The disclosure is related to a method of generating a physical uplink control channel (PUCCH) in unlicensed spectrum, which is transmitted by a user equipment, the method comprising: - generating a PUCCH format 1 in an interlaced structure by: o determining a cyclic shift group (CSG) containing a first cyclic shift member (CSMf) and a plurality of subsequent cyclic shift members (CSMn), each cyclic shift member (CSM) being defined at least by a value and a position, by: - configuring the first cyclic shift member (CSMf) with a first indication related to the CSMf value and a second indication related to the CSMf position; - deriving the plurality of subsequent cyclic shift members (CSMn) based on the CSMf value and on the relative position between CSMf and each CSMn so as to define all CSM which are mutually different; o determining a first control sequence (Si cs(n)), in one OFDM symbol within OFDM symbols allocated for control sequence, by a first base sequence (S(n)), an acknowledgment information symbol (b) and the cyclic shift group; o determining a first reference sequence (Ri cs(n )), in one OFDM symbol within all OFDM symbols allocated for reference sequence, by the first base sequence (S(n)) and the cyclic shift group.