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Vehicular Technology, IEEE Transactions on

Issue 2 • Date March 2008

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Displaying Results 1 - 25 of 65
  • Table of contents

    Page(s): C1 - C4
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    Freely Available from IEEE
  • IEEE Transactions on Vehicular Technology publication information

    Page(s): C2
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  • Modeling and Analysis of In-Vehicle Power Line Communication Channels

    Page(s): 670 - 679
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (885 KB) |  | HTML iconHTML  

    In this paper, we address the problem of power line communication inside a vehicle, focusing on channel characterization and modeling. The statistical properties of the transfer function between two points in the power distribution system are deduced from a propagation model that takes into account the complicated structure of the cable bundles. Theoretical estimates are compared to experimental results. Later on, this theoretical model, together with an impulsive noise model, will be implemented in a software communication tool that is designed to optimize modulation schemes and channel coding. View full abstract»

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  • Indoor MIMO Channel Modeling by Rigorous GO/UTD-Based Ray Tracing

    Page(s): 680 - 692
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1328 KB) |  | HTML iconHTML  

    This paper presents a multiple-input-multiple- output (MIMO) channel model based on rigorous ray-tracing techniques, which is based on a full 3-D implementation of geometric optics and the uniform theory of diffraction (3-D GO/ UTD). Results obtained from measurements and simulations of the correlation matrix and capacity of a 2 times 2 MIMO system in specific indoor environments at a frequency of 2 GHz are presented. The channel capacity has been calculated for the different local areas considered in open- and office-area scenarios, starting from the measurements carried out there, as well as from the ray-tracing simulated channels. The rigorous and quantitative comparison between measurements and simulations shows that the model accuracy is sufficient for the analysis and design of the different aspects of the full MIMO system. The results from the ray-tracing model can also be used to extract general statistical characteristics and parameterize statistical models for different types of environments, without the need to carry out large and costly measurement campaigns. In addition, the measured data are used to study the impact of the channel on the achievable capacity of a 2 times 2 MIMO system in typical indoor scenarios at 2 GHz. View full abstract»

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  • Measurement and Modeling of the Land Mobile Satellite Channel at Ku-Band

    Page(s): 693 - 703
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2229 KB) |  | HTML iconHTML  

    This paper presents the results of a measurement campaign conducted in the winter of 2002 around the city of Munich in southern Germany. The primary goal was to evaluate the link performance of the land mobile satellite channel at Ku-band and to characterize the temporal behavior of the channel to help in the evaluation of different fade mitigation techniques for future mobile satellite systems that aim at employing this frequency band. To achieve this objective, first- and second-order channel statistics will be presented, the outage probability of the channel analyzed, and a Markov-chain-based narrowband channel model proposed. View full abstract»

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  • Wide-Sense Stationarity of Mobile MIMO Radio Channels

    Page(s): 704 - 714
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (409 KB) |  | HTML iconHTML  

    Tests for the wide-sense stationarity (WSS) of multivariate random processes are developed and applied to measured multiple-input-multiple-output (MIMO) radio channel responses. Evolutionary spectral density functions are used to estimate the time-dependent power spectral density, and analysis of variance procedures are applied to determine whether the first and second moments of the data series exhibit statistically significant changes over short intervals. It is found that while the assumption of WSS is met in 40%-70% of half-second intervals for a single element at the transmitter and receiver, only 2%-12% of intervals with two elements at the transmitter and receiver are jointly WSS; furthermore, the occurrence of non-WSS intervals is not dependent on the antenna separation. The analyses also show that WSS intervals are interspersed with long non-WSS intervals. View full abstract»

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  • Space-Time Correlated Mobile-to-Mobile Channels: Modelling and Simulation

    Page(s): 715 - 726
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (400 KB) |  | HTML iconHTML  

    A single- and double-bounced two-ring parametric reference model is proposed for multiple-input multiple-output (MIMO) mobile-to-mobile (M-to-M) Ricean fading channels. From this model, a closed-form joint space-time correlation function and a space-Doppler power spectrum are derived for a two-dimensional (2D) non-isotropic scattering environment. Also, space-time correlation functions for the in-phase and quadrature components of the complex faded envelope are derived, assuming a 2D isotropic scattering environment. Finally, two new sum-of-sinusoids based simulation models for MIMO M-to-M Ricean fading channels are proposed. The statistics of the simulation models are verified by simulation. The results show that the simulation models are a good approximation of the reference model and that they outperform existing simulation models. View full abstract»

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  • Vehicle Stability Enhancement of Four-Wheel-Drive Hybrid Electric Vehicle Using Rear Motor Control

    Page(s): 727 - 735
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1288 KB) |  | HTML iconHTML  

    A vehicle stability enhancement control algorithm for a four-wheel-drive hybrid electric vehicle (HEV) is proposed using rear motor driving, regenerative braking control, and electrohydraulic brake (EHB) control. A fuzzy-rule-based control algorithm is proposed, which generates the direct yaw moment to compensate for the errors of the sideslip angle and yaw rate. Performance of the vehicle stability control algorithm is evaluated using ADAMS and MATLAB Simulink cosimulations. HEV chassis elements such as the tires, suspension system, and steering system are modeled to describe the vehicle's dynamic behavior in more detail using ADAMS, whereas HEV power train elements such as the engine, motor, battery, and transmission are modeled using MATLAB Simulink with the control algorithm. It is found from the simulation results that the driving and regenerative braking at the rear motor is able to provide improved stability. In addition, better performance can be achieved by applying the driving and regenerative braking control, as well as EHB control. View full abstract»

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  • Design and Control of a Small-Clearance Driving Simulator

    Page(s): 736 - 746
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1325 KB) |  | HTML iconHTML  

    This paper presents a driving simulation whose aim is twofold: (1) to investigate the possibility of reducing motion clearance to achieve compact and low-cost driving simulators and (2) to evaluate multimodal and immersive virtual reality motion restitution in platooning driving. The choice has been made for a driving simulator having at least two degrees of freedom (DOF). These consist of the longitudinal displacement and seat rotations. The simulator is also equipped with a force feedback steering wheel for virtual drive assistance. These components are gathered on a serial kinematics-type platform to facilitate a control scheme and avoid the architecture complexity. A comparative study was made to devise a motion cueing strategy, taking into account both the psychophysical and technological constraints. Experimentations were carried out for several case combinations of the longitudinal displacement and seat rotations. View full abstract»

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  • Investigation of Sliding-Surface Design on the Performance of Sliding Mode Controller in Antilock Braking Systems

    Page(s): 747 - 759
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1460 KB) |  | HTML iconHTML  

    Sliding mode control (SMC) has widely been employed in the development of a wheel-slip controller because of its effectiveness in applications for nonlinear systems as well as its performance robustness on parametric and modeling uncertainties. The design of a sliding surface strongly influences the overall behavior of the SMC system due to the discontinuous switching of control force in the vicinity of a sliding surface that produces chattering. This paper investigates the effects of sliding-surface design on the performance of an SMC-based antilock braking system (ABS), including a brake-torque limitation, an actuator time delay, and a tire-force buildup. Different sliding-surface designs commonly used in ABS were compared, and an alternative sliding-surface design that improves convergence speed and oscillation damping around the target slip has been proposed. An 8-degree-of-freedom (dof) nonlinear vehicle model was developed for this paper, and the effects of brake-system parameter variations, such as a brake actuator time constant, target slip ratios, an abrupt road friction change, and road friction noises, were also assessed. View full abstract»

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  • A Comparative Study of Fuel-Cell–Battery, Fuel-Cell–Ultracapacitor, and Fuel-Cell–Battery–Ultracapacitor Vehicles

    Page(s): 760 - 769
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (354 KB) |  | HTML iconHTML  

    Although many researchers have investigated the use of different powertrain topologies, component sizes, and control strategies in fuel-cell vehicles, a detailed parametric study of the vehicle types must be conducted before a fair comparison of fuel-cell vehicle types can be performed. This paper compares the near-optimal configurations for three topologies of vehicles: fuel-cell-battery, fuel-cell-ultracapacitor, and fuel-cell-battery-ultracapacitor. The objective function includes performance, fuel economy, and powertrain cost. The vehicle models, including detailed dc/dc converter models, are programmed in Matlab/Simulink for the customized parametric study. A controller variable for each vehicle type is varied in the optimization. View full abstract»

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  • Real-Time Clamp Force Measurement in Electromechanical Brake Calipers

    Page(s): 770 - 777
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (444 KB) |  | HTML iconHTML  

    In brake-by-wire systems, central controllers require accurate information about the clamp force between the brake pad and the disc as a function of pad displacement, which is usually denoted as the characteristic curve of the caliper. Due to aging, temperature, and other environmental variations, caliper characteristic curves vary with time. Therefore, automatic caliper calibration in real-time is vital for high-performance braking action and vehicle safety. Due to memory and processing-power limitations, the calibration technique should be memory efficient and of low computational complexity. In a typical electromechanical-braking-system design, clamp force measurement variations with actuator displacement is hysteretic. This paper introduces a simple and memory-efficient real-time calibration technique in which a clamp-force model is fitted to the data samples around each hysteresis cycle. The model includes a Maxwell-slip model for the hysteresis caused by friction. Experimental results from the data recorded in various temperatures show that the proposed technique results in clamp force measurements with less than 0.7% error over the range of clamp-force variations. It is also shown that, by using these measurements, the characteristic curve can be accurately calibrated in real-time. View full abstract»

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  • Clamp-Force Estimation for a Brake-by-Wire System: A Sensor-Fusion Approach

    Page(s): 778 - 786
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (695 KB) |  | HTML iconHTML  

    The elimination of a clamp-force sensor from brake-by-wire system designs is strongly demanded due to implementation difficulties and cost issues. In this paper, a new method is presented to estimate the clamp force based on other sensory information. This estimator fuses the outputs of two models to optimize the root-mean-square error (RMSE) of estimation. Experimental results show that the estimator can accurately track the true clamp force for high-speed cases as demanded by the antilock braking system controls. A training strategy has been used to ensure that the estimator can successfully adapt to parameter variations associated with wear. This paper is concluded with a discussion on the reliability of the developed clamp-force estimator. View full abstract»

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  • Diversity Performance of a Wavelet-Packet-Based Multicarrier Multicode CDMA Communication System

    Page(s): 787 - 797
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1516 KB) |  | HTML iconHTML  

    In this paper, we propose and analyze a novel multicarrier (MC) multicode (MCD) code-division multiple-access (CDMA) system employing wavelet packets (WPs) for modulation. This system can achieve robust performance against multipath fading due to the localization of WPs in the time and frequency domains. The analytical framework is presented, and the system performance with diversity is evaluated by means of bit error rates and the outage probability . Since WPs have lower sidelobes compared to sinusoidal carriers, our system is very effective in reducing the problem of intercarrier interference. The effects of system parameters (e.g., order of diversity, fading parameters, and WP type) were investigated. The major contribution is to compare the performance of the system to that of the MC/MCD-CDMA system that is based on sinusoidal carriers. The results reveal a considerable performance improvement of our proposed system over the MC/MCD-CDMA system. View full abstract»

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  • An Advanced Satellite UMTS Testbed for Laboratory and Over-the-Air Experiments of Third-Generation Mobile Services—Part II: Experimental Results

    Page(s): 798 - 809
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2250 KB) |  | HTML iconHTML  

    This paper complements its companion paper by reporting the key experimental results obtained both in the laboratory and via satellite, using the Satellite Universal Mobile Telecommunication Systems (S-UMTS) Advanced TestBed (ATB) - a comprehensive facility developed under a European Space Agency contract whose intention was to demonstrate a set of technical solutions for the efficient provision of the so-called S-UMTS services, i.e., third-generation (3G) point-to-point (i.e., interactive) and point-to-multipoint (i.e., multicasting/broadcasting) mobile services based on wideband code-division multiple access (W-CDMA). After addressing the architecture of the overall via satellite ATB demonstrator, the main test results obtained in the laboratory, as well as over the air, are summarized. Then, bit error rate and frame error rate measurement results that were taken from the forward and return links are shown for both the additive white Gaussian noise and the Ricean channels, with different orders of space diversity and different coding schemes, which were classified as either convolutional or turbo 3G partnership project coding. Finally, key results of via satellite L-band measurements are reported for both unicast and reliable multicast applications. Because of the extensive test campaign presented in this paper, the viability of adapting W-CDMA to support point-to-point (packet) and point-to-multipoint multicast services in the satellite environment, as standardized by the European Telecommunications Standards Institute, has been widely validated and experimentally confirmed. Reliable multicast techniques, exploiting a forward error correction that operates at the upper layer, were shown to be a powerful way of counteracting satellite channel impairments, thus allowing the multicast of multimedia contents in quasi-real time with good quality of service. View full abstract»

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  • Soft-Limiting Receiver Structures for Time-Hopping UWB in Multiple-Access Interference

    Page(s): 810 - 818
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1457 KB) |  | HTML iconHTML  

    A novel receiver structure based on soft-limiting is proposed for detecting a time-hopping ultrawide-bandwidth (UWB) signal in the presence of multiple-access interference (MAI). The proposed structure contains a nonlinear limiter for suppressing the MAI. Simulation results show that the proposed receiver achieves better bit-error-rate performance than the conventional matched receiver when operating in MAI. When operating in an MAI-plus-Gaussian-noise environment, the receiver structure outperforms the conventional matched-filter receiver for moderate to large values of signal-to-noise ratio (SNR). A receiver structure with adaptive limiting threshold is further proposed to ensure that the performance of the soft-limiting receiver always meets or surpasses the performance of the conventional UWB receiver for all values of SNR. Application of the soft-limiting structure in the fingers of a rake receiver is shown to enhance the signal-to-noise-plus-interference ratio. View full abstract»

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  • H_{\infty } Channel Estimator Design for DS-CDMA Systems: A Polynomial Approach in Krein Space

    Page(s): 819 - 827
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1032 KB) |  | HTML iconHTML  

    This paper considers the problem of robust channel estimation for direct-sequence code-division multiple-access (DS-CDMA) systems with time-varying multipath fading channels. Due to the lack of accurate knowledge of model dynamics and statistics of system noises, a polynomial channel estimator is developed by virtue of the Krein space theory. The estimator is calculated by performing a J-spectral factorization. In this paper, under some conditions, we obtain a closed-form solution to this J-spectral factorization, which greatly reduces the computational load of the estimator design. The simulation results show that the proposed estimator provides a robust estimation performance against various types of noises and modeling errors. View full abstract»

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  • Teletraffic Analysis of an Overlaid System Using CDMA and TDMA With Cell Coverage Area Restriction

    Page(s): 828 - 846
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (574 KB) |  | HTML iconHTML  

    Wireless communication has emerged as the most promising and one of the leading sectors of the telecommunications industry in the 21st century. To appreciate the expansion of the wireless sector, in 1990, there were only ten million cellular phone subscribers worldwide that frequently use first-generation technology. Today, there are more than one billion subscribers, and it is expected to increase to more than three billion subscribers during 2007-2010. Attempting to more efficiently use the limited frequency bands available for mobile communications, the idea of overlaying a code-division multiple-access (CDMA) system on an existing narrowband system has been proposed and explored. The basic idea of a CDMA overlay is to allow wideband CDMA waveforms to share a common spectrum with narrowband conventional waveforms to take advantage of the unexploited bandwidth available in the narrowband systems. Theoretically, the separation of CDMA and narrowband waveforms can be accomplished through notch filters. However, the filtering techniques are not sufficient for eliminating the multicross interference problem. In this paper, as a means of reducing the interference that cannot be eliminated by the use of filters, we have introduced a new proposal of an overlaid system in which we reduce the coverage area of the time-division multiple-access (TDMA) interference slots (slots inside the CDMA bandwidth are henceforth cited as cochannel slots). With this new strategy, we significantly reduce the effect of TDMA interference over the CDMA system. View full abstract»

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  • Cross-Modulation Interference and Mitigation Technique for Ultrawideband PPM Signaling

    Page(s): 847 - 858
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (933 KB) |  | HTML iconHTML  

    The detection issues of ultrawideband (UWB) signals depend on the type of modulation scheme that is used during the transmission. Cross-modulation interference (CMI) is a problem that is specific to UWB pulse-position-modulation (PPM) signaling. In this paper, the effects of CMI on the performance of noncoherent UWB receivers are analyzed. The probabilities of error for transmitted-reference (TR) and energy detector (ED) receivers in the presence and absence of CMI are derived. Optimal and suboptimal CMI avoidance algorithms, which are based on novel acquisition techniques, are proposed for Rake receivers. The results show that the performance degradation in both receivers, which is due to the CMI effects, can be significant, depending on the modulation index. TR receivers still can be functional in the presence of CMI, and the target performance level determines the modulation index to be used. It is unlikely that effects of CMI on the performance of ED receivers in the presence of CMI are more severe relative to TR receivers, and the performance level is not acceptable. As a result, PPM signaling is not an appropriate modulation technique for ED receivers that are operating in the CMI region, unless CMI mitigation algorithms can be developed. Furthermore, the proposed optimal and suboptimal algorithms are two promising schemes for avoiding the CMI effects and, consequently, for improving the performance of Rake receivers operating in the CMI region. View full abstract»

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  • Detection of OFDM Signals in Fast-Varying Channels With Low-Density Pilot Symbols

    Page(s): 859 - 872
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (573 KB) |  | HTML iconHTML  

    In fast-varying channels, an orthogonal frequency-division multiplexing system needs to insert denser pilot symbols among transmitted symbols in tracking the variation of a channel. However, using denser pilot symbols reduces transmission throughput. In this paper, we propose a pseudopilot algorithm for data detection in fast-varying channels without increasing the pilot density. Our algorithm is based on a regressional model-based least-squares-fitting approach. Within a block of received symbols, we select some data symbols and regard them as pseudopilot symbols. The receiver considers all the possible patterns of the pseudopilots and associates each of them with a data sequence and a corresponding metric. The associated data sequence, whose metric is minimum, is selected as the detected data sequence. Our algorithm is not based on a decision-directed or decision-feedback architecture because the pseudopilots do not come from any detected symbols. The proposed algorithm needs to search all the possible patterns of the pseudopilots, and the complexity may increase with the number of pseudopilots and constellation size. To reduce the number of search, we further propose two modified approaches. The simulation results show that the performance of the proposed algorithms could approach a bit-error probability lower bound that is obtained by letting the receiver know the true values of the pseudopilots. Compared with the linear interpolation method, the proposed algorithm shows obvious improvement in fast-varying channels. The proposed modified approaches could also effectively reduce the number of search while maintaining the performance. We also give the complexity analysis of the proposed algorithm and an approach to determine the degree of the regression polynomial. View full abstract»

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  • A Fast Subcarrier, Bit, and Power Allocation Algorithm for Multiuser OFDM-Based Systems

    Page(s): 873 - 881
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (359 KB) |  | HTML iconHTML  

    In this paper, we propose a real-time subcarrier, bit, and power allocation algorithm for orthogonal frequency-division multiplexing-based multiuser communication systems in downlink transmission. Assuming that base stations know the channel gains of all subcarriers of all users, the proposed loading algorithm tries to minimize the required transmit power while satisfying the rate requirement and data error rate constraint of each user. The novel algorithm simultaneously determines subcarrier, bit, and power allocation by enhancing the suboptimal algorithm by Wong while having the same computational complexity. The proposed scheme offers better performance in terms of transmit power than that of Wong , as demonstrated in the simulation results, whereas the performance of the scheme in Wong was close to that of the optimal solution. View full abstract»

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  • Predistorter Based on Frequency Domain Estimation for Compensation of Nonlinear Distortion in OFDM Systems

    Page(s): 882 - 892
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (371 KB) |  | HTML iconHTML  

    An orthogonal frequency-division-multiplexing signal is very sensitive to the nonlinear distortion of the power amplifier (PA) as a result of its high peak-to-average power ratio. Predistortion, which is an effective countermeasure for balancing off the nonlinearity of a PA, is usually necessary for the sake of mitigating the in-band distortion and the spectrum regrowth. In general, a feedback path is required to estimate the PA characteristic, and a memoryless polynomial is used in modeling the PA characteristic or constructing the predistorter. The polynomial coefficients are solved by least-square (LS) estimation or adaptive identification algorithms in the time domain. In this paper, we examine the estimation problem from the frequency domain and propose five predistortion schemes. The advantage of using frequency-domain estimation is that it is much easier to compensate the delay effect caused by the transmission and receiving filters in the feedback path. Two different criteria are used in the proposed algorithms. The first one is based on the minimization of the square error of the PA input, which is termed as the PA-input-LS criterion. The second one is based on the minimization of the square error between the input of the predistorter and the output of the PA, which is termed as PA-output-LS criterion. We also propose an easy method to cope with the delay effect caused by the transmission and receiving filters in the feedback path. The performances of the proposed schemes are compared in the simulation. The simulation results show that by using the proposed schemes, the power efficiency of the PA can be increased by at least 7 dB in the sense of total degradation for a practical IEEE 802.11a wireless local area network system with a 64-quadrature-amplitude-modulation signal constellation. View full abstract»

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  • Spatial Scheduling With Interference Cancellation in Multiuser MIMO Systems

    Page(s): 893 - 905
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (459 KB) |  | HTML iconHTML  

    This paper proposes a novel downlink spatial scheduling algorithm in multiuser multiple-input-multiple-output (MIMO) systems, which selects a good combination of terminals and base station's (BS's) transmit beams so that the BS's beams nullify interstream interference at the selected terminals. In the derivation process, we reveal the new property that the optimization problem of downlink spatial scheduling is equivalent to that of uplink scheduling under the BS's zero-forcing beamforming. Using this property, an efficient downlink scheduling algorithm is presented, applying the principle of an uplink scheduling algorithm. Numerical results show that the presented spatial scheduling achieves a much higher system throughput than a multiuser MIMO system without spatial scheduling or with conventional spatial scheduling by linear processing. We also present a realistic control structure to achieve the uplink and downlink spatial scheduling in time-division duplex systems. View full abstract»

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  • Pilot-Aided Angle-Domain Channel Estimation Techniques for MIMO-OFDM Systems

    Page(s): 906 - 920
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1413 KB) |  | HTML iconHTML  

    Early multiple-input multiple-output with orthogonal frequency division multiplexing (MIMO-OFDM) channel estimation techniques treat channels as spatially uncorrelated. However, in many situations, MIMO-OFDM channels tend to be spatially correlated, for example, due to limited scattering. For such channels, estimation performance can be improved through exploitation of prior knowledge of the channel spatial correlation, for example, by means of the linear multiple mean square error (MMSE) technique. This knowledge is, however, not always available. As an alternative, we investigate techniques in the angle domain, where the MIMO-OFDM channel model lends itself to a physical interpretation. Our theoretical analysis and simulation results indicate that the proposed angle-domain approximated MMSE (AMMSE) channel estimation technique performs well in terms of the mean square error (mse) for various channel models representing different indoor environments. When a suitable threshold is chosen, we can use the angle-domain most-significant-taps selection technique instead of the angle-domain AMMSE technique to simplify the channel estimation procedure with little performance loss. View full abstract»

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  • Exact Performance Analysis of Dual-Branch Coherent Equal-Gain Combining in Nakagami- m , Rician, and Hoyt Fading

    Page(s): 921 - 931
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (394 KB) |  | HTML iconHTML  

    The exact symbol error rates (SERs) of several M-ary modulation schemes are obtained in a unified manner for mobile radio receivers employing dual-branch coherent equal-gain combining (EGC), where the received signals on each branch follow either similar or different fading distributions. Specifically, the cases considered are Nakagami-m, Rice, and Hoyt fading on both branches, but with not necessarily identical parameters, and mixed Nakagami-m/Rice and Nakagami-m/Hoyt fading; only the integer or half-integer values of the Nakagami-parameter are considered. While the previous exact expressions for the SERs of general M-ary modulations with L-branch EGC contained double integrals, the error probability expressions derived in this paper for the case of L=2 contain only a single integral. In addition, the derived probability distributions also allow the direct obtaining of other useful performance measures, such as the exact level crossing rates, average fade durations, and outage probabilities. View full abstract»

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Aims & Scope

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

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Meet Our Editors

Editor-in-Chief
Yuguang Michael Fang
University of Florida