Gerhard P. Fettweis – författare
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4 produkter
4 produkter
859 kr
Skickas inom 10-15 vardagar
To operate future generation multimedia communications systems, high data rate transmission needs to be guaranteed with a high quality of service. For instance, the third generation cellular mobile systems should offer a high data rate up to two Mbit/s for video, audio, speech and data transmission. The important challenge for these cellular systems will be the choice of an appropriate multiple access scheme. The advantages of the spread spectrum technique are: high immunity against multipath distortion, no need for frequency planning, high flexibility and easier variable rate transmission. On the other hand, the technique of multi-carrier transmission has recently been receiving wide interest for high data rate applications. The advantages of multi-carrier transmission are the robustness in the case of frequency selective fading channels, in particular the reduced signal processing complexity by equalization in the frequency domain, and in the capability of narrow-band interference rejection.The advantages and success of multi-carrier (MC) modulation and the spread spectrum (SS) technique has led to the combination of MCM with SS, known as multi-carrier spread-spectrum (MC-SS) for cellular systems. This combination, benefits from the advantages of both schemes: higher flexibility, higher spectral efficiency, simpler detection techniques, and narrow band interference rejection capability. This volume contains a collection of papers which provide an overview of this emerging multiple access scheme. It should be of interest to researchers and practitioners working in the area of wireless communications and networking.
1 279 kr
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A self-contained guide to coordinated multi-point (CoMP), this comprehensive book covers everything from theoretical basics to practical implementation. Addressing a wide range of topics, it highlights the potential gains of CoMP, the fundamental degrees of freedom involved and the key challenges of using CoMP in practice. The editors and contributors bring unique real-world experience from running the world's first and largest test beds for LTE-Advanced, and recent field trial results from these tests are presented. With detailed insight into the realistic potential of CoMP as a key technology for LTE-Advanced and beyond, this is a must-read resource for professionals and students who want the big picture on CoMP or require in-depth knowledge of how to build cellular communication systems for the future.
1 350 kr
Skickas inom 11-20 vardagar
The importance of reducing energy costs, reducing CO2 emissions and protecting the environment are leading to an increased focus on green, energy-efficient approaches to the design of next-generation wireless networks. Presenting state-of-the-art research on green radio communications and networking technology by leaders in the field, this book is invaluable for researchers and professionals working in wireless communication. Summarizing existing and ongoing research, the book explores communication architectures and models, physical communications techniques, base station power-management techniques, wireless access techniques for green radio networks, and green radio test-bed, experimental results and standardization activities. Throughout, theoretical results are blended with practical insights and coverage of deployment issues. It serves as a one-stop reference for key concepts and design techniques for energy-efficient communications and networking and provides information essential for the design of future-generation cellular wireless systems.
537 kr
Skickas inom 10-15 vardagar
l 1 Khaled Fazel , Gerhard P. Fettweis lGerman Aerospace Research Establishment (DLR) Institute for Communications Technology 0-82234 Oberpfaffenhofen, Germany lDresden University of Technology Department of Electrical Engineering 0-01062 Dresden, Germany To operate future generation multimedia communications systems high data rate transmission needs to be guaranteed with a high quality of service. For instance, the third generation cellular mobile systems should offer a high data rate up to 2 Mbitls for video, audio, speech and data transmission [1]. In addition, the important challenge for these cellular systems will be the choice of an appropriate multiple access scheme. These trends motivated many researchers to look for multiple access systems that offer high spectral efficiency. The technique of spread spectrum originating from the military applications may allow partly to fulfill the above requirements. Advantages of spread spectrum technique are broadly known: High immunity against multipath distortion, no need for frequency planning, high flexibility, easier variable rate transmission etc. [1-2]. A multiple access scheme based on direct sequence spread spectrum, known as direct sequence code division multiple access (DS-CDMA) relies on spreading the data stream using an assigned spreading code for each user in the time domain. The capability of minimising multiple access interference (MAl) is given by the cross correlation properties of spreading codes. In the case of multipath propagation the capability of distinguishing one component from others in the composite received signal is offered by the auto-correlation properties of the spreading codes [2].