Download or read book Timing and Channel Estimation in Multiple antenna Communication Systems written by Yong Liu and published by . This book was released on 2005 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Signal Processing Channel Estimation and Link Adaptation in MIMO OFDM Systems written by Jianjun Ran and published by Cuvillier Verlag. This book was released on 2008 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Channel Modeling and Direction of arrival Estimation in Mobile Mutiple antenna Communication Systems written by Arastoo Rostami Ravari and published by . This book was released on 2005 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: Antennas that are able to adaptively direct the transmitted (and received) energy are of great interest in future wireless communication systems. The directivity implies reduced transmit power and interference, and also a potential for increased capacity. This thesis treats some modeling and estimation problems in mobile communication systems that employ multiple antennas, primarily at the base stations. With multiple antennas at the receive side, the spatial dimensions is added, and processing is performed in both the temporal and spatial domains. The potential benefits are increased range, fading diversity and spatially selective transmission. Specifically, the problems dealt in this thesis are mainly related to the uplink transmission from mobile to the base station. Two main topics are studied modeling and estimation of channel parameters. This thesis first describes the modeling of the reflected power distibution due to the scatterers close to the mobile station, in terms of the received signal azimuth at the base station with multiple-antenna. As a more realistic modeling, a multipath fading deterministic channel model is proposed to generated properly correlated faded waveforms with appropriate power distibution through azimuth spread of received signal. The purpose of the proposed channel model is to model fading received signal waveforms with Laplacian distribution of power through received signal azimuth. This thesis is divided into two parts; in the first part multipath fading by local scattering are used to derive a channel model including the spatial dimension for non frequency-selective fading. This means that the mobile is not modeled as a point source but as a cluster of a large number independent scatterers with small time delay spread to take into account angular spreading of the signal. Properly correlated fading waveforms are obtained by taking into account the angular spread of the scattered signals from a particular distribution of scatterers. By appropriate scaling of the array response vector (ARV) based non-equal locations for various received signal components as a functionc of distance from the transmitter, the reflected power a given scatterer in no longer constant but varies as a function of the distance from the transmitter. Our proposed channel model is able to produce fading signal waveform which agrees with the results of reflected angular power dispersion measured in the field, e.g. Laplacian distribution of power in azimuth. It is also shown that the channel response can be modeled as a complex Gaussian vector. Although the channel will be frequency selective in the case of multipath propagation with considerable time spread, this can be modeled as having more than one cluster of scatterers. By employing Walsh-Hadamard codewords an extension to wideband multipath fading model is achieved. It is shown that the statisctical properties of proposed model such as signal waveform's correlation, autocorrelation and crosscorrelation between generated paths, are in good agreement with the theory in space and time domain. The model can be applied to evaluate smart antenna systems and beamforming algorithms in the uplink by generating uncorrelated multipaths Rayleigh fading waveforms with certain spatio-temporal correlation and spatial coordinates relative to base stations to simulate received signals from mobiles and interferers. Bit-error-rate (BER) performance analysis of uniform linear array antenna (ULA) based on correlation matrix is also presented as an application of our proposed model for multiple-antenna evaluations. Our simulated results show 5% improvement than other published related works. One problem when modeling frequency selective fading is that each cluster has to be assigned spatial parameters. Since the joint spatial and temporal characteristics are unknown, non-parametric channel estimation approaches are required in this case in order to estimate the channel parameter, which is the subject of the second part. The second part of the thesis deals with channel parameter estimation of distributed scattering sources. Because of local scattering around the transmitter the signal waveforms appears spatially distributed at the receiver. The characterization of the spatial channel, in particular mean direction of arrival and spatial spread, is of prime interest for system optimization and performance prediction. Low-complexity spectral-based estimators are used for the estimation of direction and spatial spread of the distributed source by employing the proposed channel model for simulation. Estimated parameters from recent measurements ([PMF00]) are compared with estimated parameters from model generated waveforms as well as theoretical distribution of receiving signal's angular speed. Good agreement between them is observed which shows the correctness of our proposed channel model for simulating spatio-temporally correlated received signal at an antenna array. The estimated parameters error improved by 5% over the other published related works.

Download or read book Wireless Multi Antenna Channels written by Serguei Primak and published by John Wiley & Sons. This book was released on 2011-10-14 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a practical guide on how to use and apply channel models for system evaluation In this book, the authors focus on modeling and simulation of multiple antennas channels, including multiple input multiple output (MIMO) communication channels, and the impact of such models on channel estimation and system performance. Both narrowband and wideband models are addressed. Furthermore, the book covers topics related to modeling of MIMO channel, their numerical simulation, estimation and prediction, as well as applications to receive diversity, capacity and space-time coding techniques. Key Features: Contains significant background material, as well as novel research coverage, which make the book suitable for both graduate students and researchers Addresses issues such as key-hole, correlated and non i.i.d. channels in the frame of the Generalized Gaussian approach Provides a unique treatment of generalized Gaussian channels and orthogonal channel representation Reviews different interpretations of scattering environment, including geometrical models Focuses on the analytical techniques which give a good insight into the design of systems on higher levels Describes a number of numerical simulators demonstrating the practical use of this material. Includes an accompanying website containing additional materials and practical examples for self-study This book will be of interest to researchers, engineers, lecturers, and graduate students.

Download or read book Space Time Processing for MIMO Communications written by Alex Gershman and published by John Wiley & Sons. This book was released on 2005-08-05 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: Driven by the desire to boost the quality of service of wireless systems closer to that afforded by wireline systems, space-time processing for multiple-input multiple-output (MIMO) wireless communications research has drawn remarkable interest in recent years. Exciting theoretical advances have been complemented by rapid transition of research results to industry products and services, thus creating a vibrant new area. Space-time processing is a broad area, owing in part to the underlying convergence of information theory, communications and signal processing research that brought it to fruition. This book presents a balanced and timely introduction to space-time processing for MIMO communications, including highlights of emerging trends, such as spatial multiplexing and joint transceiver optimization. Includes detailed coverage of wireless channel sounding, modelling, characterization and model validation. Provides state-of-the-art research results on space-time coding, including comprehensive tutorial coverage of orthogonal space-time block codes. Discusses important recent developments in spatial multiplexing, transmit beam-forming, pre-coding and joint transceiver design for the multi-user MIMO downlink using full or partial CSI. Illustrates all theory with numerous examples gleaned from cutting-edge research from around the globe. This valuable resource will appeal to engineers, developers and consultants involved in the design and implementation of space-time processing for MIMO communications. Its accessible format, amply illustrated with real world case studies, contains relevant, detailed advice for postgraduate students and researchers specializing in this field.

Download or read book Space Time Layered Information Processing for Wireless Communications written by Mathini Sellathurai and published by John Wiley & Sons. This book was released on 2009-07-28 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discover cutting-edge research in wireless communications This book presents cutting-edge research in wireless communications, particularly in the fast-growing subject of multiple-input multiple-output (MIMO) wireless communication systems. It begins with an introduction, which includes historical notes and a review of turbo-information processing and MIMO wireless communications, and goes on to cover: MIMO channel capacity BLAST architectures Space-time turbo codes and turbo decoding principles Turbo-BLAST Turbo-MIMO systems The material is complemented with abundant illustrations and computer experiments that are designed to help readers reinforce their understanding of the underlying subject matter. Space-Time Layered Information Processing for Wireless Communications is an ideal resource for researchers in academia and industry and an excellent textbook for related courses at the graduate level.

Download or read book Space time frequency Channel Estimation for Multiple antenna Orthogonal Frequency Division Multiplexing Systems written by Kar Lun (Clarence) Wong and published by . This book was released on 2007 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The proposed STF channel estimator reduces to a time-frequency (TF) channel estimator when no spatial correlations exist. In another perspective, the lower-dimension TF channel estimator can be viewed as an STF channel estimator with spatial correlation mismatch for space-time-frequency selective channels." --

Download or read book Wireless Communication Systems written by Xiaodong Wang and published by Prentice Hall Professional. This book was released on 2004 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless Communication Systems: Advanced Techniques for Signal Receptionoffers a unified frameworkfor understanding today's newest techniques for signal processing in communication systems - andusing them to design receivers for emerging wireless systems. Two leading researchers cover a fullrange of physical-layer issues, including multipath, dispersion, interference, dynamism, andmultiple-antenna systems. Topics include blind, group-blind, space-time, and turbo multiuserdetection; narrowband interference suppression; Monte Carlo Bayesian signal processing; fast fadingchannels; advanced signal processing in coded OFDM systems, and more.

Download or read book Space time Array Communications written by Jason Wee Peng Ng and published by Imperial College Press. This book was released on 2007 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Space-time array communications have gained a great deal of interest in recent years. Its superior performance in practical multipath propagation environments has established it as a core aspect in next generation mobile networks, as well as several portable wireless communication systems. In fact the employment of the sensor array component has already been provided for in the current UMTS standard, and there is presently a major thrust to make space-time processing an important part of 3G/4G networks. This book hence attempts to bridge the knowledge gap, looking at the integration of two emerging technologies from an array manifold perspective ? space-time array processing and spread spectrum multiple access communications. It covers a range of novel multiuser channel estimation and reception techniques, which is designed to provide mitigations of the various associated channel impairments in accordance to its environmental context. For convenience of the readers, the book is written in a self-contained modular format with its mathematical frameworks and tools readily extendable to other research domains.

Download or read book Massive MIMO written by Hien Quoc Ngo and published by Linköping University Electronic Press. This book was released on 2015-01-16 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Wireless Channel Estimation and Channel Prediction for MIMO Communication Systems written by Farnoosh Talaei and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, channel estimation and channel prediction are studied for wireless communication systems. Wireless communication for time-variant channels becomes more important by the fast development of intelligent transportation systems which motivates us to propose a reduced rank channel estimator for time-variant frequency-selective high-speed railway (HSR) systems and a reduced rank channel predictor for fast time-variant flat fading channels. Moreover, the potential availability of large bandwidth channels at mm-wave frequencies and the small wavelength of the mm-waves, offer the mm-wave massive multiple-input multiple-output (MIMO) communication as a promising technology for 5G cellular networks. The high fabrication cost and power consumption of the radio frequency (RF) units at mm-wave frequencies motivates us to propose a low-power hybrid channel estimator for mm-wave MIMO orthogonal frequency-division multiplexing (OFDM) systems. The work on HSR channel estimation takes advantage of the channel's restriction to low dimensional subspaces due to the time, frequency and spatial correlation of the channel and presents a low complexity linear minimum mean square error (LMMSE) estimator for MIMO-OFDM HSR channels. The channel estimator utilizes a four-dimensional (4D) basis expansion channel model obtained from band-limited generalized discrete prolate spheroidal (GDPS) sequences. Exploiting the channel's band-limitation property, the proposed channel estimator outperforms the conventional interpolation based least square (LS) and MMSE estimators in terms of estimation accuracy and computational complexity, respectively. Simulation results demonstrate the robust performance of the proposed estimator for different delay, Doppler and angular spreads. Channel state information (CSI) is required at the transmitter for improving the performance gain of the spatial multiplexing MIMO systems through linear precoding. In order to avoid the high data rate feedback lines, which are required in fast time-variant channels for updating the transmitter with the rapidly changing CSI, a subframe-wise channel tracking scheme is presented. The proposed channel predictor is based on an assumed DPS basis expansion model (DPS-BEM) for exploiting the variation of the channel coefficients inside each sub-frame and an autoregressive (AR) model of the basis coefficients over each transmitted frame. The proposed predictor properly exploits the channel's restriction to low dimensional subspaces for reducing the prediction error and the computational complexity. Simulation results demonstrate that the proposed channel predictor out-performs the DPS based minimum energy (ME) predictor for different ranges of normalized Doppler frequencies and has better performance than the conventional Wiener predictor for slower time-variant channels and almost the similar performance to it for very fast time-variant channels with the reduced amount of computational complexity. The work on the hybrid mm-wave channel estimator considers the sparse nature of the mm-wave channel in angular domain and leverages the compressed sensing (CS) tools for recovering the angular support of the MIMO-OFDM mm-wave channel. The angular channel is treated in a continuous framework which resolves the limited angular resolution of the discrete sparse channel models used in the previous CS based channel estimators. The power leakage problem is also addressed by modeling the continuous angular channel as a multi-band signal with the bandwidth of each sub-band being proportional to the amount of power leakage. The RF combiner is designed to be implemented using a network of low-power switches for antenna subset selection based on a multi-coset sampling pattern. Simulation results validate the effectiveness of the proposed hybrid channel estimator both in terms of the estimation accuracy and the RF power consumption.

Download or read book Smart Antennas written by Thomas Kaiser and published by Hindawi Publishing Corporation. This book was released on 2005 with total page 891 pages. Available in PDF, EPUB and Kindle. Book excerpt: Smart Antennas—State of the Art brings together the broad expertise of 41 European experts in smart antennas. They provide a comprehensive review and an extensive analysis of the recent progress and new results generated during the last years in almost all fields of smart antennas and MIMO (multiple-input multiple-output) transmission. The following represents a summarized table of content.Receiver: space-time processing, antenna combining, reduced rank processing, robust beamforming, subspace methods, synchronization, equalization, multiuser detection, iterative methods Channel: propagation, measurements and sounding, modelling, channel estimation, direction-of-arrival estimation, subscriber location estimation Transmitter: space-time block coding, channel side information, unified design of linear transceivers, ill-conditioned channels, MIMO-MAC strategies Network Theory: channel capacity, network capacity, multihop networks Technology: antenna design, transceivers, demonstrators and testbeds, future air interfaces Applications and Systems: 3G system and link level aspects, MIMO HSDPA, MIMO-WLAN/UMTS implementation issues This book serves as a reference for scientists and engineers who need to be aware of the leading edge research in multiple-antenna communications, an essential technology for emerging broadband wireless systems.

Download or read book Channel Estimation and Feedback for Multiple Antenna Communication written by Chandra Ramabhadra Murthy and published by . This book was released on 2006 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation studies several aspects of feedback-based communication with multiple antennas, such as the estimation of the Channel State Information (CSI), the quantization of the CSI with a finite number of bits to enable its feedback to the transmitter, as well as the effect of errors in the feedback channel on the performance of the communication system. Channel estimation is doubly important in feedback-based communication because inaccurate CSI affects not only the receiver performance, but also results in sub-optimal transmission. In this context, Multiple Input Multiple Output (MIMO) flat-fading channel estimation when the transmitter employs Maximum Ratio Transmission (MRT) is studied. Two competing schemes for estimating the transmit and receive beamforming vectors of the channel matrix are analyzed: a training based conventional least squares estimation (CLSE) scheme and a closed-form semi-blind (CFSB) scheme that employs training followed by information-bearing spectrally white data symbols. Employing matrix perturbation theory, expressions for the mean squared error (MSE) in the beamforming vector, the average received SNR and the symbol error rate (SER) performance of both the semi-blind and the conventional schemes are derived. Another important issue in beamforming-based communication with multiple antennas is the feedback of CSI. Hence, the design and analysis of quantizers for Equal Gain Transmission (EGT) systems with finite rate feedback-based communication in flat-fading Multiple Input Single Output (MISO) systems is considered. Two popular approaches for quantizing the phase angles are contrasted: vector quantization (VQ) and scalar quantization (SQ). Closed-form expressions are derived for the performance of quantized feedback in terms of capacity loss and outage probability in the case of i.i.d. Rayleigh flat-fading channels. In the work described above, the feedback channel is assumed to be free of delay and noise. With the view to understand the effect of errors on quantization, this dissertation considers the more general problem of characterizing the high-rate performance of source coding for noisy discrete symmetric channels with random index assignment. Theoretical expressions for the performance of source coding for noisy channels are derived for a large class of distortion measures. The theoretical expressions are used to derive new results for two specific applications. The first is the quantization of the CSI for MISO systems with beamforming at the transmitter. The second application is in the wideband speech compression problem, i.e., that of quantizing the linear predictive coding parameters in speech coding systems with the log spectral distortion as performance metric.

Download or read book Channel Estimation and Equalization for Cooperative Communication written by Hakam Mheidat and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced MIMO Systems written by Prof. Kosai Raoof and published by Scientific Research Publishing, Inc. USA. This book was released on 2009-09 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is written for graduate students and professionals concerned with MIMO systems. It reviews mostknown multiple antenna techniques for single-use point-to-point systems, from how multiple antennas help provide diversity and multiplexing to the detection techniques for these systems. This book covers the main fields of MIMO systems with 10 chapters; each chapter covers either base-bandsignal processing aspect or application.

Download or read book Propagation Channel Characterization Parameter Estimation and Modeling for Wireless Communications written by Xuefeng Yin and published by John Wiley & Sons. This book was released on 2016-09-13 with total page 499 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive reference giving a thorough explanation of propagation mechanisms, channel characteristics results, measurement approaches and the modelling of channels Thoroughly covering channel characteristics and parameters, this book provides the knowledge needed to design various wireless systems, such as cellular communication systems, RFID and ad hoc wireless communication systems. It gives a detailed introduction to aspects of channels before presenting the novel estimation and modelling techniques which can be used to achieve accurate models. To systematically guide readers through the topic, the book is organised in three distinct parts. The first part covers the fundamentals of the characterization of propagation channels, including the conventional single-input single-output (SISO) propagation channel characterization as well as its extension to multiple-input multiple-output (MIMO) cases. Part two focuses on channel measurements and channel data post-processing. Wideband channel measurements are introduced, including the equipment, technology and advantages and disadvantages of different data acquisition schemes. The channel parameter estimation methods are then presented, which include conventional spectral-based estimation, the specular-path-model based high-resolution method, and the newly derived power spectrum estimation methods. Measurement results are used to compare the performance of the different estimation methods. The third part gives a complete introduction to different modelling approaches. Among them, both scattering theoretical channel modelling and measurement-based channel modelling approaches are detailed. This part also approaches how to utilize these two modelling approaches to investigate wireless channels for conventional cellular systems and some new emerging communication systems. This three-part approach means the book caters for the requirements of the audiences at different levels, including readers needing introductory knowledge, engineers who are looking for more advanced understanding, and expert researchers in wireless system design as a reference. Presents technical explanations, illustrated with examples of the theory in practice Discusses results applied to 4G communication systems and other emerging communication systems, such as relay, CoMP, and vehicle-to-vehicle rapid time-variant channels Can be used as comprehensive tutorial for students or a complete reference for engineers in industry Includes selected illustrations in color Program downloads available for readers Companion website with program downloads for readers and presentation slides and solution manual for instructors Essential reading for Graduate students and researchers interested in the characteristics of propagation channel, or who work in areas related to physical layer architectures, air interfaces, navigation, and wireless sensing

Download or read book Wireless Communications Over Rapidly Time Varying Channels written by Franz Hlawatsch and published by Academic Press. This book was released on 2011-05-04 with total page 457 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a result of higher frequencies and increased user mobility, researchers and systems designers are shifting their focus from time-invariant models to channels that vary within a block. Wireless Communications Over Rapidly Time-Varying Channels explains the latest theoretical advances and practical methods to give an understanding of rapidly time varying channels, together with performance trade-offs and potential performance gains, providing the expertise to develop future wireless systems technology. As well as an overview of the issues of developing wireless systems using time-varying channels, the book gives extensive coverage to methods for estimating and equalizing rapidly time-varying channels, including a discussion of training data optimization, as well as providing models and transceiver methods for time-varying ultra-wideband channels. An introduction to time-varying channel models gives in a nutshell the important issues of developing wireless systems technology using time-varying channels Extensive coverage of methods for estimating and equalizing rapidly time-varying channels, including a discussion of training data optimization, enables development of high performance wireless systems Chapters on transceiver design for OFDM and receiver algorithms for MIMO communication channels over time-varying channels, with an emphasis on modern iterative turbo-style architectures, demonstrates how these important technologies can optimize future wireless systems