| 1. |
- Jamaly, Nima, 1979, et al.
(författare)
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Study of Excitation on Beam Ports versus Element Ports in Performance Evaluation of Diversity and MIMO Arrays
- 2009
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Ingår i: 3rd European Conference on Antennas and Propagation, EuCAP 2009; Berlin; Germany; 23 March 2009 through 27 March 2009. - 9783000245732 ; , s. 1753-1757
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Konferensbidrag (refereegranskat)abstract
- The main concern of the current communication is to elicit the influences of beam-forming upon different Multiple- Input Multiple-Output (MIMO) parameters in a rich scattering environment. A detailed study of desired parameters is presented with particular stress on total radiation efficiencies observed on Element ports and Beam ports. Measurements are performed in a Reverberation Chamber (RC). The results illustrate that performance as viewed through Element and Beam ports are, in general, equal. Hence, they confirm that in a rich and isotropic scattering environment, beam-forming technique does not prove beneficial. They also demonstrate that as long as received radiation power is preserved, the shapes of the elements' patterns are irrelevant.
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| 2. |
- Persson, Patrik, et al.
(författare)
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Design and evaluation of a 2 x 2 MIMO repeater
- 2009
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Ingår i: European Conference on Antennas and Propagation, EuCAP 2009, Proceedings. - 9783000245732 ; , s. 1509-1512
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Konferensbidrag (refereegranskat)abstract
- In this paper the design and measurement-based evaluation of an amplify-and-forward 2 x 2 MEMO repeater is presented. During the design phase, simulations were made to study different scenarios and repeater parameter settings. The evaluation of the repeater was made using field trials in Kista, Stockholm, Sweden. Three scenarios were considered; coverage, outdoor-to-indoor, and LOS MEMO rank enhancement. The overall results showed good improvement in received signal strength, ranging from only a few dB up to 25 dB depending on the particular measurement scenario. Moreover, the concept of repeater-aided rank enhancement in LOS also showed good results.
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| 3. |
- Wei, Xinning, et al.
(författare)
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Joint Transmission with Significant CSI in the Downlink of Distributed Antenna Systems
- 2009
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Ingår i: 2009 IEEE International Conference on Communications, ICC 2009; Dresden; Germany; 14 June 2009 through 18 June 2009. - 0536-1486. - 9781424434350 ; , s. Art. no. 5199124-
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Konferensbidrag (refereegranskat)abstract
- Interference management is required for improving the performance of future mobile radio communication systems. In the downlink (DL) of cellular systems with base stations (BSs) located in the cell centers and equipped with omnidirectional antennas, transmission strategies such as matched filtering (MF) can’t achieve good system performance, and zero forcing (ZF) with full channel state information (CSI) of the whole system imposes a high computational cost and requires a substantial amount of feedback. In this paper, an intelligent signal processing technique with moderate complexity, i.e., ZF joint transmission (JT) with significant CSI, based on distributed antenna systems (DASs) with BSs located at three vertices of each cell and equipped with sector antennas is proposed. From numerical results, it is shown that our proposal is a good combination of BS antenna layout and signal processing technique for inter- ference management. The proposed intelligent signal processing technique can significantly benefit from the proposed smart BS antenna layout.
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| 4. |
- Wolfgang, Andreas, 1977, et al.
(författare)
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Advanced Repeaters in Cellular Communication Systems
- 2009
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Ingår i: 3rd European Conference on Antennas and Propagation, EuCAP 2009; Berlin; Germany; 23 March 2009 through 27 March 2009. - 9783000245732 ; , s. 1504-1508
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Konferensbidrag (refereegranskat)abstract
- A repeater can be used in a wireless link to improve the Signal-to-Noise Ratio (SNR) at the receiver. However, if the transmitter and the receiver use multiple antennas a repeater may serve additional purposes. In this paper we particularly investigate the effect of repeaters on the singular values of the Multiple-Input Multiple-Output (MIMO) channel matrix. Furthermore the effect of repeaters in a cellular system, the interdependence of antenna array design, and system aspects such as scheduling are highlighted.
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