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Communications Magazine, IEEE

Issue 2 • Date Feb. 1999

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Displaying Results 1 - 15 of 15
  • Optical Networks, Communications Systems, And Devices [Guest Editorial]

    Publication Year: 1999 , Page(s): 49
    Cited by:  Papers (1)
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    Freely Available from IEEE
  • Globalization of Software radio [Guest Editorial]

    Publication Year: 1999 , Page(s): 82 - 83
    Cited by:  Papers (5)
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    Freely Available from IEEE
  • Telecommunication network management: technologies and implementations [Book Reviews]

    Publication Year: 1999 , Page(s): 28
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    Freely Available from IEEE
  • Technical challenges in the globalization of software radio

    Publication Year: 1999 , Page(s): 84 - 89
    Cited by:  Papers (47)  |  Patents (6)
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    The software radio has emerged from the third-generation strategy for affordable, ubiquitous, global communications. This article reviews the concepts, architecture, technology challenges, and economics of the continuing productization and globalization of software radio View full abstract»

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  • Digital IF filter technology for 3G systems: an introduction

    Publication Year: 1999 , Page(s): 102 - 107
    Cited by:  Papers (18)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1256 KB)  

    Contemporary digital communication systems such as those being developed for the deployment of third-generation cellular require ever increasing performance levels in their signal processing chains to extract higher data rates and to provide decreasing price/performance ratios. Additionally, communication systems like 3G that must support multimode flexibility, such as the software radio, must be able to reconfigure their signal processing chains while keeping circuit complexity to a minimum. Given these constraints, DSP is the only viable alternative for baseband processing and digital IF processing. DSP is in many cases the only viable alternative to analog IF processing. Digital IF affords greater flexibility and higher performance in terms of attenuation and selectivity. It also offers better time and environment stability and lower equipment production costs than traditional analog techniques View full abstract»

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  • Complexity of a software GSM base station

    Publication Year: 1999 , Page(s): 113 - 117
    Cited by:  Papers (8)
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    There is increasing interest in developing radio-based applications in software. The new architecture for implementing mobile telephony base stations has the potential of offering many benefits: great cost savings by using one transceiver per base transceiver station (BTS) instead of one per channel, tremendous flexibility by moving system-specific parameters to the digital part, and allowing the support of a wide range of modulation and coding schemes. A very important problem in designing software radio applications is the need to estimate the required complexity of processing to dimension systems. For example, with a software GSM BTS it is critical to estimate the number of channels that can be supported by a given processor configuration, and to predict the impact of future processor enhancements on its capacity. This article focuses on the design of a software implementation of a GSM BTS and proposes a platform-independent evaluation of its computational requirements based on SPEC benchmarks. It focuses on the design and performance of a library of software modules. Portability and computational requirements are discussed View full abstract»

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  • Performance trends for analog to digital converters

    Publication Year: 1999 , Page(s): 96 - 101
    Cited by:  Papers (35)  |  Patents (2)
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    Analog-to-digital converters are key components of signal processing systems, and may even dictate system architectures due to their limitations on sampling rate and resolution. The state of the art for ADCs, including both experimental converters and commercially available parts, is reviewed. The data imply that the performance measure, P=2SNRbits·fsamp, uncertainty in the sampling process (aperture jitter) over a very wide range of sampling rates. For ADCs operating at multi-GSPS rates, the speed of the device technology is also a limiting factor (due to comparator ambiguity). Technological progress as measured by P is discussed View full abstract»

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  • Light trees: optical multicasting for improved performance in wavelength routed networks

    Publication Year: 1999 , Page(s): 67 - 73
    Cited by:  Papers (181)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (808 KB)  

    We introduce the concept of a light-tree in a wavelength-routed optical network. A light-tree is a point-to-multipoint generalization of a lightpath. A lightpath is a point-to-point all-optical wavelength channel connecting a transmitter at a source node to a receiver at a destination node. Lightpath communication can significantly reduce the number of hops (or lightpaths) a packet has to traverse; and this reduction can, in turn, significantly improve the network's throughput. We extend the lightpath concept by incorporating an optical multicasting capability at the routing nodes in order to increase the logical connectivity of the network and further decrease its hop distance. We refer to such a point-to-multipoint extension as a light-tree. Light-trees can not only provide improved performance for unicast traffic, but they naturally can better support multicast traffic and broadcast traffic. In this study, we shall concentrate on the application and advantages of light-trees to unicast and broadcast traffic. We formulate the light-tree-based virtual topology design problem as an optimization problem with one of two possible objective functions: for a given traffic matrix, (i) minimize the network-wide average packet hop distance, or (ii) minimize the total number of transceivers in the network. We demonstrate that an optimum light-tree-based virtual topology has clear advantages over an optimum lightpath-based virtual topology with respect to the above two objectives View full abstract»

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  • Optical multistage interconnection networks: new challenges and approaches

    Publication Year: 1999 , Page(s): 50 - 56
    Cited by:  Papers (19)
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    Optical interconnections for communication networks and multiprocessor systems have been studied extensively. A basic element of optical switching networks is a directional coupler with two inputs and two outputs or switching elements (SEs). Depending on the control voltage applied to it, an input optical signal is coupled to either of the two outputs, setting the SE to either the straight or cross state. A class of topologies that can be used to construct optical networks is multistage interconnection networks, which interconnect their inputs and outputs via several stages of SEs. Although optical MINs hold great promise and have demonstrated advantages over their electronic counterparts, they also introduce new challenges such as how to deal with the unique problem of avoiding crosstalk in the SEs. In this article we survey the research carried out, including major challenges encountered and approaches taken, on optical MINs View full abstract»

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  • Software radio technology: a European perspective

    Publication Year: 1999 , Page(s): 118 - 123
    Cited by:  Papers (16)  |  Patents (3)
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    Software radio has emerged as a priority theme of research in Europe. This tutorial review provides a European perspective on technical and commercial issues in the field. Significant differences exist between North American and European views of software radio in personal communications services. This article explains the reasons for these differences. It explains how the European marketplace is influencing short-term directions taken in the commercialization of software radio technology initially at the application layer. Some research is related to handset architectures and to generic RF and digital technologies focused on third-generation systems-Universal Mobile Telecommunications Systems. Software base stations, including their synergies with adaptive (often now termed soft) antennas are also addressed View full abstract»

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  • FPGA in the software radio

    Publication Year: 1999 , Page(s): 108 - 112
    Cited by:  Papers (68)  |  Patents (45)
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    As new radio standards are deployed without substantially supplanting existing ones, the need for multimode multiband handsets and infrastructure increases. This article describes how emerging FPGA technology's unique combination of size and power efficiency plus field programmability offers a transition of FPCAs from ASIC prototyping to embedded products. Software-defined receiver examples suggest an enlarged role for FPGAs in pragmatic paths toward the productization of software radio technology View full abstract»

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  • All-optical WDM multi-rings with differentiated QoS

    Publication Year: 1999 , Page(s): 58 - 66
    Cited by:  Papers (30)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2864 KB)  

    This article considers all-optical WDM networks based on a slotted multichannel ring topology, where nodes are equipped with one fixed-wavelength receiver and one wavelength-tunable transmitter; and shows how to design very effective MAC protocols that provide packet-mode transport to multiple information flows with different QoS requirements. As an example, we describe SR3, a collision-free slotted MAC protocol which combines a packet scheduling strategy (called SRR), a fairness control algorithm (called MMR); and a reservation mechanism. SRR achieves an efficient exploitation of the available bandwidth, MMR guarantees fair throughput access to each node, and SR3, by permitting slot reservations, leads to tighter control on access delays, and can thus effectively support traffic classes with different QoS requirements View full abstract»

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  • Future photonic transport networks based on WDM technologies

    Publication Year: 1999 , Page(s): 74 - 81
    Cited by:  Papers (17)
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    It is expected that the explosion in Internet traffic implies a paradigm shift from a voice network to a data-centric network. The first and most important requirement of future transport networks is the large bandwidth transport capability which enables the paradigm shift. In addition, requirements for new service attributes are becoming more tangible. Furthermore, high reliability will be indispensable because the multimedia network will be the basis for the information society. To develop the robust and efficient networks that satisfy the requirements above, new network architectures and technologies should be developed. Photonic networks employing dense WDM technologies appear to be the solution. In this article, first the basic concept of the future photonic network is depicted. Next, the capability of large-capacity fiber transmission is shown. The critical degradation factor of fiber nonlinearity is analyzed, and the effectiveness of distributed amplification is quantitatively demonstrated. Furthermore, advances in fiber amplifiers which greatly widen the usable fiber window are shown. Other key technologies such as absolute frequency referencing and multiple channel frequency management techniques are also discussed View full abstract»

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  • Broadband RF stage architecture for software-defined radio in handheld terminal applications

    Publication Year: 1999 , Page(s): 90 - 95
    Cited by:  Papers (48)  |  Patents (2)
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    Broadband RF is a general-purpose common RF stage for every standard within a set of RF bands. The RF stage architecture presented in this article is suitable for software-defined radios. This article first defines the conceptual scheme of a handheld software defined radio (SDR) terminal, and then describes how the direct conversion principle is applied to the SDR. The discussion focuses on receiver hardware implementation and systematic control View full abstract»

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  • Smart base stations for “dumb” time-division duplex terminals

    Publication Year: 1999 , Page(s): 124 - 131
    Cited by:  Papers (6)  |  Patents (1)
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    Users of mobile IT systems are calling for ever higher data rates, but such mobile radios are subject to multipath fading and intersymbol interference, often calling for complex equalizers at both ends of each link. Where the links are of short range, they often use time-division duplex. This article demonstrates how this option permits much of the complexity of channel matching and equalization to be transferred from post-processing at the many sparsely used mobile terminals to a few intensively used preprocessors at the base station or central hub View full abstract»

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Aims & Scope

IEEE Communications Magazine covers all areas of communications such as lightwave telecommunications, high-speed data communications, personal communications systems (PCS), ISDN, and more.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Osman Gebizlioglu
Huawei Technologies