In high-speed wireless transmission, it is important to improve efficiency of signal transmission using flexible transmission control that can accommodate various traffic. Traffic control techniques include time scheduling and frequency scheduling, and, for example, frequency scheduling in MC-CDMA (multi-carrier CDMA) is being studied.
In MC-CDMA, a base station selects subcarriers that have good channels based on channel quality information such as SINR (signal-to-interference plus noise ratio) which is reported from a plurality of communication terminal apparatuses and transmits data. Users use the subcarriers that have good channel states, and therefore communication at a low PER (packet error rate) is possible.
Methods for controlling resources taking into consideration a requirement for delay have also been proposed (for example, Patent Document 1). In such control methods, circuit-switching connections that accompany bandwidths capable of dynamic control are allocated to connections having strict requirements for a transmission delay. After resources are allocated to circuit-switching connections, resources are allocated from the unassigned resource pool to connections that have a high degree of allowance for a transmission delay.
Patent Document 1: Japanese Patent Publication Laid-Open No. 2001-512939