A terminal apparatus comprising: a higher layer processing unit configured to configure a mode of periodic channel state information, CSI, reporting, and a parameter I CQI/PMI for a configuration of a periodicity and an offset, the periodicity and the offset being for the CSI reporting; and a transmission unit (207, 2071, 2073, 2075, 2077) configured to, for the CSI reporting, periodically feed back a CSI component on a physical uplink control channel or a physical uplink shared channel using the mode, wherein for frequency division duplex, FDD, the periodicity and the offset are determined based on a first mapping being a mapping between values of the parameter I CQI/PMI and combinations of periodicity and offset, for a FDD serving cell of FDD-time division duplex, TDD, carrier aggregation with a primary cell with TDD, the periodicity and the offset of the periodic CSI reporting transmitted on the FDD serving cell are determined based on a second mapping being a mapping between values of the parameter I CQI/PMI and combinations of periodicity and offset, wherein the first mapping and the second mapping are different mappings, for a TDD serving cell of FDD-TDD carrier aggregation with a primary cell with TDD, the periodicity and the offset of the periodic CSI reporting transmitted on the TDD serving cell are determined based on the second mapping, and in a case that the terminal apparatus is configured with serving cells and in a case that frame structure types of two serving cells among the configured serving cells are different from each other, the terminal apparatus is considered to be configured with the FDD-TDD carrier aggregation. a higher layer processing unit configured to configure a mode of periodic channel state information, CSI, reporting, and a parameter I CQI/PMI for a configuration of a periodicity and an offset, the periodicity and the offset being for the CSI reporting; and a transmission unit (207, 2071, 2073, 2075, 2077) configured to, for the CSI reporting, periodically feed back a CSI component on a physical uplink control channel or a physical uplink shared channel using the mode, wherein for frequency division duplex, FDD, the periodicity and the offset are determined based on a first mapping being a mapping between values of the parameter I CQI/PMI and combinations of periodicity and offset, for a FDD serving cell of FDD-time division duplex, TDD, carrier aggregation with a primary cell with TDD, the periodicity and the offset of the periodic CSI reporting transmitted on the FDD serving cell are determined based on a second mapping being a mapping between values of the parameter I CQI/PMI and combinations of periodicity and offset, wherein the first mapping and the second mapping are different mappings, for a TDD serving cell of FDD-TDD carrier aggregation with a primary cell with TDD, the periodicity and the offset of the periodic CSI reporting transmitted on the TDD serving cell are determined based on the second mapping, and in a case that the terminal apparatus is configured with serving cells and in a case that frame structure types of two serving cells among the configured serving cells are different from each other, the terminal apparatus is considered to be configured with the FDD-TDD carrier aggregation.