An apparatus of user equipment, UE, comprising: a transceiver arranged to communicate with an evolved NodeB, eNB; and processing circuitry arranged to: configure the transceiver to receive from the eNB a physical downlink shared channel, PDSCH, associated with the UE and an uplink, UL, Hybrid Automatic Repeat Request Acknowledgement/ Negative-acknowledgement, HARQ ACK/NACK; determine a resource for a downlink, DL, HARQ ACK/NACK in response to the PDSCH; and configure the transceiver to transmit to the eNB the DL HARQ ACK/NACK, wherein: the UL HARQ ACK/NACK and DL HARQ ACK/NACK are symmetric; an ACK/NACK resource of the UL HARQ ACK/NACK is determined using a function of subband index, I SB, and spreading code index, I SF, used for the UL HARQ ACK/NACK, a resource index for the UL HARQ ACK/NACK is a function of at least one of a cell-specific parameter, a UE-specific parameter, a parameter signaled in a DCI format, and, as used for one of the PDSCH and a physical uplink shared channel, PUSCH, at least one of: a beamforming index, a slot index, a subframe index, a frame index and a physical resource block index, and the cell-specific parameter is configured by master information block, MIB, system information block, SIB, or dedicated RRC signaling, the UE-specific parameter is configured from one of a primary cell and a serving cell via dedicated RRC signaling, and the parameter signaled in the DCI format is one of the subband index and a Demodulation Reference Signal, DM-RS, used for the one of the PDSCH and PUSCH. a transceiver arranged to communicate with an evolved NodeB, eNB; and processing circuitry arranged to: configure the transceiver to receive from the eNB a physical downlink shared channel, PDSCH, associated with the UE and an uplink, UL, Hybrid Automatic Repeat Request Acknowledgement/ Negative-acknowledgement, HARQ ACK/NACK; determine a resource for a downlink, DL, HARQ ACK/NACK in response to the PDSCH; and configure the transceiver to transmit to the eNB the DL HARQ ACK/NACK, wherein: the UL HARQ ACK/NACK and DL HARQ ACK/NACK are symmetric; an ACK/NACK resource of the UL HARQ ACK/NACK is determined using a function of subband index, I SB, and spreading code index, I SF, used for the UL HARQ ACK/NACK, a resource index for the UL HARQ ACK/NACK is a function of at least one of a cell-specific parameter, a UE-specific parameter, a parameter signaled in a DCI format, and, as used for one of the PDSCH and a physical uplink shared channel, PUSCH, at least one of: a beamforming index, a slot index, a subframe index, a frame index and a physical resource block index, and the cell-specific parameter is configured by master information block, MIB, system information block, SIB, or dedicated RRC signaling, the UE-specific parameter is configured from one of a primary cell and a serving cell via dedicated RRC signaling, and the parameter signaled in the DCI format is one of the subband index and a Demodulation Reference Signal, DM-RS, used for the one of the PDSCH and PUSCH. the UL HARQ ACK/NACK and DL HARQ ACK/NACK are symmetric; an ACK/NACK resource of the UL HARQ ACK/NACK is determined using a function of subband index, I SB, and spreading code index, I SF, used for the UL HARQ ACK/NACK, a resource index for the UL HARQ ACK/NACK is a function of at least one of a cell-specific parameter, a UE-specific parameter, a parameter signaled in a DCI format, and, as used for one of the PDSCH and a physical uplink shared channel, PUSCH, at least one of: a beamforming index, a slot index, a subframe index, a frame index and a physical resource block index, and the cell-specific parameter is configured by master information block, MIB, system information block, SIB, or dedicated RRC signaling, the UE-specific parameter is configured from one of a primary cell and a serving cell via dedicated RRC signaling, and the parameter signaled in the DCI format is one of the subband index and a Demodulation Reference Signal, DM-RS, used for the one of the PDSCH and PUSCH.