Methods and apparatus are described for transmitting uplink control information (UCI) over an OFDMA-based uplink. In some embodiments, UCI symbols are mapped to resource elements (REs) in the time/frequency resource grid to maximize frequency diversity. In some embodiments, UCI is mapped in a manner that takes into account channel estimation performance by mapping UCI symbols to those REs that are closest (in terms of OFDM subcarriers/symbols) to REs that carry reference signals.