| 1. |
- Alayon Glazunov, Andres, et al.
(författare)
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MIMO Over-the-Air Testing
- 2012
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Ingår i: LTE-Advanced and Next Generation Wireless Networks. - Chichester, U.K. : John Wiley & Sons. - 9781119976707 ; , s. 411-441
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Bokkapitel (refereegranskat)
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| 2. |
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| 3. |
- Hammarberg, Peter, et al.
(författare)
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On the performance of iterative receivers for interfering MIMO-OFDM systems in measured channels
- 2008
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Ingår i: 42nd Asilomar Conference on Signals, Systems and Computers. - 1058-6393. - 9781424429400 ; , s. 141-145
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Konferensbidrag (refereegranskat)abstract
- This paper investigates the gains harvested through base station cooperation in the up-link for a multi-user (MU) Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) system, operating in a real indoor environment. The base stations perform joint detection using an iterative receiver that carries out multi-user detection and channel estimation via soft information from the single-user decoders. Performance evaluation is carried out using real channels from an indoor dynamic dual MIMO link measurement campaign. The measured scenario represent a real life situation where two users communicate with two base stations, each with two antennas, in an environment resembling a shopping mall or an airport terminal. System performance is evaluated in terms of both Bit-Error Rate (BER) vs. Signal-to-Interference Ratio (SIR) and Cumulative Distribution Functions (CDF) for the instantaneous BER. Also, the impact of using soft information in the channel estimation is analyzed.
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| 4. |
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| 5. |
- Hult, Tommy, et al.
(författare)
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Analytical dual-link MIMO channel model using correlated correlation matrices
- 2010
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Ingår i: Proceedings of the Fourth European Conference on Antennas and Propagation. - 9788476534724 - 9781424464319
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Konferensbidrag (refereegranskat)abstract
- Analytical Multiple-Input Multiple-Output (MIMO) models are often attractive due to their low complexity when analyzing possibilities and limitations in the system. In this paper we outline a a possible dual link extension of an analytical MIMO channel model and investigate its suitability based on measurements of a dual link MIMO scenario. The extension is based on the correlation matrix distance (CMD) as a gauge to generate correlation matrices for the additional links of the multi-link scenario.
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| 6. |
- Koivunen, Jukka, et al.
(författare)
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Dynamic multi-link indoor MIMO measurements at 5.3 GHz.
- 2007
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Ingår i: Proc 2nd European Conference on Antennas and Propagation (EuCAP 2007).
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Konferensbidrag (refereegranskat)abstract
- A dynamic multi-link MIMO channel indoor measurement campaign at 5.3 GHz is presented in this paper. The system setup is described and capacity with interference (with and without power control) results based on the dynamic multilink MIMO measurements are shown, and we experience a strong correlation between the relative capacity and SIR. Furthermore, an interference suppression metric is introduced and pathloss exponents and delay spreads are also presented, when moving from a typical office corridor to a large entrance hall at the premises of Lund University, Sweden.
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| 7. |
- Kolmonen, Veli-Matti, et al.
(författare)
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A dual-link capacity analysis of measured time-variant radio indoor channels
- 2010
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Ingår i: 2010 IEEE 71st Vehicular Technology Conference. - 9781424425181
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Konferensbidrag (refereegranskat)abstract
- There has been extensive research about single link multiple-input multiple-output (MIMO) channels, both simulated and measured, but only few studies have targeted multilink analysis with measured channel data. Hence, in this paper, we analyze the influence of spatial separation of user terminals and the human shadowing effect on the MIMO capacity and to the signal to interference ratio (SIR) in a time-variant dual-link scenario. The paper analyses the dual-link channel capacity based on simulations as well as measurements conducted using dynamic dual-link dual-polarized wideband MIMO channel sounder in an indoor office environment, and compare the results to the singlelink capacity. Here the analysis is restricted to 4 x 4 MIMO links. The following conclusions have been obtained from the analyses: 1) Compared to the single link case, the dual-link channel capacity is more affected by the SIR than the spatial separation of the users. 2) The human shadowing introduced variations of SIR up to ±10 dB, causing large fluctuations in the dual-link capacity.
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| 8. |
- Kolmonen, Veli-Matti, et al.
(författare)
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A dynamic dual-link wideband MIMO channel sounder for 5.3 GHz
- 2010
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - 0018-9456. ; 59:4, s. 873-883
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in UndeterminedIn this paper, we present and evaluate the performance of a dynamic dual-link wideband multiple-input-multiple-output ( MIMO) channel sounder. The channel sounder can simultaneously measure two wideband dual-polarized links, each with a MIMO matrix size of 30 x 30 and 30 x 32. Multi-link MIMO systems, including multiuser and cooperative MIMO, are essential parts of future high-throughput wireless local area networks and fourth-generation cellular systems. To fully understand such systems, the dynamic characteristics of multilink MIMO channels have to be measured. In this paper, we present a channel sounder that enables such measurements, including double-directional parameter estimation possibility for both links. The presented dual-link MIMO channel sounder does not suffer from the deficiencies of previous "virtual multiuser" measurement systems. Furthermore, system analysis and sample results from a measurement campaign with this channel sounder at 5.3 GHz in an indoor office environment are presented.
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| 9. |
- Kolmonen, Veli-Matti, et al.
(författare)
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Measurement-based evaluation of interlink correlation for indoor multi-user MIMO Channels
- 2010
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - 1548-5757. ; 9, s. 311-314
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in UndeterminedThe properties of the single-link multiple-input-multiple- output (MIMO) propagation channels have been analyzed in many studies based on extensive propagation measurements. In this letter, we extend the measurement-based analysis to dual-link MIMO propagation channels. Here, we examine interlink correlation by evaluating the correlation of eigenvectors obtained from multiple MIMO links. We also investigated how the physical propagation phenomena produced the interlink correlation. Results indicate that interlink correlation may exist. Sometimes it is found to be very high also for far separated receive units, depending on similarity of dominant propagation mechanisms between multiple MIMO links and also on antenna array properties.
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| 10. |
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| 11. |
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| 12. |
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| 13. |
- Poutanen, Juho, et al.
(författare)
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Multi-link MIMO channel modeling using geometry-based approach
- 2012
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Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X. ; 60:2, s. 587-596
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Tidskriftsartikel (refereegranskat)abstract
- Geometry-based stochastic channel models (GSCMs) are extended to support multi-link simulations by applying the concept of common clusters. This novel approach aims to control the correlation between different links, inter-link correlation, by adjusting the amount of power simultaneously propagating via the same clusters in the different links. The behavior of common clusters is analyzed based on dual-link channel measurements, and a multi-link GSCM is developed based on common clusters. In addition, the effects that the common clusters have on inter-link correlation and on sum rate capacity are investigated based on simulations. Finally, comparison between simulations and measurements is done in order to indicate the validity of the proposed multi-link GSCM.
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| 14. |
- Poutanen, Juho, et al.
(författare)
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Propagation Characteristics of Dense Multipath Components
- 2010
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - 1548-5757. ; 9, s. 791-794
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Tidskriftsartikel (refereegranskat)abstract
- The dense multipath components (DMC) represent the part of the radio channel that cannot be characterized by a superposition of distinct plane waves, i.e., the specular components (SC). In this letter, the propagation characteristics of the DMC are analyzed in indoor environments from two perspectives. First, the proportion of DMC in the total power is studied as a function of the distance between the transmitter (TX) and receiver (RX). Second, the characteristics of the DMC and SC are compared in angular and delay domains. The measurement results show that the amount of DMC in the total power increases as the TX-RX distance increases in both line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios. In addition, it is shown that the power of the DMC is concentrated around the same angles and delays as the SC.
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| 15. |
- Poutanen, Juho, et al.
(författare)
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Significance of common scatterers in multi-link indoor radio wave propagation
- 2010
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Ingår i: Proceedings of the Fourth European Conference on Antennas and Propagation. - 9781424464319 - 9788476534724
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Konferensbidrag (refereegranskat)abstract
- Correlation between different links is an essential characteristic for many of the forthcoming radio communication systems that utilize the multiple-input-multiple-output (MIMO) technology. This paper investigates the physical phenomena that cause the inter-link correlation by introducing a measure to quantify how large amount of energy propagates via similar propagation mechanisms in different links. The conditions for the so-called significance of common scatterers are derived and two dynamic dual-link indoor MIMO channel measurements are used to provide experimental results. The present work forms the indispensable basis for the channel modeling of multiuser MIMO communications.
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| 16. |
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| 17. |
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| 18. |
- Salvo Rossi, Pierluigi, et al.
(författare)
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Performance of an Iterative Multi-User Receiver for MIMO-OFDM Systems in a Real Indoor Scenario
- 2008
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Ingår i: [Host publication title missing]. - 1930-529X. - 9781424423248
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Konferensbidrag (refereegranskat)abstract
- This paper aims at validation of an iterative receiver for multiple-input multiple-output with orthogonal frequency division multiplexing (MIMO-OFDM) systems using real-measurement channel data from an indoor scenario. The receiver performs iterative multi-user detection (MUD) and Channel Estimation (CE) via soft information from the single- user decoders. The channel measurements were performed for a dynamic dual MIMO link scenario. The case with two users with multiple antennas interfering each other is considered. CE at the receiver exploits the frequency correlation of the MIMO link. Simulation results for the performance are shown in terms of bit- error rate (BER) vs. signal-to-noise ratio (SNR). Performance for the whole system are provided and compared with respect to the case of perfect channel-state information (PCSI) at the receiver, as well as for the single user. We also provide an analysis of BER with respect to signal-to-interference ratio (SIR). CE performance are evaluated in terms of normalized mean square error (NMSE).
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| 19. |
- Tufvesson, Fredrik, et al.
(författare)
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Multi-User MIMO Channels
- 2012
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Ingår i: LTE-Advanced and Next Generation Wireless Networks: Channel Modelling and Propagation. - : Wiley. - 9781119976707 ; , s. 187-214
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Bokkapitel (refereegranskat)
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