Wireless system capable of using shared frequency, radio resource allocation method in wireless communication using shared frequency, and base station

Abstract

A wireless system can use a shared frequency mainly used by an existing first wireless system under predetermined sharing conditions, and includes a communication unit performing wireless communication with a terminal accommodated in a communication area, at least one sensor disposed around the communication area and measuring reception power of a signal sent from the inside of the communication area via the communication unit, a memory storing beam data indicating a correspondence relationship between a beam direction of the signal and a measurement result in the sensor, a determination unit determining allowable maximum transmission power of the signal in each beam direction on the basis of the sharing conditions and the beam data, and an allocation unit allocating a radio resource to the terminal on the basis of the allowable maximum transmission power in each beam direction and channel state information reported from the terminal.

What is claimed is: 
     
         1 . A wireless system capable of using a shared frequency mainly used by an existing first wireless system under predetermined sharing conditions, the wireless system comprising:
 a communication unit that performs wireless communication with at least one terminal accommodated in a communication area of the wireless system;   an acquisition unit that acquires information regarding a reception sensitivity border of the first wireless system;   a direction determination unit that derives a transmission direction of a signal in which a distance from the communication area of the wireless system to the reception sensitivity border of the first wireless system is at a minimum by using the information regarding the reception sensitivity border of the first wireless system;   a power determination unit that derives allowable maximum transmission power of the signal in the derived transmission direction of the signal; and   an allocation unit that allocates a radio resource to the terminal on the basis of the allowable maximum transmission power and channel state information reported from the terminal.   
     
     
         2 . The wireless system of  claim 1 ,
 wherein the allocation unit calculates a wireless parameter corresponding to the radio resource by using the allowable maximum transmission power and the channel state information reported from the terminal, and allocates the radio resource to the terminal on the basis of a ratio between the wireless parameter based on the latest channel state information in the terminal and the wireless parameter based on average channel state information corresponding to a predetermined past time in the terminal.   
     
     
         3 . A wireless system capable of using a shared frequency mainly used by an existing first wireless system under predetermined sharing conditions, the wireless system comprising:
 a communication unit that performs wireless communication with at least one terminal accommodated in a communication area of the wireless system;   an acquisition unit that acquires, from a shared frequency management apparatus connected to the first wireless system, sharing conditions including allowable transmission power of a signal calculated to the extent of avoiding interference with the first wireless system;   a direction determination unit that derives a transmission direction of the signal in which a distance from the communication area of the wireless system to a reception sensitivity border of the first wireless system is at a minimum by using the sharing conditions;   a deriving unit that derives a difference between allowable maximum transmission power of the signal in the derived transmission direction of the signal and allowable transmission power of the signal; and   an allocation unit that allocates a radio resource to the terminal on the basis of the difference and channel state information reported from the terminal.   
     
     
         4 . The wireless system of  claim 3 ,
 wherein the allocation unit calculates a wireless parameter corresponding to the radio resource by using the difference and the channel state information reported from the terminal, and allocates the radio resource to the terminal on the basis of a ratio between the wireless parameter based on the latest channel state information in the terminal and the wireless parameter based on average channel state information corresponding to a predetermined past time in the terminal.   
     
     
         5 . The wireless system of  claim 4 ,
 wherein the sharing conditions include a carrier frequency, a bandwidth, and the allowable transmission power calculated to the extent of minimizing interference given to the first wireless system.   
     
     
         6 . The wireless system of  claim 3 ,
 wherein the sharing conditions include a carrier frequency, a bandwidth, and the allowable transmission power calculated to the extent of minimizing interference given to the first wireless system.   
     
     
         7 . A radio resource allocation method for wireless communication of a wireless system capable of using a shared frequency mainly used by an existing first wireless system under predetermined sharing conditions, the method comprising:
 performing wireless communication with at least one terminal accommodated in a communication area of the wireless system;   acquiring information regarding a reception sensitivity border of the first wireless system;   deriving a transmission direction of a signal in which a distance from the communication area of the wireless system to the reception sensitivity border of the first wireless system is at a minimum by using the information regarding the reception sensitivity border of the first wireless system;   deriving allowable maximum transmission power of the signal in the derived transmission direction of the signal; and   allocating a radio resource to the terminal on the basis of the allowable maximum transmission power and channel state information reported from the terminal.   
     
     
         8 . A base station in a wireless system capable of using a shared frequency mainly used by an existing first wireless system under predetermined sharing conditions, the base station comprising:
 a communication unit that performs wireless communication with at least one terminal accommodated in a communication area of the wireless system;   an acquisition unit that acquires information regarding a reception sensitivity border of the first wireless system;   a direction determination unit that derives a transmission direction of a signal in which a distance from the communication area of the wireless system to the reception sensitivity border of the first wireless system is at a minimum by using the information regarding the reception sensitivity border of the first wireless system;   a power determination unit that derives allowable maximum transmission power of the signal in the derived transmission direction of the signal; and   an allocation unit that allocates a radio resource to the terminal on the basis of the allowable maximum transmission power and channel state information reported from the terminal.   
     
     
         9 . A radio resource allocation method for wireless communication of a wireless system capable of using a shared frequency mainly used by an existing first wireless system under predetermined sharing conditions, the method comprising:
 performing wireless communication with at least one terminal accommodated in a communication area of the wireless system;   acquiring, from a shared frequency management apparatus connected to the first wireless system, sharing conditions including allowable transmission power of a signal calculated to the extent of avoiding interference with the first wireless system;   deriving a transmission direction of the signal in which a distance from the communication area of the wireless system to a reception sensitivity border of the first wireless system is at a minimum by using the sharing conditions;   deriving a difference between allowable maximum transmission power of the signal in the derived transmission direction of the signal and the allowable transmission power of the signal; and   allocating a radio resource to the terminal on the basis of the difference and channel state information reported from the terminal.   
     
     
         10 . A base station in a wireless system capable of using a shared frequency mainly used by an existing first wireless system under predetermined sharing conditions, the base station comprising:
 a communication unit that performs wireless communication with at least one terminal accommodated in a communication area of the wireless system;   an acquisition unit that acquires, from a shared frequency management apparatus connected to the first wireless system, sharing conditions including allowable transmission power of a signal calculated to the extent of avoiding interference with the first wireless system;   a direction determination unit that derives a transmission direction of the signal in which a distance from the communication area of the wireless system to a reception sensitivity border of the first wireless system is at a minimum by using the sharing conditions;   a deriving unit that derives a difference between allowable maximum transmission power of the signal in the derived transmission direction of the signal and the allowable transmission power of the signal; and   an allocation unit that allocates a radio resource to the terminal on the basis of the difference and channel state information reported from the terminal.