| 1. |
- Gunnarsson, Fredrik, et al.
(författare)
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Combining of Power Control Commands During Soft Handover in WCDMA
- 2003
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Ingår i: Proceedings of the 14th IEEE Personal, Indoor and Mobile Radio Communications. - 0780378229 ; , s. 1757-1760 vol.2
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Konferensbidrag (refereegranskat)abstract
- This paper discusses the TPC detection performance in soft handover in WCDMA. A simple TPC commands combining method is evaluated and an improved TPC combining method is proposed. Results show that although the simple combining method fulfills the 3GPP requirements, it does not perform well from the system performance perspective. The proposed combining method significantly improves the system performance.
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| 2. |
- Gunnarsson, Fredrik, et al.
(författare)
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CPICH Power Settings in Irregular WCDMA Macro Cellular Networks
- 2003
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Ingår i: Proceedings of the 14th IEEE Personal, Indoor and Mobile Radio Communications. - 0780378229 ; , s. 1176-1180 vol.2
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Konferensbidrag (refereegranskat)abstract
- In a WCDMA system, mobiles select cells based on received common pilot channel (CPICH) signal quality from the different base stations. The cell size therefore depends on radio propagation properties and transmitted CPICH power. For efficient resource utilization, it is important that the traffic is shared fairly evenly over the base stations. This is specifically challenging in irregular networks with inhomogeneous site locations and traffic distribution. This paper discusses methods for automated CPICH power planning, based on differently detailed traffic density information and predicted radio propagation. Simulations using data from a realistically planned network indicate that the tuning results in a more evenly utilized base station power. This in turn improves the overall capacity. It is furthermore fairly robust with respect to traffic density deviations from the true traffic density.
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| 3. |
- Guo, Zhan, et al.
(författare)
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A VLSI implementation of MIMO detection for future wireless communications
- 2003
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Ingår i: 14th IEEE 2003 International Symposium on Personal, Indoor and Mobile Radio Communications. Proceedings (IEEE Cat. No.03TH8677). - 0780378229 ; , s. 2852-2856
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Konferensbidrag (refereegranskat)abstract
- This paper describes a VLSI implementation of V-BLAST detection for future multiple-input-multiple-output (MIMO) wireless communications. This design is implemented using a 0.35-μm 5-layer metal 3.3 V CMOS technology. For a 4-transmit and 4-receive antennas system using QPSK modulation scheme, a detecting throughput of 128 Mb/s can be achieved. Furthermore, it is shown that the implementation complexity can be reduced further to meet the requirements for future high speed downlink packet access (HSDPA) systems with MIMO extensions in 3rd generation (3G) mobile wireless systems
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| 4. |
- Kristensen, Fredrik, et al.
(författare)
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A Generic Transmitter for Wireless OFDM Systems
- 2003
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Ingår i: 14th IEEE Proceedings on Personal, Indoor and Mobile Radio Communications, 2003. PIMRC 2003.. - 0780378229 ; 3, s. 2234-2238
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Konferensbidrag (refereegranskat)
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| 5. |
- Molisch, Andreas, et al.
(författare)
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DFT-based Hybrid Antenna Selection Schemes for spatially correlated MIMO channels
- 2003
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Ingår i: 14th IEEE Proceedings on Personal, Indoor and Mobile Radio Communications, PIMRC 2003.. - 0780378229 ; 2, s. 1119-1123
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Konferensbidrag (refereegranskat)abstract
- We address the antenna subset selection problem in spatially correlated MIMO channels. To reduce the severe performance degradation of the traditional antenna selection scheme in correlated channels, we propose to embed DFT operations in the RF chains. The resulting system shows a significant advantage both for diversity schemes and for the capacity of spatial multiplexing, while requiring only a minor hardware overhead.
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| 6. |
- Wu, Y, et al.
(författare)
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Impulse Radio Pulse Shaping for Ultra-Wide Bandwidth UWB Systems
- 2003
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Ingår i: 14th IEEE Proceedings on Personal, Indoor and Mobile Radio Communications, 2003. PIMRC 2003.. - 0780378229 ; 1, s. 877-881
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Konferensbidrag (refereegranskat)abstract
- In this paper, we investigate the design of pulse shaping UK filters for impulse radio ultrawideband (UWB) communications systems. The goal of the shaping is to meet an arbitrary spectrum mask, e.g., the mask mandated by the FCC for UWB emissions. Compared with classical FIR filter designs, the current problem introduces three new challenges: (1) it is minimax with quadratic constraints, (2) a single-sided distortion function is used, (3) delay positions are treated as tuning parameters. We first approach this problem by constructing a least-squares approximation to the minimax problem where the optimization over delays can be easily solved. With the LS solution serving as an initialization, nonlinear optimization techniques are employed to fine tune the solutions.
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| 7. |
- Xiao, Pei, 1968, et al.
(författare)
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Multiuser Detection and Channel Estimation Algorithms for M-ary DS-CDMA Systems in Multipath Rayleigh Fading Channels
- 2003
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Ingår i: PIMRC'2003, Beijing, China, 7-10 Sept. 2003. - 0780378229 ; 2, s. 1829-1834
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Konferensbidrag (refereegranskat)abstract
- In this paper, we present different linear and nonlinear iterative data detection schemes for the asynchronous direct-sequence code-division multiple access (DS-CDMA) systems employing orthogonal signalling formats and long scrambling codes. Compared to the conventional receiver and other noncoherent multiuser detectors, coherent multiuser detection schemes achieve much better performance provided that the channels are accurately estimated. To this end, we proposed several channel estimation algorithms to estimate multipath Rayleigh fading channels. Different data detection and channel estimation schemes are compared in terms of BER performance. Based on the numerical results, some recommendations are made on how to choose multiuser detectors and channel estimation algorithms in practical CDMA systems.
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