Performance enhancement using multiple‐input multiple‐output (MIMO) electronic relay in massive MIMO cellular networks

IET Networks ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 299-306 ◽  
Author(s):  
Rna Ghallab ◽  
Mona Shokair ◽  
Atef Abou El‐Azm ◽  
Ali Sakr ◽  
Waleed Saad ◽  
...  
Keyword(s):  
Cellular Networks ◽  
Massive Mimo ◽  
Performance Enhancement ◽  
Multiple Input Multiple Output ◽  
Electronic Relay ◽  
Multiple Input ◽  
Input Multiple Output

scholarly journals Performance enhancement of maximum ratio transmission in 5G system with multi-user multiple-input multiple-output

2022 ◽  
Vol 12 (2) ◽  
pp. 1650
Author(s):  
Sarmad K. Ibrahim ◽  
Saif A. Abdulhussien
Keyword(s):  
Massive Mimo ◽  
Orthogonal Frequency Division Multiplexing ◽  
Performance Enhancement ◽  
Multiple Input Multiple Output ◽  
Base Station ◽  
Standard System ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Ratio Transmission ◽  
Maximum Ratio Transmission

<span>The downlink multi-user precoding of the multiple-input multiple-output (MIMO) method includes optimal channel state information at the base station and a variety of linear precoding (LP) schemes. Maximum ratio transmission (MRT) is among the common precoding schemes but does not provide good performance with massive MIMO, such as high bit error rate (BER) and low throughput. The orthogonal frequency division multiplexing (OFDM) and precoding schemes used in 5G have a flaw in high-speed environments. Given that the Doppler effect induces frequency changes, orthogonality between OFDM subcarriers is disrupted and their throughput output is decreased and BER is decreased. This study focuses on solving this problem by improving the performance of a 5G system with MRT, specifically by using a new design that includes weighted overlap and add (WOLA) with MRT. The current research also compares the standard system MRT with OFDM with the proposed design (WOLA-MRT) to find the best performance on throughput and BER. Improved system results show outstanding performance enhancement over a standard system, and numerous improvements with massive MIMO, such as best BER and throughput. Its approximately 60% more throughput than the traditional systems. Lastly, the proposed system improves BER by approximately 2% compared with the traditional system.</span>

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.

PROBLEM STATEMENT OF JOINT ANTENNA SELECTION AND PRECODING IN MASSIVE MIMO COMMUNICATION SYSTEMS

2021 ◽  
Author(s):  
В.Б. КРЕЙНДЕЛИН ◽  
М.В. ГОЛУБЕВ
Keyword(s):  
Massive Mimo ◽  
Communication Systems ◽  
Mimo Systems ◽  
Antenna Selection ◽  
Multiple Input Multiple Output ◽  
Research Areas ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Legal Restrictions ◽  
Multiple Transmission

Совместный с прекодингом автовыбор антенн на приемной и передающей стороне - одно из перспективных направлений исследований для реализации технологий Multiple Transmission and Reception Points (Multi-TRP, множество точек передачи и приема) в системах со многими передающими и приемными антеннами Massive MIMO (Multiple-Input-Multiple-Output), которые активно развиваются в стандарте 5G. Проанализированы законодательные ограничения, влияющие на применимость технологий Massive MIMO, и специфика реализации разрабатываемого алгоритма в миллиметровомдиапа -зоне длин волн. Рассмотрены алгоритмы формирования матриц автовыбора антенн как на передающей, так и на приемной стороне. Сформулирована строгая математическая постановка задачи для двух критериев работы алгоритма: максимизация взаимной информации и минимизация среднеквадратичной ошибки. Joint precoding and antenna selection both on transmitter and receiver sides is one of the promising research areas for evolving toward the Multiple Transmission and Reception Points (Multi-TRP) concept in Massive MIMO systems. This technology is under active development in the coming 5G 3GPP releases. We analyze legal restrictions for the implementation of 5G Massive MIMO technologies in Russia and the specifics of the implementation of the developed algorithm in the millimeter wavelength range. Algorithms of antenna auto-selection matrices formation on both transmitting and receiving sides are considered. Two criteria are used for joint antenna selection and precoding: maximizing mutual information and minimizing mean square error.

Design of a wearable MIMO antenna deployed with an inverted U-shaped ground stub for diversity performance enhancement

2020 ◽  
pp. 1-11
Author(s):  
Anupma Gupta ◽  
Ankush Kansal ◽  
Paras Chawla
Keyword(s):  
Performance Enhancement ◽  
Multiple Input Multiple Output ◽  
The Body ◽  
Structural Deformation ◽  
Mimo Antenna ◽  
Tissue Phantom ◽  
Capacity Loss ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Broadside Radiation

Abstract A compact multiple input multiple output (MIMO) antenna operating at 2.45 GHz industrial scientific and medical band is presented for wearable devices. Open-end slotting is used to miniaturize the antenna dimensions. Inverted U-shaped ground stub is incorporated to reduce mutual coupling. On-body performance is analyzed on a three-layered equivalent tissue phantom model. The wide bandwidth of 300 MHz and port isolation of 30 dB are obtained from measured results. The antenna shows the efficiency of 40% and directivity of 4.56 dBi when placed at a gap of “s” = 4 mm from the body. Broadside radiation pattern and low specific absorption rate make the antenna suitable for on-body communication. Further, diversity performance is measured in terms of envelope correlation coefficient (ECC), diversity gain (DG), and channel capacity loss (CCL). The value of ECC is 0.025, DG is 9.98 dB, and CCL is 0.12 bits/s/Hz at 2.45 GHz. Antenna robustness is examined by bending the structure at different radii along the x-axis and y-axis. Performance of the proposed structure is reliable with structural deformation.

scholarly journals An Evaluation of Successive Pilot Decontamination in Massive MIMO

2018 ◽  
Vol 39 (2) ◽  
pp. 107
Author(s):  
Victor Croisfelt Rodrigues ◽  
Taufik Abrão
Keyword(s):  
Spectral Efficiency ◽  
Massive Mimo ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Pilot Training ◽  
Pilot Contamination ◽  
Fundamental Issue ◽  
Data Rates ◽  
Multiple Input ◽  
Input Multiple Output

The demand for higher data rates can be satisfied by the spectral efficiency (SE) improvement offered by Massive multiple-input multiple-output (M-MIMO) systems. However, the pilot contamination remains as a fundamental issue to obtain the paramount SE in such systems. This propitiated the research of several methods to mitigate pilot contamination. One of these procedures is based on the coordination of the cells, culminating in proposals with multiple pilot training phases. This paper aims to expand the results of the original paper, whereby the concepts of large pilot training phases were offered. The evaluation of such method was conducted through more comprehensible numerical results, in which a large number of antennas were assumed and more rigorous SE expressions were used. The channel estimation approaches relying on multiple pilot training phases were considered cumbersome for implementation and an uninteresting solution to overcome pilot contamination; contradicting the results presented in the genuine paper.

scholarly journals Partial Nulling Regularized Block Diagonalization Using Unfair Channel Selection for Post-Coding with Low-Complexity

2020 ◽  
Vol 10 (19) ◽  
pp. 6809
Author(s):  
Hyun-Sun Hwang ◽  
Jae-Hyun Ro ◽  
Young-Hwan You ◽  
Duckdong Hwang ◽  
Hyoung-Kyu Song
Keyword(s):  
Performance Enhancement ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Low Complexity ◽  
Diversity Gain ◽  
Block Diagonalization ◽  
Time Diversity ◽  
Multiple Input ◽  
Input Multiple Output ◽  
User Interference

A number of requirements for 5G mobile communication are satisfied by adopting multi-user multiple input multiple output (MU-MIMO) systems. The inter user interference (IUI) which is an inevitable problem in MU-MIMO systems becomes controllable when the precoding scheme is used. The proposed scheme, which is one of the precoding schemes, is built on regularized block diagonalization (RBD) precoding and utilizes the partial nulling concept, which is to leave part of the IUI at the same time. Diversity gain is obtained by leaving IUI, which is made by choosing the row vectors of the channel matrix that are not nullified. Since the criterion for choosing the row vectors of the channel is the power of the channel, the number of selected row vectors of the channel for each device can be unfair. The proposed scheme achieves performance enhancement by obtaining diversity gain. Therefore, the bit error rate (BER) performance is better and the computational complexity is lower than RBD when the same data rate is achieved. When the number of reduced data streams is not enough for most devices to achieve diversity gain, the proposed scheme has better performance compared to generalized block diagonalization (GBD). The low complexity at the receiver is achieved compared to GBD by using the simple way to remove IUI.

scholarly journals Performance Enhancement in MIMO-OFDMA System

2019 ◽  
Vol 9 (2) ◽  
pp. 160-165
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Performance Enhancement ◽  
Multiple Input Multiple Output ◽  
Research Area ◽  
Ofdma System ◽  
Multiple Input ◽  
Input Multiple Output ◽  
High Speed Data ◽  
Low Complex

The systematic advancement in wireless communication has provided many significant aspects towards communication domain. However, obtaining the high-speed data transmission is still a biggest concern in various multimedia-based applications. Multiple Input Multiple Output - Orthogonal Frequency Division Multiplexing Access (MIMO-OFDMA) based communication is widespread towards research area. In addition, the combination of MIMO-OFDMA with the steering antenna can lead to improved communication efficiency and offer diversity gain without changing radio frequency (RF). This paper introduces systems for power allocation and resource allocation by A) low complex compressive channel approximation (CSCE) and b) combined parallel cancelation and Viterbi encoding / decoding (PCVed). The outcome of compressive sensing based system brings reduced Bit Error Rate (BER) and less computational complexity while the performance analysis PCVed with different approaches for 4x4 transmitter and receiver.

scholarly journals Editorial: Special Issue “Massive MIMO and mm-Wave Communications”

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 519
Author(s):  
Gianmarco Romano
Keyword(s):  
Millimeter Wave ◽  
Massive Mimo ◽  
Communication Systems ◽  
Multiple Input Multiple Output ◽  
Data Traffic ◽  
Special Issue ◽  
Editorial Special Issue ◽  
Multiple Input ◽  
Key Technologies ◽  
Input Multiple Output

Massive multiple-input multiple-output (mMIMO) communication systems and the use of millimeter-wave (mm-Wave) bands represent key technologies that are expected to meet the growing demand of data traffic and the explosion of the number of devices that need to communicate over 5G/6G wireless networks [...]

scholarly journals An improvement to hybrid beamforming precoding scheme for mmWave massive MIMO systems based on channel matrix

2021 ◽  
Vol 23 (1) ◽  
pp. 285
Author(s):  
Zahra Amirifar ◽  
Jamshid Abouei
Keyword(s):  
Massive Mimo ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Wireless Systems ◽  
Achievable Rate ◽  
Percentage Difference ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Hybrid Beamforming ◽  
Mimo Technology

<p>The massive multiple-input multiple-output (MIMO) technology has been applied innew generation wireless systems due to growing demand for reliability and high datarate. Hybrid beamforming architectures in both receiver and transmitter, includinganalog and digital precoders, play a significant role in 5G communication networksand have recently attracted a lot of attention. In this paper, we propose a simple andeffective beamforming precoder approach for mmWave massive MIMO systems. Wefirst solve an optimization problem by a simplification subject, and in the second step,we use the covariance channel matrixfCk=Cov(Hk)andBk=HkHHkinstead of chan-nel matrixHk. Simulation results verify that the proposed scheme can enjoy a highersum rate and energy efficiency than previous methods such as spatially sparse method,analog method, and conventional hybrid method even with inaccurate Channel StateInformation (CSI). Percentage difference of the achievable rate ofCk=Cov(Hk)andBk=HkHHkschemes compared to conventional methods are 2.51% and 48.94%, re-spectively.</p>

scholarly journals Τεχνοοικονομική διαχείριση κινητών δικτύων πέμπτης γεννιάς (5G) και εξής

2021 ◽  
Author(s):  
Anastasia Κόλλια. Αναστασία
Keyword(s):  
Cloud Computing ◽  
Cognitive Radio ◽  
Massive Mimo ◽  
Multiple Input Multiple Output ◽  
Network Function Virtualization ◽  
Software Defined Networks ◽  
Network Function ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Antenna Systems

Σήμερα, η χρήση κινητών δικτύων αποτελεί αναπόσπαστο κομμάτι της καθημερινότητας. Οι χρήστες χρησιμοποιούν το κινητό τόσο για κλήσεις και μηνύματα όσο και για κοινωνικά δίκτυα, βίντεο, ταινίες, εφαρμογές ασκήσεις και φυσικής κατάστασης, παιχνίδια, εφαρμογές γραφείου, ημερολόγια κλπ. Η χρηστικότητα των συσκευών όχι μόνο έχει αλλάξει άρδην τα τελευταία χρόνια, αλλά αναμένεται να μεταβληθεί ακόμα περισσότερο ιδίως όταν εφαρμογές Internet of Things (IoT) προστεθούν στην ήδη διευρυμένη χρήση των κινητών συσκευών. Ακόμα, εμφανίζεται η τάση προσθήκης στο δίκτυο άλλων απλών οικιακών συσκευών και άλλου επιπρόσθετου εξοπλισμού π.χ. ιατρικών μικροσυσκευών, συσκευών παρακολούθησης, καμερών ασφαλείας κλπ. Η διδακτορική αυτή διατριβή αποτελεί μία συνολική μελέτη και περιλαμβάνει ένα πλαίσιο σχετικά με την πέμπτη γενιά κινητής τηλεπικοινωνίας. Αναλύεται η κατάσταση των Τηλεπικοινωνιών στην Ελλάδα σε βάθος. Ακόμα, περιγράφονται οι σημαντικότερες έννοιες και τα πιο βασικά βήματα και οι σημαντικότερες εξελίξεις των υπαρχουσών γενεών κινητών δικτύων επικοινωνίας. Επιπρόσθετα, περιγράφεται το θεωρητικό πλαίσιο για τα κινητά δίκτυα επικοινωνίας, καθώς και διάφοροι όροι, που είναι απαραίτητοι για την κατανόηση της παρούσας διατριβής. Αναλύονται διεξοδικά οι σημαντικότερες τεχνολογίες, που αποτελούν δομικούς λίθους για την ανάπτυξη, αλλά και την εξέλιξη στη δόμηση και ύπαρξη της 5G γενιάς κινητής τηλεπικοινωνίας, όπως έχει ήδη περιγραφεί από πλήθος ερευνητικών δράσεων και περιλαμβάνουν τις τεχνολογίες: Υπέρπυκνες Αρχιτεκτονικές (Ultra-dense), Distributed Antenna Systems (DAS), Network Function Virtualization (NFV), Software Defined Networks (SDN), Massive Multiple Input Multiple Output (MIMO), Cognitive Radio (CR), Milimeter Wave (mmWave), Cloud Computing και IoT και σύγκριση με τις σημερινές τεχνολογίες. Παρατίθενται τεχνο-οικονομικά μοντέλα, με βάση τις πιο σημαντικές τεχνολογίες, που συντελούν στην ανάπτυξη και προώθηση της 5G. Τα μοντέλα αυτά αποτελούν σημαντικό όπλο, ώστε οι πάροχοι να επενδύσουν σε νέες τεχνολογίες, να έχουν κέρδη και να καινοτομούν. Για το σκοπό αυτό επεξηγούνται τα αρχιτεκτονικά μοντέλα, τα μαθηματικά μοντέλα, οι παράμετροι, που επιλέγονται αλλά και τα αντίστοιχα πειράματα, που διεξάγονται για τις τεχνολογίες Ultra-density, DAS, NFV, SDN, Massive MIMO, CR, mmWave. Συνοψίζονται τα κυριότερα συμπεράσματα βάση των επιμέρους μελετών, που πραγματοποιήθηκαν στα πλαίσια της παρούσας διατριβής και προτείνονται ιδέες για μελλοντική έρευνα στον τομέα. Στα πλαίσια αυτά φιλοδοξείται ότι η συγκεκριμένη εργασία θα αποτελέσει ένα βασικό εργαλείο πληροφόρησης και ενημέρωσης για την επιστημονική και τηλεπικοινωνιακή κοινότητα σε ό,τι αναφορά στην τεχνο-οικονομική ανάλυση των τεχνολογιών, που αποτελούν τους θεμέλιους λίθους για τα δίκτυα Πέμπτης γενιάς.

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