Control method of radio communication system, radio communication system, and radio communication apparatus

Abstract

When communication is to be performed between communication devices having a directivity control function, a plurality of antenna-setting pairs available for the communication are stored by an initial training, and the communication is started by using one of the plurality of antenna-setting pairs. When the communication quality is deteriorated, firstly, a training signal is transmitted while successively setting each one of the plurality of antenna-setting candidates determined in the initial training in a transmitting antenna of one of the communication devices ( 400 ), and the training signal is received in a state where a quasi-omni pattern is generated in a receiving antenna of the other communication device ( 500 ). In this way, in radio communication performing beam forming, it is possible to ensure the time synchronization between the communication devices when communication is disconnected or communication quality is deteriorated due to shielding or the like.

1 . A method comprising:
 selecting, by a first communication device or a second communication device, one or more transmission beam candidates of the first communication device by performing a training in which the first communication device transmits a first training signal while changing a transmission beam direction and the second communication device receives the first training signal with a fixed beam pattern;   selecting, by the first communication device or the second communication device, one or more reception beam candidates of the second communication device by performing a training in which the first communication device transmits a second training signal with a fixed beam pattern and the second communication devices receives the second training signal while changing a reception beam direction; and   selecting, by the first communication device or the second communication device, one or more combinations of a transmission beam candidate of the first communication device and a reception beam candidate of the second communication device, by performing a training in which the first communication device transmits a third training signal while changing a transmission beam direction among the one or more transmission beam candidates and the second communication devices receives the third training signal while changing a reception beam direction among the one or more reception beam candidates.   
     
     
         2 . The method according to  claim 1 , wherein
 the selecting the one or more transmission beam candidates includes selecting the one or more transmission beam candidates by the first communication device, and   the selecting the one or more reception beam candidates includes selecting the one or more reception beam candidates by the second communication device.   
     
     
         3 . The method according to  claim 1 , wherein
 the selecting the one or more transmission beam candidates includes selecting the one or more transmission beam candidates by the second communication device, and   the selecting the one or more reception beam candidates includes selecting the one or more reception beam candidates by the second communication device.