Embodiments of the present disclosure provide, among other implementations, sequence determining methods. One example method includes: determining an index v of a sequence group, where the sequence group comprises a sequence {xn} and a sequence {ym}; generating a second sequence based on the index v of the sequence group, where the second sequence is at least one of a second sequence {fn} or a second sequence {gm}; and transmitting uplink control information or a reference signal based on the second sequence.