By Topic

Vehicular Technology, IEEE Transactions on

Issue 6 • Date Nov. 2002

Filter Results

Displaying Results 1 - 25 of 49
  • Correction to "A novel adaptive beamforming algorithm for a smart antenna system in a CDMA mobile communication environment"

    Publication Year: 2002 , Page(s): 1671 - 1672
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (190 KB) |  | HTML iconHTML  

    First Page of the Article
    View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Correction to "Forward-link capacity of a DS/CDMA system with mixed multirate sources"

    Publication Year: 2002 , Page(s): 1672
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (158 KB) |  | HTML iconHTML  

    First Page of the Article
    View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Comments on "A shaped reflector antenna for 60-GHz indoor wireless LAN access points" [with reply]

    Publication Year: 2002
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (148 KB)  

    The author comments that the shaped reflector antenna principles and theory of Smulders, Khusial and Herben (see ibid., vol.50, p.584-91, Mar.2001) are based on the papers described by Kumar (see Proc. Montech '86 IEEE Conference on Antennas and Communication, 1986, IEEE Cat. No. TH0156-0, Inst. Elect. Eng. Proc., vol.134, p.106-108, 1987 and Technology Symposium, 1990). These papers described the X-band, circularly polarized shaped beam telemetry antenna suitable for retransmitting the radar data back to an earth terminal. Smulders et al. have used the same principle, and similar types of radiation patterns are produced. However, two points are different in their paper: (1) the design frequency (60 GHz) and (2) the application of antenna for indoor wireless LAN access points. Therefore, they authors should have referenced Kumar's papers. Smulders et al. agree with Kumar's comments that reflector shaping is nothing new. However, we took into account diffraction effects (by applying the uniform theory of diffraction) whereas the shaping in the paper of Kumar is based on geometrical optics, only. We showed that according to our approach, a more smooth illumination function can be achieved and how the smoothing effect depends on the amount of edge illumination. We also showed in which way the spatial field deviation can be minimized and that this could save a few decibels in the link budget. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Authors' reply

    Publication Year: 2002 , Page(s): 1681
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (164 KB) |  | HTML iconHTML  

    First Page of the Article
    View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Author index

    Publication Year: 2002 , Page(s): 1699 - 1704
    Save to Project icon | Request Permissions | PDF file iconPDF (208 KB)  
    Freely Available from IEEE
  • Subject index

    Publication Year: 2002 , Page(s): 1704 - 1723
    Save to Project icon | Request Permissions | PDF file iconPDF (290 KB)  
    Freely Available from IEEE
  • A reconfigurable protocol setting to improve TCP over wireless

    Publication Year: 2002 , Page(s): 1608 - 1620
    Cited by:  Papers (20)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (618 KB) |  | HTML iconHTML  

    Wireless access to the Internet requires that information integrity be preserved while transmitting data over the radio channel. Automatic repeat request (ARQ) schemes and transport control protocol (TCP) are often used as error-control techniques at the link layer and at the transport layer, respectively. In this paper, we study the interactions between an ARQ protocol and TCP when the last hop of the connection path is wireless. Link layer retransmissions are used to hide losses over the wireless link to TCP and to avoid that TCP interprets these losses as signs of network congestion. By adapting the protocol parameter setting at the link and transport layers to the time-varying characteristics of the wireless channel, we obtain a reliable communication link in spite of disadvantageous radio channel conditions. The number of retransmissions of the ARQ scheme and the TCP segment size can be set to proper values that, given certain propagation conditions, enable the desired quality of service (QoS) at the transport layer. In order to derive the protocol parameter setting fulfilling the QoS requirements, we develop detailed models of the ARQ protocol and TCP by using standard Markovian techniques. Through these models, the impact of the link layer functions on the TCP performance is evaluated in the presence of different wireless environments. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A real-time DOA-based smart antenna processor

    Publication Year: 2002 , Page(s): 1279 - 1293
    Cited by:  Papers (22)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1051 KB)  

    We designed, built, and tested a real-time processor for a direction-of-arrival-based smart antenna GSM 1800 base station with eight half-wavelength spaced antenna elements. Its processing steps include direction-of-arrival (DOA) estimation, user identification, tracking, beamforming, and signal reconstruction. We demonstrate that the accuracy of DOA estimation is not of primary concern, but the robustness is. This can be assessed by a new parameter, the estimation range. Tracking of reliable user DOAs only, increases the robustness against interference. Our tracking concept is compatible with frequency hopping. We quantify the benefits of smart antennas by the statistics of the gain in carrier-to-interference ratio (C/I) and in signal-to-noise ratio (SNR), both measured at the 90 or 99% levels with actual transmitted data. In an urban environment with large angular spread and overlap of user and interferer signals, the C/I gain is as high as 18 dB. Interferer ing increases the C/I gain only slightly, but enhances robustness against angular spread, particularly if broad s are applied. Separating SNR gain in its contributions due to beamforming and diversity gives valuable insight into the way of operation. In uplink, the processor can exploit angular diversity. The entire suite of processing steps is done within less than 1 ms, demonstrating that sophisticated DOA-based smart antenna processing is feasible in real time. Our solution does not require any change in the GSM standard. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Dynamic periodic location area update in mobile networks

    Publication Year: 2002 , Page(s): 1494 - 1501
    Cited by:  Papers (19)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (492 KB) |  | HTML iconHTML  

    In mobile communications networks, periodic location area update (PLAU) is utilized to detect the presence of a mobile station (MS). In the 3GPP Technical Specifications 23.012 and 24.008, a fixed PLAU scheme was proposed for the Universal Mobile Telecommunications System (UMTS), where the interval between two PLAUs is of fixed length. We observe that MS presence can also be detected through call activities and normal location area update (NLAU). Therefore, we propose a dynamic PLAU scheme where the PLAU interval is dynamically adjusted based on the call traffic and NLAU rate. An analytic model is developed to investigate the performance of dynamic and fixed PLAU schemes. This paper provides guidelines to select parameters for dynamic PLAU. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Data transmission scheduling considering short-term fading for transmit power reduction in CDMA systems

    Publication Year: 2002 , Page(s): 1621 - 1627
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (357 KB) |  | HTML iconHTML  

    A new data transmission scheduling scheme considering short-term fading conditions in the downlink of code-division multiple access (CDMA) systems is proposed. In this scheduling method, a mobile station (MS) connected to a base station (BS) estimates the fading condition of the next frame based on the received signal power variation and feeds back this information to the corresponding BS. The BS determines the MSs to which it transmits data based on the fading information from the MSs. Analytical and simulation results show that the proposed scheme saves the transmit power greatly when the speed of an MS is relatively low and the Rician factor is small. The maximum amount of the power reduction is about 9 dB. This reduced transmit power results in the data throughput increase of CDMA systems. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On a decoupled approach to adaptive signal separation using an antenna array

    Publication Year: 2002 , Page(s): 1681 - 1685
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (334 KB) |  | HTML iconHTML  

    First Page of the Article
    View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Distributed wireless channel allocation in networks with mobile base stations

    Publication Year: 2002 , Page(s): 1407 - 1421
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (475 KB) |  | HTML iconHTML  

    In traditional cellular networks with fixed base stations, the channel reuse pattern is static and deterministic. When the cell layout is dynamic, due to the mobility of base stations, the cluster of cells within cochannel interference range changes with time. Consequently, the channel reuse pattern is highly dynamic. Moreover, base stations also need wireless channels to communicate amongst themselves. A communication session between a pair of nodes may have to switch channels due to the movement of other nodes into the neighborhood. None of the existing dynamic channel allocation algorithms for cellular networks works in such a system. Hence, there is a need for new wireless channel allocation algorithms for virtual cellular networks with mobile base stations. In this paper, principles of mutual exclusion pertaining to distributed computing systems are employed to develop such an algorithm. The inter-base-station wireless links are referred to as backbone links, while the base station to mobile node links are referred to as short-hop links. The proposed algorithm is distributed, dynamic, and deadlock-free. Disjoint sets of channels are used for backbone and short-hop links. The distributed nature of the channel allocation scheme leads to scalability and robustness, as the responsibility is no longer centralized at the mobile telecommunications switching office (MTSO). Instead, it is shared among all the mobile base stations. In addition, the issue of channel rearrangement is addressed. Channel rearrangement is the switching of channels, performed to prevent cochannel interference, when mobile base stations using the same channels, hitherto not in interference range, come within the range of each other. If multiple channels are available to support a communication session, the channel selection policy can have a significant impact on performance. A random selection from the set of available channels yields better performance at low to moderate channel demand. This is in contrast to ordered channel selection (from one end of the spectrum), which always yields the best performance for cellular networks. Results obtained by simulating the algorithm are consistent with the theoretically obtained values. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A residue number system based parallel communication scheme using orthogonal signaling. II. Multipath fading channels

    Publication Year: 2002 , Page(s): 1547 - 1559
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (916 KB) |  | HTML iconHTML  

    For pt.I see ibid., vol.51, no.6, p.1534-46 (2002). A novel signaling scheme is presented, where a set of orthogonal signals is transmitted in parallel. The signals are selected according to the so-called residue number system (RNS). Hence the system is essentially a multiple code parallel communication scheme using high-modulation alphabets. It is demonstrated that the system performance can be substantially improved by exploiting a number of advantageous properties of the RNS arithmetic. The model treated in part I of this paper is extended here to account for the effects of the multipath Rayleigh fading channel when using noncoherent demodulation. Diversity reception techniques with equal gain combining (EGC) or selection combining (SC) are concerned. The related performance is evaluated for both nonredundant and redundant RNS-based orthogonal signaling. Interleaving and forward error-correction techniques are introduced for enhancing the system's bit error rate (BER) performance. The concept of concatenated coding with a Reed-Solomon (RS) code as the outer code and a redundant RNS code as the inner code is presented, and the performance of the proposed concatenated code is evaluated. Expressions of the error probability for the above-mentioned scenarios are presented, and the associated BER performance is evaluated numerically with respect to specific system parameters. Without concatenated coding, coding gains up to 8.5 or 11 dB are achieved at a BER of 10-6 using the lowest reliability dropping technique of part I and one or two redundant moduli, respectively. The BER is substantially higher than that over the additive white Gaussian noise channel reported in part I. With the aid of RS coding, an additional 7.5-dB coding gain is achieved. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance analysis for UMTS networks with queued radio access bearers

    Publication Year: 2002 , Page(s): 1330 - 1337
    Cited by:  Papers (3)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (614 KB) |  | HTML iconHTML  

    The Universal Mobile Telecommunications System (UMTS) network consists of a core network (CN) and a UMTS terrestrial radio access network (UTRAN). The UTRAN offers radio access bearer (RAB) services between the user equipment (UE) and the CN to support mobile multimedia applications with different quality of service (QoS) requirements. Depending on the requested QoS, different types of RABs can be established at the request of the CN. The UTRAN then has to establish and maintain the RAB with the requested QoS. We study the queueing of RABs as a means for improving the bandwidth utilization while minimizing the RAB blocking probability. We develop an analytical model to study the performance for UTRAN with queued RABs in terms of RAB blocking probability and average queueing time of queued RABs. From an analytic point of view, the main contribution of this paper is the introduction of a novel recursion for the computation of the performance measures. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the synergy between adaptive physical layer and multiple-access control for integrated voice and data services in a cellular wireless network

    Publication Year: 2002 , Page(s): 1338 - 1351
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1492 KB) |  | HTML iconHTML  

    We propose a novel design to exploit the synergy between the multiple-access control (MAC) layer and the physical layer of a cellular wireless system with integrated voice and data services. As in a traditional design, the physical layer (channel encoder and modulator) is responsible for providing error protection for transmitting the packets over the hostile radio channel, while the MAC layer is responsible for allocating the precious bandwidth to the contending users for voice or data connections. However, a distinctive feature of our proposed design is that in the physical layer, a variable-rate adaptive channel encoder is employed to dynamically adjust the amount of forward error correction according to the time-varying wireless channel state such that the MAC layer, which is a reservation-based time-division multiple-access protocol, is able to make informed decisions as to bandwidth allocation. Specifically, based on the channel state information provided by the physical layer, the MAC protocol gives higher priority to users with better channel states. This novel synergistic mechanism between the two protocol layers can utilize the system bandwidth more effectively. The multiple-access performance of the proposed scheme is compared with two baseline systems. The first baseline system consists of the same reservation-based MAC protocol but with a traditional fixed-rate physical layer. The second system consists of the same reservation-based MAC protocol and the same channel adaptive physical layer, but without interaction between the two layers. All three protocols have a request queue, which stores the previous requests that survive the contention but are not allocated information slots. Our extensive simulation results demonstrate that significant performance gains are achieved through the exploitation of the synergy between the two protocol layers. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance analysis of DS-SS PN code acquisition systems using soft-decision techniques in a Rayleigh-fading channel

    Publication Year: 2002 , Page(s): 1587 - 1595
    Cited by:  Papers (3)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (632 KB) |  | HTML iconHTML  

    A soft-decision method employing multiple threshold values for PN code acquisition in direct sequence spread spectrum (DS-SS) systems is described. We apply this technique to conventional search algorithms, double dwell serial search and hybrid search, and analyze them in terms of mean code acquisition time. For the analysis, we present mathematical models of proposed algorithms under a Rayleigh-fading channel. Numerical results show that our proposed schemes outperform conventional ones because multiple threshold values mitigate the possible decline in search performance caused by the use of a single threshold in conventional algorithms. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Differentially coherent PN code acquisition based on a matched filter for chip-asynchronous DS/SS communications

    Publication Year: 2002 , Page(s): 1596 - 1599
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (375 KB) |  | HTML iconHTML  

    A pseudonoise code acquisition technique based on a matched filter with differentially coherent detection is proposed for direct-sequence spread-spectrum communications in chip-asynchronous environments. Such a technique can be confidently exploited as an alternative to noncoherent detectors, which have been extensively investigated, because it can provide very attractive improvements over its noncoherent counterpart as well as overcome the problems caused by chip asynchronization without increasing hardware complexity. The results of statistical analyses show that the proposed technique certainly can achieve much lower error probabilities. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Admission control scheme for soft handoff in DS-CDMA cellular systems supporting voice and stream-type data services

    Publication Year: 2002 , Page(s): 1445 - 1459
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (895 KB) |  | HTML iconHTML  

    The soft handoff call requests of real-time services in third-generation (3G) direct-sequence code-division multiple access (DS-CDMA) and first- and second-generation cellular systems are more important than new call requests from the viewpoint of quality of service (QoS). Rejection of soft handoff requests causes forced termination of an ongoing real-time call, which is a severer problem than blocking of new call attempts. An admission control scheme that can guarantee a higher QoS for the soft handoff requests of real-time services in 3G DS-CDMA systems is proposed for delay-sensitive voice and delay-tolerant stream-type data services. The proposed scheme (P-Scheme) accommodates both voice and data services by utilizing the full bandwidth. However, voice soft handoff call requests are given priority over new voice call and stream-type data packet requests by suppressing interference from stream-type data services according to voice soft handoff requests, and by varying interference levels. Performance of the P-Scheme is evaluated using a Markovian model. Results are compared with a conventional reservation scheme (C-Scheme) that reserves resources exclusively for voice soft handoff requests. Numerical results show that system performance can be significantly improved using the proposed P-Scheme, compared with the conventional C-Scheme, when various types of service are supported in third-generation DS-CDMA systems. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Modeling and efficient handling of handoffs in integrated wireless mobile networks

    Publication Year: 2002 , Page(s): 1469 - 1478
    Cited by:  Papers (30)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (705 KB) |  | HTML iconHTML  

    We propose and analyze two handoff schemes without and with preemptive priority procedures for integrated wireless mobile networks. We categorize the service calls into four different types, namely, originating voice calls, originating data calls, voice handoff request calls, and data handoff request calls and we assume two separate queues for two handoff services. A number of channels in each cell are reserved exclusively for handoff request calls. Out of these channels, few are reserved exclusively for voice handoff request calls. The remaining channels are shared by both originating and handoff request calls. In the preemptive priority scheme, higher priority is given to voice handoff request calls over data handoff request calls and can preempt data service to the queue if, upon arrival, a voice handoff request finds no free channels. We model the system by a three-dimensional Markov chain and compute the system performance in terms of blocking probability of originating calls, forced termination probability of voice handoff request calls, and average transmission delay of data calls. It is observed that forced termination probability of voice handoff request calls can be decreased by increasing the number of reserved channels. On the other hand, as a data handoff request can be transferred from a queue of one base station to another, there is no packet loss of data handoff except for a negligibly small blocking probability. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Directional power-based admission control for WCDMA systems using beamforming antenna array systems

    Publication Year: 2002 , Page(s): 1294 - 1303
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (507 KB)  

    A directional power-based admission control (AC) scheme is proposed for base stations deploying beamforming antenna arrays. The proposed AC algorithm is a natural extension of the conventional power based AC scheme for cells using standard sector antennas. The directional scheme takes the load per beam/direction into account in the AC decision, so the cell load is controlled in accordance with the spatial filtering gain provided by using beamforming antenna arrays. The scheme is tested by means of Monte Carlo simulations in a multicell wideband code division multiple access (WCDMA) network, where users with different bit rates are present. The obtained results demonstrate that the directional power based AC scheme allows a higher traffic load in cells using beamforming antenna arrays without jeopardizing the stability of the network. Application of a four element antenna array is found to provide a capacity gain of a factor 2.7 for a network with many low bit rate users, while the gain is reduced to a factor 2.3 for traffic scenarios with a mixture of high and low bit rate users. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Distributed dynamic channel assignment in TDMA mobile communication systems

    Publication Year: 2002 , Page(s): 1397 - 1406
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (581 KB) |  | HTML iconHTML  

    Dynamic channel assignment (DCA) has been a topic of intense research for many years, and a variety of DCA algorithms have been proposed. Nonetheless, some important issues have been neglected because of the complexity involved in their study. In particular, the impact of user motion on the performance of DCA systems has not received enough attention. In this paper, we quantify the impact of motion on the capacity and cost-in terms of average number of reassignments per call-of a variety of representative distributed fixed-power DCA algorithms. A novel adaptive algorithm especially suited for mobility environments is proposed, which achieves high capacity while controlling the reassignment rate. We also prove that most of this capacity can be effectively realized with a reduced number of radio transceivers per base station. Finally, we evaluate the degradation associated with the use of estimates of local-mean signal and interference levels-obtained by averaging instantaneous measurements-instead of the actual local-mean values. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Packet loss probability for real-time wireless communications

    Publication Year: 2002 , Page(s): 1569 - 1575
    Cited by:  Papers (17)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (449 KB) |  | HTML iconHTML  

    A novel Markov model is constructed to calculate the packet loss probability and the delay distribution of real-time wireless packets. These packets are transmitted through an erroneous channel modeled by a two-state Markov chain. If a packet transmission is not successful, the packet is retransmitted until a delay limit is exceeded. At that time, the packet is discarded and the transmission of the next packet begins. This packet-dropping process has a significant impact on packet loss probability but is seldom considered in other Markov models. Closed-form solutions are obtained, and simplified expressions assuming highly correlated errors and small error probability are derived. Under these conditions, it is found that the packet loss probability is significantly affected by the delay limit and the transition probability of the channel's remaining in the failure state. On the other hand, the probability is almost independent of the arrival rate provided the rate is not close to one. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Modeling and analysis of hierarchical cellular networks with general distributions of call and cell residence times

    Publication Year: 2002 , Page(s): 1361 - 1374
    Cited by:  Papers (16)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (884 KB) |  | HTML iconHTML  

    We present an analytic model for the performance evaluation of hierarchical cellular systems, which can provide multiple routes for calls through overflow from one cell layer to another. Our model allows the case where both the call time and the cell residence time are generally distributed. Based on the characterization of the call time by a hyper-Erlang distribution, the Laplace transform of channel occupancy time distribution for each call type (new call, handoff call, and overflow call) is derived as a function of the Laplace transform of cell residence time. In particular, overflow calls are modeled by using a renewal process. Performance measures are derived based on the product form solution of a loss system with capacity limitation. Numerical results show that the distribution type of call time and/or cell residence time has influence on the performance measure and that the exponential case may underestimate the system performance. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Deterministic channel modeling and performance simulation of microcellular wide-band communication systems

    Publication Year: 2002 , Page(s): 1422 - 1430
    Cited by:  Papers (17)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (497 KB) |  | HTML iconHTML  

    To evaluate the performance of future microcellular IMT-2000 modems, simple physical models are required, so that a number of system characteristics, such as the signal bandwidth, the antenna beamwidth, or the base station height can be accounted for at a limited computational cost. This paper describes a deterministic three-dimensional electromagnetic model, which allows simulation of the radiowave propagation for microcellular wide-band communication systems in urban areas. The model is based on a UTD ray-tracing tool and makes use of an improved mirror method. Simulated power-delay profiles are plotted against measured power-delay profiles recorded at 1.87 GHz in a street of Louvain-la-Neuve, Belgium, by means of an 80-MHz channel sounder. Despite several discrepancies, a satisfying matching is found considering three orders of reflection and single diffraction. Predictions of rms delay-spread accounting for the sounder limited bandwidth are presented. Finally, simulated and measured channels are also compared through the resulting performance of a typical IMT-2000 service in the presence of multiple access interference. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Signal design for ultra-wide-band communications in dense multipath

    Publication Year: 2002 , Page(s): 1517 - 1521
    Cited by:  Papers (27)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (358 KB) |  | HTML iconHTML  

    Ultra-wide-band (UWB) wireless communications utilizes information signals characterized by a radiated spectrum with a very wide bandwidth around a relatively low center frequency. We formulate the signal design for binary UWB communications taking into consideration the particular characteristics of UWB propagation in a dense multipath channel. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

IEEE Transactions on Vehicular Technology covers land, airborne, and maritime mobile services, vehicular electrotechnology, equipment, and systems identified with the automotive industry.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Yuguang Michael Fang
University of Florida