Abstract: In a radio communication system repeatedly using the same frequency, each base station and terminal station have directional antennas respectively, and a base station has direction-determining patterns for setting a direction of an antenna according to a timing, the adjacent base stations each using the same frequency use different direction-determining. patterns from each other, and remote base stations repeatedly use the same direction-determining patterns. The direction-determining pattern has a correlation between a timing obtained by equally dividing a frame for a communication line by a number of direction-determining patterns and each antenna direction, and a communication slot is allocated based on a timing decided according to the table to a communication line with a terminal station positioned at a particular direction.

Abstract: A first sector cell is set as an object for measurement (S101). Reception levels in each time slot in the number of TDMA-TDD frames is measured for the object cell (S102) and for all the cells (S103 and S105). The results of the measurement of a specific sector cell are added to the results of the measurement of a sector cell opposite the specific sector cell, and time slots in which control channels can be placed are extracted for each sector cell (S106 to S108). TDMA-TDD frames are then allocated such that the control channels of each sector cell coincide with time slots in which control channels can be placed (S109). In this way, control channels are placed in time slots such that a base station having a sector cell structure avoids interference from the same frequency.

Abstract: A first sector cell is set as the object for measurement (S101). Reception levels in each time slot in the number of TDMA-TDD frames corresponding to the number of sector cells within the base station is measured for the object cell (S102). This measurement is performed for all the cells (S103 and S105). The results of the measurement of the reception levels of a specific sector cell are added to the results of the measurement of the reception levels of a sector cell opposite the specific sector cell, and time slots in which control channels can be placed are extracted for each sector cell (S106 to S108). TDMA-TDD frames are then allocated such that the control channels of each sector cell coincide with time slots in which control channels can be placed (S109). As a result, a control channel placement method is provided in which a TDMA-TDD mode is employed and in which control channels are placed in time slots such that a base station having a sector cell structure avoids interference from the same frequency.