Journal Article10.1109/TIT.2002.1003822
Opportunistic beamforming using dumb antennas
Pramod Viswanath,David Tse,Rajiv Laroia +2 more
- 01 Jun 2002
- Vol. 48, Iss: 6, pp 1277-1294
TL;DR: This work shows that true beamforming gains can be achieved when there are sufficient users, even though very limited channel feedback is needed, and proposes the use of multiple transmit antennas to induce large and fast channel fluctuations so that multiuser diversity can still be exploited.
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Abstract: Multiuser diversity is a form of diversity inherent in a wireless network, provided by independent time-varying channels across the different users. The diversity benefit is exploited by tracking the channel fluctuations of the users and scheduling transmissions to users when their instantaneous channel quality is near the peak. The diversity gain increases with the dynamic range of the fluctuations and is thus limited in environments with little scattering and/or slow fading. In such environments, we propose the use of multiple transmit antennas to induce large and fast channel fluctuations so that multiuser diversity can still be exploited. The scheme can be interpreted as opportunistic beamforming and we show that true beamforming gains can be achieved when there are sufficient users, even though very limited channel feedback is needed. Furthermore, in a cellular system, the scheme plays an additional role of opportunistic nulling of the interference created on users of adjacent cells. We discuss the design implications of implementing. this scheme in a complete wireless system.
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Citations
QoS-, Queue-and Channel-Aware Packet Scheduling for Multimedia Services in Multiuser SDMA/TDMA Wireless Systems
TL;DR: Performance results obtained by simulations show that by employing the proposed queuing model and packet scheduling algorithm, the system is able to provide for diverse QoS and achieve high throughput.
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A graph theory based opportunistic link scheduling for wireless ad hoc networks
TL;DR: GOS, a distributed Graph theory based and Opportunistic Scheduling algorithm, which modifies IEEE 802.11 protocol to implement the optimal scheduling policy is proposed and theoretical analysis and simulation results both verify that the implementation achieves higher network throughput and provides better fairness support than the existing algorithms.
Decode-and-Forward Cooperative Networks with Multiuser Diversity
Zhihang Yi,Il-Min Kim +1 more
- 23 Oct 2006
TL;DR: A new scheme to combine the decode-and-forward protocol with the multiuser diversity is proposed and it is shown that the new scheme substantially increases the diversity order from approximately K/2+1 to K2/2-1, where K is number of relay terminals.
15
Opportunistic Scheduling with Frame Aggregation for Next Generation Wireless LANs
Ertugrul Necdet Ciftcioglu,Ozgur Gurbuz +1 more
- 11 Dec 2006
TL;DR: This paper argues that existing opportunistic schemes are not optimal when frame aggregation is used, and proposes new scheduling approaches that combine channel states with queue states that offer significant improvement in network throughput over non-opportunistic and greedy schedulers.
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Energy-Efficient Multi-User Resource Management with IR-HARQ
Ye Wu,Shugong Xu +1 more
- 06 May 2012
TL;DR: A basic tradeoff between energy efficiency, power, bandwidth and delay of IR-HARQ is developed, which reveals that frequency domain, rather than power domain, offers a larger space for exploiting energy efficiency with delay constraints.
15
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