A symbol multiplied by a first constant amplitude zero autocorrelation code CAZAC reference signal RS is transmitted in a timeslot from a first antenna of a user equipment on a first physical uplink control channel in a manner that multiplexes with other user equipments. A symbol multiplied by a second CAZAC RS is transmitted in the timeslot from a second antenna of the user equipment on a second physical uplink control channel in a manner that multiplexes with other user equipments. The first and second CAZAC RSs are orthogonal to one another by at least one of the cyclic shifts or a cover code applied to at least one of the first and the second CAZAC RSs. The symbols may be the same or different, and may represent an ACK, a NACK, or a scheduling request indicator. These teachings extend to more than two transmit antennas.