| 摘要 |
PURPOSE:To easily and quickly discriminate a slave station as a mobile individual positioned in a definite area. CONSTITUTION:Each slave station 1 is given a parenthesis code 1, 2,..., i,..., and is equipped with a transmitting part to transmit the radio wave of intrinsic frequency. In a master station 10, a receiving part 12 receives all the radio waves from all the slave stations 1 through an antenna 11 as they are in a radio interference state, and determines electric field intensity based on all the radio waves. A memory 14 stores the data of the electric field intensity sampled periodically by an A/D converter 13. An analyzing part 15 determines a frequency spectrum diagram related to the electric field intensity of the received radio wave by Fourier-transforming the data of the electric field intensity stored in the memory 14, and further, it determines each frequency F1, F2,...Fi,... corresponding to the maximal value of the electric field intensity. A discriminating part 16 can discrimiante the slave station positioned in the definite area on the basis of this frequency. |
