scholarly journals A Design of CP-MIMO System with Elements of a Diamond-Ring Slot for 5G Mobile-Phone

2021 ◽  
Vol 3 (2) ◽  
pp. 53-60
Author(s):  
Alyaa Sami Abdullah ◽  
Seham A. Hashem ◽  
Mahmood F . Mosleh
Keyword(s):  
Printed Circuit Board ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Circuit Board ◽  
Smartphone Applications ◽  
Printed Circuit ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Microstrip Feed ◽  
Diamond Ring

This paper proposed a Circular Polarization (CP) smartphone antenna Multiple Input Multiple Output (MIMO) system with elements of a diamond ring slot for next-generation (5G). The model's composition contains four elements. Each element has a dual-fed diamond ring slot arranged at the four smartphone corners Printed Circuit Board (PCB). A cheap FR-4 substrate with using a size of 75 x 150 mm2 as the design dielectric mater. 50-Ohm microstrip-lines T-shaped feeds the antenna ports. The orthogonal positioning of microstrip feed lines is used to achieve polarization and diversity characteristics. The paradigm results show that each port operated with an operating frequency of 3.74 GHz, with the overall system running at 3.84 GHz. Also, the results show that the MIMO system is suitable for operation in a sub-6 band that qualified for 5G smartphone applications.

scholarly journals ARREGLO DE ANTENAS CON BAJO ACOPLAMIENTO MUTUO PARA SISTEMAS DE COMUNICACIONES INALÁMBRICAS MIMO-LTE

2017 ◽  
Vol 1 (27) ◽  
Author(s):  
Eduardo Rodríguez Araque ◽  
Roberto G. Rojas-Teran
Keyword(s):  
Printed Circuit Board ◽  
Multiple Input Multiple Output ◽  
Long Term Evolution ◽  
Circuit Board ◽  
Printed Circuit ◽  
Term Evolution ◽  
Multiple Input ◽  
Input Multiple Output

Este trabajo trata de un arreglo de antenas MIMO (multiple-input-multiple-output) que opera en la banda de 2.6 GHz, una banda de Long Term Evolution (LTE), para sistemas de comunicaciones móviles inalámbricas 4G. El arreglo de antenas consiste de 4 antenas compactas tipo patch sobre un substrato dieléctrico (PCB) de 125 mm x 62.5 mm x 1.27 mm. Modificaciones del plano de tierra (GND) junto con la ubicación sistemática y orientación de cada antena en la cara posterior al plano de tierra del PCB (Printed Circuit Board) juegan un rol muy importante en la reducción sustancial del acoplamiento mutuo, esto generalmente afecta el desempeño de los arreglos MIMO.Palabras clave: Arreglo de antenas, modos característicos, correlación espacial, multiple-input-multiple-output (MIMO), acoplamiento mutuo.

A companding approach for PAPR suppression in OFDM based massive MIMO system

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ajay Kumar Yadav ◽  
Pritam Keshari Sahoo ◽  
Yogendra Kumar Prajapati
Keyword(s):  
Massive Mimo ◽  
Orthogonal Frequency Division Multiplexing ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Average Power ◽  
Base Station ◽  
Convex Optimization Problem ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Mimo Ofdm

Abstract Orthogonal frequency division multiplexing (OFDM) based massive multiuser (MU) multiple input multiple output (MIMO) system is popularly known as high peak-to-average power ratio (PAPR) issue. The OFDM-based massive MIMO system exhibits large number of antennas at Base Station (BS) due to the use of large number of high-power amplifiers (HPA). High PAPR causes HPAs to work in a nonlinear region, and hardware cost of nonlinear HPAs are very high and also power inefficient. Hence, to tackle this problem, this manuscript suggests a novel scheme based on the joint MU precoding and PAPR minimization (PP) expressed as a convex optimization problem solved by steepest gradient descent (GD) with μ-law companding approach. Therefore, we develop a new scheme mentioned to as MU-PP-GDs with μ-law companding to minimize PAPR by compressing and enlarging of massive MIMO OFDM signals simultaneously. At CCDF = 10−3, the proposed scheme (MU-PP-GDs with μ-law companding for Iterations = 100) minimizes the PAPR to 3.70 dB which is better than that of MU-PP-GDs, (iteration = 100) as shown in simulation results.

scholarly journals Energy and Information Beamforming in Airborne Massive MIMO System for Wireless Powered Communications

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3540 ◽  
Author(s):  
Yurong Wang ◽  
Aijun Liu ◽  
Kui Xu ◽  
Xiaochen Xia
Keyword(s):  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Hardware Complexity ◽  
Mimo Channels ◽  
Channel State ◽  
Active Antennas ◽  
Large Numbers ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Critical Problems

Energy supply and information backhaul are critical problems for wireless sensor networks deployed in remote places with poor infrastructure. To deal with these problems, this paper proposes an airborne massive multiple-input multiple-output (MIMO) system for wireless energy transfer (WET) and information transmission. An air platform (AP) equipped with a two-dimensional rectangular antenna array is employed to broadcast energy and provide wireless access for ground sensors. By exploiting the statistical property of air-terrestrial MIMO channels, the energy and information beamformers are jointly designed to maximize the average received signal-to-interference-plus-noise ratio (SINR), which gives rise to a statistical max-SINR beamforming scheme. The scheme does not rely on the instantaneous channel state information, but still requires large numbers of RF chains at AP. To deal with this problem, a heuristic strongest-path energy and information beamforming scheme is proposed, which can be implemented in the analog-domain with low computational and hardware complexity. The analysis of the relation between the two schemes reveals that, with proper sensor scheduling, the strongest-path beamforming is equivalent to the statistical max-SINR beamforming when the number of AP antennas tends to infinity. Using the asymptotic approximation of average received SINR at AP, the system parameters, including transmit power, number of active antennas of AP and duration of WET phase, are optimized jointly to maximize the system energy efficiency. The simulation results demonstrate that the proposed schemes achieve a good tradeoff between system performance and complexity.

Precoding for Multiuser MIMO

2012 ◽  
pp. 130-156 ◽  
Author(s):  
Elsadig Saeid ◽  
Varun Jeoti ◽  
Brahim Belhaouari Samir
Keyword(s):  
Mimo Systems ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Achievable Rate ◽  
Multiple Access Channels ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Single User ◽  
A New Technique ◽  
Improved Technique

Future Wireless Networks are expected to adopt multi-user multiple input multiple output (MU-MIMO) systems whose performance is maximized by making use of precoding at the transmitter. This chapter describes the recent advances in precoding design for MU-MIMO and introduces a new technique to improve the precoder performance. Without claiming to be comprehensive, the chapter gives deep introduction on basic MIMO techniques covering the basics of single user multiple input multiple output (SU-MIMO) links, its capacity, various transmission strategies, SU-MIMO link precoding, and MIMO receiver structures. After the introduction, MU-MIMO system model is defined and maximum achievable rate regions for both MU-MIMO broadcast and MU-MIMO multiple access channels are explained. It is followed by critical literature review on linear precoding design for MU-MIMO broadcast channel. This paves the way for introducing an improved technique of precoding design that is followed by its performance evaluation.

A Superwideband Monopole Multiple-Input-Multiple-Output (MIMO) Antenna with Dual Notched (Inverted T-Shaped Stub/U-Shaped Slit) Band Characteristics for Wireless Applications

2019 ◽  
Vol 16 (10) ◽  
pp. 4242-4248
Author(s):  
Manoj Kapil ◽  
Manish Sharma
Keyword(s):  
Ground Plane ◽  
Multiple Input Multiple Output ◽  
Impedance Bandwidth ◽  
Mimo Antenna ◽  
Wireless Applications ◽  
Research Article ◽  
Compact Size ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Microstrip Feed

In this research article, a compact MIMO (Multiple-Input-Multiple-Output) antenna with inclusion of two notched bands characteristics is presented. Designed MIMO antenna consist of dual radiating patches printed on one surface of the substrate which covers measured wide impedance bandwidth of 2.88 GHz–19.98 GHz and satisfies bandwidth ratio more than 10:1 for superwideband with compact size of 18 mm × 34 mm. Two radiating patch are placed symmetrically for MIMO configuration and notched bands to eliminate WiMAX/C and WLAN bands are obtained by attaching inverted T-shaped stub on radiating patch and etched inverted U-shape slit in microstrip feed. Isolation between the two radiating patch is maintained by adding two L-shaped stub in slotted rectangular ground plane. Measured radiation pattern are stable in operating band and offers maximum 4.23 dBi and 89% gain and radiation efficiency respectively. Moreover, antenna shows good diversity performance with Envelope-Correlation-Coefficient (ECC) < 0.5, Directive-Gain (DG) > 9.95 dB and Total-Active-Reflection Coefficient (TARC) < -30 dB.

Design of Massive Multiuser MIMO System to Mitigate Inter Antenna Interference and Multiuser Interference in 5G Wireless Networks

2020 ◽  
pp. 693-701 ◽  
Author(s):  
Naga Raju Challa ◽  
◽  
Kalapraveen Bagadi
Keyword(s):  
Communication Networks ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Matrix Computations ◽  
User Terminal ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Major Factors ◽  
Value Decomposition ◽  
User Interference

Massive Multi-user Multiple Input Multiple Output (MU‒MIMO) system is aimed to improve throughput and spectral efficiency in 5G communication networks. Inter-antenna Interference (IAI) and Multi-user Interference (MUI) are two major factors that influence the performance of MU–MIMO system. IAI arises due to closely spaced multiple antennas at each User Terminal (UT), whereas MUI is generated when one UT comes in the vicinity of another UT of the same cellular network. IAI can be mitigated by the use of a pre-coding scheme such as Singular Value Decomposition (SVD) and MUI can be cancelled through efficient Multi-user Detection (MUD) schemes. The highly complex and optimal Maximum Likelihood (ML) detector involves a large number of computations, especially when in massive structures. Therefore, the local search-based algorithm such as Likelihood Ascent Search (LAS) has been found to be a better alternative for mitigation of MUI, as it results in near optimal performance using lesser number of matrix computations. Most of the literature have been aimed at mitigating either IAI or MUI, whereas the proposed work presents SVD pre-coding and LAS MUD to mitigate both IAI and MUI. Simulation results indicate that the proposed scheme can attain near-optimal bit error rate (BER) performance with fewer computations.

scholarly journals Complex-Coefficient Frequency Domain Stability Analysis Method for a Class of Cross-Coupled Antisymmetrical Systems and Its Extension in MSR Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Yuan Ren ◽  
Jiancheng Fang
Keyword(s):  
Stability Analysis ◽  
Frequency Domain ◽  
Stability Criterion ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Complex Coefficient ◽  
Analysis Method ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Domain Stability

This paper develops a complex-coefficient frequency domain stability analysis method for a class of cross-coupled two-dimensional antisymmetrical systems, which can greatly simplify the stability analysis of the multiple-input multiple-output (MIMO) system. Through variable reconstruction, the multiple-input multiple-output (MIMO) system is converted into a single-input single-output (SISO) system with complex coefficients. The pole locations law of the closed-loop system after the variable reconstruction has been revealed, and the controllability as well as observability of the controlled plants before and after the variable reconstruction has been studied too, and then the classical Nyquist stability criterion is extended to the complex-coefficient frequency domain. Combined with the rigid magnetically suspended rotor (MSR) system with heavy gyroscopic effects, corresponding stability criterion has been further developed. Compared with the existing methods, the developed criterion for the rigid MSR system not only accurately predicts the absolute stability of the different whirling modes, but also directly demonstrates their relative stability, which greatly simplifies the analysis, design, and debugging of the control system.

Unitary and Non-Unitary Precoders for a Limited Feedback Precoded OSTBC System

2013 ◽  
Vol 62 (4) ◽  
pp. 1646-1654 ◽  
Author(s):  
Haiquan Wang ◽  
Yabo Li ◽  
Xiang-Gen Xia ◽  
Shunlan Liu
Keyword(s):  
Design Method ◽  
Mimo System ◽  
Multiple Input Multiple Output ◽  
Special Property ◽  
Block Code ◽  
Design Criterion ◽  
Fast Encoding ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Alamouti Code

In this paper, a multiple-input-multiple-output (MIMO) system with finite-bit feedback first proposed by Love-Heath is considered, where a transmitted signal consists of a precode followed by an orthogonal space-time block code (OSTBC), such as Alamouti code. A new design criterion and a corresponding design method of precoders are proposed. Simulations show that the precoders obtained by our proposed criterion and method perform better than the existing ones. Furthermore, since our proposed precoders have a layered structure, their designs can be implemented in the simplest Grassmannian manifold. Moreover, a fast encoding algorithm can be applied, which can greatly reduce the complexity of codeword selection. In this paper, we also propose non-unitary precoders and their design criterion and method based on the performance analysis and the special property of an OSTBC. Interestingly, non-unitary precoders can significantly improve performance over unitary precoders.

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