With respect to determining a resource for a HARQ-ACK signal transmission from a UE in response to a respective EPDCCH detection, the previously described variability in ECCE aggregation levels per subframe can be considered to reduce a respective resource overhead for transmitting HARQ-ACK signals. When a minimum aggregation level of one ECCE can be used in a subframe to transmit from a NodeB an EPDCCH to a UE, a respective resource for a HARQ-ACK signal transmission from a UE can be based on a first (lowest) ECCE of a respective EPDCCH, for example, as described in Equation (3). However, when only a minimum aggregation level of two ECCEs can be used in a subframe to transmit from a NodeB an EPDCCH to a UE, determining a respective resource for a HARQ-ACK signal transmission from a UE from a first (lowest) ECCE of a respective EPDCCH will result in unnecessary UL overhead as at least every other resource for HARQ-ACK signal transmissions will remain unused. In this case, the resource n_PUCCH^E for a HARQ-ACK signal transmission can be determined based on Equation (6) below.

$\begin{array}{c}{n}_{\mathrm{PUCCH}}^E=n_{\mathrm{ECCE}}-?\frac{n_{\mathrm{ECCE}}}{2}?+N_{\mathrm{PUCCH}}^E=\end{array}$