References of "Ottersten, Björn 50002797"
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See detailThe Diversity Order of the Semidefinite Relaxation Detector
Jaldén, Joakim; Ottersten, Björn UL

in IEEE Transactions on Information Theory (2008), 54(4), 14061422

Detailed reference viewed: 22 (0 UL)
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See detailStatistically Robust Design of Linear MIMO Transceivers
Zhang, Xi; Palomar, Daniel; Ottersten, Björn UL

in IEEE Transactions on Signal Processing (2008), 56(8), 36783689

Detailed reference viewed: 17 (0 UL)
See detailCapacity and Gain Analysis of a Reconfigurable MEMS Antenna
Mowlér, Marc; Khalid, Bilal; Lindmark, Björn et al

in Nordic Conference on Radio Science and Communications (RVK) (2008)

Detailed reference viewed: 91 (0 UL)
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See detailFeedback design in multiuser MIMO systems using quantization splitting and hybrid instantaneous/statistical channel information
Björnson, Emil; Hammarwall, David; Zakhour, Randa et al

in Proceedings ICT Mobile and Wireless Communications Summit (2008)

In the design of next generation multiuser communication systems, multiple antenna transmission is an essential part providing spatial multiplexing gain and allowing efficient use of resources. A major ... [more ▼]

In the design of next generation multiuser communication systems, multiple antenna transmission is an essential part providing spatial multiplexing gain and allowing efficient use of resources. A major limiting factor in the resource allocation is the amount of channel state information (CSI) available at the transmitter, particularly in multiuser systems where the feedback from each user terminal must be limited. To this effect we propose two independent approaches for an efficient representation of the channel in multiuser MIMO systems. In the first approach, channel quantization is considered where the total number of feedback bits is limited. A resource allocation scheme is proposed where the available rate is split between the scheduling phase, where all users feed back a coarse CSI quantization, and the precoding phase where the selected receivers refine their CSI. The optimum splitting of the available feedback rate provides a large increase in performance and even simple heuristic splitting gives a noticeable advantage. In the second approach, we exploit a combination of instantaneous and statistical channel information. For spatially correlated Rayleigh and Ricean channels, it is shown that the CSI to large extent can be represented by the channel norm when the long-term channel statistics are known. Within a minimum mean square error (MMSE) estimation framework, feedback of a few bits of the quantized channel norm is sufficient to perform efficient resource allocation and achieve performance close to that of full CSI. [less ▲]

Detailed reference viewed: 85 (0 UL)
See detailFeedback Reduction in Uplink MIMO OFDM Systems by Chunk Optimization
Jorswieck, Eduard; Sezgin, Aydin; Ottersten, Björn UL et al

in IEEE International Conference on Communications (ICC) (2008)

Detailed reference viewed: 98 (0 UL)
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See detailFeedback Reduction in Uplink MIMO OFDM Systems by Chunk Optimization
Jorswieck, Eduard; Sezgin, Aydin; Ottersten, Björn UL et al

in EURASIP Journal on Applied Signal Processing (2008)

Detailed reference viewed: 97 (0 UL)
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See detailGuaranteed Performance Region in Fading Orthogonal Space-Time Coded Broadcast Channels
Jorswieck, Eduard; Ottersten, Björn UL; Sezgin, Aydin et al

in EURASIP Journal on Wireless Communications & Networking (2008)

Detailed reference viewed: 101 (0 UL)
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See detailReliability Estimation of a Statistical Classifier
Devarakota, Pandu Ranga Rao UL; Mirbach, Bruno; Ottersten, Björn UL

in Pattern Recognition Letters (2008), 29(3), 243253

Detailed reference viewed: 3 (0 UL)
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See detailPerformance of TDMA and SDMA based Opportunistic Beamforming
Jorswieck, Eduard; Svedman, Patrick; Ottersten, Björn UL

in IEEE Transactions on Wireless Communications (2008), 7(11), 40584063

Detailed reference viewed: 6 (0 UL)
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See detailExploiting Long-term Statistics in Spatially Correlated Multi-user MIMO Systems with Quantized Channel Norm Feedback
Björnson, Emil; Ottersten, Björn UL

in Proceedings IEEE International Conference on Acoustics, Speech, and Signal (ICASSP) (2008)

In wireless multiple antenna and multi-user systems, the spatial dimensions may be exploited to increase the performance by means of antenna gain, spatial diversity, and multi-user diversity. A limiting ... [more ▼]

In wireless multiple antenna and multi-user systems, the spatial dimensions may be exploited to increase the performance by means of antenna gain, spatial diversity, and multi-user diversity. A limiting factor in such systems is the channel information required by the transmitter to control the intra-cell interference. Herein, the properties of spatially correlated channels with longterm statistical information at the transmitter and fixed-rate feedback of the quantized Euclidean channel norm are analyzed using a spectral subspace decomposition framework. A spatial division multiple access scheme is proposed with interference suppression at the receiver and joint scheduling and zero-forcing beamforming at the transmitter. Closed-form expressions for first and second moments of the feedback conditional channel statistics are derived. It is shown that only a few bits of feedback are required to achieve reliable rate estimation and weighted sum-rate maximization. [less ▲]

Detailed reference viewed: 96 (0 UL)
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See detailOpportunistic Beamforming and Scheduling for OFDMA Systems
Svedman, Patrick; Wilson, Sarah Kate; Cimini, Leonard J. et al

in IEEE Transactions on Communications (2007), 55(5), 941952

Detailed reference viewed: 105 (0 UL)
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See detailInter and Intra-Site Correlation of Large Scale Parameters from Macro Cellular Measurements at 1800MHz
Jaldén, Niklas; Zetterberg, Per; Ottersten, Björn UL et al

in EURASIP Journal on Wireless Communications & Networking (2007), 2007(3),

Detailed reference viewed: 3 (0 UL)
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See detailJoint Estimation of Mutual Coupling, Element Factor, and Phase Center in Antenna Arrays
Mowlér, Marc; Larsson, Erik G.; Lindmark, Björn et al

in EURASIP Journal on Wireless Communications & Networking (2007), 2007

Detailed reference viewed: 5 (0 UL)
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See detailOccupant Classification Using Range Images
Devarakota, Pandu Ranga Rao UL; Castillo-Franco, Marta; Ginhoux, Romuald et al

in IEEE Transactions on Vehicular Technology (2007), 56(2)(4), 19831993

Detailed reference viewed: 4 (0 UL)
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See detailOn the Maximal Diversity Order of Spatial Multiplexing With Transmit Antenna Selection
Jaldén, Joakim; Ottersten, Björn UL

in IEEE Transactions on Information Theory (2007), 53(11), 42734276

Detailed reference viewed: 4 (0 UL)
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See detailCorrelation properties of large scale fading based on Indoor measurements
Jaldén, Niklas; Hong, Aihua; Zetterberg, Per et al

in IEEE Wireless Communications and Networking Conference (WCNC) (2007)

Statistical channel models are attractive for their simplicity but sometimes lack in precision. In to improve modelling accuracy, statistical model parameters, which are dependent on the environment, are ... [more ▼]

Statistical channel models are attractive for their simplicity but sometimes lack in precision. In to improve modelling accuracy, statistical model parameters, which are dependent on the environment, are extended to include spatial and temporal correlation. In outdoor scenarios these parameters are assumed constant over large areas of several wavelengths hence the name large scale parameters. This paper studies the large scale fading (LSF) and the applicability of bringing this previously used outdoor variable to the indoor case. The impacts of the model of the LSF on the outdoor system-performance have been studied and several relevant models have been proposed for outdoor cases. We present the intra-site autocorrelation as well as the inter-site cross correlation of the LSF for an indoor channel. The results are based on two separate measurement campaigns conducted at KTH, Stockholm and TUI, Ilmenau, using a single mobile station (MS) and multiple base stations (BSs) to investigate such models. We observe that the areas under which the LSF could be assumed constant are, in indoor scenarios, so small that it can be assumed independent from one local area to another. Furthermore, we find results that point towards the existence of inter-site correlation in some specific scenarios. [less ▲]

Detailed reference viewed: 17 (0 UL)
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See detailFull Diversity Detection in MIMO Systems with a Fixed-Complexity Sphere Decoder
Jaldén, Joakim; Barbero, Luis G.; Ottersten, Björn UL et al

in Proceedings IEEE International Conference on Acoustics, Speech, and Signal Processing (2007)

Detailed reference viewed: 11 (0 UL)
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See detailOn Downlink Beamforming with Indefinite Shaping Constraints
Hammarwall, David; Bengtsson, Mats; Ottersten, Björn UL

in IEEE Transactions on Signal Processing (2006), 54(9), 35663580

Detailed reference viewed: 3 (0 UL)
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See detailSystem Evaluation of Optimal Downlink Beamforming with Congestion Control in Wireless Communication
Stridh, Rickard; Bengtsson, Mats; Ottersten, Björn UL

in IEEE Transactions on Wireless Communications (2006), 5(4), 743751

Detailed reference viewed: 5 (0 UL)
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See detailRealization of a Spatially Multiplexed MIMO System
Samuelsson, David; Jaldén, Joakim; Zetterberg, Per et al

in EURASIP Journal on Applied Signal Processing (2006), 2006

Detailed reference viewed: 5 (0 UL)