scholarly journals Minimizing the Probability of Bit Error in a Multi-Stage MIMO Relay System

2020 ◽  
Vol 6 (4) ◽  
pp. 36-44
Author(s):  
A. Flaksman ◽  
I. Sorokin ◽  
A. Kokarev
Keyword(s):  
Antenna Arrays ◽  
High Efficiency ◽  
Multiple Input Multiple Output ◽  
Threshold Method ◽  
Relay System ◽  
Multi Stage ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Transmission Stage ◽  
Signal Fading

This research is devoted to the investigation of the relay multi-stage relay MIMO (Multiple-Input Multiple-Output) of cellular communication with antenna arrays at each stage of transmission, in which parallel independent subchannels for data transmission are formed, are considered. The possibility of minimizing the error probability per bit of transmitted information is investigated while using the method of separate optimization of each transmission stage and the threshold method for selecting energetically strong subchannels. The presented simulation results in the case of a multipath channel with Rayleigh signal fading confirm the high efficiency of the proposed approach.

scholarly journals Constructing Dynamic Multiple-Input Multiple-Output Logic Gates

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Haipeng Peng ◽  
Gang Hu ◽  
Lixiang Li ◽  
Yixian Yang ◽  
Jinghua Xiao
Keyword(s):  
Noise Analysis ◽  
Multiple Input Multiple Output ◽  
Clock Cycle ◽  
Dynamic Logic ◽  
Logic Gates ◽  
Cost Effective ◽  
Research Direction ◽  
Threshold Method ◽  
Multiple Input ◽  
Input Multiple Output

Investigation of computing devices with dynamic architecture which makes devices have reconfigurable ability is an interesting research direction for designing the next generation of computer chip. In this paper, we present a window threshold method to construct such dynamic logic architecture. Here, dynamic multiple-input multiple-output (MIMO) logic gates are proposed, analyzed, and implemented. By using a curve-intersections-based graphic method, we illustrate the relationships among the threshold, the control parameter, and the functions of logic gates. A noise analysis on all the parameters is also given. The chips based on the proposed schemes can be transformed into different arrangements of logic gates within a single clock cycle. With these schemes in hand, it is conceivable to build more flexible, robust, cost effective, yet general-purpose computing devices.

scholarly journals Design and Analysis of Wideband Flexible Self-Isolating MIMO Antennas for Sub-6 GHz 5G and WLAN Smartphone Terminals

Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 3031
Author(s):  
Jayshri Kulkarni ◽  
Abdullah G. Alharbi ◽  
Arpan Desai ◽  
Chow-Yen-Desmond Sim ◽  
Ajay Poddar
Keyword(s):  
Common Ground ◽  
High Efficiency ◽  
Multiple Input Multiple Output ◽  
Impedance Bandwidth ◽  
Potential Candidate ◽  
Mimo Antenna ◽  
Mimo Antennas ◽  
Compact Size ◽  
Multiple Input ◽  
Input Multiple Output

A single radiator that is a part of four-port diversity Multiple-Input Multiple-Output (MIMO) antenna design is composed of four octagonal rings embedded between the two opposite sides of a T-shaped conductive layer surrounded by inverted angular edge cut L-shaped and E-shaped structures. The radiators are placed at the four corners with common ground at the center of a smartphone to form a four-element mobile MIMO antenna. The printing of the antenna is carried out on the flexible polyamide substrate (dielectric constant = 3.5 and loss tangent = 0.0027) with dimensions of 70 × 145 × 0.2 mm3. A wide impedance bandwidth of (84.12%) 2.39 to 5.86 GHz is achieved for all four radiators. The compact size of the radiators along with their placement enables the proposed MIMO antenna to occupy much less area while preserving the space for 2G/3G/4G antennas. The placement of the antennas results in self-isolation between antenna elements by achieving isolation greater than 17.5 dB in the desired operating bands. Furthermore, besides showing a high efficiency of 85% and adequate gain above 4 dBi, good diversity performances such as Envelope Correlation Coefficient (ECC) of less than 0.05, Diversity Gain (DG) of above 9.8 dB, Mean Effective Gain (MEG) of −3.1 dB, Channel Capacity of 21.50 bps/Hz, and Total Active Reflection Coefficient (TARC) of below −10 dB are achieved by the flexible MIMO smartphone antenna. The effect of bending along the X and Y-axis on the performance of the proposed MIMO antenna is also analyzed where decent performance is observed. This makes the proposed flexible four-element MIMO antenna a potential candidate to be deployed in future smartphones.

Joint Source and Relay Optimization of Multiuser MIMO Relay System

2012 ◽  
Vol 249-250 ◽  
pp. 1201-1204
Author(s):  
Fang Ni Chen ◽  
Zhong Peng Wang
Keyword(s):  
System Performance ◽  
Multiple Input Multiple Output ◽  
The Other ◽  
Mean Square ◽  
Multiuser Mimo ◽  
Relay System ◽  
Precoding Matrix ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Simulation Results

In this paper, we design the source precoding matrix and the relay amplifying matrix of a multiuser multiple-input multiple-output (MIMO) non-regenerative relay system. Different from the other algorithms, we first introduce a new model with new unknown but to be designed variables. Then we proposed an iterative algorithm to get the source precoding matrix and the relay amplifying matrix to optimize the system performance. The simulation results show that the proposed design algorithms can improve mean square error (MSE) performance.

Antenna tilt optimization for multi-cell massive multiple-input multiple-output (MIMO) systems with two tilts

Frequenz ◽  
2020 ◽  
Vol 74 (9-10) ◽  
pp. 359-368
Author(s):  
Deming Chu ◽  
Anzhong Hu
Keyword(s):  
Lower Bound ◽  
Antenna Arrays ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Base Station ◽  
Perfect Channel State Information ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Output System ◽  
Antenna Tilt

AbstractIn this paper, we study the optimization of two tilt angles corresponding to two antenna arrays in each base station (BS) of a massive multiple-input multiple-output system. We consider two scenarios with perfect channel state information (CSI) and imperfect CSI. In the limit of the number of the BS antennas, the channel orthogonality is employed to derive the limit and the lower bound of the throughputs. By maximizing the lower bound or the limit throughput, the two antenna tilt angles are optimized. Simulation results show that the throughput performance can be improved with the designed tilt angles.

scholarly journals A Survey on Over-The-Air Linearization Methods for MIMO Systems

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2225
Author(s):  
Marina Jordão ◽  
Rafael Caldeirinha ◽  
Arnaldo S. R. Oliveira ◽  
Nuno Borges Carvalho
Keyword(s):  
Radio Frequency ◽  
Power Amplifier ◽  
Antenna Arrays ◽  
Critical Review ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Linearization Methods ◽  
Multiple Input ◽  
Input Multiple Output

Transmitter antenna arrays are typically coupled to several RF chains, which imposes stringent requirements on the linearization of each power amplifier (PA) present in the system. For this and other reasons discussed in this work, Over-the-air (OTA) linearization methods are considered to linearize transmitter antenna arrays in 5G scenarios. However, several factors need to be considered when applying OTA linearization methods. In this paper, an extended critical review of validated OTA linearization methods is presented. The main goal is to point out and discuss the most prominent methods, in order to determine which one is the most suitable for a specific application. In particular, analysis for each method is performed and, subsequently, their benefits and the disadvantages are systematically discussed. This is sought to fill-in a gap in the scientific literarure and, thus, to help radio-frequency engineers in the implementation of OTA digital pre-distortion (DPD) techniques for multiple input multiple output (MIMO) systems.

scholarly journals Fractal antenna arrays for MIMO radar applications

2017 ◽  
Vol 9 (10) ◽  
pp. 2019-2028 ◽  
Author(s):  
Christoph Dahl ◽  
Michael Vogt ◽  
Ilona Rolfes
Keyword(s):  
Antenna Arrays ◽  
Angular Resolution ◽  
Multiple Input Multiple Output ◽  
Side Lobe ◽  
Mimo Radar ◽  
Side Lobe Level ◽  
Fractal Antenna ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Radar Applications

In this contribution, fractal antenna arrays are analyzed for their applicability in multiple-input multiple-output (MIMO) radars. Array geometries based on the Fudgeflake fractal and the Gosper island fractal are investigated. In addition, a concept for the combination of both fractals is shown in order to increase the flexibility concerning the number of transmitting and receiving antennas. The presented fractal MIMO concepts can be utilized in order to improve the angular resolution and to reduce the sidelobe level for a given number of transmitting and receiving antennas. It is shown that a fractal MIMO concept with 21 transmitting antennas and 21 receiving antennas improves the angular resolution to 4.6 degrees and reduces side lobe level by 3.1 dB compared to a MIMO configuration based on two linear arrays with the same number of antenna elements. In addition, the results are experimentally validated by broadband radar measurements.

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