Evoluation strategy for collaborative beamforming in wireless sensor networks

Wong, Chen How (2013) Evoluation strategy for collaborative beamforming in wireless sensor networks. Masters thesis, Universiti Malaysia Sabah.

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Abstract

The aim of this research is to improve the efficiency of the phase synchronisation algorithm in order to achieve collaborative beamforming (CB) in wireless sensor networks (WSNs). Generally, CB uses a group of distributed wireless sensor nodes, which collectively transmit a common message with different proper weights to an intended location. This group of distributed wireless sensor nodes intrinsically act as a set of virtual antenna array and inherit the natural highly directional transmission properties from conventional antenna array. However, distinct of conventional antenna array, each sensor node in CB has an independent local oscillator. It becomes a vital problem to achieve CB as the distributed sensor nodes are unaware of their phase relationship. An iterative algorithm using evolution strategy (ES) is proposed to achieve phase alignment at the intended location in static channels, which require one-bit feedback from the receiver destination. By implementing ES in phase synchronisation, each sensor node independently adjusts its phase perturbation size accordingly to speed up the phase synchronisation. Evaluations have been carried out through simulation and result show that the performance using ES is improved by 18. 7 % convergence speed as compared to the conventional one-bit feedback (C1BF) approach. In addition, inverse phase perturbation is introduced for the improved ES (IES) which further improved the convergence speed by 31.6 % over the C1BF approach. Adaptive-JES is proposed for time-varying channels and the results show that the Adaptive-JES has the ability to detect channel changes. Therefore, it can be concluded that the proposed algorithm is robust in practical implementation.

Item Type: Thesis (Masters)
Keyword: Wireless sensor networks, Collaborative beamforming, Synchronisation algorithm
Subjects: T Technology > TK Electrical engineering. Electronics Nuclear engineering > TK1-9971 Electrical engineering. Electronics. Nuclear engineering > TK7800-8360 Electronics
Department: SCHOOL > School of Engineering and Information Technology
Depositing User: DG MASNIAH AHMAD -
Date Deposited: 09 Feb 2024 11:10
Last Modified: 09 Feb 2024 11:10
URI: https://eprints.ums.edu.my/id/eprint/38184

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