tries cooperation between sectors when the channel quality information of the destination terminal is below a first threshold and performs cooperation when a cooperation destination sector does not overlap with resources to be used when the resources overlap the base station gives a preference to the cooperation destination sector fig9 shows a sequence diagram of the first embodiment operations of 701 to 707 are the same as those in fig7 except that the base station performs cooperation processing 901 between sectors after the data transmission target decision operation 705 fig1 details processing operations of the inter sector cooperation processing 901 the base station determines whether the sectors newly start data transmission 1001 and compares for sectors found to be true channel quality information of a destination terminal with a predetermined threshold first threshold 1002 this operation 1002 for example can be realized by referring to downstream channel quality information 701 sent by the terminal and a decided transmission data rate when the channel quality information is below the first threshold the base station searches for a subordinate sector that it can cooperate with 1003 a sector of a cooperation destination can be decided by referring to an active set of the terminal and a terminal managed by the base station next the base station checks the use status of time and frequency resources by existing communication of the destination sector 1004 and determines the presence of time and frequency resources that might duplicate during communication by use of hopping patterns of a cooperation source 1005 when they do not duplicate inter sector cooperation is performed when a duplication exists the resources of the cooperation destination take.