A base station adapted to execute scheduling for an uplink and scheduling for a downlink per subframe to communicate with mobile stations, the base station comprising: a control information item number estimation unit comprising means for estimating a number (N UL DCI est) of control information items usable for the uplink per subframe such that the estimated number is lower than or equal to a maximum number (N UL DCI max) of control information items usable for the uplink; and a scheduling unit which comprises: a downlink scheduling unit comprising means for determining a number (N DL DCI) of control information items for the downlink based on the number (N UL DCI est) of control information items estimated for the uplink, on the maximum number (N UL DCI max) of control information items usable for the uplink and on a maximum number (N DL DCI max) of control information items usable for the downlink and means for executing scheduling for the downlink per subframe by allocating a number (N DL DCI result) of control information items usable for the downlink such that the allocated number is lower than or equal to the determined number (N DL DCI); an uplink scheduling unit comprising means for receiving scheduling information representing results of scheduling execution for the downlink from the downlink scheduling unit, wherein the scheduling information representing results of scheduling for the downlink is the number (N DL DCI result) of control information items allocated by the downlink scheduling unit, means for determining a number (N UL DCI) of control information items for the uplink based on the received scheduling information (N DL DCI result), on the maximum number (N UL DCI max) of control information items usable for the uplink and on the maximum number (N DL DCI max) of control information items usable for the downlink and means for executing scheduling for the uplink per subframe by allocating a number (N UL DCI result) of control information items usable for the uplink such that the allocated number is lower than or equal to the determined number (N UL DCI). a control information item number estimation unit comprising means for estimating a number (N UL DCI est) of control information items usable for the uplink per subframe such that the estimated number is lower than or equal to a maximum number (N UL DCI max) of control information items usable for the uplink; and a scheduling unit which comprises: a downlink scheduling unit comprising means for determining a number (N DL DCI) of control information items for the downlink based on the number (N UL DCI est) of control information items estimated for the uplink, on the maximum number (N UL DCI max) of control information items usable for the uplink and on a maximum number (N DL DCI max) of control information items usable for the downlink and means for executing scheduling for the downlink per subframe by allocating a number (N DL DCI result) of control information items usable for the downlink such that the allocated number is lower than or equal to the determined number (N DL DCI); an uplink scheduling unit comprising means for receiving scheduling information representing results of scheduling execution for the downlink from the downlink scheduling unit, wherein the scheduling information representing results of scheduling for the downlink is the number (N DL DCI result) of control information items allocated by the downlink scheduling unit, means for determining a number (N UL DCI) of control information items for the uplink based on the received scheduling information (N DL DCI result), on the maximum number (N UL DCI max) of control information items usable for the uplink and on the maximum number (N DL DCI max) of control information items usable for the downlink and means for executing scheduling for the uplink per subframe by allocating a number (N UL DCI result) of control information items usable for the uplink such that the allocated number is lower than or equal to the determined number (N UL DCI). a downlink scheduling unit comprising means for determining a number (N DL DCI) of control information items for the downlink based on the number (N UL DCI est) of control information items estimated for the uplink, on the maximum number (N UL DCI max) of control information items usable for the uplink and on a maximum number (N DL DCI max) of control information items usable for the downlink and means for executing scheduling for the downlink per subframe by allocating a number (N DL DCI result) of control information items usable for the downlink such that the allocated number is lower than or equal to the determined number (N DL DCI); an uplink scheduling unit comprising means for receiving scheduling information representing results of scheduling execution for the downlink from the downlink scheduling unit, wherein the scheduling information representing results of scheduling for the downlink is the number (N DL DCI result) of control information items allocated by the downlink scheduling unit, means for determining a number (N UL DCI) of control information items for the uplink based on the received scheduling information (N DL DCI result), on the maximum number (N UL DCI max) of control information items usable for the uplink and on the maximum number (N DL DCI max) of control information items usable for the downlink and means for executing scheduling for the uplink per subframe by allocating a number (N UL DCI result) of control information items usable for the uplink such that the allocated number is lower than or equal to the determined number (N UL DCI).