tailieunhanh - Báo cáo hóa học: " Advanced 3D indoor propagation model: calibration and implementation"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : Advanced 3D indoor propagation model: calibration and implementation | Subrt and Pechac EURASIP Journal on Wireless Communications and Networking 2011 2011 180 Ô EURASIP Journal on http content 20ii i i80 Wireless Communications and Networking a SpringerOpen Journal RESEARCH Open Access Advanced 3D indoor propagation model calibration and implementation Ludek Subrt and Pavel Pechac Abstract A software tool implementing a semi-deterministic model which provides swift predictions accounts for all significant physical phenomena while utilising a clear-cut description of material properties is presented in this article. The software can predict signal coverage delay profiles and angle of arrivals for receivers located anywhere in a scenario using three probabilistic parameters to describe each of the materials. Probabilistic parameters can be efficiently optimised based on measured data by a genetic algorithm optimiser contained in the software tool enabling real material properties constants to be avoided. The semi-deterministic model is briefly described whereas its implementation into the tool is explained in greater detail. Measured narrowband as well as wideband data are presented and the basic principles of the computer optimisation utilised in the tool are shown. Optimised results are compared with the measured ones and deviation is determined. The principle of a simple multithreading algorithm which improves the tool performance while decreasing time consumption is presented along with computational times where a different number of threads are compared. Keywords oftware tool electromagnetic wave propagation modelling indoor scenarios ray launching genetic algorithms computer optimisation 1. Introduction The design of modern efficient wireless systems requires site-specific planning. The location of the base stations forming modern digital systems is optimised on the basis of path-loss predictions for providing users with coverage enabling reliable high-speed data transfers. Path-loss predictions can .