Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 200

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Book Description

Author: Ming Zhao
Publisher:
ISBN:
Category : Iterative methods (Mathematics)
Languages : en
Pages : 412

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Book Description
Wireless mobile communications were initially a way for people to communicate through low data rate voice call connections. As data enabled devices allow users the ability to do much more with their mobile devices, so to will the demand for more reliable and pervasive wireless data. This is being addressed by so-called 4th generation wireless systems based on orthogonal frequency division multiplexing (OFDM) and multiple-input multiple-output (MIMO) antenna systems. Mobile wireless customers are becoming more demanding and expecting to have a great user experience over high speed broadband access at any time and anywhere, both indoor and outdoor. However, these promising improvements cannot be realized without an e±cient design of the receiver. Recently, receivers utilizing iterative detection and decoding have changed the fundamental receiver design paradigm from traditional separated parameter estimation and data detection blocks to an integrated iterative parameter estimator and data detection unit. Motivated by this iterative data driven approach, we develop low complexity iterative receivers with improved sensitivity compared to the conventional receivers, this brings potential benefits for the wireless communication system, such as improving the overall system throughput, increasing the macro cell coverage, and reducing the cost of the equipments in both the base station and mobile terminal. It is a challenge to design receivers that have good performance in a highly dynamic mobile wireless environment. One of the challenges is to minimize overhead reference signal energy (preamble, pilot symbols) without compromising the performance. We investigate this problem, and develop an iterative receiver with enhanced data-driven channel estimation. We discuss practical realizations of the iterative receiver for SISO-OFDM system. We utilize the channel estimation from soft decoded data (the a priori information) through frequency-domain combining and time-domain combining strategies in parallel with limited pilot signals. We analyze the performance and complexity of the iterative receiver, and show that the receiver's sensitivity can be improved even with this low complexity solution. Hence, seamless communications can be achieved with better macro cell coverage and mobility without compromising the overall system performance. Another challenge is that a massive amount of interference caused by MIMO transmission (spatial multiplexing MIMO) reduces the performance of the channel estimation, and further degrades data detection performance. We extend the iterative channel estimation from SISO systems to MIMO systems, and work with linear detection methods to perform joint interference mitigation and channel estimation. We further show the robustness of the iterative receivers in both indoor and outdoor environment compared to the conventional receiver approach. Finally, we develop low complexity iterative spatial multiplexed MIMO receivers for nonlinear methods based on two known techniques, that is, the Sphere Decoder (SD) method and the Markov Chain Monte Carlo (MCMC) method. These methods have superior performance, however, they typically demand a substantial increase in computational complexity, which is not favorable in practical realizations. We investigate and show for the first time how to utilize the a priori information in these methods to achieve performance enhancement while simultaneously substantially reducing the computational complexity. In our modified sphere decoder method, we introduce a new accumulated a priori metric in the tree node enumeration process. We show how we can improve the performance by obtaining the reliable tree node candidate from the joint Maximum Likelihood (ML) metric and an approximated a priori metric. We also show how we can improve the convergence speed of the sphere decoder (i.e., reduce the com- plexity) by selecting the node with the highest a priori probability as the starting node in the enumeration process. In our modified MCMC method, the a priori information is utilized for the firrst time to qualify the reliably decoded bits from the entire signal space. Two new robust MCMC methods are developed to deal with the unreliable bits by using the reliably decoded bit information to cancel the interference that they generate. We show through complexity analysis and performance comparison that these new techniques have improved performance compared to the conventional approaches, and further complexity reduction can be obtained with the assistance of the a priori information. Therefore, the complexity and performance tradeoff of these nonlinear methods can be optimized for practical realizations.

Author: Ben Lu
Publisher:
ISBN:
Category :
Languages : en
Pages : 360

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Book Description

Author: George Mastorakis
Publisher: IET
ISBN: 1839530952
Category : Technology & Engineering
Languages : en
Pages : 452

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Book Description
Aimed at researchers, engineers and scientists involved in the design and development of protocols and AI applications for wireless communication devices and networks, this edited book presents recent research and innovations in emerging AI methods and AI-powered mechanisms, and future perspectives in this field.

Author: David Tse
Publisher: Cambridge University Press
ISBN: 9780521845274
Category : Computers
Languages : en
Pages : 598

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Book Description
This textbook takes a unified view of the fundamentals of wireless communication and explains cutting-edge concepts in a simple and intuitive way. An abundant supply of exercises make it ideal for graduate courses in electrical and computer engineering and it will also be of great interest to practising engineers.

Author: Tzi-Dar Chiueh
Publisher: John Wiley & Sons
ISBN: 0470822481
Category : Technology & Engineering
Languages : en
Pages : 278

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Book Description
Orthogonal frequency-division multiplexing (OFDM) access schemes are becoming more prevalent among cellular and wireless broadband systems, accelerating the need for smaller, more energy efficient receiver solutions. Up to now the majority of OFDM texts have dealt with signal processing aspects. To address the current gap in OFDM integrated circuit (IC) instruction, Chiueh and Tsai have produced this timely text on baseband design. OFDM Baseband Receiver Design for Wireless Communications covers the gamut of OFDM technology, from theories and algorithms to architectures and circuits. Chiueh and Tsai give a concise yet comprehensive look at digital communications fundamentals before explaining modulation and signal processing algorithms in OFDM receivers. Moreover, the authors give detailed treatment of hardware issues -- from design methodology to physical IC implementation. Closes the gap between OFDM theory and implementation Enables the reader to transfer communication receiver concepts into hardware design wireless receivers with acceptable implementation loss achieve low-power designs Contains numerous figures to illustrate techniques Features concrete design examples of MC-CDMA systems and cognitive radio applications Presents theoretical discussions that focus on concepts rather than mathematical derivation Provides a much-needed single source of material from numerous papers Based on course materials for a class in digital communication IC design, this book is ideal for advanced undergraduate or post-graduate students from either VLSI design or signal processing backgrounds. New and experienced engineers in industry working on algorithms or hardware for wireless communications devices will also find this book to be a key reference.

Author: Tzi-Dar Chiueh
Publisher: John Wiley & Sons
ISBN: 1118188217
Category : Technology & Engineering
Languages : en
Pages : 388

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Book Description
The Second Edition of OFDM Baseband Receiver Design for Wirless Communications, this book expands on the earlier edition with enhanced coverage of MIMO techniques, additional baseband algorithms, and more IC design examples. The authors cover the full range of OFDM technology, from theories and algorithms to architectures and circuits. The book gives a concise yet comprehensive look at digital communication fundamentals before explaining signal processing algorithms in receivers. The authors give detailed treatment of hardware issues - from architecture to IC implementation. Links OFDM and MIMO theory with hardware implementation Enables the reader to transfer communication received concepts into hardware; design wireless receivers with acceptable implemntation loss; achieve low-power designs Covers the latest standards, such as DVB-T2, WiMax, LTE and LTE-A Includes more baseband algorithms, like soft-decoding algorithms such as BCJR and SOVA Expanded treatment of channel models, detection algorithms and MIMO techniques Features concrete design examples of WiMAX systems and cognitive radio apllications Companion website with lecture slides for instructors Based on materials developed for a course in digital communication IC design, this book is ideal for graduate students and researchers in VLSI design, wireless communications, and communications signal processing. Practicing engineers working on algorithms or hardware for wireless communications devices will also find this to be a key reference.

Author: Weijie Yuan
Publisher: Springer Nature
ISBN: 981198090X
Category : Technology & Engineering
Languages : en
Pages : 157

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Book Description
This book focuses on the receiver design issue in high spectral efficiency communication systems, which is one of the main research directions in beyond 5G and 6G era. In particular, this book studies two technologies to improve the spectral efficiency, i.e., FTN signaling which transmits more data information in the same time period and NOMA scheme which supports more users with the same resource elements. Different commonly used channel propagation conditions are considered, and advanced signal processing algorithms have been developed for designing receivers, which is suitable for low-complexity receiver design in engineering practice. Moreover, this book discusses possible solutions to further increase spectral efficiency and propose practical receivers in such scenarios. It benefits researchers, engineers, and students in the fields of wireless communications and signal processing.

Author: Yen-Cheng Kuan
Publisher:
ISBN:
Category :
Languages : en
Pages : 74

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Book Description
To support the increasing demand of various high data-rate wireless communications, the 7 GHz band at 57-64 GHz has been allocated by the FCC for unlicensed system applications. This decision results in the formations of several standards aiming to develop multi-gigabit wireless communication systems, e.g., IEEE 802.15.3c, IEEE 802.11ad, and WiGig, among many others. One of their common and ultimate goals is to expedite the realization of widespread integrated circuits supporting large data transfers over the air. Designing a digital baseband receiver for the 60 GHz communication system (802.15.3c/802.11ad) requires the following features: (1) a proper architecture to mitigate design challenges of the high-speed analog-to-digital converters (ADCs) that are required by the synchronizer of the receiver; and (2) an effective technique to decouple the interferences that result from adjacent channel estimation sequences (CESs) as well as degrade the equalizer performance of the receiver. To fulfill these requirements, this work realizes the following: (1) a fractional-sampling-rate (FSR) digital baseband receiver to relax the ADC sampling rate requirement through multi-rate signal processing techniques; and (2) a high-accuracy channel estimator to reconstruct interference-less CES responses for improving the BER performance of the equalizer. Compared with the prior arts, the 65 nm CMOS implementations of (1) and (2) demonstrate the feasibilities of reducing the required ADC sampling rate by 25%, and assisting the equalizer in achieving 170x BER reduction, respectively.

Author: Mark C. Reed
Publisher:
ISBN:
Category : Code division multiple access
Languages : en
Pages : 308

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Book Description