Sequence detection method and device

A communications apparatus, comprising one or more processors, and

• a memory configure to store program instructions;
• wherein, when executed by the one or more processors, the instructions cause the communications apparatus to:
• receive a first sequence carried on a plurality of subcarriers;
• and
• differentiate the first sequence based on L granularities, to obtain a first differential sequence set comprising L sequences, wherein L is a positive integer;
• and
• obtain a differential sequence cross correlation value set corresponding to each candidate frequency domain root sequence in U candidate frequency domain root sequences, based on the first differential sequence set, wherein in a differential sequence cross correlation value set corresponding to a uth candidate frequency domain root sequence in the U candidate frequency domain root sequences, an lth first cross correlation value is a first cross correlation value between an lth sequence in the first differential sequence set and an lth sequence in a second differential sequence set corresponding to the uth candidate frequency domain root sequence, l=1, 2, . . . , L, the second differential sequence set corresponding to the uth candidate frequency domain root sequence is a sequence set obtained by differentiating the uth candidate frequency domain root sequence based on the L granularities, a differentiation granularity corresponding to the lth sequence in the first differential sequence set is the same as that corresponding to the lth sequence in the second differential sequence set corresponding to the uth candidate frequency domain root sequence, u=1, 2, . . . , U, and U is a positive integer;
• determine K candidate frequency domain root sequences in the U candidate frequency domain root sequences based on differential sequence cross correlation value sets corresponding to the U candidate frequency domain root sequences, wherein K is an integer less than U;
• and
• determine a candidate frequency domain root sequence and a time domain cyclic shift value that correspond to the first sequence, based on the first sequence and the K candidate frequency domain root sequences.

One or more non-transitory computer-readable media storing computer instructions, that when executed by one or more processors, cause a computing device to perform operations comprising:

• receiving a first sequence carried on a plurality of subcarriers;
• differentiating the first sequence based on L granularities, to obtain a first differential sequence set comprising L sequences, wherein L is a positive integer;
• obtaining a differential sequence cross correlation value set corresponding to each candidate frequency domain root sequence in U candidate frequency domain root sequences, based on the first differential sequence set, wherein in a differential sequence cross correlation value set corresponding to a uth candidate frequency domain root sequence in the U candidate frequency domain root sequences, an lth first cross correlation value is a first cross correlation value between an lth sequence in the first differential sequence set and an lth sequence in a second differential sequence set corresponding to the uth candidate frequency domain root sequence, l=1, 2, . . . , L, the second differential sequence set corresponding to the uth candidate frequency domain root sequence is a sequence set obtained by differentiating the uth candidate frequency domain root sequence based on the L granularities, a differentiation granularity corresponding to the lth sequence in the first differential sequence set is the same as that corresponding to the lth sequence in the second differential sequence set corresponding to the uth candidate frequency domain root sequence, u=1, 2, . . . , U, and U is a positive integer;
• determining K candidate frequency domain root sequences in the U candidate frequency domain root sequences based on differential sequence cross correlation value sets corresponding to the U candidate frequency domain root sequences, wherein K is an integer less than U;
• and
• determining a candidate frequency domain root sequence and a time domain cyclic shift value that correspond to the first sequence, based on the first sequence and the K candidate frequency domain root sequences.