Communication system

Abstract

Provided is a technology capable of securing satisfactory communication quality. A communication system includes a user equipment, and a base station configured to be connected to the user equipment to perform radio communication with the user equipment. The user equipment performs radio communication with a beam. When the user equipment detects a beam disappearance state being a state incapable of maintaining communication quality with the base station, the user equipment transmits a notification of the beam disappearance state with a beam having a wider half width than a half width before detection of the beam disappearance state.

1 . A communication system comprising:
 a user equipment; and   a base station configured to be connected to the user equipment to perform radio communication with the user equipment, wherein   when the user equipment communicates with a first base station while not communicating with a second base station, the user equipment measures a degree that the second base station interferes with a transmission signal from the first base station, and transmits a measurement result to the first base station, and   the first base station changes transmission power of a signal to be transmitted to the user equipment, based on a received measurement result.   
     
     
         2 . A communication system comprising:
 a user equipment; and   a base station connected to the user equipment to perform radio communication with the user equipment, wherein   when the user equipment communicates with a first base station while not communicating with a second base station, the first base station adjusts a communication condition for interference suppression between data transmission from the first base station to the user equipment and data transmission performed by the second base station, and requests the second base station to perform data transmission on the adjusted communication condition.   
     
     
         3 . A communication system comprising:
 a user equipment; and   a base station configured to be connected to the user equipment to perform radio communication with the user equipment, wherein   the user equipment is configured to perform reciprocity-using channel estimation being channel estimation using reciprocity of a channel, for each frequency band,   the user equipment transmits reciprocity capability information indicating whether or not the reciprocity-using channel estimation can be performed for each frequency band to the base station, and   the base station performs communication with the user equipment by using the reciprocity-using channel estimation in a frequency band in which both of the user equipment and the base station are allowed to perform the reciprocity-using channel estimation, based on the reciprocity capability information of the user equipment.