tailieunhanh - Báo cáo hóa học: " A hybrid global minimization scheme for accurate source localization in sensor networks"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : A hybrid global minimization scheme for accurate source localization in sensor networks | Aghasi et al. EURASIP Journal on Advances in Signal Processing 2011 2011 81 http content 2011 1 81 o EURASIP Journal on Advances in Signal Processing a SpringerOpen Journal RESEARCH Open Access A hybrid global minimization scheme for accurate source localization in sensor networks Hamidreza Aghasi1 Hamidreza Amindavar2 and Alireza Aghasi3 Abstract We consider the localization problem of multiple wideband sources in a multi-path environment by coherently taking into account the attenuation characteristics and the time delays in the reception of the signal. Our proposed method leaves the space for unavailability of an accurate signal attenuation model in the environment by considering the model as an unknown function with reasonable prior assumptions about its functional space. Such approach is capable of enhancing the localization performance compared with only utilizing the signal attenuation information or the time delays. In this article the localization problem is modeled as a cost function in terms of the source locations attenuation model parameters and the multi-path parameters. To globally perform the minimization we propose a hybrid algorithm combining the differential evolution algorithm with the Levenberg-Marquardt algorithm. Besides the proposed combination of optimization schemes supporting the technical details such as closed forms of cost function sensitivity matrices are provided. Finally the validity of the proposed method is examined in several localization scenarios taking into account the noise in the environment the multi-path phenomenon and considering the sensors being not synchronized. 1 Introduction A challenging and highly demanding signal-processing application is the localization of signal sources using the physical measurements at some sensors in the environment. Source localization has become an important task in various applications such as mobile communications global positioning system GPS radar sonar .