An electronic device for a user equipment, comprising circuitry, configured to communicate with a base station on a primary component carrier and at least one secondary component carrier in carrier aggregation, wherein the aggregated carriers are Frequency Division Duplexing, FDD, carriers, or Time Division Duplexing, TDD, carriers with different uplink and downlink configurations; configure a Physical Uplink Control Channel, PUCCH, on a secondary component carrier of the at least one secondary component carrier in addition to the primary component carrier based on configuration information from the base station; conduct Hybrid Automatic Repeat Request, HARQ, feedback on the PUCCH of the secondary component carrier in response to receiving from the base station downlink transmissions on the secondary component carrier; wherein the circuitry is configured to conduct HARQ feedback for another secondary component carrier on the PUCCH of the secondary component carrier in response to receiving from the base station Physical Downlink Shared Channel, PDSCH, transmission on the other secondary component carrier; wherein the timing of the PDSCH transmission on the other secondary component carrier overlaps with the timing of at least one downlink transmission of the downlink transmissions of the secondary component carrier; wherein the timing, at which HARQ feedback is conducted for the other secondary component carrier on the PUCCH of the secondary component carrier, is determined at least based on feedback timing of a component carrier with the highest priority among uplink component carriers corresponding to the component carrier for which there is transmission of PDSCH on the downlink subframes that are overlapping with the downlink transmission of the secondary component carrier; wherein the priority of a secondary component carrier is at least based on an expected power loss for transmission of an uplink signal by the electronic device on that secondary component carrier, in which a higher priority is assigned to a secondary component carrier with a lower expected power loss; and characterized in that the priority of a secondary component carrier is further based on the number of uplink subframes of that secondary component carrier, in which a higher priority is assigned to a secondary component carrier with more uplink subframes. circuitry, configured to communicate with a base station on a primary component carrier and at least one secondary component carrier in carrier aggregation, wherein the aggregated carriers are Frequency Division Duplexing, FDD, carriers, or Time Division Duplexing, TDD, carriers with different uplink and downlink configurations; configure a Physical Uplink Control Channel, PUCCH, on a secondary component carrier of the at least one secondary component carrier in addition to the primary component carrier based on configuration information from the base station; conduct Hybrid Automatic Repeat Request, HARQ, feedback on the PUCCH of the secondary component carrier in response to receiving from the base station downlink transmissions on the secondary component carrier; wherein the circuitry is configured to conduct HARQ feedback for another secondary component carrier on the PUCCH of the secondary component carrier in response to receiving from the base station Physical Downlink Shared Channel, PDSCH, transmission on the other secondary component carrier; wherein the timing of the PDSCH transmission on the other secondary component carrier overlaps with the timing of at least one downlink transmission of the downlink transmissions of the secondary component carrier; wherein the timing, at which HARQ feedback is conducted for the other secondary component carrier on the PUCCH of the secondary component carrier, is determined at least based on feedback timing of a component carrier with the highest priority among uplink component carriers corresponding to the component carrier for which there is transmission of PDSCH on the downlink subframes that are overlapping with the downlink transmission of the secondary component carrier; wherein the priority of a secondary component carrier is at least based on an expected power loss for transmission of an uplink signal by the electronic device on that secondary component carrier, in which a higher priority is assigned to a secondary component carrier with a lower expected power loss; and characterized in that the priority of a secondary component carrier is further based on the number of uplink subframes of that secondary component carrier, in which a higher priority is assigned to a secondary component carrier with more uplink subframes.