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| 2. |
- Gunnarsson, Frida, et al.
(författare)
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Comagotchi - a social toy
- 2001
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Ingår i: Reprints from the PCC Summer School.
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Konferensbidrag (refereegranskat)
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| 3. |
- Yu, Kai, et al.
(författare)
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A 20 MHz HIPERLAN/2 MIMO Channel Model in NLOS Indoor Scenarios
- 2002
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Ingår i: Nordic Conference on Radio Science and Communications (RVK). ; , s. 311-315
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, we present results of 5.2 GHz wideband indoor multiple input multiple output (MIMO) channel measurementsunder the EU IST SATURN project. First we show the average power delay profile for the single input single output (SISO) channel. Furthermore, our investigation shows that for non-line-of-sight (NLOS) indoor scenarios, the MIMO channel covariance matrix of each normalized tap of channel impulse response can be be well approximated by the Kronecker product of the covariance matrices seen from the transmitter and receiver respectively.Based on the above results, a wideband statistical model for HiperLAN/2 MIMO channel is presented. Monte-Carlo simulations show reasonably good agreement between the measured data and our model. Finally, weuse this model to show the capacity characteristics of theHiperLAN/2 channel in NLOS indoor scenarios.
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| 4. |
- Yu, Kai, et al.
(författare)
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A wideband statistical model for NLOS indoor MIMO channels
- 2002
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Ingår i: IEEE 55TH VEHICULAR TECHNOLOGY CONFERENCE, VTC SPRING 2002, VOLS 1-4, PROCEEDINGS. - 0780374843 ; , s. 370-374
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Konferensbidrag (refereegranskat)abstract
- Herein, results of 5.2 GHz wideband indoor multiple input multiple output (MIMO) channel measurements under the EU IST SATURN project are reported. Our investigation shows that for non-line-of-sight (NLOS) cases, the average power delay profiles fit the exponentially decaying curve quite well, therefore a simple wideband model for single-input single-output (SISO) proposed in COST259 has been used in our model. Furthermore, the investigations show that the MIMO channel covariance matrix of each normalized tap of the impulse response could be well approximated by the Kronecker product of the covariance matrices seen from the transmitter and receiver respectively. Based on the above results, a wideband statistical model is presented. Monte-Carlo simulations show reasonably good agreement between the measured data and our model. Finally, we use this model to show some capacity characteristics of Hiper-LAN/2 channels in NLOS indoor scenarios.
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| 5. |
- Yu, Kai, et al.
(författare)
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Measurement Analysis of NLOS Indoor MIMO Channels
- 2001
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Ingår i: Proceedings IST Mobile Communications Summit. ; , s. 277-282
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, we present results from measurements conducted by the University of Bristol.We study the channel characteristics of Multiple-Input-Multiple-Output (MIMO) indoor channel at 5.2GHz. Our investigation shows that the envelope of the channel for non-line-of-sight (NLOS) indoorsituations is approximately Rayleigh distributed and consequently we focus on a statistical descriptionof the first and second order moments of the narrowband MIMO channel. Furthermore, it is shown thatfor NLOS indoor scenarios, the MIMO channel covariance matrix can be well modeled by a Kroneckerproduct of the covariance matrices describing the correlation at the transmitter and the receiver siderespectively. A statistical narrowband model for the NLOS indoor MIMO channel based on thiscovariance structure is presented along with some simulation results.
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| 6. |
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| 7. |
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| 8. |
- Yu, Kai
(författare)
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Modeling of Multiple-Input Multiple-Output Radio Propagation Channels
- 2002
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In recent years, multiple-input multiple-output (MIMO)systems appear to be very promising since they can provide highdata rates in environments with sucient scattering byexploiting the spatial domain. To design a real MIMO wirelesssystem and predict its performance under certain circumstances,it is necessary to have accurate MIMO wireless channel modelsfor dierent scenarios. This thesis presents dierent models forindoor MIMO radio propagation channels based on 5.2 GHz indoorMIMO channel measurements.The recent research on MIMO radio channel modeling isbriey reviewed in this thesis. The models are categorized intonon-physical and physical models. The non-physical modelsprimarily rely on the statistical characteristics of MIMOchannels obtained from the measured data while the physicalmodels describe the MIMO channel (or its distribution) via somephysical parameters. The relationships between dierent modelsare also discussed.For the narrowband case, a non line-of-sight (NLOS)indoor MIMO channel model is presented. The model is based on aKronecker structure of the channel covariance matrix and thefact that the channel is complex Gaussian. It is extended tothe line-of-sight (LOS) scenario by estimating and modeling thedominant component separately.As for the wideband case, two NLOS MIMO channel modelsare proposed. The rst model uses the power delay prole and theKronecker structure of the second order moments of each channeltap to model the wideband MIMO channel while the second modelcombines a simple single-input single-output (SISO) model withthe same Kronecker structure of the second order moments.Monte-Carlo simulations are used to generate indoor MIMOchannel realizations according to the above models. The resultsare compared with the measured data and good agreement has beenobserved.
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| 9. |
- Yu, Kai, et al.
(författare)
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Modeling of wide-band MIMO radio channels based on NLoS indoor measurements
- 2004
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Ingår i: IEEE Transactions on Vehicular Technology. - 0018-9545 .- 1939-9359. ; 53:3, s. 655-665
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we first verify a previously proposed Kronecker-structure-based narrow-band model for nonline-of-sight (NLoS) indoor multiple-input-multiple-output (MIMO) radio channels based on 5.2-GHz indoor MIMO channel measurements. It is observed that, for the narrow-band case, the measured channel coefficients are complex Gaussian distributed and, consequently, we focus on a statistical description using the first- and second-order moments of MIMO radio channels. It is shown that the MIMO channel covariance matrix can be well approximated by the Kronecker product of the covariance matrices, seen from the transmitter and receiver, respectively. A narrow-band model for NLoS indoor MIMO channels is thus verified by these results. As for the wide-band case, it is observed that the average power-delay profile of each element of the channel impulse response matrix fits the exponential decay curve and that the Kronecker structure of the second-order moments can be extended to each channel tap. A wide-band MIMO channel model is then proposed, combining a simple COST 259 single-input-single-output channel model and the Kronecker structure. Monte Carlo simulations are used to generate indoor MIMO channel realizations according to the models discussed. The results are compared with the measured data using the channel capacity and good agreement is found.
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| 10. |
- Yu, Kai, et al.
(författare)
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Models for MIMO propagation channels : a review
- 2002
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Ingår i: Wireless Communications & Mobile Computing. - : Wiley. - 1530-8669 .- 1530-8677. ; 2:7, s. 653-666
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Tidskriftsartikel (refereegranskat)abstract
- This paper reviews recently published results on multiple input multiple output (MIMO) channel modeling. Both narrowband and wideband models are considered. We distinguish between two main approaches to MIMO channel modeling, that is,. physically based and nonphysically based modeling. The nonphysical models primarily rely on the statistical characteristics of the MIMO channels obtained from the measured data, while the physical models describe the MIMO channel (or its distribution) via some physical parameters. We briefly review different MIMO channel models and discuss their relationships. Some interesting aspects will be described in more detail and we note areas in which few results are available.
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