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Distributed downlink beamforming with cooperative base stations
- Source :
- IEEE Transactions on Information Theory. Dec, 2008, Vol. 54 Issue 12, p5491, 9 p.
- Publication Year :
- 2008
-
Abstract
- In this paper, we consider multicell processing on the downlink of a cellular network to accomplish "macrodiversity" transmit beamforming.. The particular downlink beamformer structure we consider allows a recasting of the downlink beamforming problem as a virtual linear mean square error (LMMSE) estimation problem. We exploit the structure of the channel and develop distributed beamforming algorithms using local message passing between neighboring base stations. For 1-D networks, we use the Kalman smoothing framework to obtain a forward-backward beamforming algorithm. We also propose a limited extent version of this algorithm that shows that the delay need not grow with the size of the network in practice. For 2-D cellular networks, we remodel the network as a factor graph and present a distributed beamforming algorithm based on the sum-product algorithm. Despite the presence of loops in the factor graph, the algorithm produces optimal results if convergence occurs. Index Terms--Cooperative base stations, distributed algorithm, downlink beamforming, Kalman smoothing, linear mean square error (LMMSE), localized interference, message passing, multicell processing, multiple-input-multiple-output (MIMO), sum--product algorithm.
Details
- Language :
- English
- ISSN :
- 00189448
- Volume :
- 54
- Issue :
- 12
- Database :
- Gale General OneFile
- Journal :
- IEEE Transactions on Information Theory
- Publication Type :
- Academic Journal
- Accession number :
- edsgcl.190941708