A method for radio-map construction based on the spatial variability theory

In order to improve the working efficiency of radio-map construction of the location fingerprint method in the offline sampling stage, a method for constructing the radio-map was proposed based on the spatial variability theory. The signal strength sample was decomposed into trend and stochastic components to reflect its continuity and variability in the space. After obtaining the trend component, the relationship between the trend component and the distance of transceivers was built by a signal propagation attenuation model. The signal strength of any un-sampled place in the positioning area was estimated by employing the ordinary kriging method to calculate the linear unbiased estimator of the stochastic component. Experimental results show that the proposed method produces better estimation accuracy of the signal strength than WDI. It can decrease the workload of radio-map construction and ensure the positioning precision at the same time.