A mobile radio communication system estimates the positional relationship between an own moving terminal and another moving terminal around a view obstruction. If the absolute value of the difference between detected reception power levels is lower than a first power threshold value, the own moving terminal determines that the other moving terminal is positioned within the visual range of the own moving terminal, the distance from the own moving terminal to the other moving terminal being shorter than a predetermined distance BP, or that the other moving terminal is positioned outside thereof, the distance to the visual range of the own moving terminal being shorter than the predetermined distance BP. Also if the absolute value is higher than or equal to the first power threshold value, the own moving terminal determines in a similar manner.