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
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TL;DR: In this article, a base station and method are described that improves the coverage in a fixed-beam wireless communication system by using antenna beam-jitter and channel quality information (CQI) correction.
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Fairness Based Resource Allocation for Multi-User MIMO-OFDM Systems
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