Efficient Power Allocation for Outage Restricted Asymmetric Distributed MIMO Multi-hop Networks

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Abstract:

Distributed MIMO multi-hop scheme provides high channel capacity through spatially distributed relaying nodes. The relaying nodes allow the deployment of MIMO techniques to enhance the channel capacity by utilizing uncorrelated sub-channels. However, the spatial farness of the geometrically separated relaying nodes results in the different pathlosses from the nodes of one virtual-antenna-array (VAA) to the nodes of another VAA, namely an asymmetric network. In this paper we derive an approximative expression for the end-to-end (e2e) outage probability for the asymmetric networks, where orthogonal space-time block codes (OSTBC) are utilized. Based on that, a convex optimization problem that aims to reduce the total transmission power while meeting a required e2e outage level is formulated. By applying some stringent approximations for the e2e outage probability, a nearoptimal power allocation approach with low complexity for an asymmetric distributed MIMO multi-hop network is proposed. Instead of solving the convex problem with multiple variables, the complexity of the approach is exponentially reduced. It is only the complexity of solving a high-order equation in one variable. The simulation results show that our approach achieves near-optimal performance.

Document type:

Conference Paper

Publication:

Cannes, France, 15. - 18. September 2008

Conference:

IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)

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