Multi-User MIMO Communication

An assignment on development of Cellular mobile communication Generations, Namely, From 0 G to 5 G. Including a briefing on GSM, EDGE, AMPS, GPRS, And all others categories related to this field. This is totally a briefing that was just created in 15 min. ;)

We explore the potential of combining the advantages of multiple-input multiple-output (MIMO)-based spatial multiplexing with those of orbital angular momentum (OAM) multiplexing to increase the capacity of free-space optical (FSO) communications. We experimentally demonstrate an 80 Gbit/s FSO system with a 2×2 aperture architecture, in which each transmitter aperture contains two multiplexed data-carrying OAM modes. Inter-channel crosstalk effects are minimized by the OAM beams' inherent orthogonality and by the use of 4×4 MIMO signal processing. Our experimental results show that the bit-error rates can reach below the forward error correction limit of…

— We propose an enhanced precision channel state acquisition scheme for downlink MultiUser MIMO (MU-MIMO) transmission with a large number of transmit antennas at the base station. The proposed scheme is an attempt to harvest the Channel State Information (CSI) at the transmitter by incrementally improving the precision of the channel knowledge. We show how, in an LTE-Advanced system, CSI harvesting mechanism followed by the conventional Zero-Forcing Beam-Forming (ZFBF) results in improved MU-MIMO performance, relative to the current method for acquiring CSI at the transmitter. The proposed progressive CSI harvesting scheme is also shown to yield significant saving in terms of feedback overhead. The implications of the larger MIMO systems and higher MU-MIMO ranks, and sensitivity to higher mobility are also discussed.

Distributed antenna system (DAS) is a highly diversified concept that can help lower radiated power, maximize coverage, and improve spectral efficiency. Yet, the most exciting feature of DAS is the distribution of remote radio heads (RRH) or antennas over a wide geographical area, which allows the use of less complex signal processing techniques resulting in the reduction of systems’ size and cost. These features of DAS were utilized in network MIMO, distributed MIMO, multi-cell MIMO, and distributed-input distributed-output (DIDO) systems to move away from the centralized approach as in conventional multi-user and massive MIMO systems. In this tutorial paper, we first talk about MIMO systems with their relevant technologies by categorizing them into two main approaches according to their working principles and systematic architecture; the first approach is based on a centralized (or collocated) architecture, whereas the second is based on a decentralized (or distributed) architecture. We then deep dive into all the different technologies related to these architectures one by one and explain each in detail with much more focus on the similarities and differences between them. After that, we exposition the main target of this study, which is to answer the following question "Is cell-free massive MIMO (CF-MMIMO) equivalent to the already existing and commercialized pCell technology?".  To confidently answer this question, we comprehensively and deeply study the two technologies considering the differences in their system models and look into their conceptual formulations  as well as their respective channel models. More particularly, we detail CF-MMIMO and pCell architectures while giving special attention to pCell's SDR wireless platform and stating why it is crucial for the current wireless systems. Then, we present the understandings that are acquired after careful observations and provide recommendations based upon them. In short, this study aims to focus the reader attention on the fact that all the distributed and cell-free MIMO-related technologies work on the same principle, and the way these systems are built makes them fundamentally equivalent, yet, they are displayed quite differently using different terminologies and perspectives, which can cause confusion to readers and end up misleading future researchers.
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Two linear Artificial Neural Network (ANN)-based controllers for the control of a nonlinear system are presented. The optimization and pole placement control design strategies are used. For both strategies, linear ANNs are used to model a Continuous Stirred Tank Heater (CSTH) process. Third-order discrete-time models or Adaline ANNs are used whose parameters are updated at every sampling time to provide adaptability to the controllers. Simulation tests show that the linear ANN-based controllers can overcome strong nonlinear coupling effects, reject step disturbances, and provide adequate damping to the subsystem interactions. Both ANN-based control design strategies are shown to be interchangeable with each other for the control of the CSTH process.

In recent years, Multiple-Input Multiple-Output
(MIMO) systems have emerged as a most promising technology in these measures. MIMO
communication systems can be defined intuitively [GSS+03, PNG03] by considering that
multiple antennas are used at the transmitting end as well as at the receiving end.

~ Massive Multiple Input and Multiple Output (MIMO) is asystem smart antenna that divides transmission data into multiple streams that are transmitted and transmitted via a radio antenna simultaneously using thechannel frequency same.technology Massive Multiple Input and Multiple Output has many advantages to be applied to 5G technology. The services provided include increased capacity, reliability good, high energy efficiency, reduced interference , reduced fighting between connections and having multiple antennas. Ininfrastructure in Indonesia, Indonesia has also begun to explore 5GTechnology Massive welcoming the MIMO to welcome the arrival of the 5G era for solving networking problems at indonesia. Abstrak~ Massive Multiple Input and Multiple Output (MIMO) adalah sistem smart antenna yang membagi data transmisi menjadi beberapa stream yang dimudulasi dan ditrasnmisikan melalui antenna radio secara bersamaan menggunakan saluran frekuensi yang sama. Teknologi Massive Multiple Input and Multiple Output mempunyai banyak keunggulannya untuk diterapkan pada Teknologi 5G. Pelayanan yang diberikan meliputi peningkatan kapasitas, reliability yang baik, high efficiency energy, reduce interference, ,mengurangi rebutan antar koneksi dan memiliki banyak antena. Dalam menyongsong infrastruktur diIndonesia, indonesiapun sudah mulai mendalami Teknologi 5G Massive MIMO untuk menyambut datangnya era 5G untuk mengatasi permasalahan jaringan di indonesia. Keywords-Massive, MIMO, 5G, Jaringan I. PENDAHULUAN Dengan meningkatnya jumlah yang menggunakan layanan internet setiap tahunnya, jaringan internet semakin cangih teknologi yang digunakan, hal ini membuat perangkat yang kita gunakan menuntut untuk semakin berkembang mengikuti perkembangan zaman, hal ini mengakibatkan meningkatnya layanan generasi sistem jaringan generasi ke-3 dan generasi ke-4 (3G, 4G), dan untuk mempersiapkan untuk generasi selanjutnya yaitu generasi ke-5 (5G), untuk mengatasi hal tersebut maka perlu dipersiapkannya sebuah teknologi yang bernama Massive Multiple Input and Multiple Output. Massive MIMO Merupakan bentuk sistem MU-MIMO dimana jumlah antena Base Station dan jumlah penggunanya banyak. Massive Multiple Input and Multiple Output (MIMO) adalah kunci dari teknologi unutk memenuhi memenuhi layanan permintaan pengguna dalam kinerja dan kualitas layanan (QoS) untuk sistem komunikasi generasi berikutnya Pada artikel ini akan membahas secara mendalam tentang keunggulan menggunakan teknologi Massive MIMO dalam jaringan 5G, peningkatan kapasitas, reliability yang baik, high efficiency energy, reduce interference, ,mengurangi rebutan antar koneksi ,memiliki banyak antenna dan Massive MIMO apabila diterapkan di Indonesia untuk mengatasi permasalahan jaringan yang ada. Berdasarkan Survey yang dilakukan oleh CEOWORLD Magazine(26/02/2020), mengukapkan daftar negara-negara yang memiliki koneksi internet tercepat, yang dimana posisi pertama ditempati oleh negara Taiwan, Negara ini memiliki kecepatan Download rata-rata 85,02 Mbps, kemudian disusul oleh singapura pada peringkat ke-2. Kemudian berdasarkan survey tersebut Indonesia berada pada urutan ke-92 dengan kecepatan koneksi internet sebesar 6,65 Mbps. Dan pada penelitian yang dilakukan oleh The Economist Intelligence Unit (EIU), memaparkan hasil risetnya tentang indeks internet inklusif tahun 2020. Gambar 1. Tabel metriks komparatif kecepatan internet seluler di indoneisa (Sumber: EIU) Berdasarkan data yang tertera pada Gambar 1, kecepatan internet di Indonesia lebih lambat dari pada rata-rata kecepatan internet pada negara-negara yang ada di Asia, Kecepatan unduhan di indoneisa menurut riset EIU yaitu 14 Mbps. Sedangkan kecepatan mengunduh rata-rata dinegara Asia sebesar 30,97 Mbps. Oleh sebab itu diperlukan sebuah teknologi untuk meningkatkan infrastruktur jairngan seluler di indoensia, ini akan sangat efisien mimo masif dapat digunakan di sistem saat ini seperti LTE, bagaimanapun, standar LTE hanya memungkinkan hingga 8 port antena pada Base Station. II. KEUNGGULAN MASSIVE MIMO Perkembangan jaringan seluler yang dimulai dengan 2G kemudian dikembangkan menjadi 3G hingga 4G, kini akan diluncurkannya jaringan seluler 5G. Jaringan seluler 5G ini menggunakan frekuensi 2,3 GHz dengan bandwidth 2.360-2390 MHz, sehingga dibutuhkannya suatu teknologi andal yang tidak akan menyiakan penggunaan

Radio frequency (RF) energy transfer and harvesting techniques have recently become alternative methods to power the next generation wireless networks. As this emerging technology enables proactive energy replenishment of wireless devices, it is advantageous in supporting applications with quality of service (QoS) requirements. In this paper, we present an extensive literature review on the research progresses in wireless networks with RF energy harvesting capability, referred to as
RF energy harvesting networks (RF-EHNs). First, we present
an overview of the RF-EHNs including system architecture, RF
energy harvesting techniques and existing applications. Then, we present the background in circuit design as well as the state-of-the-art circuitry implementations, and review the communication protocols specially designed for RF-EHNs. We also explore various key design issues in the development of RF-EHNs according to the network types, i.e., single-hop networks, multi-antenna networks, relay networks, and cognitive radio networks. Finally, we envision some open research directions.

With the advent of new communications technologies such as 5G, next-generation telecommunications systems and networks require high reliability. Radio over fiber technology is considered one of the best choices, which can take advantage of the benefits of optical fibers (low attenuation, high bandwidth (THz), long-distance, etc). In this case, we need to use other types of modulation, which have high spectral efficiency (SE), high capacity, a speed that addresses Gbits/s, and high performance. The objective of this master thesis is to propose and analyze the performance of radio over fiber systems used for the co-existence of 5G fronthaul and FTTH wireless access networks based on the use of dual polarization of digital modulations such as QAM, DP-QPSK, and DP-OFDM using WDM technique. Theoretically, this work will be done by mathematical analysis of our system, which will write a research report on this type of modulation and will use the OptiSystem software for simulation to evaluate the reliability of the system based on the constellation diagram, eye diagram, BER, Q factor, etc.

MIMO systems have now become a key technology in wireless communications as it provides significantly high data rates. It creates multiple paths between the transmitter and receiver to enable more data to travel in a single unit of time thus leading to increase in data rates. V-BLAST scheme has got multiple transmitters. The data stream is divided in substreams and is transmitted independently through multiple transmitters. This paper will give an overview of V-BLAST technique from theoretical point of view and its practical implementation. It envisages on the selection of desirable modulation scheme in terms of BER, system throughput and outage probability for SISO and MIMO channel with V-BLAST architecture.

In this era of wireless communication there is an integration of more and more radios into a single wireless platform enabling maximum connectivity The multiband antenna approach using PIFA structure enables size reduction, lowers SAR values, augments the bandwidth. These can be obtained by implementing several techniques for the modification of basic structure and use of ground plane. PIFA is also a preferred choice to be incorporated for LTE and WiMAX bands as it inhibits polarization diversity effectively without any decrement in the volume. Single band antenna supports a single frequency of wireless service. And in this era several wireless standards are supported by the equipments. Thus several antennas are employed for each standard leading to a huge space requirement in the handheld devices. Hence the designing of a small PIFA antenna supports multiple bands, small size, improve Gain and good radiation pattern is the prime objective.

Fifth generation cellular networks are the key systems which are being deployed in the near future. The enabling technology, Multiple-In Multiple-Out (MIMO) wireless technology makes use of varied number of antennas at the transmitter and multiple antennas at the receiver for transmission of the information in cellular communication systems. This MIMO technology acts as a foundation and aims to improve the spectral efficiency and throughput in fifth generation wireless communication systems. The most common parameters we come across in wireless communications are Bit error rate (BER), Inter Symbol Interference (ISI), Signal to Noise ratio (SNR), Signal to Interference plus Noise ratio (SINR), Successive interference cancellation (SIC), etc. The primary objective of this paper is to improve the BER performance by minimizing SIC using Zero Forcing-Successive Interference Cancellation (ZF-SIC) with optimal ordering and suppress the noise enhancement prevailing in the channel by an extended detection technique, Minimum Mean Square Error (MMSE). As a purpose to improve the channel capacity, MIMO systems are utilized for transmission purpose lately. Quadrature Phase Shift Keying (QPSK) modulation technique is utilized in the system model, which makes use of the same channel bandwidth and carries twice the information and alongside Binary Phase Shift Modulation Technique (BPSK) is also made use of in the system model to provide a comparative analysis among the detection techniques and modulation techniques discussed previously. MIMO fading distribution such as alpha(α)-mu (μ) fading channel distribution is taken into consideration to generate a channel model. The simulated results are analysed and compared with respect to their BER performance taking into account diverse values of alpha(α), mu(μ) parameters. The significance of this paper is to provide a channel efficient, minimized successive interference cancellation at the receiver end in order to make the system more reliable, less complex, interference negligent and simultaneously improve the BER performance. In the near future, these MIMO techniques form a foundation to produce more reliable systems with high terahertz bandwidth. This indeed will open to more seamless communication in various fields of technology.

during this paper we tend to discuss a method to enhance the performance of the MIMO systems by interference cancellation technique. We tend to apply it for MIMO spatial multiplexing channels with in the Rayleigh fading environment. During this we tend to introduce MIMO systems, followed by system model, and planned interference cancellation strategy, then transient discussion regarding results and conclusion. We tend to do interference cancellation on each parallel branch of the receiver that already prepared with distinct orderings pattern, by which different branches gives distinctive symbol approximate vector, so at the end of the branches, detector achieves higher detection diversity to pick the best performed branch with selection rules, during this we tend to use choice rule MMSE because it performs higher and it has low complexness. Our simulation results shows that our detector approaches performance of the best optimal detector and complexness is low.

In multiuser MIMO networks, the spatial degrees of freedom offered by multiple antennas can be advantageously exploited to enhance the system capacity, by scheduling multiple users to simultaneously share the spatial channel. This entails a fundamental paradigm shift from single user communications, since multiuser systems can experience substantial benefit from channel state information at the transmitter and, at the same time, require more complex scheduling strategies and transceiver methodologies. This paper reviews multiuser MIMO communication from an algorithmic perspective, discussing performance gains, tradeoffs, and practical considerations. Several approaches including non-linear and linear channelaware precoding are reviewed, along with more practical limited feedback schemes that require only partial channel state information. The interaction between precoding and scheduling is discussed. Several promising strategies for limited multiuser feedback design are looked at, some of which are inspired from the single user MIMO precoding scenario while others are fully specific to the multiuser setting. DRAFT

The world is going to launch a very fast 5G wireless communication system, its main purpose is to achieve a highspeed data rate that is possible through millimeter-wave communication with wide bandwidth antenna. The microstrip patch antenna may be an elementary component of a radio channel that's specified among the most effective receiver transmitting structures, due to its low cost of assembly. This paper proposed a dual-band microstrip patch antenna with a wide bandwidth that works for 28 GHz and 38 GHz frequency bands. Defected Ground Structure (DGS) and stub slot configuration have been used to achieve wide bandwidth and dual-band, the overall size of the antenna is 8.25 x 9.69x0.45 mm 3. The proposed antenna exhibits a-10-dB impedance bandwidth of 5.13 GHz and 11.63 GHz, gain of 8.31 dB and 6.38 dB and 98% efficiency for both 28 and 38.5 GHz resonant frequency respectively. A 2x2 MIMO antenna also designed where isolation is less than-20 dB between different ports.

One of the breakthroughs of LTE is the incorporation of MIMO (multiple input multiple output) between UE (user equipment) and eNB (Evolved node-B) to enhance the performance of wireless communication system. The adaptive beamforming of MIMO can minimize both transmitted power of UE/eNB and interference at the receiving end. In this paper, we emphasize on the MIMO, varying the number of antenna ports at both ends. The first part of the paper provides the architecture, special features and frame structure of LTE system. Next, the performance of the network is evaluated using simulation in Matlab-15; where comparison is made between transmitted and received psd (power spectral density), scatter plot of received symbols, BER (bit error rate) varying the antenna ports under 16-QAM modulation scheme and outage probability is determined modeling probability density function of SINR (signal-to-interference-plus-noise ratio). The performance is found much better using two antennas at the UE instead of one antenna.

IEEE Communication System Project Titles 2017 | IEEE 2018 Matlab Communication Systems Projects for ECE, IT, CSE
A New Analytical Approach to Evaluate the Critical-Event Probability Due to Wireless Communication Errors in Train Control Systems
A New Framework of Filter Bank Multi-Carrier: Getting Rid of Subband Orthogonality
A Novel Spectrum Sensing for Cognitive Radio Networks with Noise Uncertainty
Application-Aware Resource Allocation of Hybrid Traffic in Cellular Networks
Bayesian Reinforcement Learning-Based Coalition Formation for Distributed Resource Sharing by Device-to-Device Users in Heterogeneous Cellular Networks
Comparison of Collision-Free and Contention-Based Radio Access Protocols for the Internet of Things
Design of Simultaneous Wireless Information and Power Transfer Scheme for Short Reference DCSK Communication Systems
Dynamic Resource Allocation for Immediate and Advance Reservation in Space-Division-Multiplexing-Based Elastic Optical Networks
Dynamic User Grouping and Joint Resource Allocation with Multi-Cell Cooperation for Uplink Virtual MIMO Systems
Energy and Spectral Efficiency of Cellular Networks with Discontinuous Transmission
Equal Interference Power Allocation for Efficient Shared Spectrum Resource Scheduling
Evolutionary Channel Sharing Algorithm for Heterogeneous Unlicensed Networks
Expectation-Maximization-based Channel Estimation for Multiuser MIMO Systems
FBMC and LDACS Performance for Future Air to Ground Communication Systems
Generalized 3-D Constellation Design for Spatial Modulation
Group Cooperation with Optimal Resource Allocation in Wireless Powered Communication Networks
Huffman Coding Based Adaptive Spatial Modulation
Joint Rate Control and Scheduling for Real-Time Wireless Networks
Joint Spectrum and Energy Efficiency in Device to Device Communication Enabled Wireless Networks
Location Privacy Preservation in Database-driven Wireless Cognitive Networks through Encrypted Probabilistic Data Structures
Multi-antenna Wireless Legitimate Surveillance Systems: Design and Performance Analysis
Multicarrier Approaches for High-baudrate Optical-Fiber Transmission Systems with a Single Coherent Receiver
Non-linear Distortion Cancellation and Symbol-based Equalization in Satellite Forward Links
Non-Orthogonal Random Access (NORA) for 5G Networks
Optimal Resource Allocation for Power-Efficient MC-NOMA with Imperfect Channel State Information
Parallel and Distributed Resource Allocation with Minimum Traffic Disruption for Network Virtualization
Resource Allocation Strategy for Multi-user Cognitive Radio Systems: Location-Aware Spectrum Access
Spectral and Energy Efficiencies in Full-Duplex Wireless Information and Power Transfer
Spectral Efficiency and Energy Efficiency Optimization via Mode Selection for Spatial Modulation in MIMO Systems
Subband Filtered Multi-carrier Systems for Multi-service Wireless Communications
TDMA versus CSMA/CA for wireless multi-hop communications: a stochastic worst-case delay analysis
The Error Propagation Analysis of the Received Signal Strength-Based Simultaneous Localization and Tracking in Wireless Sensor Networks
Training Sequence Design for Efficient Channel Estimation in MIMO-FBMC Systems
User Association and Resource Allocation Optimization in LTE Cellular Networks

The International Journal of Computer Networks & Communications (IJCNC) is a bi monthly open access peer-reviewed journal that publishes articles which contribute new results in all areas of Computer Networks & Communications. The journal focuses on all technical and practical aspects of Computer Networks & data Communications. The goal of this journal is to bring together researchers and practitioners from academia and industry to focus on advanced networking concepts and establishing new collaborations in these areas.

MIMO systems have now become a key technology in wireless communications as it provides significantly high data rates. It creates multiple paths between the transmitter and receiver to enable more data to travel in a single unit of time thus leading to increase in data rates. V-BLAST scheme has got multiple transmitters. The data stream is divided in substreams and is transmitted independently through multiple transmitters. This paper will give an overview of V-BLAST technique from theoretical point of view and its practical implementation. It envisages on the selection of desirable modulation scheme in terms of BER, system throughput and outage probability for SISO and MIMO channel with V-BLAST architecture.

MIMO Z Channel is investigated in this paper. We focus on how to tackle the interference when different users try to send their codewords to their corresponding receivers while only one user will cause interference to the other. We assume there are two transmitters and two receivers each with two antennas. We propose a strategy to remove the interference while allowing different users transmit at the same time. Our strategy is low-complexity while the performance is good. Mathematical analysis is provided and
simulations are given based on our system.

ABSTRACT
High data rate requirements of the Long Term Evolution - Advanced (LTE-A) systems can be achieved by adopting advanced Multiple Input Multiple Output (MIMO) antenna techniques on both uplink anddownlink. The LTE air-interface supports multiple-antenna transmit arrays and different modes of multiple antenna transmissions. In this paper, performance of different MIMO techniques is evaluated using QualNet network simulator. The MIMO techniques considered for performance evaluation are Single- Input/ Multiple-Output (SIMO), Open Loop Spatial Multiplexing (OLSM) and Space-Frequency Block Coding (SFBC). The performance metrics considered are throughput, delay and jitter.

Most of the wireless communication technologies are not able to provide substantial gain in terms of reliability and capacity due to the effect of multipath fading and limited spectrum. A best solution to overcome these problems is multiple antennas techniques. This paper investigates the effect of multiple antennas at the transmitter and receiver end of SU-MIMO and MU-MIMO, using a SVD based single and multiple beamforming technique, for various Modulation schemes namely ASK, BPSK, QPSK, 8-PSK and 8-QAM. The effectiveness of these approaches has been validated with help of MATLAB simulations.

Multi-user wireless systems with multiple antennas can drastically increase the capac-
ity while maintaining the quality of service requirements. The best performance of these
systems is obtained at the presence of instantaneous channel knowledge. Since uplink-
downlink channel reciprocity does not hold in frequency division duplex and broadband
time division duplex systems, efficient channel quantization becomes important. This
thesis focuses on different quantization techniques in a linearly precoded multi-user wire-
less system.
Our work provides three major contributions. First, we come up with an end-to-end
transceiver design, incorporating precoder, receive combining and feedback policy, that
works well at low feedback overhead. Second, we provide optimal bit allocation across the
gain and shape of a complex vector to reduce the quantization error and investigate its
effect in the multiuser wireless system. Third, we design an adaptive differential quantizer
that reduces feedback overhead by utilizing temporal correlation of the channels in a time
varying scenario.

The aim of this paper is to introduce a synthesis approach that includes the control of both quantities of interested in electromagnetic theory, like the sidelobe level, and in information theory, like the channel capacity. An example regarding PSK MIMO communication system is shown to clarify the approach.

The use of aeronautical vehicles and consequently their communication traffic are growing rapidly, and soon there will be demands for channels with larger bandwidths. The L-band digital aeronautical communication system (L-DACS1) was proposed by EUROCONTROL as an OFDM based multicarrier communication system candidate, with channels " inlayed " between distance measuring equipment (DME) channels. We previously proposed a similar communication system based on the Filter Bank Multicarrier (FBMC) technique, which has some significant advantages over L-DACS1. In this paper several diversity and multiple antenna techniques for L-DACS1 and FBMC AG communication systems are investigated. The correlation coefficient between realistic receiver aircraft antenna channels is computed, and using these realistic channels—based upon NASA channel measurements—link performance is simulated to generate BER results. Simulation results show the advantages of using multiple antennas at the receiver, and the antenna separations required (as a function of link distance) to attain nearly uncorrelated channels for two suburban areas. MIMO performance gains are quantified and show significant improvement over single-antenna systems, especially for higher order modulations.

—To characterize and model an indoor power line channel, it is of utmost importance to estimate the distributed parameters accurately. These distributed parameters are influenced by several factors that may vary from each location. In this paper, the distributed parameters are estimated on Indian residential networks considering the different aspects of electrical wiring. The results obtained through simulation are compared with other commercially available simulators and are also verified experimentally using a Vector Network Analyser. The attenuation for different wiring configurations is also obtained in the paper. I. INTRODUCTION Communication over power line cables has opened new avenues in home network connectivity by ensuring data rates as high as 200 Mbps. Though PLC has a long way ahead for full scale deployment, researchers are optimistic about the commercial implementation of this technology. The major hurdle in PLC system design is to understand the parameters like noise, multipath and attenuation which make the power line a very unfriendly channel for communication. Unfortunately, these parameters not only vary with time, but also with location and topology of the network thus becoming difficult to characterize and model a power line channel. The noise in PLC channel is due to the inherent nature of the power line called as background noise and/or because of the very nature of the loads connected to the network called as impulsive noise. The background noise is regarded as stationary noise because of its nominal variation and the impulsive noise can be synchronous or asynchronous to the mains frequency depending on the type of loads connected. These impulsive noises vary with time and as a significant impact on the BER [1]. Similar to wireless channels, the PLC channels also exhibit multipath characteristics (transmission and reflection of signals) due to the varied branch length and different loads connected throughout the power line. This multipath effect degrades the signal transmitted over the power line [2]. Similarly, the attenuation in the power line is due to the distinct power cables used and the variety of loads connected across the network. One predominant factor for attenuation in the power line is due to the reflections of branch terminals [3]. Taking into account the complexity of power line channel, researchers have developed various channel modeling techniques so far which can be classified into top-down or bottom-top approach [4],[5]. The top-down approach of channel modeling is based on the multipath propagation and where as the bottom-top approach is an analytical method developed on the physical and electrical properties extracted from the network. These power line channels can be modeled using any of these approaches either in time domain or in frequency domain. In fact PLC simulators are also commercially available based upon these models [6-8]. However, to characterize a power line channel, it is very important to accurately estimate the distributed parameters of an electrical line. The various factors that influence the channel parameters are Skin effect, proximity effect, type of wiring used, wiring geometry in the cable, coupling effect etc. apart from the weather conditions which is difficult to simulate. One such detailed study is carried out in this paper to estimate the line parameters on Indian residential networks. It is nevertheless to say that the electrical distribution scenario varies from each country and so is the impact on the power line [18]. The subsequent sections of the paper are organized as follows. The section II discuss about the various factors that influence the power line channel model. In section III, the results obtained from the proposed model are compared with the models proposed by other researchers. In section IV, the results are verified experimentally on an electrical wire using a Vector Network Analyzer. In this section, the study is also extended to understand the power line behaviour for different configurations and wiring sizes. In section V, the channel frequency response is estimated on a sample network and the results are compared with the proposed model.

—Scheduling more than one user could increase system capacity of multi antenna systems. Present article reviews Multi User MIMO (MU-MIMO) communication from scheduling perspective, discussing performance gains in terms of sumrate, fairness, and computational complexity. Several scheduling techniques reported for MU-MIMO based on different algorithms are reviewed, along with partial channel state information and full channel state information. Moreover, the selection procedure of first user in leakage based and interference based scheduling algorithms is analyzed. The results show that random selection of first user does not effect the performance and have relatively less computational complexity.

In this contribution, we focus on the exposure limits and compliance distances of 5G communication systems based on large antenna arrays with high gain and multiplexing capability. In particular, starting from the observation that the antenna array continuously changes its radiation pattern to communicate with a number of user terminals, we develop a simple approach for evaluating a reliable but not overly conservative boundary for the fields radiated by the antenna array. This approach is based on the use of the Normalized Average Power Pattern, and through the paper we show its behavior and demonstrate its usefulness in some cases of interest. Finally, the obtained results are validated by means of an electromagnetic simulation of the antenna and the propagation scenario, that is achieved by means of a ray-launching code. INDEX TERMS Antenna arrays, antenna radiation pattern, 5G systems, exposure limits, massive MIMO.

Multi-user MIMO offers big advantages over conventional point-to-point MIMO: it works with cheap single-antenna terminals, a rich scattering environment is not required, and resource allocation is simplified because every active terminal utilizes all of the time-frequency bins. However, multi-user MIMO, as originally envisioned, with roughly equal numbers of service antennas and terminals and frequency-division duplex operation, is not a scalable technology. Massive MIMO (also known as large-scale antenna systems, very large MIMO, hyper MIMO, full-dimension MIMO, and ARGOS) makes a clean break with current practice through the use of a large excess of service antennas over active terminals and time-division duplex operation.

يعد تطوير الجيل الخامس لشبكات الإتصالات للأنظمة اللاسلكية من أهم مظاهر الوصول الفائق للمعلومات التي تسعى إليها الحكومات والشركات، بالشكل الذي يعمل على اتصال الأشخاص والتجهيزات مع بعضهم البعض، ويعتقد بأن هذه المرحلة من التطوير ستشكل ثورة تقنية، حيث سيتم تدفق المعلومات بشكل فوري دلالي دونما انقطاع بصورة أكثر سلاسة ومرونة مع تحقيق أعلى درجات الأمان للبيانات والمعلومات والتغطية والسرعة غير المحدودة بشكل منقطع النظير بفضل هذا الجيل من الشبكات.
وحري بالأمة العربية في ظل ما يشهده العالم من سباق متسارع نحو تطوير شبكات الجيل الخامس للإتصالات للأنظمة اللاسلكية أن تقوم بالدور الثقافي والمعرفي المنوط بها حتى لا تغيب عن ركب التطور، وجوهر هذا الدور يتمحور حول إعداد إطار استراتيجي لأرشيف عربي موحد يصف ويحصر ويسجل تاريخ وتراث ومستقبل أمتنا العربية، والذي يعد أحد  مصادر الفخر والتباهي بين الأمم، كما يعد أحد أهم الآليات التي تساعد على التصدي لمختلف أشكال الصراعات ومواجهة التیارات الفكریة المتطرفة، كمحاولة جادة في سبيل النفاذ إلى مصادر المعلومات واستيعابها وتمكينها وتوطينها في مجتمع المعرفة العربي من خلال الإفادة من شبكات الاتصالات المتطورة، بجانب توفير عوامل الإبداع وتوليد الأفكار الجديدة لتقديم المعرفة الموثوقة والمعتمدة إلكترونياً فكريا وثقافيا وعلميا الخ.
ومن ثم تناول هذا البحث مفهوم شبكات الجيل الخامس للاتصالات اللاسلكية، بوصفها تقنية المستقبل، والميزات والخدمات والتطبيقات التي تشملها مع دراسة إمكانية الافادة منها لإعداد إطار استراتيجي للأرشيف العربي الموحد ومن ثم الخروج بتصور لتأسيس أرشيف عربي موحد إلكترونيا يعتمد على الاتصالات اللاسلكية.
وخلص البحث الى ان نجاح فكرة تأسيس أرشيف عربي موحد مرهونة بالتقدم في قطاع تكنولوجيا الاتصالات والمعلومات، الأمر الذي يلقي بظلاله على أهمية:
1- حفظ وصيانة مصادر المعلومات التراثية.
2- تقليل فجوة المحتوى الرقمي العربي.
3- رفع الوعي المعلوماتي العربي.
4- تعزيز مجتمع المعرفة العربي.
5- توثيق وتحقيق التراث العربي.
6- توفير وتكامل معطيات وبيانات يمكن الافادة منها في عملية التفاعل مع متطلبات ومتغيرات العالم المعاصر.
7- استدامة الثقافة العربية التي تتطلع إلى الصدارة بشكل مؤثر فعال.
8- التركيز على مواكبة التطور، وزيادة الاعتمادية، والموثوقية للعمل على جذب الأجيال العربية الناشئة إلى المصادر المعتمدة عن تاريخ وواقع الوطن العربي.

IEEE 802.11ac is a fifth generation WiFi standard that has many advanced features than the current widely used IEEE 802.11n. In this paper, we perform experiments in two real indoor environments (that possess interference and have different multipath characteristics) to quantify the gain in average throughput provided by IEEE 802.11ac compared to IEEE 802.11n. Our experimental results show that in an environment with less multipath effect, IEEE 802.11ac provides 51% and 126% gain compared to IEEE 802.11n at a distance of 5m and 18.5m from the wireless router, respectively. Similarly, in an environment with high multipath effect, IEEE 802.11ac provides gain of 21% and 32% compared to IEEE 802.11n at a distance of 1m and 18.5m from the wireless router, respectively. We conclude that IEEE 802.11ac can effectively handle interference caused by other IEEE 802.11n (5GHz) sources and provides higher throughput than IEEE 802.11n.

—Wireless communication is a key area of research with increasing demand of high data rate applications at a low cost. Multiple input multiple output-orthogonal frequency division multiplexing (MIMO-OFDM) is the most promising technology for high spectral efficiency and for very high data throughput. Despite of being an emerging technology, it has to face a major challenge of carrier frequency offset (CFO) error, which causes inter carrier interference that ultimately leads to loss of orthogonality. This paper provides an intuitive knowledge of the concept used in the estimation of Channel distortion and CFO.

filter occupies a small size of 8.7 mm by 2.4 mm. For the measurement, a 5-mm long microstrip feed line is added at both input and output. demonstrates the EM-simulated and experimental results of the proposed filter, where excellent agreement is obtained. The measured insertion loss is found to be less than 0.8 dB at the center frequency of the UWB passband. The measured return loss is better than 13 dB over the whole UWB passband. The filter shows the two new transmission zeros at the lower and upper edges of the desired passband, which enhanced the selectivity of the lower and the upper skirts of the UWB passband.

Incorporating full duplex operation in Multiple Input Multiple Output (MIMO) systems provides the potential of boosting throughput performance. However, the hardware complexity of the analog self-interference canceller in emerging full duplex MIMO designs mostly scales with the number of transmit and receive antennas, thus exploiting the benefits of analog cancellation becomes impractical for full duplex MIMO transceivers, even for moderate number of antennas. In this paper, we present two novel architectures for the analog canceller comprising of reduced number of cancellation elements, compared to the state of the art, and simple multiplexers for efficient signal routing among the transmit and receive radio frequency chains. One architecture is based on analog taps (tap refers to a line of fixed delay, variable phase shifter, and attenuator) and the other on AUXiliary (AUX) Transmitters (TXs) that locally generate the cancellation signal. In contrast to the available analog cancellation architectures, the values for each tap or each AUX TX and the configuration of the multiplexers are jointly designed with the digital transmit and receive beamforming filters according to certain performance objectives. Focusing on a narrowband flat fading channel model as an example, we present a general optimization framework for the joint design of analog self-interference cancellation and digital beamforming. We also detail the sum rate optimization objective together with its derived solution for the latter architectural components. Representative computer simulation results demonstrate the superiority both in terms of hardware complexity and achievable performance of the proposed low complexity full duplex MIMO schemes over the lately available ones.

This paper presents a technique for the antenna beamforming in high data rate OFDM systems. The technique makes use of the QR decomposition-based recursive least s q u a r e s (RLS) a l g o r i t h m using Givens Rotation. The simulation results are obtained for the Qr factorization and QRD-RLS algorithm both for the floating-point as well as the fixed-point models. An overall architecture is created in Matlab for four sensor elements and is then simulated. The techniques used clearly indicate the improvement in the response of the system. The VHDL code is then written to describe the architecture of the overall design and is then synthesized using Xilinx ISE 10.1 software for Virtex-4 target device.

We analyze the performance of dual-hop multiple-input multiple-output (MIMO)
amplify-and-forward (AF) relay systems by considering the source-to-relay and
relay-to-destination channels undergo Rayleigh and Rician fading, respectively.
Several MIMO techniques and practical relaying scenarios are considered to investigate
the effect of such asymmetric fading on the MIMO AF relaying systems.

Antenna mutual coupling occurs naturally through the electromagnetic field.  It is sometimes neglected in design with serious  consequences. Mutual coupling has also been used to improve the performance of arrays by placing the elements closer together or with nearby parasitics. Whilst detailed design is possible through the several accurate computer packages that are available, greater understanding of what is possible by direct connection with the physics through analysis that often creates simple models. The intention of this book is to cover the main techniques that depend clearly on an understanding through Maxwell’s equations. It covers the subject of mutual coupling comprehensibly through topics written by experts in the area. These topics include coupling in wire antennas, waveguides and horns, co-sited antennas, MIMO antenna, large arrays, and measurement techniques.

Table of Contents
Chapter 1  Introduction (Trevor S. Bird)
Chapter 2  Basics of Antenna Mutual Coupling (Trevor S. Bird)
Chapter 3  Methods in the Analysis of Mutual Coupling in Antennas (Trevor S. Bird)
Chapter 4  Mutual Coupling in Arrays of Wire Antennas (Trevor S. Bird)
Chapter 5  Arrays of Planar Aperture Antennas (Trevor S. Bird)
Chapter 6  Arrays of Microstrip Patch Antennas (Trevor S. Bird)
Chapter 7  Mutual Coupling Between Antennas on Conformal Surfaces (Trevor S. Bird)
Chapter 8  Mutual Coupling Between Co-sited Antennas and Antennas on Large Structures (Derek McNamara and Eqab Almajali)
Chapter 9 Mutual Coupling and Multiple Input Multiple Output (MIMO) Communications (Karl F. Warnick)
Chapter 10  Mutual Coupling in Beamforming and Interferometric Antennas (Hoi Shun Antony Lui and Trevor S. Bird)
Chapter 11 Techniques for Minimizing Mutual Coupling Effects in Arrays (Hoi Shun Antony Lui and Trevor S. Bird)
Chapter 12  Noise Performance in the Presence of Mutual Coupling (Christophe Craeye, Jean Cavillot, and Eloy de Lera Acedo)
Chapter 13  Methods for Analyzing Mutual Coupling in Large Arrays
(Christophe Craeye and Ha Bui Van)
Chapter 14  Measurement of Mutual Coupling Effects (Alpha O. Bah and Trevor S. Bird)
APPENDIX A: Useful Identities (Trevor S. Bird)
APPENDIX B: Bessel and Hankel Functions (Trevor S. Bird)
APPENDIX C: Properties of Hankel Transform Functions (Trevor S. Bird)
APPENDIX D: Properties of Surface Fock Functions (Trevor S. Bird)
APPENDIX E: Four Parameter Noise Representation of an Amplifier (Christophe Craeye, Jean Cavillot, and Eloy de Lera Acedo)
APPENDIX F: Equivalent Noise Currents (Christophe Craeye, Jean Cavillot, and Eloy de Lera Acedo)
APPENDIX G: Basic Reciprocity Result (Christophe Craeye, Jean Cavillot, and Eloy de Lera Acedo)
APPENDIX H: On the Extended Admittance Matrix (Christophe Craeye and Ha Bui Van)
(Index