A wireless communication system includes a scheduling entity that transmits scheduling messages to first and second wireless terminals having different scheduling characteristics, wherein each scheduling message includes a reference signal cyclic shift indicator and a resource assignment. The assignment of a downlink feedback resource to the first wireless terminal is indicated by the reference signal cyclic shift indicator in the corresponding scheduling message, and the assignment of a downlink feedback resource to the second wireless terminal is indicated by a corresponding resource assignment. The scheduling entity indicates a cyclic shift that the first wireless terminal should use for its reference signal transmission using the reference signal cyclic shift indicator.