Abstract: The mobile communication system for communications between a base station and a mobile station, employing a TDD method, sets up transmission power of the base station for each of downlink time slots that are to be transmitted next, based on receiving quality of downlink time slots that have been received by the mobile station immediately prior to transmitting the next time slots, and based on receiving power level of uplink time slots that are received by the base station.

Abstract: The present invention provides a radio base station for preventing degradation of transmission quality characteristics even when there are time differences between the instant of channel estimation of uplink time slots UL#1 to UL#N and the instant of transmission of transmission data via downlink time slots DL#1 to DL#N. The radio base station includes transmit diversity controllers 141 to 14N for controlling transmit diversity to be used for downlink time slots DL#1 to DL#N and a data transmitter 15 for transmitting data via downlink time slots DL#1 to DL#N using the controlled transmit diversity.

Abstract: In a mobile communication system, interference power from adjacent cells is effectively reduced and transmission power is limited. A transmission loss estimation unit 202 and a transmission power estimation unit 204 estimate transmission power necessary for transmission of a downstream signal. According to an upstream signal from each of plurality of mobile terminal devices to a base station, a grouping unit 206 divides a plurality of mobile terminal devices into groups sharing a plurality of wireless resources according to the estimated transmission powers. Downstream signals to be transmitted to mobile terminal devices belonging to each of the groups formed by the grouping means are transmitted simultaneously with each other. Also, priorities are set for the plurality of wireless resources and the mobile terminal devices belonging to the groups divided by the grouping unit 206 are assigned according to the set priorities.

Abstract: When a mobile station communicates with a base station by way of one or a plurality of other mobile stations, the mobile station acting as a relay station determines whether the data demodulated after being received is reception data for the mobile station or transfer data to be transmitted to the other mobile station or the base station, decides a modulation mode suitable for transmitting sum data of the transfer data and transmission data if the transmission data is generated in the mobile station, and transmits the sum data while modulating the sum data according to the modulation mode decided. The base station demodulates a reception signal relayed by the mobile stations according to the modulation mode of the mobile station having directly communicated with the base station, and identifies each user data multiplexed.

Abstract: The adaptive modulation method for use in a mobile communication system employing a TDMA scheme associates a modulation scheme with each time slot within a frame, and modulates transmission data of a communication channel using the modulation scheme associated with the time slot into which the communication channel is assigned.

Abstract: Concerned is time slot allocation in the CDMA-TDD scheme. A time slot of an uplink (UL) is allocated to a mobile station MS1 in cell 1. At this time, a time slot of a downlink (DL) having the same time slot number as that of the foregoing time slot is allocated to a mobile station MS2 in an adjacent cell 2 without avoiding the allocation. If there can occur deterioration of communication quality a process of allocating another time slot or the like will be performed as in the case of a mobile station MS2-1.

Abstract: A mobile station receives a signal based on a TDD method by receiving a signal based on a FDD method to acquire information of the signal based on the TDD method in a mobile communication system. For instance, the mobile station receives a signal based on a CDMA-FDD method. Then, the mobile station acquires information (e.g. information relating to a code, a frequency and a timing) of a signal based on a CDMA-TDD method from the signal based on the CDMA-FDD method. Then, the mobile station receives the signal based on the CDMA-TDD method on the basis of the acquired information.

Abstract: A mobile communication system can limit interference from mobile stations under an adjacent base station to a minimum. In response to a time slot assignment request, a time slot management section compares available time slots stored in an assignable time slot database with a priority table of the time slot assignment, which is stored in the priority database, and assigns the time slots in accordance with the compared result. After completing the assignment, it stores a table of the frame state indicating new available time slots into the assignable time slot database.

Abstract: A channel assigning method and a communication apparatus for executing appropriate channel assignment in a mobile communication system when both a channel for a service area based on a FDD method and a channel for a service area based on a TDD method can be assigned are provided. For example, if both a channel for a service area based on a CDMA-FDD method and channels for service areas based on a CDMA-TDD method can be assigned to a request for channel assignment, and a handover frequency of the mobile station related to the request is high, the channel for the service area based on the CDMA-FDD method is assigned.