Radio communication device, radio communication system and beam control method

#This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2016-021491, filed on Feb. 8, 2016, the entire contents of which are incorporated herein by reference.

#The embodiments discussed herein are related to a radio communication device, a radio communication system, and a beam control method.

#In a radio communication system using high frequencies as in millimeter wave communication, beamforming that concentrates power by narrowing a beam in the direction of a user terminal may be performed to compensate for a propagation loss. When beamforming is performed, beams are narrowed in specific directions in which user terminals are present, and therefore areas where high-power signal can be received may be spatially isolated from each other, thus providing an effect of suppressing interference between the user terminals present in a same space. In addition, frequency usage efficiency may be increased due to an improvement in a degree of spatial multiplexing.

#FIG. 1 is a diagram illustrating an example of a radio communication system according to a first embodiment;

#FIG. 2 is a diagram illustrating an example of a radio communication system according to a second embodiment;

#FIG. 3 is a diagram of assistance in explaining beamforming and inter-cell interference;

#In a case where the CB system is applied, a plurality of base stations controlling beams may each use user information related to user terminals in adjacent cells. For example, each base station may calculate beamforming weights in consideration of channel information related to a user terminal in an adjacent cell in order to direct NULL to the user terminal. Therefore, the base stations may be coupled to each other by high-speed communication interfaces, and the user information of the adjacent cells may be transmitted and received between the base stations when beamforming is performed.

#Inter-cell interference may be suppressed by applying the CB system. However, processing loads may not be insignificant which are involved in the transmission and reception of the user information, which is performed between the base stations each time beamforming is performed, and the calculation of the beamforming weights. When inter-cell interference may be suppressed by beamforming not using the user information of the adjacent cells, it may contribute to reduction in such processing loads. In addition, when the high-speed communication interfaces may be omitted, it may contribute to reduction in cost involved in system introduction and operation management.

#According to one aspect, it is an object of the present disclosure to provide a radio communication device, a radio communication system, and a beam control method that may reduce user information obtained from base stations in adjacent cells in order to suppress inter-cell interference at a time of beamforming.