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Personal Communications, IEEE

Issue 1 • Date Feb. 1998

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Displaying Results 1 - 6 of 6
  • Smart antennas

    Page(s): 9
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  • Spectrum and technology of a wireless local loop system

    Page(s): 49 - 54
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    This article shows that the wireless local loop (WLL) may not necessarily provide more capacity than mobile cellular systems if an FDMA or TDMA system is used. CDMA has proven to have higher capacity than the other multiple access schemes due to the nature of CDMA systems. In industrial countries, the requirements of WLL are quality and service features. In developed countries, the requirement is a low-cost high-capacity system, even if voice quality must be sacrificed. Therefore, the system design aspects are different View full abstract»

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  • Smart antennas for wireless systems

    Page(s): 23 - 27
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    In this article we discuss current and future antenna technology for wireless systems and the improvement that smart and adaptive antenna arrays can provide. We describe standard cellular antennas, smart antennas using fixed beams, and adaptive antennas for base stations, as well as antenna technologies for handsets. We show the potential improvement that these antennas can provide, including range extension, multipath diversity, interference suppression, capacity increase, and data rate increase. The issues involved in incorporating these antennas into wireless systems using CDMA, GSM, and IS-136 in different environments, such as rural, suburban, and urban areas, as well as indoors, are described. Theoretical, computer simulation, experimental, and field trial results are also discussed that demonstrate the potential of this technology View full abstract»

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  • Overview of spatial channel models for antenna array communication systems

    Page(s): 10 - 22
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    Spatial antenna diversity has been important in improving the radio link between wireless users. Historically, microscopic antenna diversity has been used to reduce the fading seen by a radio receiver, whereas macroscopic diversity provides multiple listening posts to ensure that mobile communication links remain intact over a wide geographic area. In later years, the concepts of spatial diversity have been expanded to build foundations for emerging technologies, such as smart (adaptive) antennas and position location systems. Smart antennas hold great promise for increasing the capacity of wireless communications because they radiate and receive energy only in the intended directions, thereby greatly reducing interference. To properly design, analyze, and implement smart antennas and to exploit spatial processing in emerging wireless systems, accurate radio channel models that incorporate spatial characteristics are necessary. In this tutorial, we review the key concepts in spatial channel modeling and present emerging approaches. We also review the research issues in developing and using spatial channel models for adaptive antennas View full abstract»

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  • Spatial and temporal communication theory using adaptive antenna array

    Page(s): 28 - 35
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    An adaptive antenna array or a smart antenna is named a software antenna because it can form a desired antenna pattern and adaptively control it if an appropriate set of antenna weights is provided and updated in software. It can be a typical tool for realizing a software radio. An adaptive antenna array can be considered an adaptive filter in the space and time domains for radio communications, so communication theory can be generalized from a conventional time domain into both space and time domains. This article introduces a spatial and temporal communication theory based on an adaptive antenna array, such as spatial and temporal channel modeling, equalization, optimum detection for single-user and multi-user CDMA, precoding in a transmitter, and joint optimization of both transmitter and receiver. Such spatial and temporal processing promises significant improvement of performance against multipath fading in mobile radio communications View full abstract»

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  • Space-time modems for wireless personal communications

    Page(s): 36 - 48
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    This article reviews space-time modem technology for mobile radio applications. We begin with motivations for the use of space-time modems and then briefly discuss the challenges posed by wireless propagation. Next, we develop a signal model for the wireless environment. Channel estimation, equalization, and filtering techniques for space-time modems in the forward and reverse links are then discussed. Finally, we review applications of space-time modems to cellular systems and discuss industry trends View full abstract»

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Aims & Scope

This Magazine ceased publication in 2001. The current retitled publication is IEEE Wireless Communications.

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