Techniques for Enhancing the Performance of Communication Systems Employing Spread-response Precoding PDF Download

Author: Soosan Beheshti
Publisher:
ISBN:
Category :
Languages : en
Pages : 66

View

Book Description

Author: C.-C. Kuo
Publisher: Springer Science & Business Media
ISBN: 0387717692
Category : Technology & Engineering
Languages : en
Pages : 324

View

Book Description
During the past two decades, many communication techniques have been developed to achieve various goals such as higher data rate, more robust link quality,andmoreusercapacityinmorerigorouschannelconditions.Themost well known are, for instance, CDMA, OFDM, MIMO, multiuser OFDM, and UWB systems.All these systems havetheir ownunique superioritywhile they also induce other drawbacks that limit the system performance. Conventional way to overcome the drawback is to impose most of the computational e?ort in the receiver side and let the transmitter design much simpler than receiver. The fact is that, however, by leveraging reasonable computational e?ort to the transmitter, the receiver design can be greatly simpli?ed. For instance, multiaccess interference (MAI) has long been considered to limit the perf- mance of multiuser systems. Popular solutions to mitigate MAI issue include multiuser detection (MUD) or sophisticated signal processing for interference cancellation such as PIC or SIC. However, those solutions impose great b- den in the receiver. In this case, precoding o?er good solutions to achieve simple transceiver designs as we will mention later in this book. This book is intended to provide a comprehensive review of precoding techniques for digital communications systems from a signal processing p- spective. The variety of selected precoding techniques and their applications makes this book quite di?erent from other texts about precoding techniques in digital communication engineering.

Author: 陳彥良
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description

Author: Massachusetts Institute of Technology. Research Laboratory of Electronics
Publisher:
ISBN:
Category : Electronics
Languages : en
Pages : 534

View

Book Description

Author: Raed Mesleh
Publisher: John Wiley & Sons
ISBN: 1119375657
Category : Technology & Engineering
Languages : en
Pages : 284

View

Book Description
Explores the fundamentals required to understand, analyze, and implement space modulation techniques (SMTs) in coherent and non-coherent radio frequency environments This book focuses on the concept of space modulation techniques (SMTs), and covers those emerging high data rate wireless communication techniques. The book discusses the advantages and disadvantages of SMTs along with their performance. A general framework for analyzing the performance of SMTs is provided and used to detail their performance over several generalized fading channels. The book also addresses the transmitter design of these techniques with the optimum number of hardware components and the use of these techniques in cooperative and mm-Wave communications. Beginning with an introduction to the subject and a brief history, Space Modulation Techniques goes on to offer chapters covering MIMO systems like spatial multiplexing and space-time coding. It then looks at channel models, such as Rayleigh, Rician, Nakagami-m, and other generalized distributions. A discussion of SMTs includes techniques like space shift keying (SSK), space-time shift keying (STSK), trellis coded spatial modulation (TCSM), spatial modulation (SM), generalized spatial modulation (GSM), quadrature spatial modulation (QSM), and more. The book also presents a non-coherent design for different SMTs, and a framework for SMTs’ performance analysis in different channel conditions and in the presence of channel imperfections, all that along with an information theoretic treatment of SMTs. Lastly, it provides performance comparisons, results, and MATLAB codes and offers readers practical implementation designs for SMTs. The book also: Provides readers with the expertise of the inventors of space modulation techniques (SMTs) Analyzes error performance, capacity performance, and system complexity. Discusses practical implementation of SMTs and studies SMTs with cooperative and mm-Wave communications Explores and compares MIMO schemes Space Modulation Techniques is an ideal book for professional and academic readers that are active in the field of SMT MIMO systems.

Author: Parag Chatterjee
Publisher: CRC Press
ISBN: 1000531864
Category : Computers
Languages : en
Pages : 337

View

Book Description
The Internet of Things (IoT) has seen the eventual shift to the "Internet of Everything" in the recent years, unveiling its ubiquitous presence spanning from smart transports to smart healthcare, from smart education to smart shopping. With the 5G rollouts across the different countries of the world, it raises newer perspectives toward the integration of 5G in IoT. For IoT-based smart devices, 5G not only means speed, but also better stability, efficiency, and more secure connectivity. The reach of 5G in IoT is extending in multifarious areas like self-driving vehicles, smart grids for renewable energy, AI-enabled robots on factory floors, intelligent healthcare services . . . The endless list is the real future of 5G in IoT. Features: Fundamental and applied perspectives to 5G integration in IoT Transdisciplinary vision with aspects of Artificial Intelligence, Industry 4.0, and hands-on practice tools Discussion of trending research issues in 5G and IoT As 5G technologies catalyze a paradigm shift in the domain of IoT, this book serves as a reference for the researchers in the field of IoT and 5G, proffering the landscape to the trending aspects as well as the key topics of discussion in the years to come.

Author: Hien Quoc Ngo
Publisher: Linköping University Electronic Press
ISBN: 9175191474
Category :
Languages : en
Pages : 69

View

Book Description
The last ten years have seen a massive growth in the number of connected wireless devices. Billions of devices are connected and managed by wireless networks. At the same time, each device needs a high throughput to support applications such as voice, real-time video, movies, and games. Demands for wireless throughput and the number of wireless devices will always increase. In addition, there is a growing concern about energy consumption of wireless communication systems. Thus, future wireless systems have to satisfy three main requirements: i) having a high throughput; ii) simultaneously serving many users; and iii) having less energy consumption. Massive multiple-input multiple-output (MIMO) technology, where a base station (BS) equipped with very large number of antennas (collocated or distributed) serves many users in the same time-frequency resource, can meet the above requirements, and hence, it is a promising candidate technology for next generations of wireless systems. With massive antenna arrays at the BS, for most propagation environments, the channels become favorable, i.e., the channel vectors between the users and the BS are (nearly) pairwisely orthogonal, and hence, linear processing is nearly optimal. A huge throughput and energy efficiency can be achieved due to the multiplexing gain and the array gain. In particular, with a simple power control scheme, Massive MIMO can offer uniformly good service for all users. In this dissertation, we focus on the performance of Massive MIMO. The dissertation consists of two main parts: fundamentals and system designs of Massive MIMO. In the first part, we focus on fundamental limits of the system performance under practical constraints such as low complexity processing, limited length of each coherence interval, intercell interference, and finite-dimensional channels. We first study the potential for power savings of the Massive MIMO uplink with maximum-ratio combining (MRC), zero-forcing, and minimum mean-square error receivers, under perfect and imperfect channels. The energy and spectral efficiency tradeoff is investigated. Secondly, we consider a physical channel model where the angular domain is divided into a finite number of distinct directions. A lower bound on the capacity is derived, and the effect of pilot contamination in this finite-dimensional channel model is analyzed. Finally, some aspects of favorable propagation in Massive MIMO under Rayleigh fading and line-of-sight (LoS) channels are investigated. We show that both Rayleigh fading and LoS environments offer favorable propagation. In the second part, based on the fundamental analysis in the first part, we propose some system designs for Massive MIMO. The acquisition of channel state information (CSI) is very importantin Massive MIMO. Typically, the channels are estimated at the BS through uplink training. Owing to the limited length of the coherence interval, the system performance is limited by pilot contamination. To reduce the pilot contamination effect, we propose an eigenvalue-decomposition-based scheme to estimate the channel directly from the received data. The proposed scheme results in better performance compared with the conventional training schemes due to the reduced pilot contamination. Another important issue of CSI acquisition in Massive MIMO is how to acquire CSI at the users. To address this issue, we propose two channel estimation schemes at the users: i) a downlink "beamforming training" scheme, and ii) a method for blind estimation of the effective downlink channel gains. In both schemes, the channel estimation overhead is independent of the number of BS antennas. We also derive the optimal pilot and data powers as well as the training duration allocation to maximize the sum spectral efficiency of the Massive MIMO uplink with MRC receivers, for a given total energy budget spent in a coherence interval. Finally, applications of Massive MIMO in relay channels are proposed and analyzed. Specifically, we consider multipair relaying systems where many sources simultaneously communicate with many destinations in the same time-frequency resource with the help of a massive MIMO relay. A massive MIMO relay is equipped with many collocated or distributed antennas. We consider different duplexing modes (full-duplex and half-duplex) and different relaying protocols (amplify-and-forward, decode-and-forward, two-way relaying, and one-way relaying) at the relay. The potential benefits of massive MIMO technology in these relaying systems are explored in terms of spectral efficiency and power efficiency.

Author:
Publisher:
ISBN:
Category : Electrical engineering
Languages : en
Pages : 666

View

Book Description

Author: Fuyun Ling
Publisher: Cambridge University Press
ISBN: 110711473X
Category : Technology & Engineering
Languages : en
Pages : 399

View

Book Description
This practical guide helps readers to learn how to develop and implement synchronization functions in digital communication systems.

Author: Hua Fu
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

View

Book Description
For the next generations of wireless communication systems, getting higher spectral efficiencies is remaining a big challenge to answer the explosively increasing demand of throughput. Meanwhile, the energy consumption of equipments and the transmitting power density have to be reduced to achieve the objective of ''green communications''. One of the most promising strategies to deal with such issues is using multi-user multiple-input multiple-output (MU-MIMO) schemes, namely for large-scale antenna systems. It becomes then possible to simultaneously serve multiple simple device users using linear spatial precoding techniques. The objective of this thesis is to optimize the spectral efficiency of MU-MIMO systems in the context of moderate-scale antenna arrays and low energy consumption. Hence, we studied different high-energy efficiency precoding techniques based on matched filtering approach, such as maximum ratio transmission (MRT), equal gain transmission (EGT) and time reversal (TR). We were interested in the theoretical performance analysis of these techniques. In addition, we introduced a scheme based on partial frequency bandwidth overlay (PFBO) to improve and adapt the spectral efficiency of a MU-MIMO system at low signal to noise ratio (SNR) regime. In a first part, we studied the spectral efficiency of the proposed PFBO scheme with both single-carrier and multi-carrier modulations. We identified the optimal bandwidth overlap ratios that provide the maximum achievable rate for two-user SIMO and MIMO systems. Then the study was extended to a more general MU-MIMO case with an arbitrary number of users. We precisely modeled the channel behavior after precoding when using EGT, TR and MRT techniques. New closed-form capacity lower bounds not available in the literature were then obtained and shown to be satisfactory accurate. In the second part, the bit error rate (BER) performance of PFBO scheme was studied for both flat fading channels and theoretical Rayleigh channels. Closed-form BER equations were obtained. Particularly, we proposed a statistical model to reflect the behavior of the non-flat fading channel after precoding and to take into account the correlated interference terms that occur in a two-user EGT-MIMO system using BPSK modulation. This model was also validated in case of QPSK modulation and with more users. In the last part, we proposed to combine our PFBO principle with spread-spectrum OFDM techniques (SS-OFDM). We analyzed the theoretical BER performance of such a scheme using flat fading channels and theoretical Rayleigh channels. New closed-form BER approximation equations were then established and compared through simulations. Eventually, we showed that the SS component of the proposed system provides performance gains that depend on the overlap ratio used in the PFBO scheme.