Abstract: A small number of users who provide high interference in the other users, such as a user transmitting a high rate signal, are selected beforehand. First, a signal of the user is demodulated to generate a replica, and a difference between a received signal and the replica is calculated, thereby canceling the interference in signals of the other users, and further improving the system capacity.

Abstract: Taking into account an optimal reception characteristic of a communication apparatus with variable directivity, the base station apparatus of the present invention has a communication apparatus with variable directivity positively accommodate a communication with a terminal in poor reception conditions, which makes it possible to reduce power of this terminal and reduce interference, thereby increasing the subscriber capacity in the system.

Abstract: Taking into account an optimal reception characteristic of a communication apparatus with variable directivity, the base station apparatus of the present invention has a communication apparatus with variable directivity positively accommodate a communication with a terminal in poor reception conditions, which makes it possible to reduce power of this terminal and reduce interference, thereby increasing the subscriber capacity in the system.

Abstract: In a radio communication system for performing digital radio communications by using time-division multiplexed time slots, a first personal station receives its user's speech through the microphone, converts it into audio data, and transmits them on time slots to a second personal station. On the other hand, the first personal station receives non-audio data from the data processor connected with the second personal station and stores. When the audio data amount inputted to the first personal station in a unit time period is lower than a threshold and the communications between the first personal station and the second personal station are put in a silence condition, the first personal station transmits non-audio data on times slots to the second personal station. When the communications return to a sound condition, audio data transmission is restored. Whether each time slot carries audio data or non-audio data is designated by an identifier which is written in a predetermined field of each time slot.

Abstract: The caller personal station of the present invention includes the following units: a channel search unit for scanning the plurality of communication channels to search for an unoccupied channel and regarding the unoccupied channel as a multicast channel; and a simultaneous call unit for repeatedly transmitting a simultaneous call frame on the multicast channel for a first predetermined time period, the simultaneous call frame indicating a simultaneous call to the other personal stations; a multicast unit for transmitting multicast frames on the multicast channel when a second predetermined time period has passed, the multicast frames containing data to be multicast. On receiving the simultaneous call frame by sequentially sensing the plurality of communication channels, the other personal stations enter a receiving state of multicast frames on the multicast channel.