According to some embodiments, a network node in a frequency division duplex (FDD) wireless communication network is operable to schedule a first downlink transmission with a first transmission processing time on a first frequency carrier. The scheduling comprises a first downlink assignment index (DAI). The first DAI comprises a first total DAI and a first accumulative DAI. The network node is operable to schedule a second downlink transmission with a second transmission processing time different than the first on a second frequency carrier. The scheduling comprises a second DAI. The second DAI comprises a second total DAI and a second accumulative DAI. The network node expects hybrid automatic repeat request (HARQ) feedback for the first downlink transmission and the second downlink transmission in a single uplink transmission. The network node is further to transmit the scheduling for the first and second downlink transmission to a wireless device.