Investigation of the possibility of reducing errors in d etermining the coordinates of objects indoors by multi-frequency method

Purpose. To investigate the influence of LOS/NLOS conditions on the radio signal propagation and the possibility of interference mitigation by using multi-frequency method of transmitting and receiving for positioning tasks in enclosed spaces. To check the difference in measurement accuracy when receiving a signal at one frequency from receiving a signal at four frequencies by combining the measurement results of individual frequencies into one reading. To check the influence of various obstacles on the signal passing. Methodology. Design at the laboratory of UHF - generator and BLE - beacons with the ability to set broadcast frequencies and adjust transmission power. Application of a multi-frequency transmission and reception method. Findings. The possibility of increasing the accuracy of positioning of objects in closed rooms, including mine workings, through the use of multi-frequency radio signals is investigated. It is shown that the influence of re-reflections of radio signals from the walls of structures, from obstacles of various origins, and the associated interference, can be reduced by using averaged values of attenuation at different frequencies. The use of radio emitters with many frequencies as "beacons" can provide new possibilities in solving the problem of positioning objects in closed rooms. Originality. The work proposes a method for combining measurement results of individual frequencies into one reading, which will reduce interference. Multi-frequency transmission method and multi-frequency reception method are proposed to reduce the influence of interference caused at one frequency on the overall signal level. Practical value. The experimental results obtained can be used at deploying positioning systems in closed rooms, including mine workings.