Transmission space diversity controlling method and transmission space diversity apparatus

A transmission space diversity controlling method in a TDMA communication system which includes a base station having two antennas each for use for both transmission and reception and a plurality of terminal stations, the method comprising the steps of:

• using a reception space diversity controlling signal at the base station to select a best antenna for transmission from the base station;
• transmitting a control signal through an antenna to a terminal station from said base station;
• discriminating the reception quality of the received control signal at the terminal station and transmitting a reception quality information signal to said base station from the terminal station when receiving the control signal;
• at said base station, detecting the reception quality information signal transmitted from the terminal station;
• and
• performing for each terminal station a logic operation on said reception space diversity controlling signal and said reception quality information signal from each terminal station to control whether to reverse or not reverse a transmission space diversity controlling signal at the base station to thereby select on of said two antennas for transmission to a respective terminal station.

A transmission space diversity controlling apparatus for a TDMA mobile communication system which includes a base station having two antennas each for use for both transmission and reception and a plurality of terminal stations, comprising:

• reception quality discrimination means provided in each of said terminal stations for discriminating reception quality of a received control signal transmitted from the base station;
• reception quality information transmission means provided in each of said terminal stations for transmitting a respective reception quality information signal in a transmission time slot of the terminal station destined for said base station;
• reception space diversity controlling means provided in said base station for generating a reception space diversity controlling signal corresponding to each of the terminal stations;
• transmission space diversity controlling means provided in said base station for switching said antennas for transmission to said terminal stations using the reception space diversity controlling signal as a transmission space diversity controlling signal;
• reception quality information reception means provided in said base station for detecting and receiving the respective reception quality information signals transmitted from a terminal station in a transmission time slot assigned for the terminal station;
• logic means in said base station having as inputs said reception space diversity controlling signal and for each terminal station a respective one of said reception quality information signals and performing a logic operation on said inputs for each terminal station;
• reversal control means provided in said base station responsive to said logic means for controlling whether the transmission space diversity controlling signal for each of said terminal stations is reversed or not reversed thereby to select a next order one of said antennas for transmission to a respective terminal station.