally different qualities and needs from its outside partner, yet a consistent encounter should be kept up with while moving between the two. New arrangements, like small cells and distributed antenna systems (DAS), have been added to every portable age to work on the presentation and quality of experience (QoE) for indoor clients. Notwithstanding, the goal lines are moved with each new age of purpose cases, and, surprisingly, more significant levels of execution and QoE are required. The improvement in the indoor experience needed in the 5G period should be extensive. The 5G guidelines empower the organizations to help tremendous quantities of clients or associated gadgets in little spaces (up to 1 million for each square kilometer), while consuming information at multi-gigabit speeds and with low idleness and high unwavering quality. This paper give a brief review on improvement in channel capacity and QoE using massiveness of MIMO technology for 5G environment in distributed manner.

Conformal transmitarray based on metasurface fed by miniaturized filtering antenna

AbstractTo realize the requirements of 5G MIMO technology for high‐performance antennas, a novel high‐gain transmissive array antenna with conformal capability is designed in this study. The antenna consists of a single‐layer dielectric‐based conformal transmission array and a substrate‐integrated waveguide filter antenna. The transmission array is composed of a cross element and spiral elements that can achieve conformal capability. Each metasurface element is a single‐layer medium, and the same metasurface patches above and below are connected by four metal pillars. A filter antenna array fed by a substrate integrated with a waveguide fed by small‐scale low‐temperature cofired ceramic technology is used as the feed antenna of the transmission array. The physical test results are consistent with the simulation results, and the directivity of the antenna is greatly improved. The frequency range where the reflection coefficient S11 is less than −10 dB is 26.6–29.1 GHz. At the center frequency of 28.0 GHz, the gain of the conformal antenna array is greatly improved, and the peak gain is increased from 8.2 to 24.5 dB. The sidelobe level is substantially suppressed. Its high gain and beamforming characteristics make it have a high application value in 5G MIMO technology.

Sensor-Assisted Rate Adaptation for UAV MU-MIMO Networks

Propelled by multi-user MIMO (MU-MIMO) technology, unmanned aerial vehicles (UAVs) as mobile hotspots have recently emerged as an attractive wireless communication paradigm. Rate adaptation (RA) becomes indispensable to enhance UAV communication robustness against UAV mobility-induced channel variances. However, existing MU-MIMO RA algorithms are mainly designed for ground communications with relatively stable channel coherence time, which incurs channel measurement staleness and sub-optimal rate selections when coping with highly dynamic air-to-ground links. In this paper, we propose SensRate, a new uplink MU-MIMO RA algorithm dedicated for low-altitude UAVs, which exploits inherent onboard sensors used for flight control with no extra cost. We propose a novel channel prediction algorithm that utilizes sensor-estimated flight states to assist channel direction prediction for each client and estimate inter-user interference for optimal rates. We provide an implementation of our design using a commercial UAV and show that it achieves an average throughput gain of 1.24\times and 1.28\times compared with the bestknown RA algorithm for 2- and 3-antenna APs, respectively

Integrating CSI Sensing in Wireless Networks: Challenges to Privacy and Countermeasures

The path toward 6G is still long and blurred, but a few key points seem to be already decided: integration of many different access networks; adoption of massive MIMO technologies; use of frequencies above current radio spectrum up to THz and beyond; and inclusion of artificial intelligence and machine learning in standard management and operations. One additional point that is less discussed, but seems key for success, is the advanced use of channel state information (CSI) for both equalization and decoding purposes as well as for sensing ones. CSI-based sensing promises a plethora of new applications and a quantum leap in service personalization and customer-centric network management. At the same time, CSI analysis, being based on the physical characteristics of the propagated signal, poses novel threats to people's privacy and security: No software-based solution or cryptographic method above the physical layer can prevent the analysis of CSI. CSI analysis can reveal people's position or activity, allow tracking them, and discover details on the environment that today can be seen only with cameras or radars. In this article, we discuss the current status of CSI-based sensing and present some technologies that can protect people's privacy and at the same time allow legitimate use of the information carried by the CSI to offer better services.

Analysis of ways to improve the efficiency of modern satellite communication systems

Nowadays, the satellite segment in telecommunications occupies an important place and provides positioning of the global coverage system. However, the development of satellite technologies, compared to terrestrial wireless technologies, is slow. For example, the new DVB-S2 (Digital Video Broadcasting via Satellite) satellite standard contains a small number of improvements and refinements over the previous DVB-S standard. The main improvements are the introduction of codes with low density of LDPC (Low Density Parity Check) and the introduction of adaptive modulation and coding. Given the above, the object of research is modern satellite communication system. The subject of the research is the way to increase the efficiency of modern satellite communication systems. The research aims to analyze the feasibility of using a number of effective technologies in modern wireless systems, such as OFDM, UWB and MIMO, in satellite communication systems. The implementation of the considered options for the use of MIMO technology in satellite communication systems will increase the bandwidth and efficiency of these systems. However, there is a need for additional research to adapt this technology in satellite communication systems. Thus, the analysis allows forming the main directions of improving the efficiency of modern satellite communication systems. This analysis allows: – to formulate new approaches to increase the efficiency of modern satellite communication systems; – to substantiate new technological solutions for the construction of transceivers of satellite communication systems; – to identify possible areas of research to improve the efficiency of modern satellite communication systems.

A 3D MIMO Channel Model for a High-Speed Train Millimeter Wave Communication System under Cutting and Viaduct Environments

Incorporating MIMO technology with 3D geometry-based stochastic models (GBSM) is a promising channel modeling technique for 5G and beyond. These models could be extended to high-speed train (HST) environments at mmWave bands. In this paper, the proposed 3D MIMO model is composed of the line of sight component (LOS), the non-line of sight component (NLOS) from one sphere, and multiple stochastic confocal elliptic cylinders. The model is applied in the viaduct and cutting environments with a time-varying Rician K-factor. The local channel statistical properties such as the auto correlation function, stationarity distance, and the level crossing rate (LCR) are derived and thoroughly investigated at the 41GHz frequency. These properties are compared with the corresponding measured results at the same wave frequency for an HST wireless channel. There is a strong correlation between the results from the derived model and the measured results. Therefore, this model can be extended to be used for viaduct and cutting channel modeling at the mmWave band.

Massive MIMO Wireless Solutions in Backhaul for the 5G Networks

In general, the MIMO technology is used to transfer data from a protocol such as Wi-Fi in 5G networks. This is due to the increased bandwidth and capacity. The 802.11n protocol, which, using the technology described in it, allows you to reach speeds of up to 350 megabits/second. The quality of data transmission has improved even in areas where the reception signal is low. An external access point with a MIMO antenna is a well-known one. The WiMAX network can now transmit information at speeds of up to 40 megabits/second, using MIMO. It uses MIMO technology up to 8 × 8 . Thanks to this, a higher transfer rate is achieved—over 35 megabits/second. In addition, reliable and high quality connection of the best quality is guaranteed. In this paper, we continue to work and enhance technical configurations of MIMO in 5G networks. The proposed model will improve spectrum performance, improve network capability, and speed up data rates. In a saturation point, the proposed method achieves that the signal to noise interference ratio is just 42.4%, the receiver signal strength is 92.94%, the downstream traffic is 48.76%, the upstream traffic is 45.62%, the bandwidth utilization is 97.43%, the speed is 95.79%, the connectivity between the access point is 90.6%, and the network security is 96.42%.

A Stochastic Confocal Elliptic-Cylinder Channel Model for 3D MIMO in Millimeter-Wave High-Speed Train Communication System

Massive MIMO technology is among the most promising solutions for achieving higher gain in 5G millimeter-wave (mmWave) channel models for high-speed train (HST) communication systems. Based on stochastic geometry methods, it is fundamental to accurately develop the associated MIMO channel model to access system performance. These MIMO channel models could be extended to massive MIMO with antenna arrays in more than one plane. In this paper, the proposed MIMO 3D geometry-based stochastic model (GBSM) is composed of the line of sight component (LOS), one sphere, and multiple confocal elliptic cylinders. By considering the proposed GBSM, the local channel statistical properties are derived and investigated. The impacts of the distance between the confocal points of the elliptic cylinder, mmWave frequencies of 28 GHz and 60 GHz, and non-stationarity on channel statistics are studied. Results show that the proposed 3D simulation model closely approximates the measured results in terms of stationary time. Consequently, findings show that the proposed 3D non-wide-sense stationary (WSS) model is better for describing mmWave HST channels in an open space environment.

Ultra-Low-Noise MIMO Distributed Acoustic Sensor Using Few-Mode Optical Fibers

Distributed optical fiber acoustic sensing technology (DAS) based on Rayleigh backscattering (RBS) is experiencing a rapid development because of the unique capability of measuring acoustic waves along long-distance optical fiber with high spatial resolution, that has broad prospects of applications, including geophysical prospecting, seismology, pipeline security, and train tracking. Despite the numerous applications, DAS currently suffers from high noise level and insufficient signal-to-noise ratio (SNR) due to inherent low RBS coefficient (&#x223C; &#x2212;70 dB&#x002F;m) in fiber, and cannot meet the application requirements of weak signal detection. Here, an ultra-low-noise MIMO DAS system using few-mode fibers (FMF) is proposed. FMF is characterized by higher non-linear effect threshold and larger capture fraction of RBS light, and through MIMO technology, the system can realize higher diversity scale and obtain more SNR gain. In addition, &#x2018;frequency label&#x2019; method is proposed to address the signal aliasing problem in transmission modes. In preliminary experiments, a 4&#x00D7;4 MIMO &#x03A6;-OTDR system is realized, where the minimum noise floor is &#x2212;88 dB rad²&#x002F;Hz with corresponding strain resolution of 0.15 <inline-formula><tex-math notation="LaTeX">$p\varepsilon /\sqrt {Hz} $</tex-math></inline-formula>. These results pave the way for advanced acoustic applications of DAS, such as acoustic emission and marine acoustics.

Cylindrical Dielectric Lens Antenna for 5G Mobile Base Station

Abstract A wide range new technologies such as millimetre wave, massive MIMO technology, multi beam base station antenna are required in the fifth-generation (5G) mobile system. For multi beam base station application, a dielectric lens antenna is selected due to capabilities of achieving excellent radiation patterns in a wide angular range by applying the lens shaping method. A cylindrical structure is suitable for a lens antenna installation on the base station pole. In this paper, a cylindrical dielectric lens antenna is proposed and multi beam radiation patterns are investigated through the calculations by an electromagnetic simulator (FEKO) at the operating frequency of 28 GHz. As a result, good multi beam radiation patterns are achieved in the scanning angle from 0°to 30° with total gain reduction around 5dBi and antenna efficiency of about 95.9%.