Journal article
On the feasibility of distributed beamforming in wireless networks
IEEE transactions on wireless communications, Vol.6(5), pp.1754-1763
2007
DOI: 10.1109/TWC.2007.360377
Abstract
Energy efficient communication is a fundamental problem in wireless ad-hoc and sensor networks. In this paper, we explore the feasibility of a distributed beamforming approach to this problem, with a cluster of distributed transmitters emulating a centralized antenna array so as to transmit a common message signal coherently to a distant Base Station. The potential SNR gains from beamforming are well-known. However, realizing these gains requires synchronization of the individual carrier signals in phase and frequency. In this paper we show that a large fraction of the beamforming gains can be realised even with imperfect synchronization corresponding to phase errors with moderately large variance. We present a master-slave architecture where a designated master transmitter coordinates the synchronization of other (slave) transmitters for beamforming. We observe that the transmitters can achieve distributed beamforming with minimal coordination with the Base Station using channel reciprocity. Thus, inexpensive local coordination with a master transmitter makes the expensive communication with a distant Base Station receiver more efficient. However, the duplexing constraints of the wireless channel place a fundamental limitation on the achievable accuracy of synchronization. We present a stochastic analysis that demonstrates the robustness of beamforming gains with imperfect synchronization, and demonstrate a tradeoff between synchronization overhead and beamforming gains. We also present simulation results for the phase errors that validate the analysis. © 2007 IEEE.
Details
- Title: Subtitle
- On the feasibility of distributed beamforming in wireless networks
- Creators
- R Mudumbai - University of California, Santa BarbaraG Barriac - QualcommU Madhow - University of California, Santa Barbara
- Resource Type
- Journal article
- Publication Details
- IEEE transactions on wireless communications, Vol.6(5), pp.1754-1763
- Publisher
- Institute of Electrical and Electronics Engineers
- DOI
- 10.1109/TWC.2007.360377
- ISSN
- 1536-1276
- eISSN
- 1558-2248
- Language
- English
- Date published
- 2007
- Academic Unit
- Electrical and Computer Engineering
- Record Identifier
- 9984197414702771
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